The logical choice that casing machines

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In the production of contemporary high level the condition falls, how to choose appropriate treatment facilities, realize low cost, high quality transmission casing treatment, producing quality to raising the whole of transmission is crucial. The practice experience of limited company of gear-box of one steam Eton makes clear, choosing machining center is reasonable. The structural characteristic of transmission casing and form of casing of technical requirement transmission are complex, wall the thin, form that present case (graph 1) , its express a mask to much place machines place, if the bearing on casing is aperture, forked,axial aperture, fixed position cuts aperture, bolt join aperture and the assembly that all sorts of installation plane are affecting transmission directly quality and performance characteristics. Accordingly, transmission casing treatment has strict technical standards to ask, be like: The dimension precision of bearing aperture is IT6 ~ IT7 commonly, ra1 of exterior surface roughness.

6 ~ 0.

8 μ M, circularity, cylinder is spent for 0.

013 ~ 0.

025mm, the parallelism between bearing aperture is 0.

03 ~ 0.

04mm, the flatness of casing join face asks to be 0.

05 ~ 0.

08mm. The craft analysis casing that casing machines belongs to Bao Bi kind spare parts, changeful entity is allowed when holding clip, because this is when treatment, want to select site of reasonable clamp, fixed position not only, and the size that commands cutting force even. The seat that fastens as a result of the aperture on casing spends a requirement taller, face of join aperture, join is more, reason needs to use the method that working procedure centers relatively when treatment. In characteristic of this kind of structure and treatment of casing of technical requirement decision, machining center is the choice of optimization. With the housing before around combines box transmission treatment uses machining center product line to be exemple, analyse the technological process that its machine: □ by face of front of thick mill of special milling machine; □ uses special milling machine thick mill and in housing join face; □ is shown 2 times like the graph, on vertical machining center, complete side of front of mill of half essence mill, essence of life, auger, the end panel before attacking and clutch housing join each aperture, get, aperture of forked axis of bore with a reamer and all sorts of oily aperture; □ is shown 3 times like the graph, on horizontal machining center, finish with in the treatment of housing join face and join aperture, forked axis aperture, aperture of bearing of boring of thick, essence, forked axis aperture; □ is shown 4 times like the graph, use coping of mill of wide choice of horizontal machining center to join plane of face, sign, side takes force face and aperture of each join whorl; □ uses radial drilling machine to drill inclined oily hole. The arrangement of afore-mentioned process, have following characteristics: 1, rough machining and finish machining departure undertake, the internal stress that can eliminate a spare parts to add man-hour is out of shape, improve treatment efficiency. 2, use as the position with standard essence (front face and two craft aperture) preferential treatment, the technology that the treatment of place of the foreword after such making had to unite is fiducial, the equipment tool of the foreword after simplifying, reduced the fixed position error of workpiece. 3, with traditional modular machine tool treatment line is compared, craft course considerably cut, by many 30 original working procedure cut for 6 working procedure, reduced a machine tool cover an area of an area, reduced a spare parts to carry the knock against injury in the process. 4, flexible change rate taller, many breed can be machined on a product line, satisfy the requirement of market diversification. 5, use extensively of cutting tool of hard alloy of speed of tall tigidity, tall cutting, improve the treatment efficiency of the machine tool. Get the cutting rate that cuts treatment to be able to amount to 120m/min, the every tine feed that milling machines can be achieved 0.

