US2783510A

US2783510A - Cylinder block coring for v-engines

Info

Publication number: US2783510A
Application number: US339098A
Authority: US
Inventors: Dolza John; John B Burnell
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1953-02-26
Filing date: 1953-02-26
Publication date: 1957-03-05
Anticipated expiration: 1974-03-05

Description

March 5, 1957 J. DOLZA El AL 2,733,510

CYLINDER BLOCK CORING FOR V-ENGINES Filed Feb. 26, 1953 7 Sheets-Sheet 1 Inventors 1/5522 Q0/1435 BY qhz/iflagzeg/ Attorneys March 5, 1957 J. DOLZA ET AL 0 CYLINDER BLOCK comm; FOR mauczmss Filed Feb. 26, 1953 '7 Sheets-Sheet 2 Inventors Attorneys March 5, 1957 J. DOLZA ET AL CYLINDER BLOCK CORING FOR V-ENGINES 7 Sheets-Sheet 3 Filed Feb. 26. 1953 m a 2 m o 0 0 M March 5, 1957 J. DOLZA ET AL 2,783,510

' CYLINDER BLOCK CORING FOR V-ENGINES Filed Feb. 26, 1953 7 Sheets-Sheet 4 lnve ntors Attorneys March 5, 1957 J. DOLZA ET AL CYLINDER BLOCK, comm; FOR V-ENGINES 7 Sheets-Sheet 5 Filed Feb. 26, 1953 March 5, 1957 J. DOLZA ET Al. 2,733,510

CYLINDER BLOCK CORING FOR V-ENGINES Filed Feb. 26,1953 7 Sheets-Sheet e I Inventors Attorneys March 5, 1957 J. DOLZA ET AL 2,733,510v

CYLINDER BLOCK CORING FOR QV-ENGINES Filed Feb. 26, 1953 7 She etS-Sheet 7 Inventors J55 flo/zzz' \NQ HWA.U..

United States Patent CYLINDER BLOCK CORING FOR V-ENGINES John Dolza, Davisburg, and John B. Burnell, Detroit,

Mich, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application February 26, 1953, Serial No. 339,098

8 Claims. (Cl. 22-131) This invention relates to coring for engine castings and particularly to a coring arrangement and process for forming cylinder blocks of V-type engines. The features of this invention include a substantial reduction in the number of cores which must be employed and the elimination of excessive handling and sub-assembly.

Heretofore the conventional methods of arranging and assembling cores preparatory to casting cylinder blocks of internal combustion engines have required the forming, handling and assembling of a multiplicity of cores to form the final coring assembly. This coring problem is a particularly complicated one with respectto casting V-type engines. For example, conventional V-engines normally have required approximately 19 or 20 cores for the cylinder block, including cores which, in accordance with the present invention, are eliminated by a unique method of using the green sand of the mold. a 7

Moreover, conventional coring arrangements and the assembling processes require extensive sub-assembly, ineluding wiring, nailing and pasting of the cores. Each of the many cores is subject to some breakage due to handling, of course; and whenever cores are sub-assembled by pasting, as is conventionally done, there are numerous instances in which thin fins of metal remain. When these fins protrude into the water jacket passages, they tend to restrict water circulation so as to interfere with the proper operation of the engine. Such metal flashing also necessitates the use of increased machining operations, thus adding to the cost of the engine. Comparatively large amounts of core sand and binder must also be used in the conventional design.

A principal object of the present invention, therefore, is to provide a cylinder block coring arrangement and process for assembling the same in which the number of cores and quantity of core sand required are greatly reduced and sub-assembly of the cores is eliminated. A further object of this invention is to provide such an assembly and process which results in less core grinding, the eliminating of pasting, nailing and wiring of cores, less handling and core breakage, superior castings and lower overall foundry costs with respect to both personnel and materials.

