Wait for a processing technique of milling cutter milling of obliquitous helix chamfer

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Summary: Developed linkage of 5 axle control, four-axle wait for processing technique of milling of numerical control of obliquitous helix chamfer, through experimenting to the cutting of typical workpiece, when deciding the obliquitous helix chamfer such as treatment piece set of direction of the milling means of milling cutter, milling, dot removing a knife and wait for treatment method to knife method. 1 foreword is in the relevant document that processes domestic and internationally about helix chamfer or helicoid, the task such as the production that studies the key basically is centered at circumgyrate cutting tool and airscrew lamina treatment. Because the generatrix of circumgyrate cutting tool is simpler (it is cylinder more model or conic model outline) , accordingly a lot of document are discussing range of appearance of circumgyrate cutting tool when waiting for obliquitous helix chamfer to machine a problem, basically studied cutting tool makes medium point curve. Some document studied the treatment problem of airscrew lamina, the knife when the working surface equation that discussed airscrew lamina and crop milling cutter are machined the computational method with rudimental height. Returned some document to study the milling issue of cutting tool of head of ball of free curved surface. But the treatment method that at present very rare document involves the obliquitous corkscrewed yarn such as face of appearance of aleatoric generatrix swing tower and technology. The motor of new-style liquid rocket that at present our country is developing is the replacement product of engine of liquid of former spaceflight rocket. To improve cool performance, the wall appearance face in firebox of this kind of new-style engine counts 100 to wait for passageway of refrigeration of fuel of obliquitous helix chamfer to distributinging move last week, the central line contrail of its muscle and chamfer is wait for obliquitous corkscrewed yarn, the tangent that was in arbitrarily on the curve namely and the tangent way that should choose bus become calm part, this type curve also calls inclined line, if pursue,1 is shown. Because wait for wide C of the width B of muscle of obliquitous helix segregation and chamfer all narrower (B is about 1.

2mm, c is the narrowest place about 1.

5mm) , groovy deep E is deeper (make an appointment with 45mm) , because this cannot use the treatment method such as milling of turning, marvellous milling cutter, electrochemistry, can use a milling cutter to undertake milling is machined only, and the requirement keeps apart the width of muscle to answer inside corkscrewed yarn normal plane everywhere equal, the normal direction of the outline of high direction edge of muscle, cannot tilt. Firebox outline generatrix is complex curve more, or the curve of different type joins and become by a few paragraphs, its maths model is complex and changeful. If use treatment of 3 axes linkage, can make bottom land and muscle form happen tilt. Burn in what have aleatoric generatrix outline the obliquitous helix chamfer such as the treatment on face of indoor wall appearance is our country a solves urgently difficult problem in development of motor of rocket of new generation liquid. Graph 1 wait for sketch map of obliquitous helix chamfer to pursue campaign of treatment of 2 helix chamfer is analytic graph the mathematical model of the obliquitous corkscrewed yarn such as basis of treatment of linkage of the 2 5 axle control that wait for obliquitous helix chamfer, four-axle and motion are analytic, it is those who assure cutting dot and cutting tool center to connect a line from beginning to end the normal direction of edge workpiece and inside the horizontal that is located in work center axes from beginning to end, must increase a rotor to dog with real time the change of workpiece normal, win correct bottom land and muscle form to assure namely, the helix that uses a milling cutter to machine face of appearance of aleatoric generatrix swing tower needs four-axle linkage at least when groove. Graph 2 machine motion for helix chamfer analytic graph. 1.

Dynamical electric machinery 2.

Rotor 3, 4.

Circumgyrate workbench 5.

Piece milling cutter 6.

