The type selecting of machining center and order goods
- source:WEDEMEYER CNC Machining
01/300) often is ambiguous, special attention wants when ordering goods, must making clear is ISO standard, VDI/DGQ344182(Germany standard) , JIS(Japan standard) still be) of standard of NMTBA(United States. Analyse what all sorts of different level place set to detect then computational method and detect ambient conditions, ability won't produce misunderstanding. The servo that mill round precision is axis of concerned numerical control of machine tool of comprehensive assessment numerical control follows one of main index of athletic character and function of interpolation of numerical control system. A few large hole and big circular arc can use circular arc interpolation use establish milling cutter milling, no matter whether does typical workpiece have this need, control precision better to will need possibly to reach, must take this one index seriously. Numerical control precision has decisive effect to machining quality, should noticing to machine precision and machine tool precision at the same time is two different ideas. Get on manufacturer example or the positional precision on product certificate of approval regards as the treatment precision of the machine tool is a mistake. The positional precision that indicates on example or certificate of approval is the precision of machine tool itself, and treatment precision is the error total that all sorts of element place produce the whole machining complex that includes place of machine tool itself to allow an error inside. The error of whole machining complex, the reason is very complex, use linear relation ration very hard to convey. When type selecting, can consult the assess method of process capability Kp regards the type selecting of precision as the basis. Say commonly, computation should is more than as a result 1.
33. The stiffness stiffness of the machine tool affects productivity and treatment precision directly. The treatment speed of machining center greatly prep above general accuracy machine tool, electromotor power also the general accuracy machine tool that prep above is the same as norms, the stiffness that accordingly its structure designs also outclass general accuracy machine tool. Tigidity is a of machine mass main feature, but to type selecting character, undertake to what choosing a machine tool by the user rigid evaluation still does not have the standard that can draw lessons from. Actually the user is when type selecting, integrated oneself use requirement, to the machine tool advocate the implication that the choice of parameter and precision included rigid to the machine tool requirement. Force of craft requirement, permission torque, power, axis and feed force maximum can be pressed when ordering goods, the numerical value that offers according to manufacturer undertakes checking computations. With the machine tool that machines at difficult cutting material, should give to tigidity special attention. At this moment the tall tigidity to acquire a machine tool, often not dimension of spare parts of bureau be confined to, and choose dimension of opposite spare parts big the 1 machine tool to 2 norms. Numerical control system chooses cent of numerical control function to be basic function and choice function, can from control form of means, drive, feedback form, detect with measure, form of user function, mode of operation, interface and diagnose wait for a respect to measure. Basic function is provided necessarily, and after choosing a function to choose these functions when the user only, manufacturer just can be offerred, need to increase price separately, and the price is average taller. To numerical control systematic function must need to choose according to the function of the machine tool, the function that a need wants already when ordering is ordered complete, cannot omit, avoid utilization rate to create waste not high at the same time, still need to notice the associated sex between each function. In the numerical control system that can supply a choice, function discretion difference is very big, the price also can differ multiple. Answer to choose according to need, cannot seek tall target one-sidedly, lest create waste. When type selecting of much stage machine tool, choose the numerical control system of same manufacturer as far as possible, such operations, process designing, maintenance is more convenient. Want to notice at the same time, again good system, must want organic bed reliable spare parts quality and assemble quality to support, ability develops efficiency. Reference axis is counted and number of axle of coordinate of linkage number of axle and linkage number of axle all should satisfy typical workpiece to machine a requirement. The amount of general reference axis also is a mark of machine tool class. Usually, with the manufacturer, machine tool that is the same as norms, coequal precision, increase reference axis of a standard, the value increases about 35% the left and right sides. Although increase number of axle but the function of aggrandizement machine tool, still want finally to notice craft requirement and capital are balanced. Workbench function chooses horizontal machining center to have circumgyrate workbench. Circumgyrate workbench has two kinds, use at graduated circumgyrate workbench and workbench of numerical control circumgyrate. Use at graduated the span of graduation fixed position of circumgyrate workbench has certain restriction, and workbench has graduation and fixed position effect only, cutting cannot be participated in in circumgyrate process. Graduation horn has: 0.
