Be based on UG converse project to assist treatment to the computer of turbine
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Often use converse project technology, undertake to the complex objective model of existence or spare parts the digitlization of high accuracy is measured namely, the CAD model that counterpoise draws out undertakes the computer assists an analysis (CAE) , through CAM system treatment gives a product, the product that gives to treatment again undertakes shoving produce the expected result, revise and innovate, if dissatisfactory can undertake be designinged again afresh, rework and examine, till satisfactory process. Process designing of gas CNC Machining is one of CNC Machining of complex curved surface important segment, means of dosage of the cutting in CNC Machining process designing, mental allowance, means taking a knife, knife of advance and retreat, process designing was mixed at 0 o'clock the element that machines the respect such as coordinate department will affect cutting to machine efficiency, shape quality and treatment surface roughness, also concerning it is in the integral function article of converse project on foundation of compositive environment of Cimatron software CAD/CAM, the model of CAD of complex curved surface that gives to reframing in converse project undertakes CNC Machining process designing, discuss through pulling those who machine parameter principle to determining number, gave out efficiency of a kind of treatment is tall, shape the CNC Machining method with good quality. Craft of CNC Machining of 1 complex curved surface is analysed 1.
The method of 1CNC Machining curved surface appears along with what a move in chess or a movement in wushu charges a machine tool, especially the occurrence of machining center, the treatment process of free curved surface can pass numerical control process designing to come true. Complex model business uses lens of numerical control of knife of ball head lens to cut commonly, between the athletic contrail that the treatment contrail that the program gives out also is knife head heart. Numerical control machine tool cuts treatment to the successive lens of free curved surface, have cut law, annulus to cut law, layer to cut a way all right, wait for the brake of method of a few kinds of treatment such as dark magic art, the author basically is used cut law and layer to cut a way all right two kinds, cut a law to have process designing to be mixed simply all right the good point with cutting high efficiency, but because cutting tool is be expert at,cut the motion inside plane, and the curvature of curved surface differs to wait for a reason with fixed position, can bring about the rudimental height between travel to differ bigger, because this is commonly used at rough machining. The layer cuts a law to machine is to waiting for mental allowance of the excision on high area, it is character actually - kind 2 uranium of half statified processing machines a method.
In the layer Qiefajia is versed in in the process, contrail taking a knife is by limitation in 2 dimension plane, went to the lavatory of cutting tool contrail optimize, empty knife phenomenon decreases greatly, cutting efficiency is tall. Accordingly, the layer cuts a way is a kind of efficient establish treatment method. 1.
The lens to free curved surface cuts the machine tool of principle numerical control that parameter of treatment of Huang of number of 2 curved surface chooses in treatment, means of cutting dosage, mental allowance, means taking a knife, knife of advance and retreat, process designing was mixed at 0 o'clock the element that machines the respect such as coordinate department will affect cutting to machine efficiency, shape quality and treatment surface roughness. Specific and the following principle: (The principle of dosage of cutting of 1) logical choice: When rough machining, - kind give priority to in order to improve manufacturing efficiency, but when also should considering 3 semifinishing machining of economy and finished cost and precision work, grasp before assuring those who machine quality below, efficiency of cutting of give attention to two or morethings, economy and finished cost. When cutting curved surface with lens of machine tool of 3 coordinate numerical control, inside the range that permits in machine tool and cutting tool, main shaft rotate speed chooses contain as far as possible some, in order to improve treatment efficiency. (2) machines a pace to grow affirmatory principle: Treatment appearance uses rudimental knife mark when complex curved surface the law that high law will machine a pace to grow @ remain height certainly is group of watch of treatment pointing to an edge measures way to arrow, the height of the wave crest between travel of two-phase adjacent cutting and trough is poor, if the graph is shown 1 times, with knife of ball head lens treatment protruding curved surface discusses the concern between them. Graph 1 in, the distance) between center of AB=2a(cutting tool, mark of PE=h(remain