These and other objects are attained in accordance with our invention by a cylinder block coring assembly in which a plurality of sand cores each having a pair of radially extending barrel portions are used to replace the multiplicity of base slab cores, end slab cores, bulkhead cores and barrel cores heretofore used. Moreover, the present invention employs only a single water jacket core for each cylinder bank, rather than the relatively complex water jacket core assemblies conventionally used, the latter necessitating grinding and pasting of the joined surfaces. By utilizing the green sand mold to full advantage 2,783,510 Patented Mar. 5, 1957 our arrangement also eliminates the need for a separate base slab core, venting cores, and a special camshaft gallery-defining core, thereby further reducing costs. The effective use of the green sand mold likewise results in a sounder cylinder block casting due to the greater porosity of the green sand as compared with the core material.

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

Figure l is an exploded perspective view of the multiplicity of cores heretofore conventionally used in casting a V-type engine cylinder block;

Figure 2 is an exploded perspective view of the five cores used to form a V-engine cylinder block in accordance with the present invention, spacer sleeves which may be employed in assembling the cores also being shown;

Figure 3 is a perspective view of the base of a core transfer fixture which may be used in assembling the cores shown in Figure l;

Figure 4 is a perspective view, with parts broken away and in section, showing barrel-bulkhead cores of Figure l positioned on the base of the transfer fixture;

Figure 5 is a perspective view, with parts broken away and in section, of the base of the transfer fixture with the spacer sleeves and water jacket cores in assembled position on the barrel-bulkhead cores;

, Figure 6 is a perspective view, with parts broken away and in section, showing the upper portion of the core transfer fixture in position over the core assembly and fixture base;

Figure 7 is a perspective bottom view, with parts broken away and in section, of the upper half of the core transfer fixture; 35

Figure 8 isa fragmentary perspective view showing the mold assembly positioned in the drag half of a green sand mold while attached to the upper half of the core transfer fixture;

Figure 9 is a perspective view, with parts broken away and in section, showing the details of the drag half of the green sand mold, together with an end slab sand core which may be used in conjunction therewith;

Figure 10 is a fragmentary perspective view of the drag half of the green sand mold in which is placed the sand core assembly with the temporary spacer sleeves removed preparatory to the positioning of the cope half of the mold and the pouring of the molten casting metal; and

Figure 11 is a sectional view through the core assembly and the green sand mold.

Referring more particularly to the drawings, in Figure 1 is shown a multiplicity of cores, in this instance 18 in number, which constitute a typical coring assembly for a cylinder block of -a conventional V-8 internal combastion engine. This arrangement includes barrel cores 10 and 12, upper water jacket cores 14 and 16, lower water jacket cores 18 and 20, and camshaft core 22. Such an assembly also requires the employment of a large base slab core 24, front end slab core 26, and a pair of rear end slab cores 28 and 30. An upper block or face core 32 is also necessary as well as a plurality of separate bulkhead cores 34, 36, 38 and 40. The last two cores necessary to complete the assembly are the end side cores 42 and 44.

With this conventional coring arrangement for a V-type engine the adjacent faces of the upper and lower water jacket cores are initially ground to provide smooth sur- V 3 faces and even contact between these parts. Then the upper water jacket core 14 is pasted to the lower water jacket core 18, and the upper water jacket core 16 is pasted to the lower water jacket core 20 to thereby form two separate sub-assemblies. Similarly, the adjacent faces of the rear end slab cores 28 and 30 are ground to provide the smooth mating surfaces, and these faces are pasted together into a third sub-assembly.

After the completion of the above-described coring subassemblies, the base slab core 24 is positioned in the drag half of a green sand mold, and the four bulkhead cores 34, 36, 38 and .40 are placed in position on the upper surface of the base slab core between the generally cylindrical projections 46 formed thereon. The core prints 48, which are provided on both end faces near the bases of each of the bulkhead cores, engage the end portions of the core print projections 46. In this manner the bulkhead cores are maintained in proper longitudinal and lateral alignment with respect to the base slab core 24.

