Can assemble sexual design below collateral project

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As the flying development of world economy, market competition is increasingly intense, reduce product cost, carry high yield to character is measured and shorten product development cycle already became the key that the industry survives and develops. Below this kind of situation, collateral project is rising in work up as a kind of effective solution. It passes all resource of compositive enterprise, make design personnel to consider product lifecycle as early as possible (form a product to reclaim from the concept) all medium elements, undertake the product reachs his unifinication, collaterally the design of relevant process, what pay attention to inchoate concept design phase especially is collateral and harmonious, improve product quality in order to achieve, reduce cost and shorten the purpose of development cycle. A when study to collateral project on international important facet, it is to can be being assembled the gender is designed (Design For Assembly, abbreviation DFA) , machinability is designed (Design For Manufac, Turing, the research of the DFX technology such as abbreviation DFM) . They are aimed at the different level in product lifecycle to choose a design to undertake evaluating to awaiting, it is a when at present collateral project studies very active domain. In the design method that reflects collateral project idea in these, the enormous beneficial result that DFA produces in practice because of its introduces particularly fix eyes on. It inspects a Hou Xuan to design from constructional viewpoint, often be considered as the first job of collateral project. One, the concept of DFA and setting 1. The basic idea of DFA is assembled is a labor concentrated model the job. According to statistic, assemble cost to be able to achieve 40 % in the proportion in product totle drilling cost [1] . France makes clear to the findings of 355 companies, a when assemble automation main obstacle is: Normally products plan is not to face assemble, this makes the product is assembled already became one of link with the weakest manufacturing industry. How to reduce assembly fee effectively to use, it is the outstanding problem that current business place faces. DFA is to solve this one problem and grow settlement new and high technology. Say simply, DFA is one kind optimizes products plan, in order to acquire the technology that lowermost assembly fee uses. DFA is in products plan phase, through analysing an effect the product can assemble all sorts of elements of the gender, undertake evaluating to can assembling a gender of the product, go up in this foundation, give a product the proposal that designs again, through be being designed again, make the product is assembled easily, reduce the end that product assembly fee uses in order to achieve. 2. Can assemble sexual analysis to assemble an activity to be able to divide two level that go up for logic: Be a spare parts get level, namely spare parts from arrive into stuff place assemble the position; The 2 assembly that are a spare parts level, in this one phase, spare parts and spare parts have link. The element that the influence can assemble a gender is OK, cent is 3 kinds: Spare parts element, system element and craft element E23. DFA differs through inspecting these elements to be in the evaluation that the expression that assembles level will come to choose a design to be able to assemble a gender to awaiting. (Spare parts of element of 1) spare parts is constructional main unit, its quality is greater to can assembling a gender of the product to affect. In get level, the influence of the spare parts basically is behaved in dimension and appearance two respects; Assembling level, the influence of the spare parts basically is behaved in stability respect. (Craft element relies on 2) craft element what to use and assemble craft. In get level, craft element has a lot of sides to can assembling sexual influence, the transportation that includes to use method and carry a distance to wait. Assembling level, behave mix for close firm method assemble method to wait. (Element of system of 3) system factor is to point to the interaction between spare parts and spare parts. In get level, systematic element expression is a spare parts the nest between or twine. Assembling level, main show is two spare partses between cooperate clearance and cooperate section length. 3. The develops setting DFA thought traceable of DFA 70 time. At that time, people begins to notice a design to constructional importance, according to actual design then experience is mixed assemble operation practice, the design guideline that established a series of is helpful for that assemble (Design Guidelines) , in order to help the product that design personnel design gives to be assembled easily. But because get the systems analysis tool with the limitation of technology of computer soft hardware and necessary at that time lack, those thick design companion actually very be a hard job to design personnel to provide the guidance that has specific aim. 1980, professor Boothroyd of Massachusetts university put forward DFA this, concept, be accepted extensively. Subsequently, entered a climax to the research of DFA and application, appeared in succession, some influential DFA ration analyses a method. They are to be based on what assemble a principle easily to inspect influence product to be able to assemble a gender all sorts of elements, the form that uses list undertakes grading to each projects, constructional weak point is gone against in track products plan with this and try in time to amend. The actual application of these methods, effectively promoted the development of DFA technology, make can assemble a gender of the product to rise greatly. With Lucas method (flow chart sees graph 1) is exemple, the main measure that DFA ration analyses a method is: (The purpose that function of 1) function analysis analyses is to be in hold the number that the hardware reduces below the premise with product changeless function. In Lucas method, the least hardware that reduced spare parts amount to use Boothroyd to put forward counts a principle, namely a spare parts cannot incorporate with other spare parts, must have undermentioned