DE2363940A1 - PROCESS AND MOLD FOR MANUFACTURING METAL CASTING PARTS - Google Patents

Description

Process and 5Orm for the production of Lietallr black parts

The invention relates to üie tall casting process Specifically, the invention relates to method of operation, used in rietallgießen to obtain a shaped metal casting which ground after removing only a small extent or reworked ■ v / _o must earth

The manufacture of metal castings in the foundry industry generally involves pouring the molten, liquid metal into a mold and cooling it Hardening or solidification of the metal «Since the liquid

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Metal shrinks or shrinks as it cools, resulting in a faulty and imperfect formation of the casting leads if not filled with additional liquid metal in order to fill the cavities or pores produced by the shrinkage in the mold, usually during the casting process Riser or storage container for the molten metal used to 'fill the porm if necessary during add molten metal to the cooling process «,

It is necessary that these risers are provided with an opening or a passage which is in sufficient communication with the mold cavity to prevent the formation or formation of a narrowing inlet opening at this connection point in the riser, which acts as a heat sink act barren Converters würdeο This process would in fact inevitably lead to a blockage of the connection channel between the riser and the mold with cooled, solidified Lie tall lead and thus prevent the liquid metal can flow from the riser into the mold cavity, as is required to be ₀ Therefore, Risers normally provided with through-holes which have a cross-sectional diameter of considerable size,

However, the use of risers with such large through-openings has again to do with those associated with contributed to the problems encountered by the riser. ObgUsLch the lack of a constricting entry opening into them Increase generally allows a sufficient amount of the molten metal to enter the during solidification

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Mold cavity gets to the shrinkage problem in the Bypass fitting is made large by the existing one Connection cross-section formed a strong and massive connection between the molding and the riser when the liquid metal in it is cooled and hardened

Since the riser is formed in one piece with the fitting in the mold is "the riser must then be separated from the molding" This separation occurs frequently, for example by sawing apart the two sections at the level of the passage opening between the riser and the bricks The molding must then be sanded to remove excess metal and subjected to further finishing be subjected in order to obtain a smooth surface in the area of the separation zone

The separation process is further complicated by the fact that the mold is often lined at the junction between the riser and the molding with metal _o This excess metal is such as "dampening or buffering"? / Een the molding and the separation point provided in order to help that a breakage or cracking of the molded articles is prevented even when it is separated by force, or at least under application of force by Steiger _o this food metal must also be removed by grinding before the post-processing wirdo performed this treatment · steps are time consuming and expensive, particularly in view of on labor and time costs «,

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Another. Problem with the use of risers and the introduction melted over them The metal in the mold cavity is in the control of the Me tall flow between the riser and the mold cavity While it is often desirable to retain the molten metal in the riser "for a sufficient period of time, in order to allow a distribution or separation of impurities such as SoBe slag or the like in such a way, that the impurity content of the flowing metal into the mold cavity is reduced, have the for To achieve this effect, the required rejuvenation the riser through hole often led to the problem of metal clogging discussed above

This problem has been posed when casting metals such as aluminum or magnesium through the use of metal or pilterns - Sieves to catch larger foreign bodies or impurities in the flow channels for the liquid metal However, these "partially dissolved" filters or sieves can are not used when casting steel, because the very high temperatures that occur lead to melting this filter lead o

'The. The invention therefore aims to provide a method and a device for producing metal castings using at least one riser which, after cooling, ensure easy separation of the riser from the cast molding _e

The invention also aims to reduce the flow of the molten

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Lie tails about the oteiger-Durchgangsoffiiung in the A..rr: ihohl control raura au, and thereby achieve that impurities, '«/ Ie So3o Jchlacke, calibrated in oteiger apart from the oteiger passage opening secrete and distribute "

jJin another purpose of ürfinduü. is to carry out the method and the "device so or" embody, 'IaB small blocking the Verbindungskc ^v: as occurring between CTEIA ■ iteiger and jj'ormiiohlraun, and that nevertheless after cooling the otei he _ü slightly from the xietall - "- v can ußstück separated / ground ,,

Eeoen a light! 'Rermung of otaigers of üeu iietall-GrUJBstück aims to Jrfinciung also, the required grinding and / or rTaohbearbeitungsvorgänge far as i / ie to remove excess de tails, after ireiinung possible herabsusetzen _o

Another purpose of the invention is to creating arrangements as simple as possible and

resistant
as well as / against high temperature temperatures, as they occur with semolina from dtahl, and still achieve a slight separation of a dteiger part and a jormguss part into its part components ₀

This is done in the case of a metal internal casting process according to the invention achieved by 'that between the oteiger and the u-ussstück a narrowing is formed through which a clean Removal of the riser after the pouring process is made easier «,

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BATH ORIGINAL

This is preferably achieved by prior to your pouring of the liquid detail a consummation of corrosion is inserted between the riser cavity and the itorm cavity, through which the lie tall flow is advantageous is regulated in the J? ormhohlrauni

