US2768414A - Flask and mold for v-6 cylinder block - Google Patents

Description

Get. 30, 1956 J. DOLZA FLASK AND MOLD FOR v-s CYLINDER BLOCK 4 Sheets-Sheet I Filed Dec. 8, 1954 'ATTORNE Qct. 30, 1956 J. DOLZA 2,76,414

FLASK AND MOLD FOR V-G CYLINDER BLOCK Filed Dec. 8, 1954 4 Sheets-Sheet 2 ATTORNEY Y 0d. 30, 1956 DQLZA FLASK AND MOLD FOR V-6 CYLINDER BLOCK 4 Shets-Sheet 5 Filed Dec. 8, 1954 ATTORNEY 0d. 30, 1956 DOLZA FLASK AND MOLD FOR V-6 CYLINDER BLOCK 4 Sheets-Sheet 4 INVEQNTOR Filed Dec. 8, 1954 names of John ;Dlza and John B. Burnell.

FLASK AND MOLD Fen ii-s entrants BLOCK .lohn Dolza, Davisburg, Mich, assign'or to General Motors Corporation, Detroit, "Mich, a corporation of Delaware Application December 8, 195 4, SerialNo. 473,;8'69 9 Claims. 01. 22-101 This invention relatesto foundry casting operations and more particularly to a flask andmold construction for use in casting cylinder blocks of internal combust ion engines.

In thepast, conventional methods of arranging and assembling cores preparatory to casting cylinder blocks of internal combustion engines have required the forming, handling and assembling of amultiplicity ofcores-to form the final coring assembly. This problem is a-particuilar ly complicated one with respect to casting V-type engines. For example, typical eight cylinder V-engines normally have requiredapproximately 19 or '20 cores for the cylsand of the drag half of the mold. Moreover, more accurate and complicated core transfer fixtures must be em- 'ployed in production because of the elimination of the base slab core.

A principal object of the present invention, therefore, is to provide a flask which permits accurately locating a cylinder block coring-assembly in the drag half of the mold and at the same timealso eliminates the'need for a conventional large base slab core. This'is accomplished by a novel construction of the drag half of the flask.

A further object of this invention is to provide a foundry mold, particularly the drag half thereof, having a reusable metallic supporting plate in place of'green sand or'the conventional base slab' core. T his'new arrangement affords accurate alignment of cores in the drag half of the mold and at the same time facilitates transfer of the coring assembly to the mold. I

These and other objects are attained in accordance'with the present invention by a'simple an'inex-pensive flask and/or mold construction in whichan assembly plate,

preferably formed of a ferrous base-metal, is positioned be' first located on the plate and the plate thereafter employed as a basefor transferring the cores to-the-drag half of the mold.

Regardless of whether the'assemb'ly-plate -is used-as a {core transfer-base'of 'merel-y performsacore locating function, it is provided with locating means whichpfernnts rates Patent accurate positioning of the final core assembly on its upper surface. Inasmuch as this plate is reused for an indefinite period of time, care mustbe exercised in gating the mold and in handling the shake-out so that the plate will remain free from metal flash and handling damage.

Other objects and advantages of this invention will more fully appear from the following detailed description of preferred embodiments of the invention shown in the accompanying drawings, in which:

Figure 1 is an exploded perspective view, showing the cores used to form a cylinder block of a V-type s'ix cylinder internal combustion engine and the relationship of these cores to the assembly plate employed in accordance with the present invention;

Figure 1a is a perspective view of the assembly plate shown in Figure 1;

Figure 2 is a perspective view showing the cores .of Figure 1 in position on the assembly plate; 7

Figure 3 is a perspective view, with parts broken away and in section, of the drag half of the green sand mold, together with an end slab core which maybe used in conjunction therewith;

Figure 4 is a fragmentary perspective view of the drag half of the green sand mold in which the assembled cores and plate are placed preparatory to the positioning of the cope half of the mold andthe pouring of the molten casting metal;

Figure 5 is a sectional view of the assembled flask, green sand mold and coringarrangement shown in Figure 4; and