one of 3 reasons [3] : A. With other there is opposite motion to ask between the spare parts; B. Ask as a result of function and must use the data that differs with other spare parts; C. To safeguard and be replaced, ask to be able to disassemble. (The figure that 2) carries an analysis to tell part of beyond the mark analyse, dimension, weight come whether certain part conveys easily and directional, give out oneself its are carried index and carry rate. Carry rate is too old, make clear transport property not beautiful, be necessary to improve a design or choose appropriate transportation technology. (3) cooperates to analyse the outfit in rigging a process through analysing a spare parts to match direction, assemble force size and whether to need the element such as special tool, come to those who decide a part cooperate index and cooperate to lead. Cooperate to had been led big, make clear cooperate to design not beautiful, need to improve. (4) clip holds an analysis to be used at the transfer matic such as the robot to assemble, wait in order to decide whether the spare parts has the fragility that appropriate clip holds the surface and part. In recent years, the DFA technology that faces collateral project is becoming the research heat of production automation domain gradually. A subclass that collateral project regards it as DFA brings into his under overall frame, gifted its new connotation. 2, the development direction of DFA 1. Confine and the confine that are not worth existing DFA method and insufficient expression are in: (1) can assemble sexual evaluation to often happen after the detailed design of the product is finished, because of structure of this pair of products simplify to mere be confined to incorporates or reduce a hardware, the overall situation that the component in original design differentiates and end change; Cannot provide sufficient and active support to the notional design of the product thereby; (2) confine can assemble a gender of specific spare parts at the analysis, and the assembly with less actual consideration craft, assemble condition and assemble an environment, make can assemble sexual evaluation to lack stated specific aim consequently; (3) depends on user handiwork to fill in computational form and scale assemble ordinal flow chart, perhaps pass what man-machine interaction asks user answer is many to concern the issue that assemble below computer software support, not only trival, efficiency is low, and make mistake easily; (4) gives out to be able to assemble sexual evaluation of the spare parts only, indicate its to be not worth, but did not give out to design a proposal again, the improvement of the design relies on an user completely also; (5) lack devises regular administrative mechanism to can assembling a gender, the feedback that designs regulation, augment and revise was not taken seriously, what in be being evaluated consequently, exist is same kind the problem often weighs recrudesce to be born. Nextpage2. The limit that expands direction to have DFA method and inadequacy manacled its application and promotion already badly. As the progressively development that studies to collateral project, DFA also is in get improve and developing ceaselessly, its should nod is: (1) reflects the collateral moving mechanism in products plan, craft, production process adequately, make DFA can be shared with CAD implementation information, realize CAD/DFA/CAAPP(Computer Aided Assembly Process P1an then, Ning, the computer is auxiliary assemble craft to design) compositive; (2) is based on the DFA system that three-dimensional spare parts describes, duplicate work what reduced message of input spare parts on one hand in great quantities, on the other hand, use three-dimensional spare parts to describe only, ability makes examine the dimensional position between the spare parts affects, include to assemble a relation to become a possibility; (3) is based on a product to assemble the DFA system of craft actually, can realize more complete DFA analysis, can analyse in specific ship-fitter art the products plan problem below the condition; (4)DFA expert system, use the technology that is based on regulation and method of object-oriented process designing, below the support of knowledge base and database, will judge through inferential machine given design program and the rationality that assemble program, give out to design a proposal again; (5) design compatibility analyses DCA(Design Com, Patibility Analysis) , be about to all sorts of DFX method union rise unified try to consider, offer a kind to come from different point of view to load the expert of different duty assess awaits the model of idea of a kind of design that chooses a design, in order to acquire the design with best overall situation. 3, the DFA frame below collateral project is compared with traditional DFA photograph, the DFA below collateral project basically has two characteristics: It is direct get from CAD system assemble information, implementation can assemble the automation that the gender evaluates; 2 it is supportive CAAPP, be versed in through evaluating the assembly with logical choice art, or right given assemble craft to undertake optimizing. Adoption technology basically includes: Face constructional CAD system, feature modelling is mixed diagnostic identifying and expert system technology. 