The workpiece when ferrule clamp is out of shape imitate

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Clamping apparatus of 1 preface 　 makes a machine tool in the cutting position between machine tool and workpiece, cutting tool, a of workpiece total system main component, according to cutting course design, in accessible appearance precision respect has important place. Mette thinks, machine in high speed turning (HSC) in, clamping force does not have an influence to workpiece circularity. Bahr seeks testimony use flexible the radial of the annular work that place claw and has cutting below common cutting speed brace up place. The circumstance makes clear, metrical circularity is followed inside, between external diameter proportional increase, reduce and increase the wall is thickly significantly namely. The maths that clamp of workpiece of the following introduction affects to be out of shape analyses the result of research. The 100Cr6 steel that the person such as Brinksmeier studied GKZ anneal forgings inside ferrule, outside Ap of deepness of precision of turning treatment appearance and cutting speed Vc, cutting and the impact that feed measures F. This job is in special research domain SFB570 studies treatment is out of shape pilot " be out of shape project " undertake inside limits. System of one proper clamp is used to secure work before cutting. Fc of centrifugal force of Fspo of state clamping force and clip claw presses the You Jing of Fsp of dynamic effect clamping force that appears in treatment type (1) get: Fspo of static clamping force by clip dish the structure is designed and the attrition condition inside clamping apparatus decides. Action decides since ungual to clip clamping force, for the clamp system that operates to using wedge actuating device for example, it is sliding friction deputy attrition is worth μ . Outside eliminating tribology position, the contaminative condition of slip face is right clip dish action efficiency also has apparent effect. Be in very below disadvantage, for example when cutting is cast-iron, mould dirt is right clip dish action coefficient can reduce 80 ％ above. K of centrifugal force coefficient gives out can bring about reduce / the clip claw that raises clamping force Fsp leaves mental efforts share. Clip claw leaves mental efforts by the radial that place claw the product of the position, quality that place claw and the 2 power cipher out of the angular velocity that place claw. Action leaves Fc of mental efforts part to be placed the effect of claw and workpiece system stiffness at the clip claw of total clamping force. The clamp graph of the thin wall workpiece that reachs by Wagner (graph 1) show the concern that gave to place ungual centrifugal master piece to be used at Fsp of total clamping force. Should regard what Jiang Xinggang spends as to string together by the system that places dish of ／ to place claw and work place to form among them receive. CF by clip dish the radial stiffness with clip claw and overturn stiffness composition. CW is workpiece stiffness. Place to wedge dish for, k of centrifugal force coefficient can press type (2) approximate cipher out: The largest total clamping force, get in machine tool respect the limitation of clamping apparatus and fluid drive device, and be restricted workpiece by concessional and stretch metabolic. The purpose that states research below is to beg a flexibility to be out of shape the relationship that uses clamp system with place, the workpiece that measures with cutting ferrule is radial brace up place undertake contrast. Be based on type (1) with type (2) a lot of influencing factor that concern dynamic clamping force, measured the clamping force of action. Machine to the surface inside ferrule (exterior clamp) for, examining clamp system is to swing ungual system, and machine to outside face (in-house clamp) for, it is arched ungual system (graph 2 upside) . 2 change a plan with clamp system model the model that 2 bottom show the clamp system that in giving cutting to experiment, uses. When outer ministry gripping sleeve is encircled (graph 2a) , total clamping force distributings to swing in 6 on claw. In-house clamp (graph 2b) when the arched claw that goes up through be being placed in ferrule internal diameter can make clamping force almost action at ferrule whole inside apparently. The ferrule internal diameter that wants treatment is Di ＝ 130 ㎜, external diameter is Da ＝ 150mm. As a result of ferrule inside, external diameter proportion is larger, stiffness is accordingly lesser, with the clip of ideal stiffness when building a model claw reachs arched claw to be premise. In addition, below condition of two kinds of clamp 120 ° rotate symmetry makes build a model to simplify greatly. Unit area load divides a pace to decide: Above all the clamping force that the experiment determines 3 ungual chuck. The unit face stowage that holds the geometrical relation between the system to beg an action to go up at workpiece according to workpiece and clip next carries on his shoulder or back. When exterior clamp, with SMWAuto - measuring instrument of the DGM270 that Blok company produces clamping force measures clamping force. Among them Psp of pressure of clamp of machine tool adjustable and N of main shaft rotate speed can change. Undertake with clamp pressure 20bar cutting studies, fall in static circumstance (Min of ／ of N ＝ 0r) the clamping force Fsp of generation is 20kN about. Swing to decide an on interface active force of exterior clamp of claw and ferrule, introduced the model that the graph shows 3 times. Through using 3 ungual chuck, fsp of total clamping force differentiates for Fsp/3 of 3 identical component of force. Be based on swing ungual geometrical dimension, clamping force differentiates for tangential Ft of component of force and Fr of radial component of force, if pursue,institute of 3 right plans is shown. The interface between claw of a clip and workpiece surface uses an embossing (fall in static circumstance) beg piece. Graph 3 left graphic representation go out to swing ungual embossing. One swings ungual actual area class is 823mm2, namely every place that place claw guides the person's force distributings to go up in the face of the about 23 ％ that always place ungual area. Swing with every ungual clamping force Ft and Fr together, get corresponding unit area load inputs parameter as simulative. When using clamp of arched ungual interior, when building a model, set out from the ideal surface contact between the surface inside arched claw and ferrule. In place the distance condition between claw to fall considering each segment of a circle, can beg an unit area load from this. 3 results 　 3.