Figure 6 is 'a'fragmentary sectional view of a:modifica tion of the flask,'mold and coring arrangement shown .in

As shown in Figure 1, the barrel-bulkhead cores 76,

'78 and "80 comprise body or bulkhead-definingportions 86, 8S and' 9il, respectively, which are approximately triangular'in vertical transverse cross section, and;gen

erally cylindrical barrel portions 92 and 94, which definethe leftand rightcylinder banks, respectively. Large longitudinallyextending core locators 95 and 97 are;pro-

vide'd at the bottom of each.bulkhead-defining;portion to permit the accurate locating of the barrel-bulkhead cores 7 on an assembly or transfer plate 99. The assembly of these cores results in' a coring arrangementin' which the body or bulkhead-defining portions-86,-88 and 90 'of the barrel-bulkhead cores have their adjacent end surfaces abuttingone another and the bottoms of the;core 'locators and 97 resting on the Upper-surface -93 of the assembly plate. This plate in turn is seated on the bottom wall of the drag half of the flask.

The water jacket core 82 ispositioned so that the adjacent generally cylindrical barrel portions 92 of the barrel-bulkhead-cores. extend through a plurality of openingsor'bores 96 formed in the water jacket corelSZ. LikeWise,'the -water jacketcore 84is provided with a plurality of openings 98 which extend through the core and into which the adjacent .barrel portions 94vof the barrel-bulkhead cores project. In this mannerthe various segments of the water jacket cores each, in effect, forms a sleeve having internal, generally cylindrical walls which are spatially separated from the barrel portions 92. Figure 5 best shows this arrangement of the cores after they are assembled in the green sand mold.

In order to maintain the barrelbulkhead cores 76, 78 and S0 in proper position on the upper surface of the assembly plate 99, this plate is provided with an upwardly extending flange 101 around its edge. As shown in Figures la and 2, the ends of the assembly plate, as well as its side edges, are formed with this flange, which preferably is integral with the plate. With this construction, the outer side surfaces of the core locators 95 and 97 on the bottoms of the three barrel-bulkhead cores engage the inner vertical surfaces of the side portions of the flange 101, while the outer end surfaces of the barrel-bulkhead cores 76 and 89 contact the inner surfaces of the end portions of this flange. In this manner the assembled cores are retained in proper position within the mold since they aer prevented from moving either longitudinally or laterally relative to the flask and the green sand therein.

As hereinbefore indicated, the assembly plate 99 may be a permanent part of the drag half of the flask. Hence this plate may be formed integral with the bottom wall of the drag or it may be secured thereto by bolts or other appropriate means. However, when the assembly plate 99 is not a permanent part of the mold but is employed as a loose piece, in accordance with the preferred embodiment of the invention, it may serve as a core transfer fixture as well as for locating the assembled cores in the mold. Under these circumstances, it is desirable to provide the assembly plate 99 with downwardly extending dowel pins 105 or their equivalent which engage suitable mating openings or recesses 107 in the bottom wall 103 of the drag half 159 of the flask. This relationship between the flask and the assembly plate is best shown in Figure 5. With this arrangement, when the assembly plate 99 with the various cores positioned thereon is transferred to the mold, the plate and assembled cores can be aligned properly with respect to the mold by engagement of the pins 105 with the openings 107. Alternatively, as shown in Figure 6, dowel pins 106 could be attached to the bottom wall of the drag and extend upwardly therefrom, the openings 108 for receiving the dowel pins being provided in the assembly plate. It is not necessary to have the dowel-receiving openings 107 and 108, whether formed in the flask wall or in the assembly plate, extend completely through that part. Mere recesses which mate with the dowel pins, if the mating parts are formed with sufficient accuracy, normally will suffice.

As shown in Figures 1, 2 and 5, a small base core 109 is employed when the assembly plate 99 is used to transfer the cores to the mold. Such a base core is necessary to provide proper gating of the engine block casting while preventing the molten casting metal from contacting the assembly plate. On the other hand, when the assembly plate is to be used as a permanent or semi-permanent part of the mold, as shown in Figure 6, this base core may be formed of green sand.

