US2853062A - Engine structure - Google Patents

Description

Sept. 23, 1958 H. F. BARR ETAL ENGINE STRUCTURE 2 Sheets-Sheet 1 Filed Sept. 29. 1954 i AN m f fl X ,W R w; 1 7a a i f 4 X0 1 0.0. W mm Sept. 23, 1958 H. F. BARR ET AL 2,853,052

' ENGINE STRUCTURE Filed Sept. 29, 1954 2 Sheets-She et 2 INVENTORS ATTORNEY ENGINE STRUCTURE Harry F. Barr, Franklin, and Adelbert E. Kolbe, Detroit, MICIL, assignors to General Motors Corporation, a corporation of Delaware Application September 29, 1954, Serial No. 459,012

4 Claims. (Cl. 12341.74)

This invention relates to internal combustion engines and particularly to combustion chambers and to means for handling heat generated in combustion chambers in internal combustion engines for automotive and other uses.

In combustion chambers and particularly in combustion chambers formed in the heads of internal combustion engines it has been the practice to make a particular effort to supply cooling liquid directly to all the surfaces of all of the walls of the head and block surrounding the combustion chambers employed in an engine. It has been difi-lcuit to do this, particularly around the spark plug openings in some engines, without making the spark plugs relatively inaccessible and without increasing the dimensions of the engine head in places where it is desirable for other reasons to make the head small.

It is now proposed to eliminate the cooling cavity means in the parts of the head surrounding the spark plugs and for a considerable distance in all directions from the spark plugs and to increase the thickness of the metal around the spark plugs and in all directions from the spark plugs so that heat may be conducted from the spark plugs and away from the combustion chambers and to places in the head and the engine block where large and relatively unrestricted quantities of cooling liquid are available for absorbing the heat.

It is also proposed to employ a particular type of combustion chamber which is especially adapted for use in high speed, high compression, internal combustion engines for automotive and other uses and which may include the spark plug and combustion chamber heat dissipating features of the invention.

It is further proposed to construct the engine heads in V type and other engines so that the exhaust gas may be discharged from the engine without creating excessive back pressure and without excessive absorption of heat by the cooling liquid employed in the engine.

It is still further proposed to employ an arrangement of exhaust manifolds and spark plugs wherein the exhaust manifolds will not interfere with the accessibility of the spark plugs and the spark plugs will be cooled by air circulated by the engine fan and will not be excessively heated by the exhaust manifolds.

In the drawing:

Figure 1 is a cross-sectional View of the V type internal combustion engine for automotive and other uses and embracing the features of the invention. I

Figure 2 is a fragmentary view of the engine disclosed by Figure 1 and illustrating particularly the combustion chamber, valve and spark plug arrangement in one of the cylinders of the engine.

Figure 3 is a cross-sectional view illustrating the lower surface of one of the engine heads as the structure might appear in the plane of line 3-3 on Figure 2 looking in the direction of the arrows thereon.

Figure 4 is a fragmentary cross-sectional view of an engine cylinder and particularly illustrating the engine valves. Figure 4 is taken substantially in the plane of nited States Patent 2,853,062 Patented Sept. 23, 1958 line 4-4 on Figure 2 looking in the direction of the arrows thereon.

The invention may be embodied in an engine 10 in which an engine block 11, engine heads 12, inlet manifold 13 and exhaust manifolds 14 are employed. In the present instance the block 11 is a 90 V type engine block employing cylinder banks 16 in which obliquely disposed rows of cylinders 17 are formed. Each of the cylinders 17 includes a cylinder side wall 18 formed in the block 11 and an end wall 19 formed in one of the heads 12. The cylinders 17 are adapted to receive reciprocating pistons 15 connected by connecting rods 20 to crankpins 21 formed on the engine crankshaft 22.

