The research that bits temperature distributings is cut in orthogonal cutting

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Preface considers to cut face and knife in order to cut in orthogonal cutting originally, bits interface is border, the temperature that cuts bits certainly distributings. As a result of before the temperature on knife face distributings to wear away to cutting tool, the working status of cutting tool and knife, the attrition between bits has conclusive effect, need enough attention and research. Heretofore, the analytic method that to cutting the temperature on the face to distributing basically two kinds differ. The first kind of method pays attention to the average temperature that cuts a face to go up, another kind of method is the analytic method that is a delegate with Hahn and Weiner. Hahn thinks cutting treatment can regard the shift on infinite body as the process of a planar heat source, planar heat source and this cutting movement way become proper point of view, the temperature on its distributings the temperature that can replace era to cut a face to go up continuously distributings. Can see, hahn method did not consider workpiece and the athletic way that cut bits to differ. Weiner avoids this kind to cause analytic model and actual condition to simplify abhorrently greatly. But he still assumes cut bits perpendicular cut a face to pour out of, cut face and work surface to intersect place temperature is room temperature. To avoid afore-mentioned simplify reasonably very much the error that the cipher out that reach estimate assumes place is caused, the author puts forward new simplify attrib border condition, analyse computation to cut by Weiner model at the same time the temperature on the face distributings and contrast was analysed different the temperature that cuts a face to fall distributings. Analyse result and be identical of photograph of actual cutting temperature. Graph the model cutting bits that 1 orthogonality becomes bit continuously the 1 temperature that cuts a face to go up distributings graph 1 gave out the cutting model that orthogonality cuts bits continuously. Workpiece moves with speed V relative to cutting blade and to it perpendicular, cutting ply HD, cut bits ply Hch, cut bits the velocity of flow of advanced knife face is Vch. By material successional Vt= is Vchhch, with the single rate that cut bits the delegate becomes bits process, this decided in some stress of going from place to place is worth next workpiece material to produce plasticity to be out of shape. Because the heat source of cutting motion is one even planar heat source, can assume knife, heat build-up of bits interface attrition also is even planar heat source. According to afore-mentioned cutting process models, but further set is moving on direction conduct heat it is a temperature of the cutting on workpiece to control equation to be (in 1) type: A -- medicinal powder hot coefficient X -- the positional coordinate Y on cutting speed direction -- be in perpendicular the positional coordinate on cutting speed direction; Its are initiative in be type of 8 (2a) Y=tanfx (2b) of ＜ of Q=0x=00 ＜ Y with attrib border condition: R -- material density L -- thermal conductance N -- geometry is invariable (1 - Cosb)/cosblimq=0 (2c) is in cut an area even heat flux Q is set on AB, the hot balance type that goes up considering the element (2b) gave out attrib border condition. Introduce new parameter Z=y-tanfx, handle equation of attainable contented and attrib border condition into travel maths (the equation of 2) (the solution of 1) . Manage together, the temperature that cuts a face to go up is when Z=0 (in 3) type: Erf X -- error function Erf Cx -- the complementary function of error function 1 - Erf X applied when seeking solution to afore-mentioned problems with. For variable Lapulaci commutation reachs his to go against commutation. Weiner analysis considered to cut bits and the position that cut a face to be poured out of into perpendicular direction only. This research considers more general case. The model that because this can say,builds on this foundation is pair of Weiner models widen refine with essence of life. Graph 2 2 dimension conduct heat cut face temperature distributinging figure the influence of 3 geometry set pursues the 2 temperature that gave out to cut a face to go up distributing and the cutting speed influence to temperature. Graph 2 in the circumstance of the accurate stability that the curve shows a temperature edge to cut rapid growth or saturated condition, still can see, as cutting speed rise, the time that achieves saturated state institute to use decreases. Accordingly, when cutting speed achieves some to be worth, the hypothesis in resembling Rapier model cuts face temperature to be constant value have stated reason. From the graph 2 still can see higher cutting rate can bring about inferior stable temperature; As cutting speed rise, stable temperature is reduced somewhat. Because the heat in cutting is conducted,this is take actor, be lost of face heat build-up is cut to give the scale that cuts bits below higher cutting rate bigger. Graph 3 gave out to press type (the result of heat source of 3) calculative cant and the flow direction that cut bits brief melt into and cut face posture the approximate solution below perpendicular circumstance (graph 1 in B=f-g=0, type (the N=0) in 3) . Pass both comparison knowable distributinging curve of these two temperature is more adjacent. When using afore-mentioned hypothesis, both the biggest error between is more than 3.