A preferred method of assembling the cores in the green sand mold, when the assembly plate 99 is to be used as a core transfer base, is as follows. The small base core 109 is first positioned on the upper surface of the assembly plate 99 with the barrel- bulkhead cores 76, 78 and 80 placed over the base core. As shown in Figure 2, the bottom surfaces of the core locators 95 and 97 thus are seated on the upper surfaces 93 of the assembly plate, while the outer side surfaces of these core locators abut the inner, vertical surfaces of the upstanding flange 101 at the edge of the assembly plate. The inner, longitudinally extending surfaces 75 of the core locators 95 and 97 are in surface engagement with the sloping side surfaces of the small base core 25.. Hence, when molten metal is poured through the longitudinal gates 224, as is hereinafter more fully explained, it does not come into contact with the assembly plate.

Figure 2 shows the exact positions of the barrel-bulkhead cores on the metal assembly plate. Since the adjacent end faces of the barrel-bulkhead cores abut one another and the lower lateral edges of these cores are in contact with the flange 101, the cores are prevented from sliding on the assembly plate.

After the barrel-bulkhead cores 7 6, 78 and 80 are positioned on the assembly plate or core transfer plate 99, a plurality of metallic spacer sleeves 114 may be employed to properly space the water jacket cores 82 and 84 from the barrel portions 92 and 94 of the barrel-bulkhead cores. These sleeves, which are best shown in Figure l, are preferably slightly conical in shape, and their smallest internal diameters are somewhat smaller than the outside diameters of the barrel portions of the barrel-bulkhead cores. Thus, when the spacer sleeves are assembled over the barrel portions of the barrel-bulkhead cores, the outward taper of their inner surfaces prevents their sliding downwardly on the barrel portions to an excessive extent. Hence these sleeves are of such a shape and length that their inner or lower edges are spatially separated from the sloping side surfaces of the body or bulkhead-defining portions 86, 3S and of the barrel-bulkhead cores. When the spacer sleeves 114 are securely in position around the barrel portions 92 and 94 of the barrel-bulkhead cores, the two water jacket cores 82 and 84 are placed over the sleeves and the barrel portions so that the latter protrude completely through the openings 96 and 98 in the water jacket cores, as shown in Figure 2.

When the various cores are properly arranged on the assembly plate or core transfer plate 99, these cores are in condition to be transferred to the green sand 153 in the drag half 159 of the metal flask. As shown in Figure 3, the green sand in the drag has been molded so as to form core prints 160 in which core print projections 162 at the ends of the water jacket cores 82 and 84 may rest. Likewise, as can be seen from Figure 5 core prints 190 are also provided for core locators 192 at the bottom of the water jacket cores. Various other indentations, such as recesses 166, are printed in the sloping side surfaces of the green sand in the drag to form appropriate crankcase parts of the cylinder block casting.

A sprue core 168 is shown in Figure 3 as insertable within a generally rectangular recess 170 in the green sand in the drag. A vertically extending groove 172 formed in the end wall of the green sand mold cooperates with a similar groove 173 in the sprue core to form a sprue for the molten casting metal. This sprue, of course, is open to the atmosphere at its enlarged, rectangular upper end 174 and communicates with the mold cavity at its lower end by means of the longitudinally extending recess 176 in the green sand of the drag. The sprue core 168 is provided with a similar recessed design to form a generally cylindrical gate and sprue. When the sprue core is inserted within the recess 170 and the other cores are in assembled position within the mold, the inner face of the sprue core abuts the adjacent end or rear face of the end barrel-bulkhead core 80, as shown in Figure 4. These two cores provide an interjacent cavity which forms the rear main bearing block of the cylinder block.

When the assembled cores and assembly plate 99 are thus properly located within the mold cavity, the base of the assembly plate 99 is seated on the upper surface of the bottom wall 103 of the drag half 159 of the flask. Also the core locators 162 and 192 on the water jacket cores 82 and 84 are supported by the core prints 160 and respectively, in the green sand in the drag.

