The dimension public errand that is based on technology of three-dimensional drift analysis designs application
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Css" Type=text/css Rel=stylesheet> is in truckload in all sorts of error that design and make each level, component deviation is to bring about truckload one of crucial factors that assemble total deviation. Component public errand is to decide mould, check is provided, the foundation of public errand of tool clamping apparatus, limit system is decided, a large number of adjustment that what allocate unreasonable meeting to cause mould, clamping apparatus, cause manufacturing cost to rise. Domestic and international advanced car designs a company to set dimension project branch, use technology of tolerancepublic errand allocation to assign tolerancepublic errand goal precision of public errand of various and hand-in-hand travel to optimize, assure product quality. Technology of tolerancepublic errand allocation is to show the basis is truckload quality of official of impressions of function of each subsystem product, inside and outside and overall technology requirement, the economic craft ability that considers production system, in truckload development design phase allocates tolerancepublic errand reasonably for component. Mainstream public errand manages mode to have two kinds, it is day fastens an enterprise to be a foundation with experience, will truckload tolerancepublic errand target is layer upon layer distribute assembly of white automobile body, motherboard assembly, big assembly, small assembly and sheet, make through project model car come the noncombatant duty that test and verify adjusts set; 2 it is Euramerican it is technical measure with advanced drift analysis software, combine engineering experience, through fictitious copy whole dimension catenary true means is finished truckload reach management of component public errand. The article will introduce extensive inferior car technology center shows level is how to combine domestic component to produce engineering capability, draw lessons from public errand of Euramerican and advanced three-dimensional drift analysis to manage software technology resort, public errand of implementation automobile body manages systematization and standardization. Software of 1 three-dimensional drift analysis and software of management of algorithmic and professional noncombatant duty basically have 3DCS and Vis_VSA, analysis of public errand of a hardware that develops by DCS and UG company respectively, assembly parts and design software. What at present home can apply these software to undertake tolerancepublic errand is designed independently is truckload the plant is less, home begins the public errand that is based on three-dimensional drift analysis to design working more ground is to adopt with commerce advisory company applies these software to develop measurement system jointly. The public errand in the article manages what analyse computational application theoretically is 3DCS software. 1.
The method that public errand of algorithm of software of 1 drift analysis analyses has extreme value law and method of statistical public errand two kinds, according to distributinging character undertakes the method calls way of statistical public errand sealing closed circuit and the analysis that comprise annulus public errand. Describe to facilitate, define tolerancepublic errand function first. Tolerancepublic errand function is the desire in dimension catenary solution seals closed circuit or compositive annulus and foregone composition annulus are mixed the expression that seals relation of closed circuit function, set tolerancepublic errand function to be: Y=f(x1, x2, x3, ... , in Xn)(1) type, y seals closed circuit or the dimension that form link and deviation for what the desire solves; N is foregone composition annulus and a number that seal closed circuit; X1, x2, ... , xn is the known compositive link of mutual independence and the dimension that seal closed circuit and deviation. To linear dimension catenary, can give tolerancepublic errand function from the derivation in the formula of extreme value law; To nonlinear dimension catenary, tolerancepublic errand function does not have unified expression, want to decide according to the geometrical relation of dimension catenary. Law of Monte Carlo imitate is used to undertake tolerancepublic errand imitate is analysed in 3DCS software. The basic idea of Monte Carlo algorithm solves a problem to be begged when place is the probability that some kind of random incident appears, or when the expectation of a certain random variable is worth, plant through some " experiment " method, the frequency that appears with this kind of incident estimates the probability of this one random incident, perhaps get the certain number feature of this random variable, regard the solution of the problem as its. Beg question of solution public errand with Monte Carlo algorithm, it is a problem translate into that seeks a noncombatant duty of closed circuit dimension actually beg the statistical problem that solves a random variable to handle; Those who seal public errand of closed circuit dimension is affirmatory, the method that uses random imitate and statistical test seeks solution, the result that gets with this kind of method accords with actual condition quite. Undertake with law of Monte Carlo imitate the concrete step of tolerancepublic errand analysis is: Constitute the distributinging pattern of annulus clearly each; The distributinging rule that according to computation precision asks to decide basis of N; of random imitate frequency constitutes annulus measure each and distributinging limits, undertake sampling randomly to its respectively, get annulus of a group of foregone composition is mixed thereby those who seal closed circuit dimension is random sample (X1, x2, x3, ... , xn) ; will sample randomly (X1, x2, x3, ... , xn) generation enters tolerancepublic errand function, computation seals closed circuit or compositive annulus dimension sealedly, get an increment of this dimension; measure 3, 4 repeat N second, can get sealing the N stature appearance of closed circuit dimension, make an example; A closed circuit to seeking solution or compositive annulus example undertake statistic is handled, the average that seals closed circuit dimension certainly thereby, standard deviation and public errand. The computer flow casing of law of Monte Carlo imitate. According to random imitate theory, when undertaking random imitate to constituting annulus measure each, can be in through arising first (0, the random number that distributings equably on 1) , next again according to random sampling formula, what conversion becomes other distributinging law is random sample. Set beforehand in 3DCS software controlled all sorts of function, can come according to needing to choose place to need to distributing imitate composition annulus loses a person, these inputs all use law of Monte Carlo imitate to emulate. According to Lin Debai case - row dimension (Lindberg-levy) center limit is theorematic, no matter form link,distributing variably randomly how, its a certain number of independent and random variable takes sample the sum always is approximate and obedient normal school. When engineering design uses 3DCS software, when having special statement, compositive annulus distributings general set is normal school function. Through the analysis, through N second sample, value of Monte Carlo imitate and the error with integral normal school 2 can press type undertakes estimating: ε ≤ (λ σ ) / in √ N(2) type, σ is standard deviation; λ is the parameter that concerns with believe level; According to type formula (2) can see sampling frequency N is bigger, analytic error is smaller. Project of synchronism of drift analysis model builds car of 2 fictitious model dimension project development is one crosses a branch (include supplier chime to help development unit) the system is compositive the job, drift analysis job uses synchronous project mode to begin. 2.