1. The geometry that faces constructional CAD system convention built modular CAD to provide the expressive means of complete geometrical information, but the information of many blame geometry that it will exist in engineering design hard stocks a database. The feature built a model to overcome geometry to build modular defect, provided blame geometry information, wait for the expressive method of information like material, precision, but it remains those who be based on product part class, cannot be conveyed and put saving to match body to comprise the correlation between the component. Consequently, geometry builds model and feature to build a model to fail to achieve the support that designs to the gender can be being assembled below collateral project. Generally speaking, the function of the product comes true by individual spare parts rarely, more circumstances are to pass in assembling system 0, the mutual campaign between the component will come true. This kind of motion is by what assemble the constant change generation that the quantity concerns between the spare parts inside body, so good assembles system correctly to in order to realize its function, must build its between interior spare parts mix correctly integrated concern. Assemble the base that builds a model to build model and feature to build a model in geometry to go up, offerred in the computer expression and memory assemble body to form a part between the method of correlation, make DFA can undertake to single component the gender is evaluated can be constructionaled not only thereby, more important is, it can pass the description that concerns to the mutual position between assembly parts among them to undertake emulate and be interferinged checking, through be opposite among them between assembly parts cooperate, the connection description that assembles information has noncombatant duty analysis and mix integratedly assemble alignment program, can come true thereby more advanced analyse with comprehensive DFA. Assemble the development way that proposes a model to will become the CAD below collateral project. 2. The feature is designed and diagnostic identifying feature amounted to spare parts information to provide significant measure for complete the earth's surface. The way that produces a feature has two: Diagnostic design and feature identify. What diagnostic identifying points to is from the feature that geometrical formative identifies a place to need in three-dimensional substance. Because the feature is the CSG from information of side of the side in model of spare parts substance or B, Rep expresses and each other the develop between attacks the extraction in information comes out, accordingly, diagnostic identifying needs special algorithm. Can identifying the diagnostic amount that give also is finite, craft information identifies impossibly come out. Differ with diagnostic identifying, diagnostic design asks to define library of a feature beforehand above all, in designing a process, choose place to require a trait from inside diagnostic library, of the ode with specific parameter, include to be not geometrical information, the CSG that uses a feature next or B, Rep expresses to have Boer operation, get the integral part model that comprises by the feature, thereby leave out diagnostic identifying works. But looking because of the character that defines beforehand always is finite, can make diagnostic modelling is in go up somehow not as agile as geometrical modelling. To learn from others's strong points to offset one's weakness, should hold concurrently in diagnostic modelling with two kinds of methods, can give priority to with diagnostic design, in the meantime, prove in practice to those the feature that is effective identifies algorithm, should give reservation, regard a feature as the beneficial complement of the design. 3. The DFA method with expert system existing technology basically is to belong to method of calculation of a kind of maths, it shows to constructional weak point is gone against in the design through grading. And actually, a lot of knowledge that DFA is evaluated and design again are to belong to heuristic knowledge or experience sex knowledge, be conveyed hard with mathematical mathematical model and computational formula. Accordingly, the DFA that wants real existing specific aim is analysed and give out to design a proposal again, must apply knowledge to if expert system will solve,handle a technology. Much DFA regulation is stocked knowledge base, inferential machine basis assembles information, scanning knowledge base, once discover the requirement that match, spark corresponding design a proposal again. It is OK that the knowledge base that at the same time expert system provides maintains a function undertake modification mixing to DFA regulation according to the circumstance augment. If the graph is shown 2 times,be based on the DFA frame of afore-mentioned thoughts. Current, diagnostic modelling already had commercial software (like Pro/Engi, Neer) , and assemble build a model to still be in research phase. Consider to make clear, it is the platform that prop up with Pro/Engineer, development faces the function that assemble, the ability that can make its have a description to assemble information [4] . The assembly that is based on a feature CAD system can assemble information completely with be being offerred for DFA, give out in order to assemble the form of database and spare parts database respectively. Former stored detailed product assembles the spare parts between body to make an impact, latter is the detailed description of each pair of spare parts information. Pass certain changeover mechanism, can change them further to be based on the product model of STEP/Express standard, the CAD system that can make DFA Lai Yu notting comply specific thereby [5] . Assemble order to arise via inference from inside assembling a database, DFA falls in the support of technology knowledge base and time cost database, can assemble time of the choice in technology program from a few the optimal program with little, low cost. Yi Ke of spare parts element, craft element, system element comes out with be being extracted from inside product model, for DFA the analysis is used. Of generation design proposal feedback to give CAD the system again, use at improving the adverse to assembling share in original design. Final output is to face constructional design and optimized ship-fitter as a result art. They can be sent the system such as DFM further, realize collateral project to fall to be opposite from each different life level of the design make an on-the-spot investigation. Since collateral project puts forward oneself, caused the attention of each country government, academia and industry industry. Our country also takes this seriously very much, state committee of science and technology sets out from strategic height, will collateral project labels CIMS crucial technology to tackle key problem project, regard CIMS as the direction of further progress. Begin the research of technology of the DFX below the collateral project that includes DFA inside actively, the application that is sure to be collateral project creates capacious prospect. CNC Milling CNC Machining