The spacer sleeves 114 may then be withdrawn from the openings 96 and 98 in the water jacket cores and from around the barrel portions 92 and 94 of the barrel-bulkhead cores. As hereinafter more fully explained, the support provided at appropriate locations by the bottom surfaces of the green sand maintains the barrel-bulkhead car n prq r s o t. im r y, th s re-mi ts 16 which support the core printprojections 162 help retain thewaterjacket cores in assembledposition and spatiall y separate these cores from the barrel portions 92 and 94 of the barrel-bulkhead cores. In this manner annular cylinder walls having equal thicknesses throughout their circumferences are formed in the cylinder block. Although spacer sleeves 114 are employed in the embodiment of theinve'ntion shown in the drawings, it will be understood that a transfer fixture could equally well be designed to retain the spatial relationship between the water jacket cores and the barrel-bulkheadcores without the use of such spacer sleeves by the provision of suitable retractible locating pins. Such a construction generally wouldbe preferable to one using spacer rings and would facilitate assembly of the cores and mold.

I Qf course, if the assembly plate 99 is not used as a core transfer ,base, the small base slab core 169 may be formed of green sand, as hereinbefore indicated. Under these circumstances, the assembly plate is positioned on the bottom wall 103 of the drag half 159 of the flask before any of the cores are locatedon the plate and before-the green sand 158 is in the mold. As previously explained, the assembly plate actually may be constructed asa permanent part of the flask. The green ,sandis then dumped or otherwise introduced into the drag half of the flask and printed into the proper contour. The s rnall bas e slab core 109 would thus be formed in the same manneras the rest of the green sand in the drag. Of course, with this latter method, it is usually advisable to make various minor changes in the shape of the core locators 95 and '97 and the adjacent green sand to effect minor economies. ,This modification of the flask, mold and coring assembly is shown in the fragmentary sectional view of Figure 6 The construction and arrangement of the mold, flask andc'ores are otherwise similar to the construction and arrangement shown in Figure 5 and hereinafter described in greaterdetail. a a The arrangement of the cores after being assembled in the green san in the drag 159 is shown in Figure 4.

{The copehalf 188 of the flask containing green sand 1 86 is then placed inposition over the drag and retained'in alignment "by t he locating pins or do wels 180, 'as'hown in figure 5 Thus assembled, the green sand mol'dand cores are in condition for pouiingof ,the'molten casting metal. The formed spine and gate'176 -1 72 17 3' 174 may be connected to another sprue portion in or through the green sand in the cope. The'eX act positioning of the cores relative to the green sandfin both the dop and the drag is best shown'in the sectional view of Figure 5. Thus it will be seen that the water jacket cores 82 and 84 are supported by means of' core prints 190 in the sloping side walls of the green sand of the drag, these core prints engaging the core print projections or core locators 192 formed on the lower surfaces of the water jacket cores'82 and 84,. This support is in addition to that provided by the longitudinal core print projections 162which "are seated in core prints, 164l formed in the green sand on the mold parting line 193 at both ends of the mold cavity. a M

As shown in Figure 5, generally cylindricalprojections or mold locators 194 are shown as formed on the upper surfaces of the water jacket cores and, when these cores are assembled within the mold, engage lower, sloping surfaces of the green sand 186 in the cope. These locators prevent floating of the water jacket cores during the metal pouring operation. If desired, recesses for the core locators 194 may be printed into the cope in order to perform a further locating function. Likewise, the top surfaces of the upper camshaft gallerydefining portion 196 of the barrel-bulkhead cores may be provided with vertically extending, generally cylindrical projections or core locators 198 which, as shown in Figd al ure 5, may be adapted to engage a core 2010 forn'1'ed in the green sand of the cope. Horizontal surfaces of the green sand in the cope near the sides merger rest upon theupp'er horizontal surfaces 210 of the barrel portions of the barrelbulkhead cores, while adjacent vertical surfaces of this green sand abut the generally vertical end walls the barrel portions, as shown at '212.

