US2902021A - Cylinder block - Google Patents

Description

Sept. 1, 1959 c. B. LEAcl-l 2,902,021

CYLINDER BLOCK 5 sheets-sheet 1 Filed Sept. 29. 1954 'im =r-f ffl . Wj: .LL

ATTORNEY Sept. 1, 1959 y l c. B. LEACH 2,902,021

' CYLINDER BLOCK Filed Sept.; 29, 1954 5 Sheets-Sheet 2 W @ZM ATTORNEY Sept. 1, 1959 c. B. I EACHv 2,902,021

' CYLINDER BLOCK Filed sept. 29, '1954 5 sheets-sheet s ATTORNEY Sept. 1,- 1959 c. B. LEAcH 2,92021v CYLINDER BLOCK Filed Sept. 29, 1954 5 sheets-sheet 4 INVENTOR ATTORNEY Sept. 1, 1959 c. B. LEAcH 2,902,021

` CYLINDER BLOCK Filed Sept. 29, 1954 5 Sheets-Shea 5 INVENTOR ATTO R N EY nited States Patent f Motors Corporation, Detroit, Mich., a corporation of Delaware Application September 29, 1954, Serial No. 459,143

l() Claims. (Cl. 12S- 195) This invention relates to internal combustion engines and the like, and more particularly to an improved cylinder block for V-type and other engines.

It has been heretofore proposed to design cylinder blocks, with respect to the Various projections extending therefrom, so that the blocks may be cast by different methods, including the method disclosed by U.S. application S.N. 339,098, now Patent No. 2,783,510 filed February 26, 1953 in the name of Dolza et al.

The purpose of the heretofore proposed cylinder block design may be considered to be twofold. First, it is suggested that the projections and depressions embracing the exterior surfaces of the block may be designed in a manner so that cores are not necessary in shaping the exterior of the block and so that the pattern of the cornplete exterior of the block may be removed from the cope and drag molds. Second and contrary to previously employed methods of coring a cylinder block, the heretofore proposed design contemplates making the projections and depressions embracing the interior surfaces of the block so that a single core may be employed for each crankthrow compartment and associated cylinder cavity, with the core mold parting lines lying in planes passing transversely through the block and through the axes of the cylinders. In other words, the heretofore proposed design teaches that the surfaces of the projections and depressions embracing the various internal and external walls of the block need not and should not have reentrant angles or pockets with respect to any direction of separation of block or core molds.

This invention contemplates a block structure having projections and depressions so formed that the block may be cast by any desired method, including the method described above. However, the proposed block has additional improvements over blocks previously known. These improvements further facilitate the ease and economy with which such blocks may be made, regardless of the method of casting or other means of fabricating the same.

For example, it has been the usual practice in cylinder block construction to provide relatively deep side walls for the crankcase portion of the block, with a bolting flange extending laterally from the free ends of these Walls to which an oil pan may be attached. These deep walls and the bolting flange thereon were thought essential to provide sufficient lstrength to the crankcase portion of the block, and to the block structure generally, which may be likened to a beam. Numerous bolts were used in securing the oil pan to the bolting flange in order to insure sufficient unit pressure on the oil pan gasket. However, the high side walls on the crankcase portion of the block result in an engine that is too high for the modern automobiles having low profiles, and the numerous oil pan securing bolts increase ythe cost of assembling the engine.

It has been found that it is not necessary to provide these high side walls for the crankcase portion of the block, and this constitutes vone of the improvements of the proposed block over previous cylinder block strucliatented Sept. 1, 1959 tures. One reason why this is possible is that the upper portions of the block and other portions of the engine, such as the manifolds, subsequently applied to the block may be constructed in a manner to add sufficient strength in any direction to the block. Further, it has been found that it is not necessary to provide an oil pan bolting flange extending laterally, either inwardly or outwardly, from the free ends of the crankcase walls. This constitutes a second advantage of the proposed block over` blocks now used or known. Some of the metal formerly' comprising such a bolting flange may be added to the: crankcase side walls to provide shorter, thicker walls which additional thickness will then sufficiently increase the strength of the shorter side walls. Since the side: walls at the oil pan line thus present a considerably narrower surface to the oil pan gasket than when a bolting flange is provided, the unit pressure on the oil pan gasket will be sufficient with the use of fewer bolts. This reduction in the number of bol-ts, which is a third advantage of the proposed block, has made it possible toprovide less prominent bolt-receiving bosses on the thicker crankcase side walls, with the bosses being; located only at the junction of the side walls with the transverse walls in the block forming the separate crankthrow compartments.