Workpiece pursues if the graph is shown 3 times,chamfer of helix of component of treatment of 3 helix chamfer machines a component. The rotate speed of 1 passes milling motivation electric machinery control of communication frequency conversion, share 8 archives speed, the M that uses CNC machining dictates process designing is controlled. Rotor of blame servo pilot 2 use at adjusting helix angle (consult the scale of the place indicates) , use special tool to be opposite accurately knife. The workbench of circumgyrate of rigid numerical control of drive of servo electric machinery 3 in the circumgyrate inside horizontal, inside the horizontal that is used at making sure cutting dot is located in work center axes from beginning to end, make cutting chooses way of normal of the outline outside the work that with this axis the dot of cutting of the edge that connect a line of centre of turning circle handles, in department of machine tool coordinate this rotor definition is B axis. The workbench of circumgyrate of rigid numerical control of drive of servo electric machinery the circumgyrate of 6 mixes the 4 workpiece in be being used at completing treatment graduation, this rotor is A axis in the definition in department of machine tool coordinate. To make sure muscle is wide equal, use two milling cutter 5 treatment, a spacer is placed between 2 milling cutter, spacer ply is segregation muscle width namely. Axis of X of additionally 3 straight bobbin, Y, W fastens medium directional definition to see a picture in machine tool coordinate 2 with the graph 3. In treatment, besides undertaking outline contrail interpolation to axis of X, W, swing to B axis even the coordinate error that cause undertakes compensating. The height that Y axis uses at adjusting cutting to nod (make axes of dot and this work center is inside same horizontal) , it and other reference axis concern without linkage. The numerical control cutting that the milling treatment of the obliquitous helix chamfer such as the surface outside finishing aleatoric generatrix swing tower needs to undertake linkage of 5 axle control, four-axle. To finish the numerical control process designing that helix chamfer machines, developed the system of data processing of automatic process designing that is aimed at afore-mentioned treatment exercise program technically, the interference error that processes through analysing helix chamfer, put forward those who choose a milling cutter diameter to simplify algorithmic. Wall of firebox of motor of rocket of some model liquid receives the processing technique of 3 typical workpiece, enlarge Duan Rutu is shown 4 times, its outline generatrix uses discrete data to nod descriptive curve to form with a group point-blank by a paragraph. In straight line segment and joint of music line segment, workpiece diameter changes quickly with curvature happening, form " larynx " department section, "Larynx " transfer smoothly of department section one of main difficult point that treatment is this workpiece treatment. Graph the counters mill to go against mill to be able to eliminate mechanical component gap certainly impact of the affirmatory milling means of 4 milling means, reduce the vibration in cutting process. But as a result of firebox workpiece material agglutinant stronger, the width that keeps apart muscle is narrower, groovy close look is broad to muscle deeper, machining the discovery in the process, choose how old feasible feed speed and main shaft rotate speed no matter, all can cause helix muscle to be torn off badly, make the exterior surface roughness of bottom land and muscle too big. Linear, if the graph is shown 4 times,the curve arranges mill, if be machined according to ① of the direction in the graph, AO paragraph for linear, here spray pipe is columnar outline. Manage treatment removing a knife from this paragraphs start A, more convenient to the knife, the preparation before be helpful for machining works, simplify operation requirement. But discover in actual cutting, means of this kind of milling puts in the following problem: Graph 5 " laryngeal " phenomenon blocking a knife pursues 6 linear, of the move about arm when the curve arranges mill suffer force to be in extremely easily " larynx " ministry " card knife " or " frowsty car " if use,change cutting tool newly and when feed rate is slower (<30mm/min) , add man-hour to be able to be passed smoothly " larynx " ministry. But when cutting tool wears away or feed speed is more than 50mm/min, can be in " larynx " ministry happening " card knife " phenomenon, make arbor, cutting tool and workpiece are damaged (5) seeing a picture. The structure of the happening of this kind of phenomenon and B axis move about arm and direction getting power is concerned. If the graph is shown 6 times, be in right now " larynx " ministry, cutting tool suffers the feed direction of force Fc and B axis to all have the tendency that makes cutting deepness increases. Wear away when cutting tool after becoming blunt, the little impact that the vibration of rigid structure and change of CNC Machining block cause can become cutting tool herein " card knife " influencing factor. Pursue attaint of form of 7 rears muscle pursues 8 curves, the adjustment of the long veins that stand out that the linear means that arrange mill machines and axis of 9 B of the graph that place muscle pursues muscle becomes 10 pairs of knives and helix of the injury when removing a knife to nod a rear to retreat a knife by linear Duan Xiangqu line, b axis move about arm is in " larynx " the bigger