Deepness of 3mm, cutting can amount to 6 ~ 8mm. The watch is shown 1 times for, machining center (cutting tool of use hard alloy) with common modular machine tool (cutting tool of use high-speed steel) the contrast that waits for a respect in efficiency, precision and cutting tool cost. Can see, machining center is rigid power of electric machinery of good, each main shaft is great, use hard alloy cutting tool to replace the commonly used high-speed steel cutting tool on modular machine tool, can raise treatment effect to lead 3 ~ 5 times, can raise treatment precision considerably. When large quantities of quantities are produced, can satisfy the requirement of product and craft completely, although odd cost rises a cutting tool somewhat, but consider from the many sided such as the performance/price ratio of depreciation of labour cost, equipment and product, its total cost is reduced substantially. 6, the machine tool is had be measured automatically and cutting tool wears away compensation function, in making its wait for finish machining working procedure in aperture of bearing of boring of essence of life, stability of batch treatment accuracy class is in IT6 class above. The it is certain to choose every machining center to have standards of machining center, particular function and first-rate scope of application. Machining center cent is horizontal and vertical two kinds, horizontal machining center is comfortable at machining box spare parts, wait like pump housing and casing; Vertical machining center suits treatment board kind spare parts, as above lid, cover board, dash forward the predestined relationship. The machining center horizontal of identical norms arranges an in part than the petty gain on vertical price, use efficiency is a bit poor also, accordingly, finish identical craft content, use vertical machining center to compare horizontal machining center more economy, but the craft sex of horizontal machining center is more extensive. Accordingly, consider the price and the need that machine craft integratedly, normally the amount of horizontal and vertical compares the machining center in product line to be about 2: 1, basically realize the manufacturing metre that balances quite. 1, the rated load of quantity of storage capacity of the power that the norms with the choice the mainest machine tool of machine tool norms has journey of rod of amount of rod of workbench dimension, movement, movement, main shaft and torsion, knife and workbench. The biggest casing that with Eton transmission the factory produces is exemple, basic measure is this casing 430mm of × of 520mm × 320mm, for the space with clamping device enough put apart, choose workbench dimension to be the horizontal machining center of 630mm × 630mm, journey of axis of X, Y, Z is 1000mm, 800mm, 810mm respectively, main shaft outputs power to not be less than 20kW, 466Nm of the biggest torsion, higher power and torsion are a when the machine tool improves cutting efficiency main index. Because aperture of the treatment on casing is relatively dispersive, so machine tool workbench has function of 360 ° graduation, additional, use double cross to change tray to be able to improve work efficiency effectively. It is normally in vertical machining center, knife storage capacity is measured not under 20; In horizontal machining center, knife storage capacity is measured not under 40. Knife library capacity shoulds not be too big, because the knife library cost of high capacity is high, the orgnaization is complex, cutting tool management is intricate, every change a kind of new product, the member that the machine tool adjusts a person is about to ask to undertake arranging to cutting tool according to craft. 2, the choice basis of machine tool precision casing kind the machines precision to choose a machine tool precision of place of spare parts key. The fixed position precision of the machine tool and the integrated precision that repeated fixed position precision to reflect each motion part, repeat fixed position precision especially, the fixed position stability that it reflected this axial to be nodded in fixed position of the random inside effective journey, this is to measure numerical control axis whether the main index of stable and reliable job. The software of system of machining center numerical control can is opposite the pitch error that controls an axis and retrorse difference value undertake compensating, also can go up to undertaking transmission catenary the systematic error of each link undertakes stability is compensated. Feed breaks momentum to also can compensate a function to compensate with backlash reversely in transmission catenary, for example, axis of a numerical control is 40mm to the athletic injunction that grant, actual measurement shift is apart from for 39.

985mm, can say to lose momentum reversely for 0.

015mm, compensate by numerical control system 0.

The motion of 015mm is measured, can make coordinate moves origin. To because each axis is mechanical servo of transmission catenary, drive yuan character of job of parts of an apparatus differs the repeatability error that cause, cannot receive total compensation with interpolation method. 3, the use efficiency of the machine tool is in treatment process, main shaft rotate speed is decided by place of stuff of the workpiece that be added, if machine nonferrous metal, must choose higher rotate speed. The mainest factor that affects treatment efficiency is the time that change a knife, because to similar casing kind complex part, every treatment is made, need to change about 40 ~ 50 cutting tool. Use the roller cam form that takes mechanical arm to change knife orgnaization (graph 5) change knife orgnaization than bamboo hat type (graph 6) , the time that change a knife shortens greatly, it is about 5.