The thicker side walls permit still other advantages over the heretofore proposed block design discussed above and relating to the projections extending from the surfaces of the block. Not only may the usual but lesser number of bolting bosses at the oil pan line be made less prominent by locating the same at or near the junctions of the transverse walls in the crankcase portion of the block with the side walls thereof where there is more metal area due to the increased thickness of the side walls, but the bosses may be eliminated entirely where these side walls are made sufficiently thick to permit satisfactory location of the bolt hole. Thus the necessity of adding metal to fill in reentrant recesses between bosses and adjacent walls, as taught by the herefore proposed design, is either minimized or entirely eliminated, at least as far as these particular projections are concerned. This is equally true whether the, less prominent bosses are provided in the interior or.l exterior sides of the crankcase side Walls.

Still another advantage of the propo-sed block is the absence of a continuous top wall extending between the cylinder portions thereof. This provides a greater area on which the green sand in the cope mold may be supported by the inner cores in the event that the method of casting described in the above identified application is used. It also eliminates considerable metal in the block and thereby reduces ultimate engine weight. The absence of the usual top wall need not weaken the cylinder block structure, however, if sui-table 'members are provided connecting the cylinder portions thereof. In the proposed block structure, a wider tie or structural member extending between the inner walls of the cylinder portions is provided above the central transverse wall of the crankcase portion of the block. To further strengthen the crankcase transversely, additional stiffening ribs or tie members are provided at the top of each of the other transverse walls dividing ythe crankcase into the separate crankthrow compartments. These latter stiffening ribs extend diagonally of the block between pairs of oppositely disposed and offset push rod guide bosses and can thus be made shorter and more compact than if they extended transversely of the block.

The proposed block structure contemplates reducing the thickness of the rear end wall of the block to a minimum where possible to save metal and weight and l so that a minimum of subsequent machining of such wall will be required. The rear wall of the block therefore contains depressions, as around the rear bearing support, which may be provided by utilizing a rear end slab core if the casting method heretofore proposed and described above be employed. This end slab core does not interfere with the placement of the other cores, however, and the rear end projections on the block may beA shaped so that the slab core may be just as easily made as the other cores.

FFhese and other advantages of the proposed block will become evident when the structure is further considered in greater detail.

In the drawings:

Figure l is a topplan view of a cylinder block embodying the invention. In Figure li and the succeed-ing figures, core and mold lines are represented' lines. The solid lines represent the as-cast surfaces of they block, while broken lines running parallel to and spaced from solidv lines represent subsequently machined surfaces of the block.

Figure 2 is a longitudinal cross-section view taken on the plane of line 2 2' of Figure l and looking in the direction of the arrows.

Figure 3 is a bottom plan view of the block shownby Figures l and 2. Figure 3 is ytaken in the plane of line 3 3 of Figure 2 and looking in the direction of the arrows.

Figure 4 is a fragmentary transverse cross-sectional view `taken in the plane of line 4 4 of Figure 1- andv looking in the direction of the arrows.

Figure 5 is an end elevational view taken in the planeV of line 5 5 of Figure l and looking in the direction of the arrows.

Figure 6 is an end elevational view taken in the plane of line 6 6 of Figure 2 and looking in the direction of of the arrows.

Figure 7 is a trans-verse cross-sectional view taken in the plane of line 7 7 of Figure 1 and lookingr inthe direction of the arrows.

Figure 7a is an enlarged fragmentary viewpartlyl in cross-section illustrating in detail the structure of the crankcase side walls of the block and the manner of securing the oil pan thereto.

