The cutting tool way document uses the APT language form, this language approaches to English natural language, it describes the current engine bed condition and the knife point path. Its content and form not engine bed structure, numerical control system type influence.

But different CAD/CAM software produces the cutting tool way document form has differently, for example: "Transfers the nth cutting tool, the length compensates selects in a register the value", indicated this function instruction indicates the form in the different CAM system to be different. For example several kind of CAD/CAM system indicates the form like table 1 to show.

Table 1 CAD/CAM system indicates the form

2.NC procedure form multiplicity

The NC procedure is composed by a series of segments, the usual each segment contained processing operation on foot to order. The segment usually is by N, G, X, Y, Z, F, S, T, the M..... address character and the corresponding numerical value is composed.
(1) the ISO-1056-1975 standard to partial preparations code function, the assistance function code function has made the unified stipulation, for example: The G00 fast spot position movement, the G01 straight line insert makes up, the G02 clockwise circular arc inserts makes up, the G03 anti-clockwise circular arc inserts makes up, G04 in remains. But also has massively has not made the unification stipulation ' not to assign the code ', does not assign ' G ' the code according to need independently to formulate its code function by the numerical control system factory, if table 2 shows.

Table 2 according to needs independently to formulate ' G ' the code function

Has not made the unification stipulation ' M ' the code to act according to the appurtenance function by the numerical control engine bed factory which its engine bed has to formulate its code function. If the Japanese Hitachi precision instrument company makes flexible processing unit HG500, has 16 trays (PPL), the tray may the automatic exchange, realize nobody processing. In order to control the tray automatically to enter the main engine, it uses M87 ~ M89 code to control the A.P.C gate the switch:

(2) some numerical controls system certainly does not strictly observe the ISO-1056 standard stipulation to the partial G code function, but is voluntarily defines, if table 3 shows.

Table 3 Toshiba numerical control system voluntarily defines G yard function

(3) the individual numerical control system NC procedure has used the quite special code form, if HEIDENHAIN the TNC 426 systems, right compensate the straight line to insert make up the sentence form: FL X+10 Y+10 RL, corresponds to the standard code: G01 G42 X10 Y10.

3. Technical demand multiplicity

Along with the technical development and the application progress, the present postpositioned processing technology has not been able to pause in merely is to the cutting tool way document code conversion, but was increased from the concrete processing demand characteristic, the concrete numerical control engine bed and the numerical control system characteristic embarks, entrusts with the postpositioned processor by the more functions request.

The high speed numerical control processing appearance not only proposed to the engine bed structure and the numerical control system the new request, planned, the craft parameter establishment and the processing restraint establishment regarding the processing craft also set the new request. Thereupon some merchants developed have specially supported the high speed processing the postpositioned processor. This kind of postpositioned processor has regarding the equipment high speed processes the controller the engine bed, may draw support from the expert system tool which this postpositioned processor disposes, describes own high speed processing demand characteristic, the postpositioned processor may produce the corresponding code, the activation/abolishes the corresponding high speed processing operational order, may act according to uses the demand to carry on the simulation. Regarding has not provided high speed processes the controller the engine bed, this postpositioned processor also can establish to the speed change maximum permission increase, according to allows 惯��?the hypothesis permission most Canada/to decelerate, hypothesis rise time constant and loop gain time-constant, hypothesis speed over modulation data and so on.

Also like each numerical control system when curved surface processing, uses the curved surface fitting model 不尽相同, some fit the model with Nurbs, some fit the model with Bezier, some fit the model with Polymial, but also some fit the model with Spline, the postpositioned processor faces the support corresponding many kinds of curved surface fitting model the question.

In project practice, when meets the similar processing object the similar processing demand, after frequently may use the effective NC processing procedure which has to carry on the revision to use. How however guarantees the revision result the accuracy is a question, cannot all put to the engine bed comes up the debugging, this when single unit processing especially is important. In addition, the existing many CAD/CAM system processing simulation only is take the cutting tool way document which produces as the foundation carries on the processing simulation and the interference inspection, this obviously is insufficient. Therefore, establishes take the NC code instruction collection and its the corresponding parameter as the information source simulation (including logical simulation and process simulation) appears extremely importantly. Below therefore, a perfect postpositioned processor should have the function:

(1) connection function: The postpositioned processor can automatically distinguish, read takes the cutting tool way document which different CAD/CAM software produces.