flexibility that the ministry forms is out of shape in whole music line segment is machined in cannot slow down. When machining a chamfer to retreat a knife, flexibility of generation of B axis move about arm is out of shape time put, can make caudal muscle form is damaged, if pursue,7 are shown. Cannot come true " clip muscle " treatment by the graph 7 visible, if be in workpiece diameter is majorrer the helix chamfer that still machines photograph of as minor as the diameter part to be the same as an amount, can remain between two muscle more not cutting part. Machine a requirement according to the spare parts, must remain this part also cutting is the wide short muscle such as as long as other veins that stand out (call " clip muscle " ) . Check discovery through effective treatment, by linear, direction of treatment of curvilinear suitable mill is machined " clip muscle " when, dot removing a knife reachs pair of knife methods to all decide very hard. Curve, if the graph is shown 4 times,arrange mill point-blank, if press directional ② to use,arrive by music line segment the suitable mill means of straight line segment, although be mixed to the knife,compare difficulty of dot removing a knife certainly, but better solved " larynx " ministry " card knife " , attaint of caudal muscle form, cannot machine " clip muscle " wait for great technology issue. Graph 8 to use a curve, arrange what mill means cutting machines to close point-blank, chamfer of enlarge Duan Luo coming back and " clip muscle " . The machine tool is right of knife and the affirmatory B axis of dot removing a knife when adjusting treatment helix chamfer, to win proper muscle form, must assure center of cutting dot, cutting tool (it is the spacer center between two milling cutter actually) with B axis centre of turning circle is in to go up point-blank. Before the helix chamfer that has any outline is machined, need to adjust B axis first, make B axis component is in the condition when machining outline of columnar Duan Lun. Dosage is expressed detect pair of knife piece on move about arm, make direction of axis of W of edge of move about arm (namely DEG is linear) (9) seeing a picture. The B axis compensation that computation causes because of B of helix angle of upend arbor roll is worth B, b of circumgyrate of your B axis, make centre of turning circle is in center of cutting dot, cutting tool and B axis one goes up point-blank (namely DEF is a linear) , next B axis to clear, right now B axis as it happens is in the position that machines chamfer of columnar Duan Luo coming back. The computational formula of B is B=arctan(Lhsinb/Lb) type in: Lh -- Lb of upend arbor length -- B of length of horizontal move about arm -- helix dip is right knife method and computation of dot removing a knife show work 4 times to the graph, use a curve, when the linear means that arrange mill undertakes cutting, must solve pair of knives and problem of setting of place removing a knife, the B rod that must remove a knife to nod S certainly namely, X axis and W axis coordinate (10) seeing a picture. Because S dot is located in disperse to select area, it is quite difficult to the knife to use this to nod directly. After B axis is affirmatory, in the CNC Machining program that creates in system of automatic process designing, the B axis coordinate that gets disperse to nod outline fine to nod S is worth B0, the normal way that S chooses sees graph 10) for NN(. Write numerical control program, bb of circumgyrate of your B axis, even B axis swings to machine the state that S orders. Because a side of S dot is 4 ungual chuck, do not have pair of knife spaces, because this cannot nod pair of knives in this. Low speed of your milling cutter rotates, in the workpiece of top a side end faces a knife, the coordinate of X axis machine tool that writes down systems of next here numerical control to show is worth, set for XT, the X way that gets by workpiece blueprint this end panel is nodded to S is apart from a value, write down for XW, criterion the XS of X coordinate value that S nods is XS=XT+a-dX+XW type in: A=rccosd+(hc+0.

5hg)sinddX=rcsinB0 Rc -- piece Hc of milling cutter radius -- piece Hg of milling cutter ply -- low speed of knife of spacer ply Ling Xi rotates, the cylinder in top a side paragraph outside outline is right knife, the coordinate of W axis machine tool that writes down next here system place to show is worth, set for WT, the W way that gets by workpiece blueprint this cylinder outline is nodded to S is apart from a value, write down for WW, criterion the WS of W coordinate value that S nods is WS=WT+WW-dW type in: DW=rc(1-cosB0)4 epilogue uses a milling cutter to machine face of appearance of aleatoric generatrix swing tower wait for obliquitous helix chamfer, be equivalent to using plane of a circumgyrate (piece milling cutter) go wrapping helicoid of subsidiary channels in the human body through which vital energy, must use so at least the treatment program ability of four-axle linkage assures correct bottom land and muscle form. Introduce B of circumgyrate reference axis achievable dog to the real time of workpiece normal, but increased to machine difficulty. The helix chamfer that uses the article to put forward processing technique, can solve the technical difficult problem that chamfer of helix of typical spare parts machines. This technology applies successfully already at group of Chinese spaceflight science and technology 7103 factories tens of the formal treatment of serious work, obtained favorable result. CNC Milling CNC Machining