5s left and right sides. The cutting tool with commonly used machining center and clamping apparatus 1, of clamping apparatus choosing clamping apparatus is treatment of the spare parts that finish is important assure, clamping apparatus design is reasonable, ability assures to spare parts installation goes to the lavatory and satisfy treatment precision to ask. Accordingly, when designing fixture, need to consider following factor: (1) the fixed position of workpiece is standard with the requirement to clamp: Machining center is multitask foreword center treatment, the spare parts is in in outfit clip, want thick mill, thick boring already, want boring of mill of essence of life, essence again, requirement clamping apparatus wants to be able to bear already big cutting force, want to satisfy the requirement of fixed position precision again. (2) the join means of clamping apparatus, workpiece and mesa of machine tool job: Machining center workbench should have center of fiducial T chamfer, revolving stage on the face flank of mesa of fixed position aperture, job is fiducial etc. (3) when clamping apparatus is designed, must consider contrail of cutting tool motion: Clamping apparatus cannot produce interference with contrail of cutting tool of each working procedure. When using the knife that carry mill to machine a spare parts for example, cannot mix with the impaction bolt of clamping apparatus in feed contrail and place of contrail giving a knife interference of pressing plate happening; Because broach reachs boring arbor to wait to be interfered easily with clamping apparatus, accordingly, when casing is machined, can consider to use its interior space to schedule clamp plant (graph 7) . (4) clamping apparatus must consider clamp to be out of shape when the design: The spare parts is when rough machining, cutting muscularity, need clamp muscularity, but should prevent to press workpiece clip be out of shape, accordingly, dot of the strong point that must choose clamping apparatus cautiously, fixed position is nodded with clamp, the clamp dot of pressing plate should approach strong point as far as possible, avoid to increase clamping force in area of spare parts supportless. (5) clamping apparatus must tear open outfit is convenient: The clamp means of clamping apparatus has hydraulic pressure clamp, pneumatic clamp and hand to move clamp. Below the circumstance that machines qualification of dimension of part semifinished product in place, use hydraulic pressure to intensify moving clamp clamping apparatus to be able to improve the efficiency that dismantles outfit part compatibly. (6) not big to batch, often alternate again the spare parts of breed, should first consideration uses group clamping apparatus or built up fixture, in order to save the charge of clamping apparatus and preparative time. 2, the chooses machining center to use cutting tool cent of cutting tool is knife handle part and cutting tool part. Cutting tool part and general cutting tool are same, wait like broach, tap, boring cutter, reamer. But the diameter that must consider cutting tool, length and self-prossessed. (1) the sort of knife handle: Different machine tool specifications produces business with what differ, chooses knife handle norms and series have each different. Common knife handle cent is BT series (commonly used) , CAT series, DIN series (Germany is commonly used) . The norms of knife handle is according to the different cent of machine tool norms again 30, 40, 50 wait for many breed. (2) the note that chooses knife handle and cutting tool: Must consider the generalization of knife handle above all, for example, the factory has Eton transmission 30 machining center, although produce manufacturer to differ, but the knife handle of the choice is only two kinds, horizontal machining center chooses BT50 knife handle, vertical machining center chooses BT40 knife handle, raised the utilization rate of knife handle not only, still reduced cost of cutting tool government; Next, cutting tool of first selection standard, reduce the use of special cutting tool as far as possible. Special cutting tool applies to large quantities of quantities to machine production in, if compound cutting tool can save handling time effectively, but in at present the manufacturing condition of car component much breed, small lot falls, using special cutting tool is not economic choice. 3, the chooses pair of machine tools refrigeration of machining center accessory, defend, lukewarm control of oil of platoon bits, main shaft, cooling fluid is lukewarm wait for accessory for control, requirement reliability is high. The rationality that cooling guard designs on machining center machine tool is to measure a machine tool the important sign of integrated level. The cooling fluid spurt that the graph shows horizontal machining center 8 times uses formula of shower of bull, multibarrel cooling, rinse, and have main shaft inside cold device, make cutting tool is had inside cold function. Brief summary and photograph of traditional modular machine tool are compared, use machining center to machine casing kind spare parts, no matter from improve treatment quality, improve manufacturing efficiency, still reduce manufacturing cost respect, the effect is remarkable. Choose machining center, must consider its to machine economy, must wait for many sided consideration from material of clamping apparatus of parameter of machine tool norms, cutting, tool, workpiece, production lot namely. Additional, the quality of personnel grooms also is indispensable. CNC Milling CNC Machining