1 calorie of clamping force when tightening are right radial brace up the effect that place pursues 4 show piece when constant the radial that examining clamp system condition is applying to issue ferrule when clamping force Fsp=20kN brace up place. With swing when ungual system or clamp of arched ungual system, the whirl that can bring about 120 ° symmetry, so, need to inspect ferrule only 120 ° cut paragraph enough. In the graph 4 in, swing ungual fixed position is mixed in 60 ° 120 ° position, arched ungual mid fixed position is in 90 ° position. The generation when ungual exterior clamp swinging than using when using arched ungual in-house clamp about 2. The circularity of 5 times. This but the type of ascribe active force: When using arched ungual in-house clamp, force and arched ungual mid parallel guide along radial direction. When exterior clamp, of total clamping force can pass both sides to swing to score force claw guides, can achieve evener clamping force to distributing so. With respect to the circularity of the surface inside simulative ferrule and outside face, the relation that the change of clamping force reachs the graph is shown 5 times. Metabolic means does not follow the change of clamping force and change (graph 4) . Graph 5 in the circularity when different clamping force by radial brace up the cipher out needing a value that places maximum and the least value. The line sexual relationship of circularity and clamping force is result of metabolic of ferrule pure flexibility. Analysis of VonMises comparative stress makes clear, the load pressure that brings through clamp does not succumb more than the limit 420.

8MPa, that is to say, be like the annular work that processes in SFB570, pass clamp to won't produce plasticity to be out of shape. The ferrule that machines through additional cutting only in the experiment just can arise permanent be out of shape. 3.

2 simulative and metrical radial brace up place comparative figure 6 show a surface inside ferrule to measure with simulative radial brace up place. In addition still gave out to swing each ungual angle position. Beg to ferrule clamp condition gave imitate value. Do not grant to consider to the influence of cutting process among them. The change of the local cutting deepness that is out of shape by clamp workpiece flexibility place is caused especially also did not bring into imitate likewise in computation. In different card claw swings twice deputy between claw (it is for example between ungual 3b and La) appears computational maximum and the dependency that measure the least value are very apparent. Measure go against change to be able to make following explanations with imitate metabolic: If pursue,workpiece happened through in-house clamp 4 in radial brace up the flexibility that places imitate to be worth place to show is out of shape. In the inhomogenous sex that cutting deepness appears in subsequently cutting treatment. The circularity that produces from this and amplitude of radial and stretch metabolic comparative, but metrical circularity is bigger. Assume different cutting deepness brings about workpiece surface moment of inertia inhomogenous. If the clamp of workpiece is loose, criterion torsion replies, those who stay is bend with what clamp brings about those who bend to be gone against to increase. One pair swings between claw (for example La and 1b) metrical ferrule metabolic change can make qualitative specification by imitate value. But the position of measured value and the maximum that imitate is worth and the least value has a few phase shift in the appreciably inside this limits (△ ф ) . Ideal clamp condition is not to make an explanation below this usable and actual condition. In addition, from ideal round ferrule considers in imitate. This kind of hypothesis falls in actual condition also is not unlimited ground is applicable likewise, because ferrule forgings,can cause deviate ideal appearance. Graph the radial that the 7 surfaces outside showing a cutting ferrule measure brace up place and imitate of simulative of in-house clamp flexibility is radial brace up place. Can see apparently measure radial brace up 3 when place periodic. This is by what show like imitate result place inside the surface uses place of arched ungual clamp to arise. Apparent, the ferrule metabolic absolute value that measures on outside face should compare imitate to be worth tower above a lot of (the attention pursues 6 with the graph of 7 scale different) . In imitate computation end considers the cutting force of cutting process and action. Same in the imitate that undertakes oversight by type (1) because place ungual centrifugal master piece,use the clamping force that causes increase and the workpiece flexibility that increases from this is out of shape. Apparent, metrical external diameter is radial brace up the local maximum that place and simulative flexibility are out of shape the least value has dependency. They mutual a phase shift that has about 10 ° . Those who measure is as radial as simulative brace up placing the ф of phase shift △ between is by swing the place of phase shift overlay of ungual clamp and arched ungual clamp arises. Machine above all in cutting experiment inside the surface (with swing claw makes exterior clamp) , machine outside face next. At this moment among arched claw to swing ungual pair of intermediate deflection 30 ° . Through inside, outside the stretch metabolic is different absolute value when clamp gets radial of outside face imitate thereby brace up place measure radial relatively brace up place lesser deflection. 4 summary and look into use simulation of FE of clamp metabolic pure flexibility but the radial that ferrule of qualitative specification cutting measures below lax condition brace up place. Clamp makes workpiece happening flexibility is out of shape and bring about the cutting deepness with different ministry of treatment the current political situation. Be out of shape with the flexibility that arises through clamp place photograph comparing, the ferrule after this can bring about treatment bends reversibly. Money night tide, because local and different cutting is naked,spend, still can be in ferrule is circumferential on moment of inertia with different generation, accentuated again so of turning ferrule bend. Inside, the radial with outside different face brace up placing is outer, inside the result that the different clamp system that uses in treatment brings about. Imitate result makes clear, outside face is radial brace up place local the influence that the position of the least value and maximum is located relatively by exterior clamp and in-house clamp. For can the change of the dimension after ration forecasts cutting and appearance deviation, outside be out of shape except the flexibility that arises because of clamp place, still need the material purify amount that imitate produces by cutting place. Need to consider the inhomogenous sex of the cutting deepness that is out of shape as a result of ferrule flexibility place arises especially. CNC Milling CNC Machining