The end slab core sub-assembly, consistingof cores 28 and 30, is then positioned in the end of the green sand mold and abuts the end of the base slab core 24- and the adjacent face of the bulkhead core 34. The recess 50 formed in the bottom of the end slab core 30 rests upon and engages the nearest end projection 46 on the base slab core 24, thereby maintaining the rear end slab core assembly in proper lateral position with respect to the assembled bulkhead cores and base slab core.

Next the camshaft core 22 is placed on top of the smooth upper surfaces of the abutting bulkhead cores 34, 36, 38 and 40. The rear end of the camshaft core 22 is positioned against and maintained in longitudinal alignment by the core print projection 52 which extends forward from the inner face of the rear end slab core 30.

Then the barrel portions 54 and 56 of the barrel cores 19 and 12 are inserted through the openings 58 and 60 provided in the water jacket core sub-assemblies formed by

water jacket cores

14 and 18 and 16 and 20, respec-.

tively. The assembled barrel cores and water jacket cores sub-assemblies are next positioned in the green sand in the drag half of a mold so that the ends of the barrels abut the flat sloping side faces 62 and 64, respectively,

of the bulkhead cores. The upper block wall core 32 is then placed over the assembled cores so that the recess or slot 66 in its lower surface rests on and is guided by the camshaft core 22.

Following the positioning of the core 32, the rear end side cores 42 and 44 are placed over the rear end slab core assembly formed by cores 28 and 30 so that the inner arcuate walls 68 of the former are seated upon the outer semi-cylindrical surfaces of the end slab core assembly. When the cores 42 and 44 are in this position, the

green sand in the drag supports their lower edges and their outer vertical faces 70, thus maintaining these cores in proper location. Positioning of the front end slab core 26 against the projections 72 on the bulkhead core 40 The outer end face of core 26 above-described cores could be arranged in sub-assemblies by pasting, wiring, nailing or other known means in a manner other than thatdescribed. The assembling procedure indicated above, however, is one frequently used in automobile cylinder block manufacture. In most in- .stances, a considerable number of these cores are first sub assernbled in a core transfer fixture and deposited by means of this fixture in the green sand in the drag half of the mold. The green sand in the cope is then placed in position over the assembled cores and the green sand in the drag, and molten casting metal is poured into the V that only five basic cores are required to cast a V-type cylinder block of a 120 six-cylinder internal combustion engine. Three combined barrel and

bulkhead cores

76, 78 and 80 and a pair of

water jacket cores

82 and 84 are all that are required. If it is desired to cast a V-8 cylinder block, instead of a V6 engine block, this can be done by employing the same basic cores and necessitates the use of only oneadditional barrel-bulkhead core, bringing the total number of cores required to six. Of course, slightly longer water jacket cores would be used, each containing an additional opening for receiving the two extra barrels. These five and six core arrangements, therefore, compare with the approximately twenty cores conventionally required.

As shown in Figure 2, the barrel-bulkhead cores 76, I8 and 80 comprise body or bulkhead-defining portions 86, 88 and 98, respectively, which are approximately triangular in vertical transverse cross-section, and generally

cylindrical barrel portions

92 and 94, which define the left and right cylinder banks, respectively. The assembly of the cores shown in Figure 2 results in a coring arrangement in which the body or bulkhead-defining

portions

86, 88 and 90 of the barrel-bulkhead cores have their adjacent end faces abutting one another and their bottom surfaces resting in the green sand in the drag half of the mold. The water jacket core 82 is positioned so that the adjacent generally cylindrical barrel portions 92 of the barrel-bulkhead cores extend through a plurality of openings or bores 96 formed in the water jacket core 82. Likewise, the water jacket core 84 is provided with a plurality of openings 98 which extend through the core and into which the adjacent barrel portions 94 of the barrel-bulkhead cores project. In this manner the various segments of the water jacket cores each, in effect, forms a sleeve having internal cylindrical walls which are spatially separated from the barrel portions 92. Figure 11 best shows this arrangement of the cores after they are assembled in the green sand mold.