Combustion chambers 23 are provided for each of the cylinders of the engine between the walls of the heads, the pistons and the cylinders. The combustion chambers 23 include firing chambers 24 extending into the end walls 19 in directly opposed relation to and on one side of the cylinders 17 and minimum mechanical clearance spaces 26 surrounding the firing chambers 24 and extending between the ends of the pistons 15 and the adjacent surfaces of the end walls 19, when the pistons 15 are at outer dead center positions within the cylinders 17. The firing chambers 24 may be wedge shape in formation and may be formed in the end walls 19 by firing chamber end walls 27 disposed obliquely to the axes of the cylinders 17 and by firing chamber side walls 23 extending laterally with respect to the firing chamber end walls 27 and toward the ends of the cylinder side walls 18. The planes of the inner surfaces of the firing chamber end walls 27 may intersect the ends of the cylinders 17 along chords of substantial length to provide the squish areas 29 at one side of each cylinder of the engine and at the thin edges of the firing chambers 24. It is preferred to construct the firing chambers 24 of maximum volume in relation to the surface area thereof within the walls 19 and to make the squish areas 29 as extensive as possible. This will provide an extensive turbulence in the firing chambers 24 on the compression stroke of each cylinder of the engine, thereby providing efficient combustion at high compression ratios and with relatively low octane fuels.

On one side of each cylinder 17 and formed in the side walls 28 around the ends of the firing chambers'24 that project the greatest distance into the heads 12 are wall sections 31 in which spark plugs 32 are adapted to be mounted in openings in the central parts of the wall sections and extending from the atmosphere to the larger end of the firing chambers 24. The wall sections 31 are formed by merging cooling liquid jacket wall means 33 for each head 12 with the cylinder end walls 19 around parts of the side walls 28 for the firing chambers 24 and around the larger ends of the firing chambers 24. The cooling liquid jacket wall means 33 form head cooling cavity means 34 in the heads 12 and outwardly of the cylinder end walls 19 of the heads 12. The spark plugs 32 for the cylinders in each row of cylinders 17 are aligned and are disposed substantially in parallel relation to one another and extend into the firing chambers 24 with the axes thereof substantially in parallel planes extending through the axes of the cylinders 17. The wall sections 31 extend around the firing chambers 24 substantially equal distances in opposite directions from the spark plugs 32 and in the present instance to the extent of about The wall sections 31 also extend outwardly and inwardly from the spark plugs 32 and inwardly thereof terminate in the relatively wide securing surfaces formed on the end walls 19 and against which the heads 12 are secured to the block 11. The relatively wide securing surfaces formed on the end walls 19 of the heads 12 engage metallic gaskets 36 which on the opposite surfaces thereof engage relatively wide and oppositely disposed securing surfaces formed on the block 11 around the ends of each of'the cylinders 17. Cooling liquid cavity means 37 are formed in each bank 16 of the cylinders 17 in the block 11 and between the cylinder side walls 18.-and outwardly disposed jacket .wall means 40.

The cooling cavity means37 terminate inlaterally extending and relativelywide cooling cavity surfaces 35 in directly opposedrelation to the wall sections 31. Outwardly of the cylinders 17. the wall sections 31 terminate beyond the firing chambers24 in laterally extending and relatively wide cooling surfaces 38 formed in the head cooling cavity means 34. As the opposite ends of the wall sections 31 the wall sections 31 also terminate in relatively wide and laterally extending cooling surfaces 39 forming parts of the cooling cavity means 34 within the heads 12.

Around. the spark plugs 32 it will be apparent thatthe wall sections 31 are thicker than the length ofthe threaded ends 41 of the spark plugs 32 to provide good cooling of the spark plugs. The wall sections 31 may be provided with recesses 42 within which the spark plugs are seated and which fit the ends of the spark plugs asclosely as possible to bring the metal of the wall sections 31 as close as possible to the threaded ends and seated parts of the spark plugs. 'From examining the figures of the drawing it will be apparent that the thickness of the wall sections 31 adjacent the spark plugs 32 is greater than that of either of the walls 19 or 33 and may be as great as the combined thickness of the walls 19 and 33. Also the thickness of the wall sections 31 increases outwardly-in -all directions from the spark plugs 32. At the peripheral edges thereof the wall sections terminate in the relatively wide and laterally extending cooling surfaces 35, 38 and 39. It will be further observed from examining the drawing that-the cooling surfaces 35, 38 and 39 may be exposed to large quantities of cooling liquid in the cooling cavity means 34 and 37 within the heads and block and are not therefore subject to circulation of cooling liquid through restricted passages formed in the head and blocks.