Referring to the drawings in greater detaila cylinder block 10 embodying the invention comprises aA block for a V-type engine having eight cylinders. However, inregard to various individual features thereof, the proposedblock 10 may just las well comprise aV block for any type of engine, such as in-l-ine engine having any desired number of cylinders for example. The proposed block has the usual crankcase 12 having transverse walls 14 thereinv extending between the side walls 16 and :dividing the crankcase into separate crankthrow compartments 1=8`. The transverse walls 14l and the endy walls 20 and 22 of the blockv are formed according to normal practicek to provide endA mainl bearing supports 24 and 26 and intermediate main bearing supports 28',- as well as end camshaft supports 30 and 32 and intermediatey camshaft supports 34. The block may haveA the usual rows of cylinders 36 extending obliquely from the'crankcaseA 12, with the cylinders 36 being slightly offset in adirection lengthwise of the cylinder block. The rows ofv cylinders 36 may have outer upper or outer end walls 38, lower or `inner end walls 39,- inner side walls4tl`ancl outer side walls 41. The outer side walls 41 extend from andA form continuations ofthe side walls 16 of the crankcase 12. The front and rear walls 20 and 22v of .the block 10 also provide the front and rear end walls for the rows of cylinders 36. Extending from the inner side walls 40 of the rows of cylinders 36 are pairs of annular bosses or projections 42 having subsequently machined therein axial openings 43 which. constitute guides for the. valve litters.

Itwill be noted that. the inner side walls 40V ofn the rows of cylinders 36 are not connected by a top wall of the crankcase 12 extending between these inner side walls of the rows of cylinders 36 but that these inner side walls are separated by substantial openings 44 running lengthwise of the cylinder block between the front end wall 29 of the block which may be extended upwardly to provide a laterally extending web or stilening rib 46 for the front of the block. A similar laterally extending web or stiffening rib 48 spaced somewhat inwardly from the rear wall 22 of the block is also provided.

In any method of casting blocks it has usually been thought necessary to suitably prevent upward floatation of the crankcase cores by the green sand in the cope half of the mold, and where the usual top wall connecting the inner walls of the cylinder portions has been provided, necessary openings of limited size have resulted in this top wall due to portions of the cores forming the inner cavities of the cylinder block extending upwardly' from such inner cavities. The relatively large openings 44 in the upper part of the crankcase 12 considerably reduce the amount of metal in the block' and provide greater area for the' prevention of core floatation.

Openingsv 44 at -the top of the crankcase 12 in addition to providing the advantages mentioned above, necessarily weaken the cylinder block structure to some' extent in a transverse direction, and it is therefore necessary to provide stiffening members or ribs, in addition to the end ribs 46 and 4S already mentioned, to make up for the absence of the usual top' wall. Such transverse strengthening may be accomplished by the use of a number of different' structural members which will now be pointed out in detail and some of which constitute further' novel features of the proposed block.

One type of transverse support for the block are the' ribs or struts 50 extending diagonally between the offset push rod guide bosses 42. These struts are tied in" with the lower portion of the block in that they are formed integrally with the top of the transverse walls 14, and

' they are shortened and strengthened by the fact that they extend from the offset bosses 42. The two outermost of the struts S0 are provided with enlargements 52 adapted to be subsequently drilled or tapped to receive' threaded fasteners to secure a cover yfor the chamber thus formed between the rows of cylinders 36'. It has already been pointed out that the end wall 20 at the' front ofthe block is extended upwardly to provide a' laterally extending web 46, and that a similar laterally extending web 48 is provided at the Itop of the rear of the block. Another stiffening member for the cylinder block 1() is the platelike web 54 joining the inner walls 40 of the rows of cylinders 36 near the center thereof, with the web 54 extending both rearwardly and forwardly from the central transverse wall 14. This web is best' shown by Figure 4, which also indicates that the' web' 54 may have an arched shape and may be' formed integrally with the central transverseV wall 14 andy the' central diagonally extending stiffening'rib 50;

In the drawings the mold parting lines and the cores for the particular casting method previously referred t'o are indicated by broken lines. In this connection it will be noted that the cylinder block mold par-ting line' lies generally on a horizontal plane extending through the widest portion A A of the block, as shown by Figure 7. Exceptions may be made at localized areas, such as at lines B B and C C to include the prints for the water jacket cores 56 and at line D D to include the machining locating pads 53 at the corners of the block. This location of the mold parting line indicates that a block such as `the one proposed may be cast in a manner so that the green sand cope 60 and drag 62'molds may form the entire outer surfaces of the cylinder block without the use of external cores. To facilitate such a method, it'is to be noted that' as to the projections extendingfrom the exterior of block 10 in either half of the block above or below the block mold parting line, except the pro ections on the front and rear faces of the block, are formed in a manner to eliminate any reentrant recesses which would prevent the removal of a pattern representing the complete as-cast Surface of the block from the mold. This general condition of the design of the various projections is evident from an examination of typical prominent projections such as the transverse end webs 46 and 48, diagonal ribs 50, valve lifter guide bosses 42, cylinder end flanges 64, camshaft lubricant passages 66, `and the central platelike web 54 on the top half of the block and the downwardly extending crankcase 12 in the lower portion of the block, including the bolt receiving bosses 68 at the oil pan line 70;

