US2276018A - Metal founding - Google Patents

Description

March 19, 1942. D, C PB LL 2,276,018

METAL FOUNDING Filed June 7, 1941 2 Sheets-Sheet 1 March 10, 1942- D. J. CAMPBELL METAL FOUNDING Filed June "1, 1941 2 Sheets-Sheet 2 I Snvenfqr figymld w]! (Ittorneg Patented Mar. 10, 1942 UNITED STATES T :OFFEI'CE 2 Claims.

My present invention relatesto improvements in metal founding, and particularly to themethod of producing baked or dried-molds andcores of granular sandlike material, and as 'areemployed in producing hollow metal castings; and the objects of my improvements are, first, toprovide baked or dried molds and cores of granular sandlike material that will be simple and of less parts or portions than like material molds and cores heretofor employed; second, to provide baked-0r dried molds and cores of granular sandlike materials that will eliminate fins on the castings produced; third, to provide baked or dried molds and cores of granular sandlike material that will be of one integral member; fourth, to provide baked or dried molds and cores of granular sandlike material that will be of lessproduction cost than baked or dried sand molds heretofor produced.

I attain these named objects and such otherobjects as may appeanbythe-method disclosed by the following description and accompanying drawings, in which;

Figure l is a vertical sectional view of the upper portion of an internal combustion engine cylinder block, and in which is shown passage Walls produced by cores produced by my improved method.

Figure 2 is a longitudinal sectional view of the core insert which is of low melting temperature material which when removed by melting, provides the cavity within the mold or core, wherein the wall of the passageshown in Figure 1 is formed.

Figure 3 is atransversevsectional view-taken through a .box and portionof a mold orcore as just produced and readyto be turned over for'the removal of the box, the view showingthe insert as placed in the box and the granular sandlike material packed around it.

Figure 4 is a transverse sectional view of the portion of mold or coresimilar to that shown in Figure 3, the view differing therefrom in that the box in which the mold or core portion is formed, removed and showing the mold or core portion resting on the drier plate with low melting temperature material forming the passage wall forming cavity running from the mold or core.

Figure 5 is a transverse sectional view of the mold or core portion removed from the drier plate and the low t mperature melting material melted and run from the mold or core portion; the view is taken on line I, I, of Figure 5.

Figure 6 is a top plan View of the mold or core walls, 5, 6, and 6.

portion, the view showing'theline I, 1, upon which Figure 5 andthe mold or core portions shown in Figures 2, 4 and 5 are taken.

Throughout the several views of the drawings,

similar numerals refer to similar parts or portions ofthe rnold or core, the drier plate and low temperature melting insert pertaining to my present invention, and referring first to Figures 1 and 2:

Numeral I, represents the upper portion of a cylinder block for internal combustion engines,

the cylinder block portion having been formed interiorly and part exteriorly by the mold portion I, has cylinder bore 2 and at the top, cylinder head engaging facet and the passage or passages 4 which may b employed for either the admiscast of a very low temperature material which -may be a wax or a metal alloy containing tin,

lead and bismuth or a lik melting temperature reducing material, which is preferably cast in a permanent mold for accuracy, the insert having extending upward from its "bottom, placement socket I4 and include walls I5, I6, I6, I! and I8, which correspond to walls 5, I5, '6, 1 and 8 of the cylinder block, the wall I8 have extend- :ing upwardtherefrom,'bosses I 8' engagedbythe low melting temperature melting metal pin I3 which when withdrawn forms the outflow gate Referring now specifically to Figure 3, numeral ,20 represents-the box wherein the portion of the -mold forming the interior and portions of the exterior of the cylinder block I is formed and in which the insert I 3vis positioned with its socket M engaging dowel pin '2I extending upward through boss \22 on which theinsert I3 rests ,as well on ledge 23 with its upper wall I8 resting on ledge 24 of the cylinder bore wall 25 of cylinder forming member 26 also positioned in the box 20 and surrounded by space 21 having a portion of the mold portion forming the cooling fluid chamber II and I2. Numeral 28 designates the granular baked sandlike portion of the mold, which before baking was packed in the box 20 around and through the insert I3 positioned in the box by dowel pin 2I, around the member 25 and over wall IS, the packing of the mold material is preferably done by blowing the material into the box and around the insert by air under pressure, although the packing of the mold material can be :done by jolting or hand ramming. The box 20 having been packed full of mold material and all surplus of the material extending above the box, struck 01f, the drier 30 is placed over the box with its flat plate 3| against the mold material in the box and the box including the drier is turned over and placed on a support with its downwardly extending ribs 32 resting on the support, in addition to the ribs 32 of which there is one at each end of the drier, and trough 33 extending the distance between said ribs, and incline drain grooves 34. The box 20 with its mold portion contents and the drier having been turned over, the box is withdrawn from the mold material and the member 35 which is placed in the box before turning over, is placed in an oven and baked at a suitable temperature, which is usually above 350 degrees Fahrenheit, and sufficiently high to melt the insert l3 into a highly fluid state and the metal pin l3 within the outflow gate I321, into a somewhat sluggish molten state, and in which state the sluggishmolten metal of the pin l3 gives way and the highly fluid material flows rapidly from the outflow gate 131: and the cavity formed by the insert [3.