In order to rigidly secure the. heads 12 to the block 11 each cylinder 17 is provided with a bolt circle in which five or more bolts 43 are disposed in openings extending through the heads 12 and into openings in the outer surfaces of the block 11. The openings in the block are formed in bosses formed by merging the outer ends of the cylinder side walls 18 with the jacket walls 40 in the limited area around the ends of the bolts 43. It will be noted that a pair of the bolts 43 are located on opposite sides of each of the spark plugs 32 and extend through the enlarged opposite ends of the wall sections 31. The ends of the wall sections 31 are enlarged outwardly to provide bosses 44 which permit the pairs of the bolts 43 to extend through the heads 12 and into the bosses formed in the block in parallel relation to the axes of the cylinders 17. It will be noted that the bosses 44 materially increase the exterior surfaces of the wall sections 31 for radiation of heat from the wall sections 31 and the convection cooling thereof by air circulated by the engine fan. The pairs of bolts 43 at the opposite ends of the wall sections 31 are aligned in each bank 16 of the cylinders 17. Likewise, the remaining three bolts for each cylinder 17 are aligned in two rows on the opposite sides of the cylinders 17.

The inlet and exhaust valves 46 and 47 respectively for each cylinder of the engine are adapted to open through ports 48 formed in the firing chamber end walls 27. The ports 48 are aligned for each row of cylinders of the engine. Inlet passages 49 for each cylinder of the engine extendacross the head cooling cavity. means 34 and terminate in ports formed in the wall means33 which communicate with branch passages 51 of the inlet manifold 13 for the engine.

It is proposed to exhaust theproducts of combustion from each cylinder of the: engine with a minimum of heat rejectionto the cooling liquid ofthe engine and a minimum back pressure in the exhaust system forthe engine. To accomplish this it is proposed'toextend the cooling cavity walls 33 on the exhaust side of the heads 12 in planes substantially parallel to the planes of the wall sections 31 and as near as possible to the planes of the wall sections 31. This will make it possible to provide short and relatively straight exhaust passages 52 which are adapted to extend outwardly from the exhaust ports and laterally across the cooling cavity means 34 in the heads 12. It will be noted that the exhaust passages 52 which terminate in 'the walls 33 extend'outwardly from the exhaust ports substantially within the geometrical limits ofthe cylinders 17 extended and a considerable dis tance from the parts of the spark plugs 32 which project outwardly from the wall sections 31 and beyond the cooling cavity wall means 33. This'is done to provide good access to the spark plugs 32 and to provide good cooling for the outwardly projecting ends of the spark plugs 32.

The exhaust passages 52 communicate with branch passages 53 opening into collecting passages 54 which extend lengthwise of the exhaust manifolds 14 for each bank of cylinders of the engine. It is proposed to make the branch passages 53 as short as possible so that the ends of the spark plugs 32 may extend outwardly in opposed relation to outer walls 56 of the manifolds 14 and within which the collecting passages 54 are formed. The collecting passages 54 therefore may extend lengthwise of the engine and parallel to and a substantial distance above the rows of spark plugs 32 and still not extend beyond the ends of the spark plugs 32 so far that the spark plugs may not be readily accessible. The manifold outlets 57 maybe disposed between two of the spark plugs 32 and may exhaust the products of combustion from each manifold of the engine through exhaust pipes 58.

It will be apparent that satisfactory cooling of the combustion chambers of the engine is provided for by the large and relatively thick wall sections 31 which increase in thickness from the spark plugs 32 to large and unrestrited cooling cavity means within the head and the block. These relatively thick wall sections will rapidly conduct the heat generated within the firing chambers away from the spark plugs and to the cooling cavities 34 and 37 where the heat will be absorbed by the cooling liquid employed in the engine. Also due to the extended exterior surfaces of the wall sections 31 much of the heat will be radiated to surrounding bodies capable of absorbing heat and much will be conducted away by the air circulating around the engine. This air will also tend to cool the spark plugs and 'to prevent the spark plugs from being excessively heated by the exhaust'manifold of the engine.

Due to the position of the exhaust manifold means for the engine and to the relatively short branch passages of the. exhaust manifold means it will be apparent that the heat radiating surfaces of the exhaust manifold will be limited. Also due to the fact that the exhaust passages extend somewhat directly outwardly of the cylinders of the engine it is possible to position the exhaust manifold a considerable distance away from the spark plugs without increasing the back pressure in the manifolds but rendering the spark plugs less subject to heating and more accessible.