As to the interior of the proposed cylinder block, it will be noted that the block may be cast by the use of single cores 72 forming each of the separate crankthrow and associated cylinder cavities, with the mold parting line E-E for the cores 72 passing through the axes of the individual cylinders 36 and transversely of the block near the center of the separate crank throw compartments 18. To facilitate this method of casting it will likewise be apparent that the surfaces of the projections such as the various flanges 74 and 76 surrounding the main bearing and camshaft supports and the slope of the inside surfaces of the side walls 82 are formed so that the above cores may be freely removed from core molds having parting lines as described above. Though the proposed cylinder block may be cast by the above described method, it is emphasized that the structure, both internal and external, of the proposed block 10 is such that the block may be cast by any desired method, and that it is in no way limited to the above described method or any other method.

It is to be noted, however, that whatever method of casting is employed, the metal in -the rear wall 22 of the block and the amount of subsequent machining thereof may be reduced to a minimum by the use of a slab core 78 to form the rear end of the block with reentrant recesses immediately around the rear main bearing support 26 and at other portions thereof. Considerable savings may be made in this manner, despite the use of the extra core. Such a slab core may be inserted into the drag mold 62 without interfering with the placement of the other cores and, in addition, provides more suitable prints 80 for receiving the ends of the water jacket cores 56.

It is further apparent from Figures 2, 5, 6, and 7 that prints may be provided in the greens and drag mold 62 to accurately position the internal cores 72 and the end slab core 78 at the bottom of the drag mold.

Another important novel feature of the proposed cylinder block involves the `free edges 82 of the side walls 16 of the crankcase 12 of the block a-t the oil pan line 70, as best shown by Figures 7 and 7a. As described above, it has been found that it is not necessary to provide the usual high side walls for the crankcase portion of the cylinder block but that relatively short side walls 16 may be provided which permit the advantage of a considerably more compact iinal engine assembly having a considerably shorter vertical dimension. Closely associated with this advantage is still another advantage to be gained by removing the usually laterally extending oil pan bolting ange at the bottom of the crankcase. Thus some of the metal which ordinarily constitutes such a flange may be employed to provide crankcase side walls 16 having a thickness greater than the average wall thickness of the block, which thicker wall has been found to provide suiiicient strength to provide a rigid block structure. As shown by Figure 7a, the oil pan gasket 86 between the bolting flange 88 on the oil pan 90 and the free edges S2 of the crankcase side Walls has lesser pressure or sealing area than if a wider bolting ange were provided on the crankcase side walls. With the use of this lesser area and with the same number of oil pan securing bolts 92 as previously employed, the unit pressure on the gasket 86, and thus the sealing effect of the gasket, would be greater than that heretofore provided. However, the higher sealing pressure is not necessary, and it is therefore apparent that the narrower free edges 82 at the oil pan line permit the use of fewer oil pan securing bolts 92. This further permits the use of fewer less-prominent bosses 68 located only at the junctions of the transverse walls 14 with the side walls 16 of the crankcase 12 Where there is already more metal, with the resulting advantage of quicker more economical assembly of the oil pan 9() to the crankcase 12. The bosses 68 may be provided at the outside of the crankcase side walls 16 which eliminates the necessity of providing a lcore to form such bosses at the inside of the crankcase walls and Which permits the easier removal of the cores 72 from the cylinder block casting.

From the foregoing description and drawings it is apparent that there has been provided a cylinder block which may not only be cast by any known method, but which may be cast more easily and economically regardless of the method of casting.