(2) NC procedure production function: The numerical control engine bed has the straight line to insert makes up, the circular arc inserts makes up, from moves the knife, the jig bias, cooling and so on a series of functions, the function realization is through a series of codes combination realization. The code structure, the order the NC form decision which stipulated by the numerical control engine bed. In the current world some famous postpositioned processor companies develop the general postpositioned processor, it provides one kind of function database model, the user according to the numerical control engine bed special details replied it proposed the question, through the question replied the production user assigns numerical control engine bed special-purpose postpositioned processor. The user only needs to have the engine bed operation knowledge and the NC programming knowledge, can write satisfaction the special-purpose postpositioned processor. When provides when the database cannot satisfy the user the request, it provides the development permission user carries on the revision and the translation. Therefore may defer to the numerical control engine bed the function to establish a relational database, how does each function realize, by the user according to the engine bed structure, the use numerical control system assigns the control the code and the code structure.

(3) expert system function: The postpositioned processor not only carries on processing, the transformation to the cutting tool way document, but also must be able to join the certain craft knowledge. If high speed processes processing, processes when the guide screw cuts the parameter the choice and so on.

(4) reverse simulation function: Establish take the NC code instruction collection and its the corresponding parameter as the information source simulation. It including two parts:

NC procedure main body structure inspection and NC procedure grammar structure inspection; Numerical control processing process simulation. Take the NC procedure as the foundation, the simulation simulation processing process, the judgement path accuracy and the processing parameter rationality.

Different structure engine bed, different numerical control systematic, different programming custom, its NC procedure structure and the form are infinitely varied. Therefore, the reverse simulation difficulty is extremely big. At present, not yet has maturer commodity software.

In summary, must cause the numerical control procedure which produces not after the manual revision, directly should use in the numerical control engine bed processing, then must aim at each numerical control engine bed to have custom-made the special-purpose postpositioned processor. The cutting tool way document form which this request development personnel is familiar with which uses the CAM system and produces, to be familiar with uses the numerical control engine bed and its the numerical control system code function and its indicates the form, but this work is the intelligence is crowded the process which and the work crowdedly has both at the same time. Is near in front of the CAM system is multitudinous, in the engine bed and its the numerical control system multitudinous situation, develops the special-purpose postpositioned processor the work to appear from the beginning quite arduously. Therefore, appeared in recent years take has developed the general postpositioned processor as a foundation, correlation technology and so on application numerical control code guidance had custom-made the numerical control engine bed special-purpose postpositioned processor the procedure, with the general postpositioned processor solution general character question, with had custom-made the postpositioned processor solution individuality question. The practice indicated that, this is one effective method. This courtyard applied this method from 1996, developed one after another has had custom-made including Dragon Gate type five processings centers, Dragon Gate type vertical processing center, the horizontal-type flexibility processing unit, the vertical processing center, the numerical control lathe, the turning center and so on the many kinds of types engine bed ten kind of special-purpose postpositioned processors, the numerical control system including FANUC, TOSNUC, MITSUBISH, A2100, A850, MAZAK and so on, has covered this courtyard product and the use numerical control equipment, and has obtained the good effect in the project application. Among them, to the three axle belt rotary table horizontal-type processing center, five processings centers special-purpose postpositioned processor development, has established this kind of structure engine bed postpositioned processing structural model, accumulated the development experience.

Below briefly introduced this courtyard application general postpositioned processor has custom-made the development to use in the HC800/FANUC-15MA special-purpose post-processing method:

The use has custom-made develops software... ... Pro/E NCPOST module. This module the ICAM general postpositioned processing development which produces for the Canadian ICAM technology company.
Use CAM software... ... Pro/E CAM module. Using the Pro/E CAM module, the design processing environment, carries on the simulation processing simulation, produces the cutting tool way document.
NC procedure application object... ... Horizontal-type processing center HC800. This engine bed makes the production for the Japanese Hitachi precision instrument company, the equipment ' X ', ' Y ', ' Z ' three straight reels, a rotary table, a capacity is 120 the knife chain shape knife storehouse, six exchanges trays; The control system is FANUC-15MA mainly uses in the box body class components processing.

(1) first understood the engine bed the structure, the engine bed provide the appurtenance, the engine bed have the function and the function realization way (manual or is automatic).

