Be based on the research of Cad/capp compositive technology that the feature designs

This is with respect to the requirement in products plan process, the design of the spare parts and technology program must have good diagnostic collect by nature and expedite iformation flow.

In traditional CAD pattern, cad system pays attention to the mechanical function of the product and geometrical modelling method, and tag information to handle to making tolerancepublic errand and the information such as all sorts of technology requirements serve as only, when undertaking Capp, often need to have spare parts news afresh (include geometrical feature) input.

Wasted material resources of much labor power to undertake repetition work not only so, and go against Capp to be evaluated to producibility of Cad system feedback, achieve the goal that optimizes products plan.

Compositive the design concept that changes Cad/capp system to be based on collateral project, the design of the spare parts the feature is enclosed together with production feature.

The feature is based on to build a model in design phase, await the products plan news that when craft plans, system of automatic successive Cad makes, answer relatively with treatment method, the numerical control program that creates Cam place to need and the production that offer Mis place to need manage data.

Make the spare parts is in whole computer is compositive information of the implementation in making is collected, what deliver and machine a process is straightway [1] .

1 be based on a feature build a model 1.

1 feature definition classifies Cad and Capp to regard a design as two phase of the process, having different meaning and expressive form to the feature of the spare parts.

The design feature of the spare parts basically points to appearance feature, production feature information includes craft feature.

Considering the need with compositive system, those who collect feature of face of shape of in order to to be a foundation is mutiple level descriptive method.

the design feature and the difference demarcate between production feature are inside the category of project semantics, use the significant exterior essential factor on parameter of classification of characteristics, feature and feature to convey.

According to this one thought, is the feature the definition: ? Post Wo Fu cook of favour of Wujia of garden of Tuo of level ground of bail of Tiao fall from the sky is tranquil collect loses Guo Weng? to be able to be planted by some basic cutting machines a composition.

Achieve design feature and the unity of production feature thereby.

According to afore-mentioned definitions, can differentiate the feature of the spare parts give priority to feature and auxiliary feature.

Advocate the feature basically depicts a part inside, the basic geometry appearance of outside face and shape face element, appearance of geometry of secondary of spare parts of auxiliary feature description and the feature that set a requirement in the existence on characteristic of function, structure, craft, auxiliary feature leech on to advocate feature.

1.

2 graphs database to the axis kind spare parts, according to the axis kind the geometrical characteristic of the spare parts, disclose its different shaft part, the hardware should consider while shaft part is differentiating advocate, complementary feature and shape face element.

Graphical database is built on this foundation.

Of the database build can use following two kinds of methods undertake, the Cad with different correspondence of every kinds of method proposes modular way.

The graphical database that 1) is a foundation with parameter plot the essence of database of this kind of graph is to include shaft part parameter to change the character of plot program and diagnostic information field to occupy a library.

Every record in the database includes the craft feature variable of feature of shaft part geometry, the parameter plot program with corresponding at the same time correspondence.

Au-tolisp, Objectarx writes the process designing environment in using Autocad2000 to parameter changes plot course and be contacted together through Ase and Asi and exterior database.

When plot, according to the craft information that answers relatively is being collected from inside the database while parameter calls plot program, classics after affirming, enclose together with graphical geometry dimension in saving exterior file.

Its characteristic is technical maturity, the operation is handy, library structure is compact, information is delivered orderly, benefit feedbacks at information.

But add and revise graphical database to have certain difficulty, must be familiar with Auto-cad process designing.

The database of this kind of form does not include the graphical database that 2) is a foundation with dimension drive technology plot program, in joining geometry of basic figure along with variable, feature to join variable to save outer ministry database however.

When plot, use dimension driver to change graphical form through geometrical parameter, enclose craft feature information to output in exterior file again.

The advantage is to facilitate new shaft part data increases in the database it is record, easy to revise.

But must use dynamic database.

1.

3 features description and information of feature of the process that build a model include: 1) diagnostic label information, namely diagnostic name and information of feature of appearance of;2) of diagnostic label name, content has diagnostic concealed type denotive appearance parameter, structure parameter, position parameter and feature are explicit dimension of;3) of denotive face collect and tolerancepublic errand information, namely public errand of shape size, fixed position dimension, dimension and form news of demand of quality of surface of tolerancepublic errand;4) .

Data structure of the feature is as follows: Serial number advocate diagnostic code (< shape size and public errand > [exterior surface roughness] [appearance public errand] [positional public errand] [etc of fixed position dimension] ) ([size of < shape of complementary feature code reachs {tolerancepublic errand > [exterior surface roughness] [appearance public errand] [the position, next work even if build a model.

In axis of the scale in Cad kind the process that spare parts job pursues, end establishs modular procedure to be based on a feature, introductory section goes all out here install the means that build a model to generate spare parts job to pursue.

Is concrete step: ? Mei of level ground of to joke ㄖ is able to bear or endure the icon that clip end says to ブ ? presses different appearance feature to single out correspondence, immediately plays a diagnostic parameter dialog box below this icon to undertake interactive input, next by plot module (parameter plot program or dimension driver) scale graph and make tag necessarily, at the same time will all information is added in outside data file, we call this one file graphical feature file.

Such, figure of project of each pieces of spare parts is corresponding a specific diagnostic file, and each shaft part in the graph a record in corresponding feature file.

When undertaking modification to shaft part, the corresponding record in the file also is changed subsequently.

System of 2 　 Capp is right of Cad system information recombine processing axis kind the information that the spare parts produces in Cad process, besides the diagnostic information of section, still include partial whole information, if the technology asks,medium heat treatment requirement, hardness asks to wait.

And the complete information that Capp system asks to be involved to place has complete description, for this, differentiate the information of the generation in Cad it is 3 kinds, convey spare parts message with three-layer structure, namely spare parts layer, feature layer and geometrical layer.

Spare parts layer includes layer of feature of; of means of type of brand of spare parts name, plan bugle call, material, semifinished product, heat treatment and properties to include parameter of feature of code of diagnostic name, feature, appearance, dimension and public errand, form layer of geometry of surface roughness of tolerancepublic errand, surface and; of fixed position dimension basically points to.

Use the knowledge base of Capp and inferential machine, the labor situation that makes a part automatically / working procedure, the choice machines equipment, arrangement processes order, choose cutting tool and affirmatory cutting dosage, final work out gives craft file, see figure below.

The advantage incorporate of compositive system of 3 epilogue Cad/capp is in: 1) considered a spare parts integratedly in the beginning of the spare parts is designed to machine element, accord with the requirement that collateral project designs.

Avoided information to repeat an input, raised the design quality of the spare parts and machinability.

2) is in after uniting design feature and production feature definition, facilitate undertake associated designing in enterprise interior net, improve the efficiency of the design.

Can use Internet net to come true to be designed remotely in coordination further.

3) lays next foundations to realize unifinication of the Cad/cam in Cims.

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