The fdnly other areas of contact between the green sand and the coring assembly ,are wlie're the vertical outer surfaces 214 of the longitudinally extending projections 215 at the bottom of the b'arrel bulkhead cores 76, 78 and 180 abut the, p' aijallel surfaces of the green sand 153 in the drag half 159 of the flask. The Side rojec- 't'ions or. rid'g"es "215, which overlap the upper edges 'of flange 101 of the assembly plate, 99, prevent the molten casting metal from contacting ,the plate 99 For the sake of simplicity and 'to more clearlyshow the relationship between the core lo'cat'ors 9 5 and '97 and the plate 99, these ridge have been omitted from the perspective views'of Figures l, and 2. 'In the arrangement shown in 'Figure 6, the ridges 215m not necessary since the green sandflin the drag extends inwardly at 217 over the flange 101 and into abilhn ill, with the outer surfaces of thecor'e 'locators and 97. This construction likewise 'preventsme molten casting metal from cond st at v R'eferring again to Figure ,5, a plurality of appropriate vertically extending vents 216 are formed in the cope to permit the escape'or thec'o're gases generated during and after pouring of the casting irie'tal. These vents eelainfinicate. with the openings ifseexten i through the iipper surfa sof 'barrelhportioiis 9 2 and 94am catha t h nea than]: the barrel-bulkhead cores 7s, Z8 and'8i). Theopen'ings ineach 5r the barrel parents "be the barrel-bulkhead cores are gangularly extended, as indicated at 218, through the rel portions toith e bottoih of'thes'e cores. the arrangement shown, these openings or passages prefer- ,40 ably intersect at --a lowerjlongitutlinally extending vent 22s, Likewisefeach" the'openings or veins 150 in t'he biilkhead portions r-th'e barrel-bulkhead cores prererablye ite'rids vertically throughalmo'st the entireheight barrel bulkheadicorein it is formed, in-

b'rizontal, longitudinally extending exceedingly simple 7 and requires 'rater'eohneet d, longitudinally extending gates 224 are shown in Figures Sand 6 a's being provided in the bases or bot tomportions of'the barrel-bulkhead cores 76,

7 8 and :86. These gates communicate with the sprue 176- 172-173 174 to distribute the molten casting metal through laterally extendin g gates 226 in the barrelbulkhead cores. Of course, the gating can be varied to suit the needs of the particular foundry using this coring assembly, the gatingsystem shOWn being merely an example of one arrangement which has proved to be highly "satisfactory. M

In order to reduce the amount of cast i'ronrequired and to simplifythe cooling problem, in some instances it"may be'desirable toadd a rear end slab core and/or enr'ndfsiabfdr Meteo /emf the fly wheel-housing and front cover forthe timing mechanism housing are desired to be incorporated in the cylinder block casting, a fly wheel housing core as well as a front end core shouldbe included in the coring assembly.

While specific embodiments of this invention have been shown and described, it will be understood that various changes in the details of construction of the cores, mold and flask, as well as variations in the method of assembling the cores and mold, may be made without depart- 7 ing from the scope of the invention as set forth in the following claims.

I claim:

1. A flask for use in casting a cylinder block of an internal combustion engine, said flask comprising a drag half having a horizontal bottom wall and generally vertically extending side and end walls, said bottom wall having a plate provided with upwardly extending, longitudinal flanges for maintaining a coring assembly in proper position on said bottom wall.

2. A metallic flask for use in sand molding operations, said flask comprising a drag half having a bottom wall and a detachable assembly plate positioned on the upper surfaces of said wall, said plate being provided with projections adapted to maintain a coring assembly in position on the upper surface of said plate, said plate and bottom wall being provided with mating recesses and projections for retaining said plate in proper position on said wall.

3. A flask construction for use in foundry casting operations, said flask comprising a metallic drag half having a generally horizontal bottom wall and a detachable metallic assembly plate positioned on the upper surface of said wall, said plate having a plurality of upstanding flanges adjacent its outer edges for maintaining a coring assembly in position on the upper surface of said plate, said plate and bottom wall being provided with dowel pins and recesses for receiving said dowel pins for retaining said plate in proper position on said wall during metal casting operations.