A preferred method of assembling the cores in the green sand mold, in accordance with our invention, is shown in Figures 3 through 10, a core transfer fixture preferably being usedto expedite the assembly of these cores. The base of the transfer fixture is shown in Figure 3 and includes a generally flat, horizontal plate 100 to the bottom of which are attached supports or legs 102. A pair of box or end frame portions 104 and 105, each of which is provided with an upstanding aligning pin or dowel 108, are mounted on the base plate near the ends thereof.

Between these box portions and fastened to the upper surface of the bottom plate 100 is a generally rectangular guide frame 110. In assembling the cores on the base of the transfer fixture, the bottom portions of the barrelbulkhead cores are placed within the recess 112 defined by the upper surface of the base panel 100 and the inner surfaces of the frame 110. Figure 4 shows the exact positions of the barrel-bulkhead cores on the base of the transfer fixture. The adjacent end faces of the barrelbulkhead cores abut one another, and the lower lateral edges of the cores are in contact with the inner surfaces of the guide frame 110. Once so assembled on the base of the transfer fixture, these cores are securely maintained inposition by the frame and are prevented from sliding either longitudinally or laterally.

After the barrel-

bulkhead cores

76, 78 and 80 are positioned Within the recess 112, 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 2, are preferably slightly conical 'in shape and their smallest internal diameters are somewhat smaller thanthe 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 fsurfaces prevents their sliding downwardly on these barrel portions to an excessive extent. Thus these sleeves are awash) so designed and are of such a length that their inner or lower edges are spatially separated from the sloping side surfaces of the body or bulkhead-defining

portions

86, 88 and 90 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. This assembly of these cores on the base of the core transfer fixture is shown in Figure 5.

The upper half of the core transfer fixture, indicated generally by the details of construction of which are best shown in Figure 6 through 8 and which will be hereinafter more fully described, is then placed in position over the assembled cores and the base of the transfer fixture. This upper half of the transfer fixture includes a generally rectangular frame 116, the inner edges of which define an elongated opening through which the upper portions of the assembled molds project. A pair of openings 118, one at each end of the frame, are provided in the frame for receiving the aligning pins 108 projecting from the base of the fixture. The core-clamping portion of the upper half of the fixture is formed by a plurality of longitudinally extending bracket members and transversely extending members 122 secured to- .gether by screws or other suitable means. Members 122 in turn are rigidly affixed to the frame 116.

A plurality of blocks 124, which are shown as being generally semi-cylindrical in shape, are attached to the upper surface of frame 116 and function as cylinders for transversely extending retaining pins 126 which are slidably mounted therein. The longitudinally extending bracket members 120 are similarly provided with openings 127 in which vertical pins 128 are 'slidable. Levers or handles 130 may be atfixed to these vertically retractible pins and project laterally through slots 132 formed in the side surfaces of :members 120, as shown. Such a construction permits vertical movement of the handles 130 in slots 132 to vertically slide the pins 128, and these handles may also serve as means for retaining the pins within the supporting members 120. The blocks or cylinders 124 may likewise be provided with slots or handles,

not shown, or the longitudinally extending bars 134 may be aifixed to the ends of pins 126 and laterally movable therewith. In this manner, the bars 134 may serve as handles by means of which the pins 126 may be reciprocated into and out of mold-engaging position.

Angularly extending retaining pins 131 likewise are shown as provided in blocks 133 rigidly secured to the outer side surfaces of transversely extending supporting members 122. These blocks also may be provided with slots 135 through which levers or handles 137 project. The handles, of course, are afiixed to the retractible pins 131 and are slidable within the slots to reciprocate the pins at an angle relative to the frame of the core transfer fixture. This angle is preferably such that the pins 133 are slidable in a direction generally parallel to the barrel portions of the barrel-bulkhead cores.