What is claimed is:

1. A lcylinder block for V-type engines and the like, comprising a hollow body having a crankcase portion and spaced cylinder portions having adjacent sloping walls, said crankcase portion terminating in walls of sufficient thickness to receive means for securing an oil pan to said crankcase portion, said cylinder portions being separated by spaced non-circular openings at the top of said crankcase portion and between said adjacent walls, spaced rows of oppositely disposed and offset pairs of valve lifter guide bosses protruding from said adjacent Walls of said cylinder portions and partially defining the edges of said spaced openings between said adjacent walls of said cylinder portions, and structural members extending diagonally between said oppositely disposed and offset pairs of said push rod guide bosses, said members further defining said spaced openings.

2. A cylinder block for V-type engines and the like, comprising a hollow body having a crankcase por-tion and spaced cylinder portions, said crankcase portion terminating in Walls of suicient thickness to receive means for securing an oil pan to said crankcase portion, said cylinder portions being separated by spaced non-circular openings at the top of said crankcase portion and between said adjacent walls, spaced rows of oppositely disposed and oiset pairs of valve lifter guide bosses protruding from said adjacent walls of said cylinder portions and partially defining the edges of said spaced openings between said adjacent walls of said cylinder portions, structural members extending diagonally between said oppositely disposed and offset pairs of said valve lifter guide bosses, said members further defining said spaced openings, and a single additional tie member integrally associated with one of said structural members and extending between said cylinder portions.

3. A cylinder block such as that defined by claim l and further characterized by said hollow body having projections extending from the exterior surfaces thereof, all of said projections except those extending from the rear end surface of said body increasing in cross-section as the cross-sectional planes parallel to horizontal reference planes passing through the widest portion of said body approach said reference planes.

4. A cylinder block such as that defined by claim l and further characterized by said hollow body having projections extending from the interior surfaces thereof, all of said projections decreasing in cross-section as the crosssectional planes parallel to vertical transverse reference planes passing through the axes of the cylinders in said cylinder portions approach said reference planes.

5. A cylinder block for V-type engines and the like, comprising a hollow body having a crankshaft receiving portion and spaced cylinder portions having adjacent sloping walls, said cylinder portions and said adjacent sloping Walls extending obliquely from said crankshaft receiving portion, said crankshaft receiving portion terminating in walls of suiiicient thickness to receive means for securing an oil pan to said crankcase portion, said cylinder portions being separated by spaced non-circular openings at the' top of said crankshaft receiving portion and between said adjacent walls, spaced camshaft supporting means including central camshaft supporting means extending lengthwise of said body between said cylinder portions and said adjacent walls, spaced rows of valve lifted guide bosses protruding from said adjacent walls of said cylinder portions and partly defining the edges of said spaced openings, stifening ribs extending diagonally between oppositely disposed and odset pairs of said valve lifter guide bosses, said ribs further defining said spaced openings, and a single additional tie member integrally associated with the central rib of said diagonal stiifening ribs and extending between said cylinder portions and covering said central camshaft supporting means.

6v. A V-type cylinder block for internal combustion engines and the like, comprising a 'hollow body having a lower crankcase portion and cylinder portions extending obliquely from said crankcase portion, said crankcase portion being open at the bottom thereof and having side walls extending the length thereof and spaced lateral walls4 connecting said side walls intermediate the ends thereof to provide separate crankthrow compartments, said lateral walls being formed to provide lower main bearing and upper camshaft supports, said cylinder portions each hav-v in-g spaced outer and inner walls extending the length of said body, said inner walls being substantially spaced from one another at the edges thereof adjacent said camshaft supports to provide an elongated opening at the top of said crankcase portion and between said cylinder portions, said crankcase and said cylinder portions being en'- closed at the ends thereof by Walls constituting the end walls of said body, a portion of the front wall of said end walls extendingy beyond said cylinder portions to provide a substantial stiifening rib between said cylinder portions", spaced rows of valve lifter guide bosses extending from said inner walls of said cylinder portions, other stiffening ribs extending diagonally across said elongated opening between offset pairs of said valve lifter guide bosses, and' an additional tie member extending between said inner walls of said cylinder portions, said tie member being integrally' associated with one of said vdiagonal st'iff'ening` ribs and extending from both sides thereof to partially cover said elongated opening near the center thereof.