There is a constriction device according to the invention from a thin-walled, breakable component

Preferably, the invention consists Einschnurungs ~ device of a thin and provided with a passage opening -rfand which the ^ΐ ι ο at least one dimension: raihohlrauffl.es is adapted exactly and at least one wall surface forming the Zormhohlraums "

The wall thickness is according to the invention with regard to the The thermal conductivity of the material should be sufficiently small, about heat losses and the resulting premature cooling and hardening or solidification of the molten material avoid iletalls at the junction *

Further advantages and features of the invention result from the claims as well as from the following description, and the drawings in which the invention is explained and illustrated by way of example »show;

! fig * 1 with a longitudinal section of a typical casting mold one i'orm cavity, one Üteiger cavity, and one usual gate and gate system, in which a

η _

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BATH

Sinschnürungs-device according to the invention used is,

Mg »2 a sectioned partial view seen when viewing line II-II in J ¹ Ig _{0 1,}

3 ¹ Ig ₀ 3 a view of the constriction device used, seen from the Steiger cavity, in a view in section III-III in FIGS. 2 and 3

4 a seen in the direction of the arrows IV-IV in FIG Cross section of the lacing device according to the invention

Pig. 1 shows an invention generally designated 10 according to constriction device, which is inserted into a form 11 made of green sand, also known as a Uaßguß form. As usual, the mold 11 consists of an upper mold part 12 which is fitted onto a lower mold part 13 is ο The connection of these two while is through the line 14 illustrated

Molten metal is cut through a conventional gate— system 15 with a pouring funnel 16, a funnel barrel 17 and a barrel 18 poured into the mold at the lower end the funnel barrel 17 is tapered or throttled, to regulate the flow of metal through · The liquid metal flows over the funnel barrel 17 and the Run 18 to a riser cavity 22 and from there over a. Riser opening 25 into an adjacent mold cavity 24 »The mold cavity 24 naturally corresponds to the desired one

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Shape model.

The mold cavity 24 is, as shown, by an upper, A surface 26 arranged along the connecting line 14, a lower surface 27 and cylindrically shaped side surfaces or Walls 28 delimited »The riser opening 25 cuts through the mold cavity 24 preferably along with one of the wall surfaces smaller dimension, in the present exemplary embodiment on the side surface 28 with a vertical distance between the upper and lower wall surfaces 26 or «, 27 certain height Ho

The cross-sectional surface area of the riser opening 25 is essentially rectangular, see FIG. 3, and advantageously has and preferably a vertical dimension corresponding to the height H of the mold cavity 24

The rejuvenation apparatus 10 illustrated in Figo 4 consists essentially of an outer reinforcing ring 48 whose inner surface is tapered to form a thin wall 45 in cross-section _o, the radius R between the projection or board edge 42 of the outer reinforcing ring 48 is sufficiently large to provide a To provide a smooth transition to the inlet side .35 of the wall 45 in order to eliminate stress concentrations in between, which could otherwise arise due to the high temperatures of the liquid metal to reduce when pouring »

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The wall 45 also has an opening 46 through which ... liquid metal flows into the mold cavity 24 passing through the boundary surfaces 26 and 27 of the mold cavity indicated is. The opening 46 is delimited by a rounded hand edge 47 of the found 45, whereby the opening 46 is approximately in the center plane of the 7 / and 45 has the smallest diameter ο

The taper device 10 is made of a non-meltable one Composed of material and can be broken in parts, to allow them to be easily removed from the hardened uie tall molding can be broken away «, a series of conventional fired ones ceramic tiles are suitable for this purpose

The wall 45 creates a constriction or constriction in the I & tallformling between its riser part and its casting part, so that it is ensured that the riser can easily break away from the Gussstück γ / ground when the metal cooled and hardened iss required that the wall 45 is sufficiently thin and has sufficient thermal conductivity to transfer a sufficient amount of heat to a properly controlled solidification of the Itormlings ensure and a premature blockage of the passage channel between the riser and the I-shaped cavity to prevent with hardened metal «.

The exact thickness of the wall 45 depends on the relative thermal conductivity of the constriction device 10

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Enclosing material .. However, the device 10 is preferably formed from a ceramic material, and in this pail a wall thickness of about 1/8 "(about 0.125 min) is sufficient» Essentially, door thicknesses of about 1/16 " (about 0.063 mm ) to about 1/4 ^fI (about 0.250 mm). The opening 46 forms the only connection between the riser 22 and the internal cavity 24 and is dimensioned relative to the size of the throttle point 20 so that the jiietallstrom is controlled during the pouring in order to allow that the level or height of the molten metal in the riser cavity 22 rises slightly above the opening, during the iOrm cavity. is filled _e impurities such as ZoSo slag and G-rus and the like normally float on top of the metal, so that their penetration into the JPorm cavity 24 is advantageously prevented _{or the like}

