Moscow-VAZ, the largest auto maker in Russia, produces about 70% of all cars in the country. When the company needed to manufacture a series of special milling machine tools equipped with pallet changer for loading various parts, the car maker turned to its Chief Engineer of Technological Equipment Production, Boris Abramovich Rutenberg. His department designs and produces just about everything for the auto manufacturer, including metal-cutting machines, non-standard equipment such as washers and dryers, welding robots, electronic devices for cars and machine tools complete with control systems and parts.
In this case, VAZ asked Rutenberg to design a two-sided spindle machine tool for milling and making center holes for parts, as preparation for further treatment on a lathe. The tool has to manipulate different pallet types used for fixturing or holding various parts. Rutenberg says, "Our main goal was to develop a unified parametric model of this machine tool to reduce time and cost of developing this project and all similar projects in the future."
To help accomplish this, Rutenberg turned to T-Flex, a 2D and 3D parametric modeler from Top Systems (Moscow). T-Flex, though popular in Russia since 1989, made its U.S. debut just this year with the release of T-Flex Parametric v6.1. T-FLEX uses the ACIS Geometric Modeler from Spatial Technology, Inc. (Boulder, CO), interfaced with its own BARANOV 3D Kernel.
"For this project we used the 2D version of the software," says Rutenberg. "At the moment we don't use 3D widely because we don't have many computers powerful enough for 3D modeling." They use the Hewlett Packard Vectra P75 and P100 with 16MB of memory. However the company did test the 3D version to check compatibility with legacy data. "We proved that we won't have any principal problems in converting data to 3D when we get to that point," he says.
| Engineers at VAZ, the largest car manufacturer in Russia, designed this pallet changer for milling machine operations using T-FLEX software from Top Systems. The simplicity of the design belies the capability of the software.
While Rutenberg's group was able to draw upon seven years of experience with machine tools, they had to design the pallet changer from scratch. They began by developing a parametric model of a pallet changer, taking into account all the variants of operation including changing dimensions and parts such as supports, carets, and arms. Pallet changers differ in size depending on the workspace layout, size of the machine tools, processing zone, and loading/unloading parameters. Also, they can be supported by two, three, or more legs; have one or two hand carriages; and act with or without hand rotation, or with left or right hand position. The parameters of all tool movement zones may also be different.
Engineers made changes by assigning values for necessary constraints. In all, there are 24 parameters and three possible modifications of assemblies. They include the same subassemblies but with different parameters. "This allows us to design pallet changers for any possible set of equipment," says Rutenberg. "We already designed 17 pallet changers for aggregate machine tools for VAZ' main production line and other customers, and have an order for 300 machines for another automotive plant."
| This engine, designed in T-Flex, shows the 2D and 3D parametric ability of the solid modeler.
Rutenberg says he tried other software packages such as MicroStation, KOMPAS (Russian 2D Drafting software), AutoCAD, SolidWorks, and Pro/Engineer, but he likes T-Flex best. "The main reason why we prefer T-FLEX is the opportunity to create parametric drawings without programming and a better user interface. T-FLEX also outperforms other packages on parametric functionality. Also important for us was T-FLEX's low price and effective upgrade policy."
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T-Flex Parametric Pro is a 2D and 3D feature-based design tool for mechanical CAD users. This is a line-based drawing system rather than the more common point based. The designer uses construction lines, circles, ellipses, splines, and functions to create geometric shapes. Any thing can be related to anything else. At the simplest level, one line can be parallel to another at a fixed or variable distance.
T-FLEX includes fully parametric drawing documentation, including dimensions, tolerances, text, bill of materials, and drawing notes. Changes to the model will be automatically and parametrically reflected in all drawing documentation. New 3D functions include direct blending having variable radius blending. In addition, you can select vertices, edges, and faces in the 3D model for locating and performing 3D operations. New construction methods for 3D Nodes and LCS's allow easy construction directly in the 3D window based upon existing 3D elements. Full Undo and Redo (unlimited) is still available, as is the unique Historical Backup. You can automatically save up to 99 historical copies of your design session, separated by any amount of time.
Export: IGES, DWG, DXF, SAT, STEP, STL, IV, BMP, POV, VRML, WMF, EMF, BMF, AVI
Import: DXF, DWG, IGES, SAT, IV, OLE
Price: Although price varies on quantity and country purchased, it ranges from $1,500 to $3,500 per seat.
Operating system: Windows NT 4.0 or Windows 95/98
Dimensions can conform to ANSI or ISO standards with one click.
Hardware: For 2D: Pentium 233, 64 MB RAM For 3D: Pentium 133, 64 MB RAM (minimum); Pentium II 400, 256 MB RAM, open GL supported video card (recommended)