Times;120 of Times;72, 3 ° mixes 5 ° Times;720, 5 ° 1 ° Times;360, fibrous root asks to choose according to the treatment of specific work. Numerical control revolving stage can realize aleatoric graduation, regard B axis and other axis linkage as control. Vertical machining center also can configure numerical control dividing head. But must decide according to real need, with economy, practical for the purpose. Trade knife unit automatically (the working quality of ATC) and ATC of knife library capacity and the performance characteristics that knife storage capacity measures immediate impact machine tool, quality and price. Knife library capacity it is a principle in order to satisfy spare parts of a sophisticated treatment to the need of cutting tool. All cutting tool that should analyse cipher out to machine spare parts place to need according to the craft of typical workpiece is counted, will choose knife library capacity from this. When the amount that should ask is too large, can decompose working procedure appropriately, decompose a workpiece it is two, treatment of 3 working procedure, in order to reduce knife library size. Want to pay close attention to weight of the dimension of the biggest cutting tool, biggest cutting tool at the same time. The choice of ATC basically considers to change knife time and dependability. The time that change a knife is short can improve productivity, but the time that change a knife is short, construction of the common unit that change a knife complex, fault rate cost is tall, high, time of knife of beyond the mark strong exchange can make the price rises substantially and make fault rate rises. Have about in the breakdown that occupies statistical machining center 50% concern with ATC, because this is below the premise of contented use requirement, choose the ATC with high reliability as far as possible, with reducing fault rate is mixed overall cost. Form of unit of cooling means refrigeration is more, the unit of shower type refrigeration that the machining center that contains complete shield partly distributes to have large flow, some matching that have cutting tool inside cold device (type of the Leng Fang inside the cutting tool that passes main shaft or outside receive) of type of the Leng Fang inside cutting tool, partial machining center afore-mentioned a variety of cooling means all are configured. Precision is taller, special the part with material or larger mental allowance, in machining a process, must cool adequately. Otherwise, the heat that treatment causes is out of shape, influence precision and manufacturing efficiency. Answer to undertake choosing according to the actual condition such as workpiece, cutting tool and cutting parameter commonly. Automatic pallet changer chooses to raise machine tool utilization rate, optional choose friends changes workbench, when so that the machine tool is normal,working, still can install workpiece on pallet changer. If the machine tool wants to bring into FMC, FMS, automatic pallet changer is must, such facilitating machine tools enter automatic content to shed a system. Deploy necessary accessory, cutting tool to issue the action of brandish machine tool to fill, when type selecting orders goods, except the consideration basic function is mixed outside basic spare parts, still should choose function of a few choices, option reach accessory, those who avoid because of lacking an accessory that tens of thousands of yuan of money can buy influence machine tool is normal move. And, the unit price that signs a contract to buy accessory alone greatly the accessory that lead plane of prep above be accompanying offers money together is monovalent. Discreet choice knife handle and cutting tool are the key that makes sure the machine tool moves normally. Expert of foreign metal cutting thinks " a value the numerical control machine tool of 250 thousand dollar the play of its efficiency depends on greatly a value the establishs milling cutter property of 30 dollars " . Visible, provide the cutting tool with good performance, it is to reduce cost, win one of crucial measure of benefit of the biggest economic integration. But the need amount of knife handle and cutting tool is large, the proportion that holds installation cost is very large, exceed the investment of equipment itself even sometimes. Accordingly, the variety that first-rate chooses way or wants according to typical work place and amount are certain, and in use acquires in succession. When providing knife handle, the level that should note hole of machine tool main shaft, standard that pull a hammer and manipulator clip maintain the level of place. A lot of manufacturers are only listed in example and manual main shaft standard, oversight the standard that presses hammer, manipulator clip to hold position, special attention wants when ordering goods. The consideration is different between the machine tool the versatility of cutting tool, when order