4. A molding assembly for use in metal casting operations, said assembly comprising a metallic flask having a drag half provided with a generally horizontal bottom wall and generally vertical side and end walls, said bottom wall being provided with a plurality of longitudinally and laterally extending upstanding flanges, green sand packed within said drag half between said vertical walls and said flanges, and a plurality of cores positioned on the upper surface of said wall between said flanges.

5. A molding assembly for use in casting a cylinder head of an internal combustion engine, said assembly comprising a metallic flask having a drag half provided with a generally horizontal bottom wall, a metallic assembly plate seated on said bottom wall and having means engaging the upper surface of said wall for maintaining said plate in proper longitudinal and lateral position with respect to other portions of said flask, said plate having upstanding flanges provided adjacent its peripheral edges, green sand packed within said drag half of the flask and surrounding said assembly plate, and a plurality of cores positioned in a cavity defined by said green sand and having depending core locators seated upon the upper surface of said assembly plate, said core locators engaging the inner surfaces of said flanges for maintaining said cores in position with respect to the drag half of the mold.

6. A molding assembly for use in casting a cylinder block of an internal combustion engine, said assembly comprising a metallic flask having a drag half provided with a metallic plate seated on its bottom wall, said plate having upstanding flanges formed adjacent its outer edges, green sand within said drag half of the flask forming the casting-defining side and end surfaces of said mold, a plurality of sand cores having downwardly projecting locators positioned on the upper surfaces of said assembly plate and engaging inner surfaces of said flanges for maintaining said cores in proper longitudinal and lateral position with respect to said flask, a lower surface of said cores being provided with a passage extending longitudinally relative to said flask for conveying molten casting metal poured into said molding assembly, a molding member formed of sand and a suitable binder positioned on the upper surface of said assembly plate interjacent said core locators, said molding member providing the lower wall of said passage, and a cope half of a green sand mold positioned over said drag half and assembled cores.

7. A molding assembly for use in casting a cylinder block of an internal combustion engine, said assembly comprising a metallic flask having a drag half provided with a metallic plate seated on its bottom wall, said plate having upstanding flanges formed adjacent its outer edges, green sand within said drag half of the flask forming the casting-defining side and end surfaces of said mold, a plurality of sand cores each provided with a pair of laterally spaced, downwardly projecting core locators positioned 011 the upper surfaces of said assembly plate and engaging inner surfaces of said flanges for maintaining said cores in proper longitudinal and lateral position with respect to said flask, a lower surface of each or said cores between said pair of core locators being provided with a passage extending longitudinally relative to said flask, and a molding member formed of sand and a suitable binder positioned on the upper surface of said assembly plate beneath said cores and interjacent said core locators, the adjacent surfaces of said cores forming the upper and side walls of said passage and the upper surface of said molding member forming the lower Wall of said passage, said passage thereby being adapted to function as a gate for the distribution of molten casting metal poured into said molding assembly.

8. A method of forming a mold and coring assembly for use in metal casting operations, said method comprising packing green sand into a drag half of a metal flask, positioning a plurality of cores on a metallic assembly plate, thereafter transferring said assembly plate and cores positioned thereon to said drag half of said flask, and subsequently positioning said assembly plate and cores in said drag half so that the bottom surface of said plate abuts the upper surface of the bottom wall of said flask.

9. A method of casting a cylinder block of an internal combustion engine, said method comprising packing green sand into a drag half of a metal molding flask, positioning a plurality of cylinder block cores on a metallic assembly plate between upstanding side walls thereof, transferring said assembly plate and cores positioned thereon to said drag half of said flask so that the lower surface of said plate is seated upon the upper surface of the bottom wall of said drag half, thereafter positioning a cope half of a green sand mold over said drag half and assembled cores, pouring molten casting metal around said cores and into the mold cavity formed between the drag half and the cope half of the green sand mold, and permitting said molten metal to solidify.

H. W. Dietert: Foundry Core Practice, American Foundrymans Society 1950, pages 329-330.

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