If desired, other angularly arranged blocks 136 may be affixed to the inner face of the transverse bracket members 122, and provided with retractible pins 138 which are s-lidable in a direction normal to the core barrels. Still other blocks 140 may be mounted on members 122 and provided with retaining pins 142 which are reciprocable generally perpendicular to the axes of pins 138. 'Longitudinally slidable pins 144 are also shown as supported by vertically extending arms 146 provided at the rearward end of the core transfer fixture. As with the other retaining pins, these pins may be actuated by means of handles 148.

In removing the assembled cores from the base of the core transfer fixture, the upper half of the fixture is lowcredover the base so that the aligning pins or "dowels 108 project through the openings 118 and prevent-eitherlongitudinal or lateral movement of the upper half of the transfer fixture relative to the fixture base. To retain the molds in proper assembled position during transfer from the base of the mold transfer fixture to the drag half of the green sand mold, the various retractible retainer pins are inserted into special openings provided in the cores. More specifically, the handles 130 are depressed, thereby lowering pins 128 into openings 150 provided in the upper face of the bulkhead portions 86, 88 and 98 of the

barrelbulkhead cores

76, 78 and 80 and in the

barrel portions

92 and 94 of these cores near the ends thereof. Similarly, pins 126 are moved radially inwardly toward the center of the core assembly to engage openings 152 in the vertical end surfaces of the barrel portions of the barrelbulkhead cores. In like manner, pins 142 may be used to engage openings 154 in the upper surfaces of the water jacket cores or such pins may be used merely to engage the outer surfaces of the water jacket cores. If it is desired to do so, any of the other retractible pins may be moved into mold-retaining position.

All of the aforementioned pins and holes are not shown in the drawings to be in alignment, and it is not necessary to have all of the retractible pin engaging the cores in order to retain the latter in assembled position during transfer. Actually, only pins 126 are required to hold the assembly for transfer to the drag. The various other retractible pins are primarily designed as checking pins to check the core assembly for proper core location, alignment of vent passages and core supports, etc. Moreover, some of these pins may be used in place of sleeves 1.14 to space the water jacket cores from the barrel-bulkhead cores.

Upon positioning a suitable number of the retractible pins in the appropriate locating holes, as indicated above, the assembled cores are in condition to be transferred to the green sand 158 in the drag half 159 of the metal flask. As shown in Figure 9, the green sand in the drag has been molded so as to provide core prints 160 in which core print projections 162 at the ends of the water.

jacket cores

82 and 84 may rest. The various other indentations, such as grooves or slots 164 and recesses 166, are provided to form appropriate crankcase parts of the cylinder block casting.

A sprue core 168 is shown in Figure 8 as inseitable 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 provided 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 17!) 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 Figures 8 and 10. These two cores provide an .interjacent cavity which forms the rear main bearin block of the cylinder block.

Upon transfer of the assembled cores and the upper half 1-15 of the assembly fixture to the green sand 158 in the drag 159, the fixture is positioned over the drag so that aligning pins or dowels 180 projecting from the upper surfaceof the molddrag extend through the openings 118 in the upper half of the transfer fixture and maintain the fixture and assembled cores in proper alignment with respect to the drag. When the cores are thus properly located within the mold cavity, the bases of the barrel-

bulkhead cores

76, 78 and 80 are seated on the upper surfaces 184 of the bottom of the mold cavity and the core projections 162 of the

water jacket cores

82 and 84 are supported by the core prints 160 in the green sand 7 in the drag. The various locating pins in the upper half of the transfer fixture are then retracted from the locating holes in the cores, and the fixture is removed from the drag, leaving the core assembly in proper assembled position in the drag half 158 of the green sand mold.