goods, answer to reduce phyletic, type as far as possible. Already but resource is shared, reduce the investment in cutting tool respect, also facilitate management. Of the machine tool in forming, the device that discharge bits, guard and to Dao Yi etc all is must. Notice sex of form a complete set at the same time, a few righter although not be,must choose, but if the price is not high, bring a lot of to using, also answer to be chosen as far as possible. Cannot because little the attachment with a very low value and the generation when making costly machine tool moves is disadvantageous. Although machining center can undertake getting,the problem that 3 need note notices the adaptability of function and treatment, a variety of treatment such as mill, boring. But when specific choice, still answer to whether suit according to needing to consider machine tool function. Want to notice the following: When complex curve is machined, want to consider the curvilinear interpolation function that whether CNC needs somewhat, or the surface roughness that what chooses to means approachs treatment curve and assure a requirement. When three-dimensional treatment, the cutting tool structure that should consider to choose to suit, consider the ability of to program even. Some still must provide unit of automatic process designing or postposition handles process designing installation. When need undertakes whorl cutting () of blame tap means, should look to whether have function of whorl cutting function, corkscrewed yarn interpolation and main shaft roll and feed synchronism function not only, consider a machine tool to whether have radial feed unit even, whether to have main shaft position of aleatoric on direction of rotation angle is exact fixed position function. Otherwise, used whorl cutting function to still cannot undertake whorl cutting in numerical control system only. Taper hole is machined (be not form cutting means) when, the machine tool should have function of 3 coordinate linkage or cutting tool to want to have radial feed function. When using the non-traditional machining such as boring of King Kong bore with a reamer, float and extruding treatment, want to consider to change the condition of the knife automatically aptly already, want to consider to choose appropriate cutting tool structure and cutting dosage again. Purchase a share along with all the others when buying lead plane as far as possible fragile component and other accessory. If the enterprise has the program that uses DNC, FMS, CIMS, or should undertake the network is made, want to notice communication function, the choice has RS-232C, even the system of interface of MAP(manufacturingautomationprotocol) network news report. Technical service notices whether the supplier has good technology to serve ability, be like to program personnel, operation personnel, machinery and electric maintenance technician groom, of proper time guarantee freely, long-term and rapid maintenance serves, just assist pair of typical workpiece to do craft to analyse for goods, undertake craft experiments machining feasibility, try cut workpiece and assume service of whole set technology, till throw production in the round. The dependability that the dependability machine tool of the machine tool runs decided the overall quality of the machine tool. Machining center is used in, breakdown happening time antedates far the first time of bearing changes period. Numerical control system creates the appearance that stops machine a few months as a result of breakdown of some one plug-in unit board not scarce, invalidation of a sensor causes a machine tool to lose partial function to also have more happen. Below existence condition, in process of user type selecting, can pass pair of old users to undertake visitting, understand a few use situations of the machine tool more. The noise of the machine tool and modelling green are made and clean production is contemporary produce one of serious content. To machine tool noise, each national capital has specific level. At present sound quality also is labelled to evaluate one of standards of machine mass. Many machine tools not only control noise grade, and also raised a requirement to murmur control. Namely when the machine tool runs, outside allowing to exceed bid except noise grade, still should vinegary ear cacophony does not arise. Although do not exceed the order and degree that noise level provides,vinegary ear cacophony points to commonly, but the weird sound that can hear however. Machine tool modelling is OK also the impressions quality that a general designation is a machine tool, technology of machine tool modelling is the ergonomics actual application in machine tool industry. Sanitation of safe to industry, human body and manufacturing efficiency are producing machine tool model potential, but very main effect. Content of a requirement should serve as machine tool modelling when type selecting. CNC Milling