7. A cylinder block for V-type internal combustion engines and the like, comprising a hollow body including an upper cylinder portion having -rows of spaced cylinders and a lower orankcase portion having side walls and transverse walls, said' transverse walls extending between said side walls to provide separate crankthrow compartments, said side walls being of substantially greater thickness than the average wall thickness of said body and of slightly lesser thickness at the oil pan line thereofthan' at any other portion thereof and said side walls havingwider portions at the outside surfaces thereon only at points opposite the junctions of said transverse walls withV said sidewalls.

8. A cylinder block forV V-type internal combustion engine, comprising a hollow body havingV a lower crankcase portion having side walls and transverse walls extending between said side walls to divide said crankcase portion' into separate crankthrow compartments, said transverse wal-ls being formed to provide main bearing and camshaft supports, spaced cylinder portions extending obl'iquelly from said 4crankcase portion and having spaced cylinder openings therein communicating with said separate crankthrow compartments, and different other projections ex-` tending fromv the external and internal surfaces of' said body, all of said projections extending' from the exterior surfaces of said body except at the' rear end face thereof increasing in cross-section as the cross-sectional planes parallel to horizontal reference planes passing through the Widest portion of said body approach said horizontal reference planes, said projections extending yfrom said rear face of said body `sometimes decreasing in. cross-section with respect to said reference planes, and all of said projections extending from the interior surfaces of said body decreasingv in cross-section as the cross-sectional planes parallel to 'Vertical transverse reference planes passing through theV axes of said cylinder openings approach said vertical reference planes.

9.. A cylinder block for internal combustion engines and the like and comprising, a hollow body including an upper cylinder portion and a lower crankcase portion,- said fupper cylinder portion having a row of spaced cylinders therein, said lower crankcase portion having side walls and transverse walls therein extending downwardly from said upper cylinder portion, said transverse walls being formed to extend between said side walls to provide crankthrow compartments in said lower crankcase portion,- said side walls being formed to provide bolt receiving bosses extending across and projecting from the outer side surfaces of said side walls and outwardly of said crankthrow compartments, said bolt receiving bosses being` formed to extend outwardly of said side walls substantially to the same extent from said cylinder portion to the lower edges `of said side walls, said side walls and certain of said transverse walls and said bolt receiving bosses being formed to terminate in a common andr cntinu'ous lower edge forming an opening in said lower crank'case portion and over which an oil pan is adapted to be secured, said side walls and said certain of said transverse walls and s'a-id bolt receiving bosses being not greater' in thickness adjacent said edges than between said edges and said cylinder portion.

10'. A cylinder block for an internal combustion engine and the like and' comprising, a hollow body including an upper' cylinder portion and a lower crankcase portion, said side l'l'pper` cylinder portion having a row of spaced cylinders therein, said lower' crankcase portion having side 'walls' and transverse walls therein extending downwardly from said upper cylinder portion, said transverse walls being formed to extend between said side walls to provide crankthrow compartments in said lower crankcase portion, said side walls being formed to provide bolt receiving bosses extending across' and projectingr from the outer side' surfaces of said side walls and outwardly of said crankthrow compartments, said bolt receiving bosses being formed in said sidewalls in opposed relation toA said transverse walls and' to provideV in said lower crankcas'e' portion approximate continuation's of said transverse walls outwardly of said side walls, said side walls and certain of said transverse walls and said bolt receiving" bosses being formed to terminate in a common and continuons' lower edge forming an opening in said lower crankcas'e portion and over which an oill pan is adapted to b`e` secured, said side walls and said certain of said transverse Walls and said bolt receiving bosses being not greater in thickness adjacent said edges than between said edges and said cylinder portion.

References Cited in the le of this patent UNITED' STATES PATENTS 1,000,188 Morse Aug. 8, i911 1,022,413 Goldstine Apr. 9, 1912 1,836,189 Salisbury Dec. 15, 1931 1,862,222 Kjasten June 7, 1932 1,897,783 Anibal Feb. 14, 1933 2,025,297 Meyer Dec. 24, 1935 2,259,385 Lindenmuth Oct. 14, 1941 2,429,1'05` Paxman Oct. 14, 1947 2,442,917 Butterfield June 8, 1948 2,451,271 Balster Oct. 12,- 1948 2,504,973 Gehres Apr. 25', 1950 2,632,340` DOlZa et al. Mar. 24, 1953 ,wat ...an

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