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 barrelbulkhead cores. As will be hereinafter more fully explained, the support provided at appropriate locations by the bottom surfaces of the green sand maintains the barrel-bulkhead cores in proper position. Similarly, the core prints 160 which support the core print projections 162 retain the water jacket cores in assembled position and spatially 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 cmbodiment of the invention shown in. the drawings, it will be understood, as hereinbefore indicated, that the transfer fixture could equally well be designed to retain the spatial relationship between the water jacket cores and the barrel-bulkhead cores without the use of such spacer sleeves by the provision of other suitable retractible locating pins. Such a construction generally would be preferable to one using spacer rings and would facilitate assembly of the cores and mold.

The arrangement of the cores assembled in the green sand mold after removal of the upper half of the transfer fixture is shown in Figure 10. The cope half 188 of the flask containing green sand 186 is then placed in position over the drag and retained in alignment by the locating pins or dowels 180. Thus assembled, the green sand mold and cores are in condition for pouring of the molten casting metal. The formed sprue and gate 172 173174176 may be connected to another sprue portion in or through the green sand in the cope. The exact positioning of the cores relative to the green sand in both the cope and the drag is best shown in the sectional view of Figure 11. It will be seen from Figures 9 and 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 162 which are seated in core prints 160 formed in the green sand on the mold parting line at both ends of the mold cavity.

As shown in Figure 11, generally cylindrical projections 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 the lower 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, 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 gallery-defining portion 196 of the barrelbulkhead cores may be provided with vertically extending, generally cylindrical projections or core locators 198 which, as shown in Figure 11, may be adapted to engage core prints 260 formed in the green sand of the cope. The lower lateral surfaces of the green sand in the cope rest upon the upper horizontal wall surfaces 210 of the barrel portions of the barrel-bulkhead cores and abut the generally vertical end walls of the barrel portions, as shown at 212. The only other areas of contact between the green sand and the core assembly are where the bottom surfaces 214 of the bases of the barrel-bulkhead cores are supported by the green sand of the drag half of the mold.

A plurality of appropriate vertically extending vents 216 are formed in the cope to permit the escape of the,

core gases generated during and after pouring of the molten casting metal. These vents communicate with the openings extending through the upper surfaces of barrel portions 92 and '94 and camshaft gallerydefining portions 196 of the barrel-

bulkhead cores

76, 78 and 80. The openings 150 in each of the barrel portions of the barrel-bulkhead cores are angularly extended, as indicated at 218, through the barrel portions to the bottom of these cores. As shown in Figure 11, these openings or passages intersect at a lower longitudinally extending vent 220. Likewise, each of the openings or vents 150 in the bulkhead portions of the barrel-bulkhead cores preferably extends vertically through almost the entire height of the barrel-bulkhead core in which it is formed, intersecting an upper horizontal, longitudinally extending vent 222 and terminating at the lower longitudinal vent 220. It will be noted that the venting arrangement in this coring assembly is exceedingly simple and requires no special venting or breather cores as have heretofore normally been used in engine block coring.

Longitudinally extending gates 224 are shown in Figure 11 as being provided in the bases or bottom portions of the barrel-bulkhead cores and communicate with the sprue 176-172-173-17l distributing the molten casting metal through laterally and upwardly extending grooves 164 in the green sand in the drag. Of course, the gating can be varied to suit the needs of the particular foundry using this coring assembly, the gating system shown being merely an example of one arrangement which has proved to be highly satisfactory.

In order to reduce the amount of cast iron required and to simplify the cooling problem, in some instances it may be desirable to add a rear end slab core and/or a front end slab core. Moreover, if the fly wheel housing and front cover for the 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 should be included in the coring assembly.