Drift analysis model builds car of 1 fictitious model engineer of product of development technological process according to truckload development time node provides information of interface of product digital-to-analogue, spare parts; Craft engineer offers production workmanship, assemble the information such as order; Dimension engineer offers product measure to match target, product initiative public errand, fiducial information; Drift analysis engineer plans to finish according to analytic time truckload inside and outside acts the role of drift analysis model build, provide drift analysis report; Built fictitious model car drift analysis model is OK and fictitious measure condition of each interface dimension deviation; The measure that develops early days set to obtain a product matchs a target, after drift analysis report is finished, basis of dimension project manager analyses a result, the area to sit a meeting that matchs a target to reaching size inputs output evenly. In this process, endeavor to match a target to reach size and optimize design of products plan, technology, tolerancepublic errand design, drift analysis engineer optimizes a design to change new input to what make fictitious model car drift analysis model, evaluate the size that whether can reach set to match a target. In process of dimension project development, product structure design and the implementation that produce workmanship design to match a target to product measure are having crucial effect; Be based on fictitious model car product of research of drift analysis model and technology design are optimized, model of the product in saving physical bolt car many rounds to make a process, mould and the development time that manufacture tool and cost. Of drift analysis model establish development technological process. Nextpage2.
Research of 2 management of tolerancepublic errand allocation are truckload the need in developing a process is right thousands of the public errand of spare parts and size assembly is done optimize management. Extensive inferior car technology center is some closer year of ceaseless practice attempt, draw lessons from North America to use advanced public errand to manage software experience, plant of combinative country leader and supplier are actual productivity, summary gave the tolerancepublic errand allocation of a from above to below and from bottom to top to manage a method. Start formally as the project, match data and the market fixed position that develop a model according to the competitor, dimension working party will be preliminary finish truckload dimension matchs a target build. The dimension that in developing a process, the project can try hard to realize these set matchs a target, retain model market competition ability. It is with the development of taillight and standard of side wall clearance exemple, allocate management to do examine to from above to below and public errand of from bottom to top commentate. According to competitor data, be united in wedlock before project experience, set taillight and side wall clearance match target public errand to be + / - 0.
Xx, link experience and target demand, from above to below distributes target of this public errand sheet of the shell plating inside assembly of white automobile body, motherboard assembly, side wall assembly, side wall; Various assembly and sheet after tolerancepublic errand allocation ends, will various public errand loses a person the common difference that fictitious model car makes from bottom to top in drift analysis model distributes research, evaluate what whether can satisfy set to match a target. If various public errand allocates,can satisfy dimension to match a target, release these public errand blueprint in, the public errand that finish manages the job; If car of the first round of fictitious model evaluates the dimension that cannot satisfy set to match a target, need reapportion various assembly public errand, perhaps evaluate whether to need to change design of product, technology. The reapportion of tolerancepublic errand is based on system of fictitious model car to finish, system of fictitious model car can give out the contributive rate that various assembly achieves to matching a target, it is a foundation with this contribution rate, reapportion is various tolerancepublic errand. 2.