Referring now to Figure 4 which represents the drier 30 with the mold portion 38 thereon as removed from the oven in which the mold portion was baked, and having the member 35 removed from under the over extending portion 36, the view also shows the low temperature melting insert 13 in a highly fluid molten state flowing from the outflow gate I312, which usually takes place within the baking oven in which the insert I3 is melted and brought to a free fiowable state before the outflow gate forming pin l3 becomes molten to a point where it gives way and thereby allows the molten insert to gush or flow freely from the outflow gate. In Figure 4, and also in Figure 5 showing the mold portion in top side down position but ready to be applied to other portions of the mold in which to cast a complete cylinder block, numeral 31 designates the cavity in which is cast the walls 5, 6, l and 8 of the cylinder block, the said cavlty 31 having been formed by the insert [3 and left as a cavity when the insert has been melted and been removed by flowage through the outflow gate I312.

In carrying out my improved method of metal founding, I produce preferably by casting or shaping in a permanent mold or die the insert which may be of the form disclosed, or any other form corresponding to a cavity I want in the mold and that could not be produced except by a multiplicity of cores or a complicated mold having loose members comprising the pattern forming the mold cavity, having provided the insert which is of a very low melting temperature material such as bay wax, paraflin and the like or of metal or metals having a very low melting temperature, I mount the insert in the box or foundry flask in which the mold or portion thereof is to be formed, and pack the mold granular material having a binder in the box or foundry flask in which is formed the mold portion or portions are formed, and around the insert mounted in the box or flask, and a second insert comprising a pin of metal placed in engagement with the first named insert, the said second insert being of a metal having a melting temperature point higher than the melting temperature point of the first named insert, but lower than temperature at which the mold material binder will become burned, and therefore causing the first named insert to be melted on highly fluid before the metal pin insert melts and gives way, thereby allowing the material of the first named insert to flow freely from the outflow gate I312 that is provided by the melting of the pin insert, and thereby leaving the mold cavity in which is formed the 5, 6, 6, l and 8 of the cylinder block.

Having described my present invention, the rights pertaining thereto I desire to secure are set-forth in the following enumerated claims.

I claim:

1. In metal founding, the method of producing hollow molds of granular sandlike material, the method consisting in providing a box in which to form a mold'portion, mounting in the box an insert of low temperature melting material and a second insert of metal having a higher melting temperature than the first named insert and to forman outflow gate for the material of the first named insert and extending from the first named insert to the exterior of the mold portion, filling and packing granular mold material having a binder mixed therewith in the said box against the said inserts, placing a drier plate having a trough over the open side of the box and against the mold material, turning the drier, box and mold material over until the drier is under the box, withdrawing the box from the mold material, placing the drier and mold material in an oven and drying the mold material at, sufficiently high temperature to first melt and liquify the first named insert and thereafter melt the second named insert sufliciently to allow the liquifled metal of the first named insert to flow through the gate formed by the second named insert and into the said trough.

2. In metal founding, the method of producing hollow molds of mold material, the method consisting in providing a mold having embedded therein a mold insert of low melting point material and an outflow gate plugged with a material having a higher melting point than the melting point of the mold insert material and heating the mold portion to a temperature that will melt the mold insert and thereafter the said plug and thereby allow the melted material of the insert to flow from the mold portion.

DONALD J. CAMPBELL.

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