Apart from a reduction of the total number of cores required, the above-described novel method of core assembly provides many additional advantages. For example, as hereinbefore indicated, this arrangement eliminates the special breather or venting cores normally employed to provide for the escape of core gases. Moreover, our arrangement involves only one core assembly rather than the several sub-assemblies heretofore required, thus eliminating the necessity of nailing or pasting such core sub-assemblies together. It will also be noted that the green sand in the mold is used considerably more extensively than with the coring arrangement previously used, thereby resulting in a considerable saving in both labor and materials. Further savings are provided by a reduction in the amount of core-making equipment, core driers, etc., required, together with the attendant reduction in labor costs. For example, if an end slab core is used, it is the only core which invariably requires the use of a contour drier, unlike conventional coring assemblies requiring a multiplicity of such contour driers. Although it may be desirable for particular engine designs to also employ contour driers with the barrel-bulkhead cores, only plate driers are needed for the remaining cores of the present invention. With respect to reducing the amount of materials necessary, it will be observed that the core sand bulk necessary with our arrangement is substantially decreased as compared with the arrangement shown in Figure 1. Moreover, the present invention makes it possible to use green sand to form sounder cylinder block castings at a considerably reduced cost as compared with methods heretofore used.

While a specific embodiment of our invention has been shown and described in detail, it will be understood that various changes in the details of construction of the coring arrangement and in the methods of assembling the cores and mold may be made without departing from '9 the scope of the invention as set forth in the following claims.

We claim:

1. A coring assembly for insertion in a green sand mold for casting acylinder block of 'a' V-t'ype internal combustion engine, said coring assembly comprising a plurality of sand cores having end faces adapted to be placed in abutting relationship, said cores each having a generally triangular crankcase-defining body portion and an integral upper portion for forming a camshaft gallery of an internal combustion engine, each of said cores having side faces provided with outwardly extending and angularly disposed generally cylindrical barrel portions, and a pair of sand water jacket cores each having a plurality of generally cylindrical openings extending therethrough insertable around said barrel portions, said cores, when so assembled, providing a space interjacent said water jacket cores and said barrel portions for receiving molten casting metal.

2. A mold and coring assembly for casting a cylinder block of a V-type internal combustion engine, said assembly comprising a drag half of a green sand mold having its upper surfaces recessed to partially define a mold cavity, barrel-bulkhead cores positioned in said drag half of the mold, said barrel-bulkhead cores each being pro: vided with a body portion which is generally triangular in cross section and a pair of cylinder-defining portions angularly extending therefrom, the upper parts of said body portions defining a camshaft gallery of the cylinder block to be cast, a pair of Water jacket cores having openings in which said barrel portions are positioned, said Water jacket cores having core locators depending therefrom and engaging core prints formed in the green sand in the drag, and a cope half of a green sand mold positioned over said cores and said drag half, portions of said cope half contacting the green sand of the drag and the barrel portions of the barrel-bulkhead cores.

3. A mold and coring assembly for casting a cylinder block of a V-type internal combustion engine, said assembly comprising a drag half of a green sand mold having its upper surfaces recessed to partially define a mold cavity, a plurality of sand barrel-bulkhead cores positioned in said drag half of the mold, said barrel-bulkhead cores each being provided with a body portion which is generally triangular in cross section and a pair of extending cylinder-defining barrel portions angularly extending from faces of said body portion, the upper parts of said body portions defining the camshaft gallery of the cylinder block to be cast, a lower surface of said body portion being positioned on an upper surface of the green sand in the drag half of the mold, a pair of water jacket sand cores having generally cylindrical openings in which said barrel portions are positioned, the walls of said openings being spatially separated from the side walls of said barrel-bulkhead cores, said water jacket cores each having core print projections extending from the lower surfaces thereof and engaging core prints formed in the green sand in the drag half of the mold, a plurality of core locators formed on the upper surfaces of the sand water jacket cores and extending generally upwardly therefrom, and a cope half of a green sand mold positioned over said cores and said drag half, said cope half being provided with lateral portions contacting upper surfaces of the green sand in the drag and the ends of the barrel portions of the barrel-bulkhead cores, a portion of said green sand cope being seated upon the camshaft gallery-defining portions of the barrel-bulkhead cores, portions of the green sand in the cope which are laterally intermediate said ends of the barrel portions and said camshaft gallery-defining portions being seated upon the core locators formed on the upper surfaces of the water jacket cores.