knife high) , p is curvature radius, 0 for curvature center, r is cutting tool radius. The arc length when curvilinear arc CD very hour, can consider as its a paragraph of circular arc that is radius with P approximately, accordingly, can get rudimental knife mark high H and the relation that machine situation dog days are like type (1) place is shown. (1) pursues pace of treatment of high law control grows mark of 1 remain knife to be able to pass rudimental knife mark so the value of high H, will control treatment pace to grow, will ensure with this the treatment precision of workpiece. (3) decides the basic principle of mental allowance: In assure complex model face treatment reduces mental allowance as far as possible below whole premise. (4) walks along knife means and principle of cutting direction choice: The basis is machined the geometrical appearance of spare parts surface, below the premise that assures to machine precision, make cutting handling time as far as possible short, and in cutting treatment process, cutting tool gets power smooth. The cutting tool motion that machines in area of three-dimensional curved surface makes a technology with respect to mark in, can use 3 kinds of following means taking a knife: Move back and forth means taking a knife, home remedy cuts knife way to means taking a knife, annulus. (5) feed means chooses a method with what remove knife means: Treatment precision asks to press tall curved surface, to be absent the feed of workpiece or the place that retreat a knife leaves the mark that be stationed in a knife, should choose the feed of the direction cutting arrow of edge curved surface or direction of edge circular arc, way that retreat a knife. (6) process designing the choice principle 0 o'clock: Should make process designing at 0 o'clock the dimension datum coincide with workpiece; Should make the operation when program of work out numerical control most simple.
Avoid error of computation of occurrence dimension catenary: The machining error that cause is the smallest; Process designing should be chosen at 0 o'clock searching easily, facilitate in machining a process metrical place. The CNC Machining of the curved surface of 2 CNC Machining of eddy current curved surface that are based on UG is one of important step of converse project, the free curved surface that through process designing only treatment gives to nod cloud " data to weigh Ju by " , converse project just is in real value. The CNC Machining method of turbine Yan Li studies below. 2.
Coordinate of 1 definition treatment is to make system of process designing personnel and the course of whole CNC Machining that runs a product conveniently, need to define department of coordinate of a treatment above all before process designing. Some is machined in converse project when complex curved surface, because the specific measure of secret range cannot get, because this suggests the new coordinate that uses a system to be generated automatically is fastened, set process designing in this to machine the origin that coordinate fastens at 0 o'clock. 2.
2 building cutting tool data-base and choice treatment category to build cutting tool data-base is a basis the cutting tool of library of this cutting tool of machine tool of unit numerical control and the cutting tool that treatment curved surface wants to choose are phyletic, build warehouse of a cutting tool, the concerned parameter of cutting tool, in inputting cutting tool library like horn of cutting blade length, cutting and arbor length. Knife of used lens of φ 8mm ball is machined in article. Because UG software can undertake the 2 lens to 5 uranium cut the process designing of the CNC Machining such as car of treatment, numerical control and line cut, should choose to machine a category before process designing so, the lens that 3 axes choose in rough machining here cuts treatment, the lens that chooses 5 sleeve in careful work cuts treatment in order to improve efficiency. 2.
The bulk of semifinished product of basis process designing will decide the builds effective treatment semifinished product size of semifinished product of 3 process designing. Want process designing treatment to give turbine appearance hidden side, must build the process designing semifinished product of turbine first. Because be dimensional positive aspect.
Not only dimension of its Mai Li decides hard, and the position in machining coordinate to fasten is bad also and firm, so need settles the size that wants process designing semifinished product certainly and the position that its are in. For this, press curved surface size first, the semifinished product of the smallest treatment that the method that builds process designing semifinished product with software builds a treatment automatically to give curved surface place to need, examine its dimension and the position in machining coordinate to fasten, build process designing semifinished product next. Built process designing semifinished product is shown 2 times like the graph. Graph embryo of 2 turbine wool pursues 2.