The GX ¹ OQe and JüOrm. The surface area of the jorm cavity 24 adjoining the riser opening 25 and the cross-sectional area of the riser passage 25 primarily determine the size and shape of the constriction SS ¹ O direction 10 _o The outlet wall 36 forms the front wall surface of the iOrm cavity 24 and is desired for this ZLäche Sorrn formed the reinforcing ring 48 with the ¥ and 54 extends behind the opening of the andflächen by the ¥ 26 and 27 limited Formhohlraumsj as indicated by the section z hn itte 41 of the reinforcing ring 48 as illustrated most clearly in I ¹ Xg ₀ 3 can be seen, the inlet wall 35 is larger than the riser passage opening 25o. The riser opening 25 in the illustrated embodiment has the same height as the

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Mold cavity 24 "

A recess 43 is provided for receiving the tapering device IO in the form. The recess 43 is preferably arranged so that they are as narrow as possible and allows tight fit of the constriction device 10 between the mold cavity 24 and the riser opening 25, to prevent the ingress of molten metal, which would require additional grinding and reworking, to prevent··

The constriction device 10 is held firmly and securely in the form 11 with the helix of the parts of the reinforcement ring 48 extending into the form 11, see I ¹ Ig _{0 1 and 2}

The pinch device 10 may any conventional means are produced with the aid _o the manufacture by shell molding or injection molding is, however, often advantageous, since these methods are "highly adaptable and allow in an advantageous manner, the respectively required embodiment according to the surface of a shape model to received

The mold 11 is produced in the usual manner in that Molding sand is poured into the upper mold half and the lower mold half around a model, not shown,. which corresponds to the shape of the desired casting. The constriction device 10 is inserted into the recess 43

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inserted when the mold is opened and the model is removed is ο While the recess 43 can be formed in the shape using any desired method, however it is usually formed by the impression of a core added to the mold model »compartment flows into the closing of the mold the poured into the pouring funnel 16 metal through the funnel barrel 17 down into the barrel 18 and begins the To fill riser cavity 22 »The constriction opening 46 causes the liquid level of the molten metal in the riser rises above opening 46 to prevent foreign matter such as slag or the like floating on the surface of the liquid metal into the mold cavity 24 when it is filled. During the solidification of the molten metal, the wall 45 allows the Transfer of heat from the metal in the riser to the metal in the adjacent mold cavity so that a suitable The solidification process of the moldings is ensured »After complete solidification and cooling, the mold 11 becomes ordinary placed on a mechanical shaking device to to loosen the mold wall surrounding the metal. During this mechanical shaking process, the relative small size of the constriction between the riser and the molding, the riser usually already broken off due to the forces of inertia. During this process, the constriction device 10 broken and crumbling off the molding “· This eliminates the otherwise necessary, cumbersome Removing the riser by hand * Since the taper is also relatively close to the surface of the molding the SOrmling is essentially free of excess

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Metal usually found during or after the removal of the Steigers remained on the surface of iTomiling There is therefore no need for a grinding treatment that would otherwise be required or other preparatory work to be carried out.

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Claims (1)

Process for the production of iietallgußteile with a easily and cleanly detachable riser, characterized dai. · Means of forming a narrowed connection between the main part of the riser (22) and the ii'ormhohlrauni (24) are inserted before melted lie tall over the riser and the lacing means in the iormhohlraum is poured, and that after solidification of the molten metal destroyed the j? orm and possibly at the same time the 8-dough and the constriction means are broken away from the molded casting » Fo rm for performing the method according to claim 1 with a iOrmhohlraum and an associated riser cavity and means for forming a constriction between the. Steiger and the casting and for .regulating the flow of the liquid metal from the riser into the Iorm cavity, characterized in that these means have a constriction device (10) which at the junction between the jj'ormhohlraum (24) and the riser cavity (22 ) is inserted in the form (11), 3ο JPorm according to claim 2, characterized in that the Constriction device made from a breakable, thin-walled (45) Component (10) with a through opening. (46) and a thickened ring-shaped reinforcing edge (48) consists « - 15 409826/0407 4ο form according to claim 1 or 2, characterized in that the Sinschnüruhgsvorrichtung (10) made of a ceramic Material "consists of" 5 » Mold according to claim 3, characterized in that the wall thickness of the thin-walled part (45th)" of the constriction s-Yorrichtung (10) between about 1/16 "(about 0.063 mm) to about 1/4" (about 0.250 mm) lies, 6ο form according to claim 2, characterized in that · the The passage opening (46) of the constriction and control device (10) is so small that a flow molten metal is inhibited or prevented by the riser in the mold cavity, so that the liquid level of the molten metal is held in the riser above the passage opening ", 7ο form according to claim 2, characterized in that the Opening of the binding gate direction (10) through a rounded edge (47) of the thin wall part set isto 409826/0407