4. A process for forming a sand mold and core assembly to be used in casting a cylinder block of a V-type internal combustion engine, said process comprising positioning upon the base of a transfer fixture a plurality of barrehbulkhead cores each having a pair of outwardly extending cylinder-defining portions, placing a plurality of water jacket cores around said cylinder-defining portions, thereafter positioning the upper half of said transfer fixture over the formed core assembly and base, subsequently engaging openings in said assembly with movable pins in said upper half of the transfer fixture, removing said upper half and attached core assembly from said base and locating said assembly in the drag half of a green sand mold, withdrawing the pins in said fixture from the openings in said assembly and removing the upper portion of the fixture, and thereafter placing the cope half of the green sand mold over said core assembly and drag half.

5. The process of casting a cylinder block of a V-type interal combustion engine, said process comprising positioning upon the base of a core transfer fixture a plurality of sand cores each having a generally triangular crankcase-defining body portion and a pair of outwardly extending and angularly disposed cylinder-defining portions, arranging said cores so that the body portions thereof are in abutting relationship and the corresponding cylinder-defining portions of each core are aligned to form a pair of banks, placing a water jacket sand core having a plurality of generally cylindrical openings on said fixture base so that said cylinder-defining portions extend through said openings, thereafter positioning the upper half of said transfer fixture over the formed core assembly and base, subsequently engaging openings in said assembly with retractible pins in said upper half of the transfer fixture to maintain said cylinder-defining portions and water jacket cores in spaced relationship, removing said upper half and attached core assembly from said base and positioning said assembly in the drag half of a green sand mold, retracting the pins in said fixture from the openings in said assembly and removing the upper portion of the fixture, thereafter placing the cope half of the green sand mold over said core assembly and drag half, and finally pouring molten casting metal into the formed mold cavity between said mold halves and core assembly.

6. A coring assembly for use in a green sand mold for casting a cylinder block of a V-type internal combustion engine, said coring assembly comprising a plurality of sand cores having end faces adapted to be placed in abutting relationship, said cores each having a body portion with an integral upper portion for forming a camshaft gallery of an internal combustion engine, each of said cores being provided with a pair of barrel portions extending outwardly on opposite sides of said body portion, and a pair of sand Water jacket cores each having a plurality of generally cylindrical openings extending therethrough insertable around said barrel portions, said cores, when so assembled, providing a generally annular space interjacent said water jacket cores and said barrel portions for receiving molten casting metal.

7. A coring assembly for use in a green sand mold for casting a cylinder block of a V-type internal combustion engine, said assembly comprising a plurality of abutting baked sand cores each having a body portion with an integral upper portion for forming a camshaft gallery of an internal combustion engine, each of-said cores also being provided with a pair of angularly disposed cylinderdefining barrel portions extending outwardly from said body portion on opposite sides thereof, all of said barrel portions on one side of said body portions being in alignment with one another, and a pair of baked sand water jacket cores each having a plurality of generally cylindrical openings through which the barrel portions on one side of said body portions extend, said water jacket cores being spatially separated from said barrel portions.

8. A mold and coring assembly for casting a cylinder block of a V-type internal combustion engine, said assembly comprising a drag half of a green sand mold hav- 11 ing its upper surfaces recessed to partially define a mold cavity, barrel-bulkhead cores positioned in said drag half of the mold, said barrel-bulkhead cores each being provided with a body portion and a pair of cylinderdefining portions angnlarly extending from said body portion on opposite sides thereof, a pair of Water jacket cores having openings in which said barrel portions are positioned, said water jacket cores having core locators depending therefrom and engaging core prints formed in the green sand in the drag, and a cope half of a green sand mold positioned over said cores and said drag References Cited in the file of this patent UNITED STATES PATENTS Kerr et a1. Oct. 7, 1913 Walther May 30, 1922 Stoney July 1, 1930 Hagemeyer Aug. 26, 1941