Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D29/00—Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots
  • B22D29/001—Removing cores
  • B22D29/003—Removing cores using heat

Definitions

• the invention relates to a method for casting moldings.
• the invention relates generally to the molding of molded parts, i. on the foundry technology.
• foundry cores and / or forms are usually made of separate parts, brought together and connected together to form a mold or a Kempaket or mold package.
• form / core packages are then filled with molten metal to produce, for example, a metallic workpiece, wherein in series production the molten metal to be filled FormVKakakete successively lined up the production line.
• moldings are cast in a mold, which in turn consists of cores or a core package. After firing and completing the mold, it is transformed into another core sand, i. in a kind of support form, integrated, namely, to ensure the required mechanical stability can.
• a core package alone is not sufficient and the provision of the support form is absolutely necessary.
• the support form is so far greensand forms in which the Kempaket is inserted.
• Metallic molds have also been used so far, and such metallic molds are extremely expensive and, moreover, wear out quickly.
• the mold material / core package forming mold material is then to be removed from the molded molding. Due to a binder, the molding material must be disposed of or recycled in a special way. The same applies to previously used support forms or green sand molds, which are also provided with binder. The recycling of the mold sands / Grünsands associated effort is considerable, especially in expensive treatment plants additives such as bentonite, etc. must be removed.
• the present invention is therefore based on the object to design the above-discussed generic method in such a way and further that reduces especially in gray cast iron or cast steel the effort to be operated at a reproducible result, especially in relation to the recycling of the materials used.
• the residual heat should be used in the solidified molding.
• the support form previously made of greensand is needed, it is necessary, on the one hand, with the manufacture and other On the other hand, the costs associated with recycling, ie the total cost of production, can be considerably reduced.
• a support form is still provided, which, however, to the core package - aware - spaced.
• the support form can be generated from plates of different temperature-resistant materials, namely according to the modular principle.
• the items could be reciprocally adjustable, latched or otherwise fastened together. It is essential that a space remains between the actual casting mold, ie the core package, and the support form. This space between the core package and the support form is backfilled with a pourable bulk material.
• This bulk material defines an isostatic pressure around the core package on all sides so that, due to this pressure, the core package can withstand the outward pressure created during molten metal casting.
• the bulk material is guaranteed in any case that the core package can withstand the pressure generated during casting and it is on top of that guaranteed that any fugitives, cracks or the like through no melt penetrates to the outside.
• the energy stored in the melt or in the molding and in the core package is not readily sufficient to carry out a further-reaching process, for example to burn the binder contained in the core package.
• a further-reaching process for example to burn the binder contained in the core package.
• the support mold is opened or removed, after the solidification of the melt, so that the actual support function of the support form is no longer necessary.
• the bulk material is at least largely removed.
• the remaining core package is again isolated with the already solidified molding therein, so that the residual heat contained therein can be used without the bulk of the bulk material.
• the core package is placed on a thermally insulating base as part of the support form for positioning the core package in the support form.
• a thermally insulating base as part of the support form for positioning the core package in the support form.
• a thermally insulating hood is used in an advantageous manner, which may be made in one piece or in several parts. In the case of a one-piece embodiment, this could be put over the core package, for example via a pulley block, a manipulator or with other aids. Specifically, the hood is placed around the core package with the molded part therein on the base and complements the hood with the base for a thermal insulation on all sides. Once the binders of the core package are burned or at least dissolved, the hood is removed again, so that remains on the basis of at least largely freed from the molding sand molding.
• the bulk material is essentially the same material as the core-molding material, preferably without any additives.
• the cores consist of molding material (for example made of quartz sand) with binder, the same molding material, preferably without binder, can be used as the bulk material.
• the bulk material could have substantially the same grain size as the molding material, so that the molding material together with the bulk material - after recycling the molding material - can be used again with identical or different grain size.
• pure sand preferably so-called dry sand without additives, could be used as the bulk material, which causes no problems in further processing with the molding sand. This is especially true for identical or nearly identical grain size.
• quartz sand is particularly suitable.
• the backfilling in the space between the core package and the support form can be achieved by means of funnels or suitable technical aids by merely pouring it in of the bulk material to obtain a bulk density realize.
