Page 10 - December
P. 10

METALWORKING EQUIPMENT AND TOOLS                                                                                                                                                         METALWORKING EQUIPMENT AND TOOLS
        Simulation model of a foundry complex for                                                                                  cast part from new alloys for modern technology, transfers a computer
                                                                                                                                        A  design engineer, developing a  three-dimensional  model of  a

        machine tool parts                                                                                                       model of a part to a foundry technologist. The model of the part shows
                                                                                                                                 surfaces to be machined, holes, possible radii of curvature, and various
                                                                                                                                 thickenings. The casting technologist determines the position of the
                                                                                                                                 model in the mold, allowances for machining, outlines the places of
                                                                                                                                 installation of risers, gating systems, molding sands.
                                                                                                                                        Then  computer  modeling of  the  casting  manufacturing
                                                                                                                                 technology is carried out: calculations of gating systems and metal
                                                                                                                                 supply points; calculations of profits and places of their installation;
                                                                                                                                 possible  defects  and  their  significance  for  the  characteristics  of
                                                                                                                                 strength, density and reliability of the finished part.
                                                                                                                                        When developing a computer model of the design of a part,
                                                                                                                                 and then the casting technology of its manufacture, it is necessary
               One of the main problems of the foundry at present is the creation of scientific foundations                      to  take  into  account  not  only  the  chemical  composition
        for the design and CAD of structures of cast parts and their elements, which ensure the production                       of  the  alloy,  its technological properties,  but  also
        of proper castings with a minimum weight and configuration, regulated by the microstructure                              the  characteristic  features  of  its crystallization and
        for machine parts (OST2-MT21-2-90), taking into account the current operating stress, strength                           solidification, the width of the solid-liquid zone during
        and  reliability.  In  the  automated  design  of  cast  parts,  the  most  important  thing  is  to  take               solidification. For example, for ductile cast iron with spheroidal graphite - the
        into account the complex relationships between the design of cast parts, their structure and                             amount of pre-shrinkage expansion, the rate of lowering of the level of liquid metal in the head
        mechanical properties. This complexity causes limitations in the application of the quantitative                         and the nature of the location of shrinkage porosity. To solve these problems, it is necessary to
        approach, which is associated with significant mathematical difficulties arising in the search                           take into account the thermophysical properties of the molding mixture and the density of the
        for an optimal solution due to the huge number of changing parameters that characterize the                              mold packing, fluctuations in the pouring temperature of the alloy, and other factors affecting
        manufacturing technology, design and properties of the cast part. It should be noticed that                              the quality of the casting as a whole.
        numerical  simulation  on  a  computer  cannot  yet  give  specific  data  on  the  number,  size  and                          In this regard, the approaches to solving the problems of manufacturing large iron and
        nature of the location of internal defects, and even more so it does not give an answer to the                           steel castings, namely, the installation of risers and metal supply points, given in the works of
        expected mechanical properties of cast parts.                                                                            V. M. Golod and V. A. Denisov [1], V. V. Desnitskiy [ 2, 3], etc.
               Computer-aided design of the structure of a cast part is possible only with sufficiently                                 As a result of the research carried out on the processes of forming a casting on the basis
        substantiated initial data for compiling a software package. Such initial data in the development                        of computer modeling, it seems possible to proceed to experimental studies of the quality of
        of a drawing of a part are the magnitude and nature of the acting load during operation, wall                            casting  manufacturing;  cutting  out  templates  from  different  casting  zones;  investigation  of
        thickness, the ratio of the thicknesses of the mating walls, the distance between the vertical                           macro- and microstructure, location of porosity and non-metallic inclusions; determination of
        walls in  Z-shaped  structural  elements,  the  magnitude  of  the  radii of  the  curvatures  in  the                   mechanical properties on samples cut from various casting zones, including those with a casting
        inner corners of the mates, structure and possible defects. To obtain such initial data, we have                         crust.
        developed a methodological basis for the design of elements of cast parts, which consists in                                    Based on the results of experimental studies of the quality of a casting made using a
        the characterization of research components, a set of tools and a sequence of research in the                            computer model, a designer and a casting technologist are finalizing the design of a cast part
        process of solving this problem.                                                                                         and  its  manufacturing  and  control  technology,  which makes  it possible to  design  a  casting
               The essence of the methodology for designing elements of cast parts is based on the                               complex using engineering logistics.
        following basic provisions:                                                                                                     Foundry  complex  engineering  logistics represents  solving  a  complex
        ● Scientifically grounded principles of designing elements                                                               analytical,  organizational  and  technological problem.  To successfully  solve
        of  cast  parts  can  be  obtained  only  on  the  basis  of                                                             this problem  and  achieve  the  goals  of  the  project,  the  enterprise  must
        comprehensive studies of the crystallization process of                                                                  implement a program of control actions, aimed at the formation of
        alloys and structural properties of cast parts. Taking                                                                   special working structures and the rational use of labor and intelligence
        into account only one of these factors leads either                                                                      of the members of the logistics engineering team. Rational project
        to an overestimation of the mass of cast parts,                                                                          management within the framework of logistics engineering is one
        or to a decrease in their strength and reliability                                                                       of  the  fundamental  factors  in achieving  the  goals.  To  achieve  the
        during operation;                                                                                                        set  goals,  it is necessary  to  divide the  project  management  work
        ●  a  comprehensive  study  of  the  crystallization                                                                     into stages. This applies equally to both the existing and the newly
        process  of  alloys  and  structural  properties is                                                                      created the enterprise.
        recommended to be carried out on model samples,                                                                                  Project  management  of  a  foundry  complex  based  on
        including structural elements of cast parts;                                                                             engineering  logistics  requires  a  deep  understanding  of  the
        ● the quantitative relationship between the design                                                                       essence and specifics of technological processes. Therefore, the
        of  cast  parts,  their  structure  and  mechanical                                                                      project should be implemented under the supervision of one or
        properties is the basis for the design of technological                                                                  a group of top managers of the enterprise with high professional
        and reliable parts. This relationship should take into                                                                   knowledge  and  experience.  Unwillingness to  admit  mistakes,
        account  the  composition  of  the  alloy,  the  specific                                                                ignoring large and small problems inevitably leads to the loss
        technology  for  making castings, the  magnitude and                                                                     of the company's competitive advantages in
        nature of the operating loads during operation.                                                                          the market.





     10   Stanochniy park                                                                                                                                                                                                     Stanochniy park       11
   5   6   7   8   9   10   11   12   13   14   15