5% . Should notice to cut bits and the condition that cutting a face to become the hypothesis that hangs down to be poured out of continuously is the horn before cutting horn to be equal to cutting tool, namely F ＝ G. This is meant cutting corner is changeless, need not consider the metabolic case in cutting. Although this is planted circumstance not suit is actual, afore-mentioned numeric analysises show this hypothesis cuts face temperature and character is reasonable. What Gao Lingmin uses here is infra-red the change that bits temperature cuts when measuring Wen Yi to measure turning to process 45 steel. In surveying a system here, after sensor receives infrared ray, its changeover becomes telegraphic name, again linearization is worth with obtaining corresponding temperature. All measure 3 weight that take cutting power in every experiment, the temperature that has monitoring be measured in order to ensure to its is the measurement below stable state cutting. Have a test below orthogonal cutting condition of course, dot A is cut bits, workpiece, cut face posture node. In the graph 2 in, the temperature near A of the dot below all sorts of cutting speed is more than 170 ℃ , with room temperature 25 ℃ photograph is compared, experiment curve and equation (the attrib border condition with affirmatory 2) is very abhorrent, we are form of fundamental the other side with this experiment (2a) tries to amend. In Qe=qamh+(qA-qamh)exp(-py) type: Qamh -- room temperature QA -- the measurement that nods A temperature P -- can calculate what cutting temperature makes cut a face to average temperature is close to or be equal to test value in order to cut to adjust invariable and similar move comfortable at pressing type (of 3) cut face temperature to distributing analysis, with type of attrib border condition (2a ' ) replace form (2a) , get about civilian more complex expression (in 3) type: The correction of attrib border condition analyses meeting generation to affect to cutting face temperature. Can see by equation (3 ' ) the Weiner model that the result edge that reach cuts face temperature incremental ratio to improve is fast. Although type (2a ' ) more accept easily, can obtain relatively appropriate shears to cut face temperature, the measurement that nods A temperature still is a problem. When numeric analysis shows QA changes inside 60 ℃ ; In the dot B is in temperature to change to not be more than 10 ℃ . By type (2a ' ) give out reasonable attrib border condition improves the result to original model apparent. The 2 temperature that cut bits distributing to be machined in cutting in, cutting area metal comes in point of a knife cut bits surface of one workpiece freedom is in the first be out of shape classics plasticity is out of shape and translate into cuts the area bits. Workpiece speed changes Vch of the speed that cut bits for V. The characteristic that heat of cutting area metal delivers is in the first be out of shape likeness is inside the area. Above the control equation that gives out in the part is comfortable analyse at cutting bits temperature to distributing. Use new H - department of X Cartesian coordinate and cutting process parameter, criterion the control equation that cutting temperature changes is like next forms (parameter R=rcvchhch/l is heated up in 4) type, its corresponding attrib border condition is (in type of 5a) (5b) (5c) : Dqe -- using the heat that cuts bits to go up at cutting the temperature increment of bits to assume is even, BC is planar heat source. On, the cutting that gets in the part face temperature QB uses as here an attrib border condition. Notice we took two different coordinate departments, should establish the connection between them. The consideration nods P, it can be in respectively (X, y) or (H, try to convey below X) ; Have here have (6) has X=(hch-x)cosf/cosb to (H, the QB in X) coordinate department is explicit, type (6) generation enters type (the Weiner model that 3) gets refining, era enters type (the correction model that 3) gets the author puts forward. See pattern to beg (4) and (5) , era is entered and divide via changing, get (7) is divided via changing, get (it satisfies 8) hot equation, attrib border condition and type (5b) and type (5c) . If satisfy type (type of 5a) criterion requirement (5a) and type (8) is completely equal, namely Qe(r, the viewpoint that X)=qd (9) cuts from tangent looks, type (the solution of Am of the coefficient in 9) does not exist. We but have the aid of at numeric method. The