• the weight of the bulk material results in an isostatic pressure acting on the core packet which counteracts the outward pressure encountered during casting with molten metal to maintain the shape. The individual cores of the core package will thus hold together securely.
• the backfilling can be done by blowing in the bulk material.
• a density of the bulk material can be achieved, which is above the bulk density.
• a further compression of the bulk material can be achieved if the backfilling is supported by bulk material by vibration.
• the vibration can be induced, for example, by means of ultrasound or else mechanically, in which case the entire support form or a functional element located therein or in the support form can be used as a resonator. In any case, it is essential that preferably vibration induced by ultrasound promotes the compaction of the bulk material.
• the support mold is used for thermal insulation of the casting mold before and / or after casting and for deliberate use of the process heat within the casting mold or insulation for the controlled treatment of the cast molding and / or of the molding material forming the core pack.
• the process heat can be used to burn the organic or inorganic binder in the molding material, so that special recycling measures are no longer required thereafter. A special disposal of the Form material as special waste is then also no longer necessary, you should not want to continue using the molding material.
• the process heat can be used for the temperature treatment of the cast molded part.
• the molded part could be cooled regulated, with a thermal insulation by the support form along with backfilling plays a very special role.
• flue gases produced during combustion of the binder are retained within the device for heat insulation. They can be vacuumed at the end of the isolation process. The concentrated presence of noxious gases considerably facilitates their disposal or destruction, which considerably simplifies the process.
• Fig. 1 is a schematic view of the arrangement of a core package with spaced support form and by means of bulk material hinterhelltem space between the core package and the support mold and
• Fig. 2 is a schematic view of the arrangement of a core package of FIG. 1, but without bulk material and with it over hood for thermal insulation.
• the core package 1 shows, to clarify the method according to the invention, in which arrangement the casting mold 2 to be understood as the core package 1 is provided for pouring the melt.
• the core package 1 comprises a plurality of individual cores, which are completed together to form the core package 1.
• the core package 1 forms the casting mold 2.
• Fig. 1 can further recognize that the core package 1 is positioned in a support mold 3, which in turn is composed of individual parts 4 like a frame or made in one piece. Between the support form 3 and the core package 1, a space is formed, which is backfilled by a flowable bulk material 5 and thus builds between the support form 3 and the core package 1 isostatic pressure defined by the weight. In this state, the metallic melt is poured into the mold or in the core package 1 and ensures that the core package 1 dimensionally stable withstand the resulting internal pressure during casting.
• the parts 4 of the support form 3 can be used several times.
• quartz sand is an option. preferably with the same grain size as the molding material of the individual cores or of the core package 1.
• the bulk material 5 can be compacted, for example by means of vibration beyond the bulk density, in order to increase the isostatic pressure in relation to the core packet 1.
• the bulk material 5 can be compacted, for example by means of vibration beyond the bulk density, in order to increase the isostatic pressure in relation to the core packet 1.
• the support mold 3 together with bulk material 5 serves for the thermal insulation of the casting mold 2 and can therefore be formed before or after casting for the deliberate use of the process heat within the casting mold or insulation and thus for the controlled treatment of the cast molding and / or of the molding pack Use molding material.
• the process heat is absorbed too much by the bulk material 5 and also by the support mold 3.
• the support mold 3 and the bulk material 5 has been removed. Instead, a thermally insulating cover 6 is also placed on the thermally insulating Basjs 8. so that the residual heat held under the hood 6 can be used for example for burning the binder present in the molding material.
• the hood 6 is removed and the molding 7 is at least largely freed from the molding material of the former core package 1, namely because the bond between the components of the molding material is canceled.
• the method according to the invention has the enormous advantage that on the one hand the process heat is used and on the other hand that no molding installation is required for molding the molding.
• the process heat utilization is favored by the fact that the sand-to-iron ratio is favored by removing the bulk material.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mold Materials And Core Materials (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

Family

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Family Applications (1)

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Cited By (1)

Families Citing this family (4)

Citations (3)

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• 2005
  • 2005-09-26 DE DE102005046027A patent/DE102005046027A1/de not_active Withdrawn
• 2006
  • 2006-09-01 WO PCT/DE2006/001541 patent/WO2007028362A1/de not_active Ceased
  • 2006-09-01 US US12/065,823 patent/US20090145570A1/en not_active Abandoned
  • 2006-09-01 EP EP06791345A patent/EP1960137A1/de not_active Withdrawn
  • 2006-09-01 BR BRPI0615461-1A patent/BRPI0615461A2/pt not_active Application Discontinuation

Patent Citations (3)

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