All spare parts public errand in catenary of dimension of the hypothesis in the process of hypothesis condition drift analysis in 3 drift analysis are fluctuant around nominal value, and be in tolerancepublic errand limits; All spare partses are the rigid body that does not have deformation suppose; Contribution leads an analysis to be based on geometrical line sexual relationship. The physical element that at present technical measure cannot anticipate (the flexible, motion of laminose spare parts the) such as inertial motion, gravitational element, hot element (painting technology) etc cannot input a condition as what be three-dimensional drift analysis, these elements are uncertain; These elements can be brought match deviation, need is eliminated according to producing a circumstance actually to adjust; In addition, the analysis in drift analysis model cannot reflect the change of the environment in producing a plant as a result. What technology of three-dimensional drift analysis can forecast is deviation wave motion, cannot forecast all be worth deflection. Online adjust, the special technology such as repair is three-dimensional drift analysis is fictitious in model car system not plan into. Be based on data analysis, prep above of degree of confidence of result of drift analysis guiding principle 70% , result of drift analysis of rigid spare parts is close to actual production more, flexible spare parts degree of confidence is inferior; Experience shows systematic tigidity is taller, the productivity of factory and supplier is stronger, result of analysis of fictitious model car and be identical of actual production data are spent taller. Degree of confidence of result of 3 drift analysis studies technology of three-dimensional drift analysis is in extensive inferior car technology center has applied old, experience of development of old dimension project proves fictitious model car prep above of degree of confidence of systems analysis result 70% . Project early days is developed, need of accessibility of aim of the measure in system of fictitious model car is in general set 10% less than; Between virtual campaign, production branch can do solid car to match according to actual condition, on catenary of this shell plating online adjust, the special technology such as repair, also become the contributive factor that achieves dimension goal. After drift analysis model builds fictitious model car, drift analysis software is a foundation with Monte Carlo algorithm fictitious outfit car, implementation is opposite each truckload cooperating area does fictitious analysis. In view of length limitation, the article produces tie actually data, list 3 to already appeared on the market only the to technology of three-dimensional drift analysis specific application in process of model dimension development; Cover truckload upright model cooperates around and craft evaluates application. Express taillight of 1 some model and analysis of side wall clearance to measure bit of mean square to differ probability of out of tolerance as a result 10.
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The 53% lids before expressing 2 some models and before protect clearance rank to differ consistency to analyse mean square of result feature target to differ <2mm1 of consistency of clearance of probability of out of tolerance.
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<2mm12510 of consistency of 99% rank difference.
The 96% lids before expressing 3 some models and ala child board the Gai Yuyi before clearance rank differs analytic result child board cooperate to measure bit of target (± ) tool analyses a result (± ) probability of out of tolerance (%) analyses a result without tool (± ) clearance of OOS(%) of probability of out of tolerance is left.
751.
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91% rank difference are left 111.
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42%2.
4020.
84% clearance are left 20.
750.
951.
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61% rank difference are left 210.
980.
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Right 1 11 of 44% rank difference.
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86% rank difference are right 211.
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768.
83% case taillight of one some model and side wall clearance fit, dimension objective setting is clearance 1.
5 ± 0.
8; 4 are decorated to measure a place equably in model of three-dimensional drift analysis, difference of mean square of the largest position is result deviation 0.
38, fictitious assemble probability of statistical out of tolerance 10 thousand times for 3.
53% , if the watch is shown 1 times; Appear on the market actual production wave motion is the biggest after production office space data all is worth for 0.
413, data of later period production is in control line less than, if pursue,4 are shown. Experience makes clear, similar tail light and side wall this kind of tigidity is stronger cooperate area, theoretical analysis and real data degree of confidence are tall. Case is built before 2 some models with before protect cooperate, clearance and consistency of rank difference left and right sides are less than 2mm. Clearance of drift analysis result controls fictitious model car consistency 6.
99% out of tolerance, rank difference controls consistency 10.
96% out of tolerance. It is in view of bumper flexible spare parts, build before in rigging a process actually, have adjust craft to make sure periphery cooperates, some time produces data actually to show data of 69 cars statistic is medium, clearance controls consistency out of tolerance 7.
14% , rank difference controls consistency out of tolerance 8.
57% , car of out of tolerance needs to pass online adjust or repair achieves design requirement, if express,2 are shown. The lid before early days of 3 some models studies case shuts attitude tool to make sure periphery cooperates effectiveness. Tool of the lid before the tradition builds the shell before open condition is installed afore commonly, the condition after the lid is shut before has change, need readjust. Adjust an amount to decrease, tool of the lid before shutting attitude to install arises subsequently. Pass in system of fictitious model car fictitious assemble, can come true to be forecasted to the research of tool effectiveness. Before Gai Yuyi child board cooperate clearance rank to differ, or so side builds two to measure a dot to do each fictitious assemble. Watch in be system of fictitious model car, 3 have fall without tool operating mode, before Gai Yuyi child board probability of clearance rank poor out of tolerance is compared, from use tool can see in comparing probability of the biggest out of tolerance 4.
52% for clearance right 1 measures a place; Do not use tool probability of the biggest out of tolerance 28.
61% for clearance left 2 measure a place, can reach installation tool has larger contribution to assorted implementation. During later period production is started, manufacturing data also achieved design target to be worth, wave motion is the biggest office data. Fictitious model car drift analysis system optimized choice respect to produce positive effect in craft. 4 conclusion are the Monte Carlo algorithm that the article introduced three-dimensional drift analysis to use, fictitious drift analysis model builds model car the allocation of from above to below of the public errand in developing project of flow, dimension and from bottom to top designs method and drift analysis process medium hypothesis condition; Combinative extensive inferior car technology center real case uses many own development projects, listed project early days numerical value of computation of theory of three-dimensional drift analysis and later period produce data actually, the proof can be passed built system of car of fictitious project model, the automobile body that finish assembles match optimize, tolerancepublic errand design, can decrease to undertake physical bolt car makes an activity to realize dimension to match many rounds then, managing project develops time and cost. CNC Milling