(2) the engine bed provides numerical control system, familiar this system NC programming including function code composition, meaning, whether has is different with the ISO-1056-1975 standard code form.

(3) applies the general postpositioned processor guidance template, grasps the knowledge according to the above, asks the question by the strip reply template, has custom-made the special-purpose postpositioned processor. The general postpositioned processor basis outside input information, transfers its internal database model, after judgement, arrangement, combination, production user request special-purpose postpositioned processor.

Application the HC800/FANUC-15MA special-purpose postpositioned processor processing cutting tool way document which has custom-made according to this method, the production NC procedure approximately 80% may use, but also some 20% must do further develops.

(4) when the general postpositioned processor provides the data model cannot completely satisfy the user the request, or the user needs to optimize when processes the NC procedure, then using development software revises the database model. This needs the development personnel to grasp the CAM module the application method, grasps the cutting tool way document the form, and has the software development and the processing craft aspect experience.

This special-purpose postpositioned processor application engine bed for provides a rotary table the three axle horizontal type processing center, the work table rotation cannot participate in the cutting motion. The engine bed provides six exchanges trays, may realize the tray automatic exchange. The knife storehouse for the chain shape structure, the capacity is 120 the knife, may choose in advance the next cutting tool during processing. Does not have this kind of engine bed in the Pro/E CAM module and the NCPOST module the database model. In order to consummate this special-purpose postpositioned processor, causes its automatic production the NC procedure no longer to need artificially to make the revision, may carry on the specific establishment to the CAM module processing environment parameter, and carries on the great programming with the NCPOST module development language, establishes this kind of engine bed the data model. In order to optimize the production the NC procedure, with great red-tape operation general postpositioned processor interior data output structure. For example: In the NC procedure uses all work pieces coordinate system and the engine bed coordinate system value relations, may begin the automatic setup in the NC procedure, the numerical control engine bed may directly debate the knowledge, does not need the manual input; Before the work table rotation, the host 轴头 returns far; Trades in front of the knife to output the cutting tool name and so on.

The special-purpose postpositioned processor has custom-made which after the above work produces the NC procedure to use in this courtyard leading product VMC750B - 30,101 headstocks body processing, processes the components completely satisfy the blueprint request. In addition, they under the Pro/E CAD/CAM integration software environment, may realize "the reverse simulation function".

At present the commercialized general postpositioned processor, Canadian ICAM Corporation's CAM-POST software has the typical nature. This software may cover domestic and foreign popular 90% above CAD/CAM software and 90% above NC system, the function is stronger. The cutting tool way document which it may read which takes covers CAD/CAM software produces, has custom-made NC system special-purpose postpositioned processor which covers, it mainly divides into the following two parts:

(1) QUEST: Database template system.

In the database template contains the question and the solution method which each kind of type the engine bed and the control system possibly meets. The user according to the need, answers the question, obtains the special-purpose database. When the database template cannot satisfy the user the request, may use Post-processor Development to establish the great procedure, carries on two times of developments.

(2) GENER: Has the database using QUEST, the NC procedure which which produces by the CAM system the cutting tool way file conversion numerical control engine bed can directly distinguish.

ICAM Corporation newly promotes CAM-POST V-12 has the processing function which the high speed processing requests, can support Bezier, NURBS, Polynomial and the Spline four curved surface draws up with the model, has established the expert system tool in QUEST and so on, enable software the function greatly to have the expansion.

In recent years, the computer hardware technology leap development, caused the microcomputer the performance price to compare unceasingly enhances. At present in the world many well-known CAD/CAM software company has begun to develop based on microcomputer CAD/CAM software, enables originally only software which moves on the workstation, similarly may move on the microcomputer. The hardware cost large scale reduces, enables CAD/CAM to be able widely to apply.

The modern industry gradually to the multi- varieties, the small batch direction was developing, highly effective needs, to be fast, the highly flexible manufacture system, the CAD/CAM widespread application has provided the possibility for it, and promoted this kind of development. Postpositioned processor having custom-made is joins CAD/CAM software and the processing equipment essential technology, it directly affects the CAD/CAM integration.

Can process the different type form the cutting tool way document, and makes optimized processing, adapts the different type engine bed, the different type system, the different type components processing demand, the production NC procedure does not have artificially to make two times of revisions, but directly should use in the engine bed is the postpositioned processor technology development direction.