addition that notices M Exp(-m2p2tanb/Rhch) drops quickly, mix with the part replace Qe(h, a) is feasible. If use M ＋ ,1 is mixed as the part, criterion coefficient A0, a1, ... , the generation of foregone QB value that Am can nod 1 times by M ＋ enters type (9) . Such, the temperature that cuts bits distributings for (after 10) coefficient Am gets, what cut bits temperature to be able to regard Weiner as the model is patulous. So that such processing apply QB at type (3) , have the result differential, the amendatory that obtains an author to put forward cuts face temperature to analyse a model. Graph 4 gave out to pursue 2 in below lowermost cutting speed with cut face temperature the corresponding temperature that cut bits distributings. Can see highest temperature is in the some place that the knife leaves to be nodded high on one bits interface, in the knife, temperature gradient is very big near bits interface; This is total trend, main reason is a knife, there is intense friction between bits. (A) model (B) cuts bits temperature to analyse a scheme distributinging model of the 4 temperature that cut bits reachs the temperature that cut bits to distributing in special situation (below B ＝ 0) , can assume Qs is constant. This up-to-date style (9) can simplify for (11) at this moment Yu Xian of rich family name is progressional, corresponding coefficient is (12) (13) type (13) generation enters type (12) , as a result of,use new parameter G=lc/hch the action of edge, the temperature of the brim that cut bits is lower than the temperature of other part. Use infra-red measure lukewarm measure directly only take cut the temperature with mid bits, can get when X=hch forecast temperature, these results are in graph 5 in give out. The test value that is 84 M/min and 120m/min in cutting speed and forecast a value to be in with ancon graph 5 in give out. Graph distributinging chart of 5 cutting temperature 6 knives, the temperature that bits interface temperature distributings to be constant by tangent plane temperature is forecasted be more than test value; And the error that improvement Weiner result cuts A of surface of bits interface freedom to be in in workpiece is bigger. The temperature that the author reachs distributings relatively accurate estimation is to be based on equation (2a ' ) , the result is more largish than real value. The account that produces an error assumed surface of freedom of the ground floor that cut bits is heat insulation. To the graph 5 shown cutting cases, both trend is consistent. All these all use formula in clew (2a) makes attrib border condition obtain cutting face temperature to distributing is improper. And the cuts bits temperature distributinging model precision that the article offers is used quite. Afore-mentioned test results make clear, the model that this research offers analyses a method to distributing to cutting bits temperature than other theory more appropriate, set out from this model can obtain relatively accurate knife, bits interface temperature distributings. The graph shows the temperature below speed of 3 kinds of cutting 5 times to forecast a value to be in graph 6 in give out. From the dot B begins cutting temperature to show drab rise, till face of the knife before cutting bits to leave, follow cutting rate rise, cutting temperature also rises. But it is when cutting rate is higher, the temperature near dot B is inferior however. This one phenomenon discusses cutting speed to change to be affected to conducting heat in front specification and explanation gave out in the part. 3 conclusion reach through the analysis above the following and main conclusion. Assume in the model previously all bits freedom surfaces are workpiece room temperature, and test data has bigger difference to it; The model that give out compares suit actual. Calculate to simplify, it is the flow direction that cuts bits approximately with cut face posture perpendicular, in actual cutting, it is feasible that the analysis cuts face temperature to distributing. Below higher cutting rate, the edge cuts a face to obtain stability or saturated condition quickly to edge cutting temperature, below this kind of circumstance Rapier puts forward to cut what face temperature is constant to simplify the model has certain rationality. The test result that measures directly makes clear, introduce the computational model that the author offers, can get metallic cutting temperature distributings relatively satisfactory result. CNC Milling CNC Machining