PartMaker: automated development of control programs for modern CNC equipment. Tooling design

The essence of program control of metalworking machines is the development of control programs in numerical form, which allow solving geometric, logical, technological and terminal problems in relation to a specific type of CNC.

The solution of the geometric problem provides the shaping of the part by the corresponding movement of the tool or workpiece.

The logical task is to ensure that the automation of the machine is controlled in a certain logical order.

The technological task is aimed at ensuring the specified quality of the resulting part.

The terminal task is to provide communication with the operator through terminal devices - terminals.

As applied to the H-22-1M system, these tasks are solved in the manner described below.

UE - a set of commands in the programming language, corresponding to a given algorithm for the functioning of the machine for processing a particular workpiece.

When turning, the mutual movement of the tool (the top of its blade) is carried out along a certain trajectory (the contour of the workpiece). Separate sections of the workpiece contour can be considered as geometric elements (line segments, circular arcs, etc.). The intersection points of geometric elements are called geometric reference points. Each reference point in the selected coordinate system can be described by numbers (coordinates). The combination of numbers that define a number of successive positions of the tool is the main part of the UE. The coordinates of geometric reference points can be absolute, i.e. set for each point relative to the zero point, or relative (set in increments), set in the direction of tool movement from one reference point to another. When programming, it is necessary to specify the speed of movement of the tool between individual reference points, a number of auxiliary technological commands. Points of the calculated trajectory at which the law describing the flow conditions changes technological process, are called technological reference points.

Each UE begins with the character% - "beginning of the program".

Designation "number" control program should be located immediately after the symbol "beginning of the program". When placing several UEs on the program carrier, it is allowed to write one more character “program start” before the symbol “beginning of the program”. Numbering of program blocks starts from the next block.

Each frame contains geometric and technological data that must be provided when machining the section of the workpiece between two reference points.

The basic numerical unit of the UE is the frame. The block is perceived by the CNC system as a whole and contains at least one command. The frame has a specific format for a specific type of CNC. The frame is made up of words. Each word contains specific information (command). A word consists of an address (Latin capital letter) and data (mathematical sign "+" or "-" and numbers). The first word in a frame is always "frame number" - address N, data - a three-digit number. The number serves to systematize the program and has no effect on its course. The rest of the words in the frame can be arranged arbitrarily, but the following sequence of words (at their respective addresses) is recommended:

N, G, X, Z, I, K, F, S, T, M, L.

Using the words X, Z, I, K, L, a geometric problem is solved.

The words G, F, S, T, M provide a solution to the logical problem.

The solution of the technological problem in the system is not provided.

The terminal task is determined by the design of the system itself.

The main stages of development of the control program.

Modern machine-building production is hard to imagine without CNC machines. program management. Today they are widely used both in industrial giants and in small enterprises. Undoubtedly, the successful development of the engineering industry is impossible without the active use of CNC equipment and production automation.

The increase in the fleet of CNC machines leads to an increase in requirements for the technological preparation of production, including the quality of the development of control programs (NC).

Today, all major CAD developers as part of their software systems offer modules for the development of NC programs for CNC machines. The advantages of these modules include the fact that, being integrated into computer-aided design systems and, accordingly, ensuring the correct exchange of models between design and technological modules, they allow you to successfully develop NC for the main types of metalworking equipment with standard technological capabilities - for milling, turning and electroerosive machines . The disadvantages of many systems are the need for highly qualified technologists to work in a CAM system, often an uninformative user interface, the need to perform numerous manual operations, insufficiently developed program diagnostic functions to detect errors, limited opportunities for creating NC programs for the most modern or unique species equipment.

To solve all these problems, the developers of specialized software (software) undertook. For example, to check and optimize the UE, the engineering and consulting company SOLVER (SOLVER) suggests using software package Vericut by CGTech (USA), which reduces processing time by 30-50%.

In addition, the market for software products for production offers software for automated preparation of NC, which we will discuss in more detail.

PartMaker: Automated NC Development

For the automated development of NC programs for CNC metalworking equipment, SOLVER offers (for the first time in Russia) to use the PartMaker software package from IMCS (USA). Along with the preparation of NC programs for the traditional group of metalworking machines (lathes, milling machines and EDM), this modern and efficient software makes it possible to develop programs for the most modern and unique equipment, including automatic longitudinal turning machines (SwissType) and multi-purpose turning and milling centers .

The modular structure of PartMaker allows you to purchase only the software that is relevant for the enterprise at the moment, and retrofit the software package with new modules as needed. The software includes five main modules for the development of UE:

For automatic longitudinal turning machines - SwissCAM;

For turning and milling machines - Turn-Mill;

For lathes - Turn;

For milling machines - Mill;

For EDM machines - Wire EDM.

Convenient user interface: easy software development, rapid development of UE

The main advantage of PartMaker is the ease of creation and verification of UE. The software runs under Windows. To simplify and speed up the development of UE, a system of graphic and text prompts is used. In addition, PartMaker uses a machining database to store manufacturing experience on cutting tool usage, cutting conditions, and repetitive operations. All this facilitates the development of software and allows the technologist (rather than a programmer) to quickly get trained and start developing high-quality programs.

For programming in PartMaker, use modern technique visual programming. Details with complex processing are divided into groups of planes and surfaces of revolution, and with the help of pictures-tips, the desired type of processing is selected. The processing strategy is set by the user. For example, you can complete a full cycle of processing one surface, and then move on to processing another, or process all surfaces with one tool, replace it with the next one (according to the developed technology) and process all surfaces again.