It will also be apparent that the small amount of metal required to provide the relatively thick wall sections 31 will actually make the engine more economical to construct. The cost of this added metal will not amount to as much as the saving in coring and scrap which will result from the elimination of the extensive and restricted passages which heretofore have been employed in an effort to cool the spark plugs in the adjacent parts of the combustion chambers of an engine. The reduced length and the relative straightness of the exhaust passages also contribute to the economical production of the engine as does the simplicity of the exhaust manifolds and the reduction in length of the branch passages of the manifolds which lead to the collecting passages therein.

It is also possible to assemble and to service the engine at a lower cost due to the position of the exhaust manifolds and the compactness of the exhaust manifold and exhaust passage construction which permits the spark plugs to be readily accessible for installation and service.

The ability of the wall sections 31 to rapidly dissipate heat makes it possible to construct a high speed, high compression ratio engine capable of operating on relatively low octane fuels and at relatively low cost.

We claim:

1. An engine comprising a block and a head and having a cylinder formed therein for a reciprocating piston operable in said cylinder, said head and said block being secured together throughout the oppositely disposed securing surfaces of said head and said block, said block being formed to provide a cylinder side wall and said head being formed to provide. a cylinder end wall, said block and said head being formed to provide jacket Wall means outwardly of said side wall and said end wall and forming cooling cavity means in which cooling liquid may be employed for cooling said engine, said side wall and said end wall and said piston being formed to provide a combustion chamber including a firing chamber for said cylinder in opposed relation to said piston, inlet and exhaust valves for said cylinder and opening through ports in said end wall and into said firing chamber, inlet and exhaust passages formed in said head and extending through said cooling cavity means in said head and said jacket wall means and from said ports to manifold means adapted to be secured to said head jacket wall means, a plurality of bolt openings formed in said head and said block and having bolts extending therethrough and securing said head to said block, said bolts being arranged in spaced relation around said block and head and at intervals around said cylinder, said end wall including a wall section formed in said head at one side of said firing chamber and between a pair of said bolt openings, said wall section extending from a junction between said head jacket wall and said end wall, at said pair of said bolt openings and the outer extremity of said side of said firing chamber and inwardly toward and terminating at said securing surface of said head, and a transverse opening formed in said Wall section between the atmosphere and said firing chamber and adapted to receive a spark plug for igniting combustible mixture compressed in said combustion chamber.

2. An engine as defined by claim 1 and in which said Wall section terminates at the junction of said head jacket wall and said end wall in laterally diverging parts of said end wall where an enlarged surface of said end wall is presented to said cooling liquid in said head cooling cavity means.

3. An engine as defined by claim 1 and in which said wall section has a thickness which is substantially greater than the thickness of the remainder of said end wall or said head jacket wall means throughout an area on one side of said firing chamber that extends for a distance substantially equal to the distance said firing chamber extends into said head and which wall section terminates adjacent the side wall in said block in a securing surface having a width as great as the oppositely disposed securing surface on said block and in directly opposed relation to said jacket cooling cavity means in said block.

4. An engine as defined by claim 1 and in which said wall section has a thickness which is substantially greater than the thickness of the remainder of said end wall throughout an area on one side of said firing chamber that extends for a distance substantially as great as the distance said firing chamber extends into said head and which wall section terminates adjacent the side wall in said block in a securing surface having a width as great as the oppositely disposed securing surface on said block and in directly opposed relation to said jacket cooling cavity means in said block and in which said securing surfaces on said head and said block are in intimate thermal contact with one another through metallic gasket means on which said head is secured to said block.

References Cited in the file of this patent UNITED STATES PATENTS 1,205,095 Kelly Nov. 14, 1916 1,531,430 Wrentmore Mar. 31, 1925 1,617,986 Blank Feb. 15, 1927 1,708,426 Moore Apr. 9, 1929 1,994,548 Vincent Mar. 19, 1935 2,016,734 Wittenberg et al. Oct. 8, 1935 2,154,358 Ross Apr. 11, 1939 2,380,066 Pescara July 10, 1945 2,635,418 Leach Apr. 21, 1953 2,700,964 Nallinger Feb. 1, 1955 FOREIGN PATENTS 1,028,555 France May 26, 1953

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