Cent of CNC Machining of process designing of 4 rough machining is rough machining and finish machining. When machining complex curved surface, the surplus of about 70% is excised when rough machining.
Consequently many treatment man-hour is used up at process of thick fine workmanship. Should choose a kind for this reasonable, hire treatment method efficiently to undertake process designing is machined. Because the Mai Li of the outside face of turbine is deep and remote rate radius is certain the place is less, and secret rate change is big also, to can use a knife treatment gives its appearance and contented precision requirement, diameter of ball acute knife chooses a little bit small, its are worth for 8; Feed also chooses the direction that cut arrow to cut support of the people to leave with the means that retreat a knife, with benefit the treatment quality at improving the appearance; Cutting dosage is: Main shaft rotate speed is 4000r/min, every treatment condition is chief for Lmm, pace of the treatment inside the layer grows also is 1mm, the surplus of rough machining is 1.
6mm, exterior surface roughness is 0.
05mm. Graph the 3 effects after hiring treatment for turbine imitate pursue. The graph honours the rough machining imitate of the face is encircled outside 3 turbine 2.
Finish machining of numerical control of process designing of 5 finish machining must satisfy the precision that blueprint asks, so the principle of finish machining process designing is improve treatment efficiency as far as possible below the premise that assures to machine precision. And the specific geometry develop that the treatment method choice when process designing and the set that machine parameter should machine curved surface according to place attacks the relation will decide. The outside range of turbine is more sophisticated, have sunken have protruding, exterior curvature size is differ. From hire treatment imitate graph to look, pace of the treatment between the layer grows is Lmm, the pace of adept cutting grows the layer also is Lmm when, machining the effect is not very good. Machine precision to rise so, advocate knife means by reciprocating type instead one-way type taking a knife, although handling time bewitching a few, but treatment precision is taller, this accords with the principle with first precision of finish machining process designing. Cutting parameter is: 5000r/min of main shaft rotate speed, cutting tool diameter is means of knife of φ 6mm, advance and retreat and rough machining appearance, exterior surface roughness 0.
01mm, pace of the treatment between the travel of travel cutting grows to remain according to aforementioned high law comes to knife mark affirmatory. each relevant parameter make choice of, treatment stage long set is 0.
01mm. Graph the imitate of 4 outside face finish machining that are the turbine that undertakes process designing by afore-mentioned means and parameter pursue, it is thus clear that with rudimental knife mark high law controls treatment pace to await, can obtain faster face to machine quality. Graph the finish machining imitate of the surface outside 4 turbine pursues 2.
The program that the aftertreatment of foreword of 6CNC Machining spoke should make weave comes true on numerical control machine tool.
Return so that the file of cutting tool contrail what had woven in UG changes amount to to accuse a machine tool to be able to know document of other NC code. The treatment management environment that passes UG/CAM the file of cutting tool contrail of the outside face corresponding turbine, classics aftertreatment seeks solution implement changeover is NC code file. After the installation that completes work semifinished product on workbench of numerical control machine tool, word tries, calculate generated NC code file through denouncing machine be defeated by a person to control a system to numerical control machine tool, can duplicate in before last of work semifinished product those who go out to seek the outside range of the turbine that go out instead through converse project is complex model face. 3 conclusion are in the converse project of curved surface of geometrical model freedom.
Need complex to the spare parts curved surface to undertake CNC Machining process designing, it is one of important segment of converse project, the craft parameter such as means of dosage of the treatment method that chooses to abandon manage only, cutting, mental allowance, means taking a knife, knife of advance and retreat ability is OK machine efficiency with taller cutting, shape well quality and the curved surface that first-rate machines surface roughness. Concern according to what machining the specific geometry develop of curved surface to attack, in the CAD/CAM of UG compositive environment falls, the program that chooses appropriate cutting tool to machine method undertakes hiring, finish machining, this is one kind can improve treatment efficiency already, can obtain better appearance to machine the way of quality again. CNC Milling