Visualization of processing is possible both at the stages of creating technological transitions, and for the entire program as a whole. Simulation of processing processes is carried out on the computer screen with a dynamic three-dimensional demonstration of material removal. It is possible to rotate, scale and change the point and panorama of observation. In this case, you can observe the simultaneous operation of several tools, as well as the process of transferring the part to the counter spindle. For the workpiece, it is possible to set the translucency mode, as well as create a cut that allows you to see the process of processing internal cavities or closed areas. With four-axis machining, rotation of the workpiece around the tool can be observed. For Swiss-type lathes, the software simulates the movements of the bar inside the guide bushing, allowing you to see the actual machining process taking place on the machine.

PartMaker has its own built-in graphics editor for creating mathematical models of machined parts using graphic primitives (points, lines, arcs, chamfers, etc.). The user interface is designed in such a way as to facilitate and speed up the process of creating model geometry as much as possible. This is facilitated by standard Windows commands: "Copy", "Cut", "Paste", etc. You can perform corrective operations such as shifting and rotating the image. It is also possible to import 2D models into PartMaker in DXF format and 3D models from any CAD/CAM system, including Pro/Engineer, AutoCAD, SolidWorks, Unigraphics, etc. If necessary, imported models can be modified by a technologist and then returned back to the design system.

Development of UE for machining

Programming machining PartMaker conducts technological transitions depending on the type of processing (turning or milling), including for turning-milling centers and automatic longitudinal turning, and includes the following features:

2-axis milling with 3-axis tool positioning, machining of pockets with any number of ledges, taking into account climb or upstream milling, as well as the introduction of an offset mode;

contour milling;

1. Complex "CNC Machine"

V general view The structure of the "CNC Machine" complex can be represented as three blocks, each of which performs its task - a control program, a CNC device and a machine tool.

All blocks of the complex work interconnectedly in a single structure. The control program contains an enlarged coordinated description of all stages of the geometric and technological formation of the product. From an information point of view, the main thing in this description is that. that it does not allow for ambiguous interpretations. In the CNC device, information is transmitted in accordance with the UE. and then used in the computational cycle, the result of which is the creation of operational commands in real machine time.

The machine is the main consumer of control information, the executive part. control object. a in a constructive sense - a supporting structure on which mechanisms are mounted with automatic control adapted to receive operational commands from the CNC. Among such mechanisms are primarily those that are directly involved in the geometric shaping of the product. These are the mechanisms of coordinate feeds, the directions of which are different.

In the control process, feed mechanisms require the greatest amount of processing of calculation information, therefore, the complexity of CNC devices largely depends on the number of controlled coordinates, the complexity of the geometric problem of shaping.

The main tasks solved by CNC systems:

· Input and storage of system software. In devices of the lower classes, it is inherent in the design and cannot be changed. V modern systems ah can be entered and configured from the outside and is intended for machines of different classes.

· Input and storage of control programs in a non-volatile device.

frame interpretation. 2 frames are read - the first is processed, the second is preliminarily analyzed for continuous operation. Modern systems read and analyze up to 1000 frames.

· Interpolation. The CNC calculates intermediate points with the specified accuracy. Modern NURBS systems receive an electronic model of the workpiece from the CAD / CAM system, curved surfaces are transmitted in the form of splines and polynomials, processed by the device itself and converted into signals to feed drives.

· Feed drive control. In addition to motion control along the trajectory, additional modes for coordinating the true position of the working bodies with the control system, zeroing the machine, braking control.

Control of the drive of the main movement (on, off, angle control, speed stabilization)

logical control

Tool size compensation

Tool change

· For modern systems it is possible to correct errors of measuring and mechanical devices, adaptive control of processing, accumulation of statistical information, automatic built-in control, communication with a high-level PC, technical diagnostics.

Stages of preparation of control programs.

The development of a technological process for CNC equipment requires more detail in solving all technological problems. It is necessary to divide the operation into steps by reference points. A step is a movement of the tool along a geometric element, during which there is no change in modes. Technological commands define the conditions for performing movements. The sequence of elementary movements and technological commands determine the content of control programs.

The development of the technological process consists of three stages:

Route TP;

Operational TP;

· Development of UE.

The choice of parts for processing on CNC machines in mechanical engineering technology. The main factor is the economic benefit from:

Reductions in piece-calculation time

Machine time

Auxiliary time

Improving product quality, etc.

The sequence of development of UE:

The sequence of development of UE (manual programming):

Sequential programming of individual processing steps.

1. Separation of the operation into transitions.

2. Determining the basing of the part.

3. Determining the sequence of transitions (if the surface is machined with an accuracy of more than 11 grades, it is advisable to perform a finishing pass with a separate tool). The result is an operating card

4. Purpose of the tool. In addition to the type of cutting tool, you must specify the block number, determine the orientation of the cutting edge and its position relative to the datum point. This allows you to get a tool setting chart.

5. Separation of transitions into moves.

6. Calculation of cutting conditions

7. Construction of the trajectory of movement of each tool with indication of reference points

8. Calculation of coordinates of control points.

9. Definition of technological commands

10. Program coding

11. Program debugging and test part processing, editing.

Fundamentals of CNC programming. (ISO 6983 standard for SINUMERIK 840D, 810D, FMNC controls).

The generation of these control systems uses new programming methods along with the old commands. These include DIN66025 commands and so-called high-level language commands.