US2687714A - Air-cooled cylinder head for internal-combustion engines - Google Patents

Description

Aug. 31, 1954 E FLATZ ETAL 2,687,714 Y AIR-COOLED CYLINDER HEAD FOR INTERNAL-COMBUSTION ENGINES Filed 0G15. 2, 1951 Il IIIIII .I

`provide an Patented Aug. 31, 1954 AIRQcooLED CYLINDE NAL-CoMEUsT R HEAD FOR INTER- ION ENGINES Emil Elm, Bergisch-Gladbach, Josef Hvel,

Koln-Bruck, and Otto many, assignors to K Aktiengesellschaft, K

l 1 The present invention relates to cylinder heads and, more particularly, for air cooled internal combustion engines, which is `connected to the cylinder pertaining thereto by means of screws or bolts and is provided with channel means adapted to communicate with said cylinder to convey gaseous meda thereto and/or therefrom.

Oneof the most diicult problems in the designing of air cooled internal combustion engines, especially of an air cooled diesel engine with a combustion `chamber separate from the main combustionchamber, consists in the designing of the cylinder head. This fact has its reason in the almost unsurmountable problem of properly transferring to the cooling air the heat conveyed to `the cylinder head by the combustion process. In this connection, the most endangered part of the cylinder head is thewall or web between the valves. In order suiiciently to cool said web, it is necessary to blow a sufficiently` large quantity of cooling air from outside the cylinder head above said web. However, the cross section available for theflow or passage of cooling air for this purpose are excessively narrowed down by the passages or channels leading outwardly from said valves. Consequently, priorto the present invention, the cooling of the web area of the cylinder head was always insuflicient. Thus, as a result of overheating ofthe web, cracksin the cylinder head occurredand were unavoidable.

Itis, therefore, an object of this invention to air cooled cylinder head for internal combustion engines which will overcome the above mentioned drawbacks. `It is another object of this invention to provide an air cooled cylinder head for internal combustion engines, in which the cross section of thel passage through which the cooling air may reach the web area between the valves will be materially increased. It is still another object of this invention to provide an air cooled cylinder head for internal combustion engines, in which the connecting screws or bolts for connecting the cylinder head to the cylinder pertaining thereto will not force Vthe passages, controlled by the valves and intended for conveying gaseousrnedia therethrough, to be located closer relative to each other.

Itis also an object of this invention to provide Ian `air cooled cylinder for internal combustion engines, in which the valves controlling the gas conveying channels or passages `are so arranged in thecylinder head as to yieldan increased free area therebetween through which an increased quantity of `air may` reach the web area between .said Vabres-l i Cordier, lckner-Humboldt-Deutz Koln-Kalk, Geroln, Germany Application October 2, 1951, Serial No. 249,242

`Claims priority, application Germany October 16, 1950 concerns a cylinder head Flg. 1.

These and other objects and advantages of the Fig. 3 is a section along the line III- III of to the cylinder.

General arrangement In order 'to valves and thus to enlarge particularly at the, valves.

Structural arrangement Referring now to the drawings in detail, the

ystructure shown therein represents a cylinder inder 23 by connecting screws or bolts 6, 1, 8, and 9. These' screws or bolts arev passed from' the cylinder head through the cylinder into the crank case (not shown in the drawing). The cylinder head is characterized in that the connecting screws or bolts 6 and 1 and the channels or passages 4 and 5 for conveying the'gaseous media are arranged so that the central axes of said screws or bolts and of said channels or passages intersect. When evenly distributing the screws 6, 1, 8 and 9 over the marginal circumferential area of the cylinder, the great advantage' is obtained that between the gas conveying channelsl or passages there will be more space for the passage of cooling air. Consequently', also more cooling fins III can be arranged between the channels or passages 4 and 5. The connecting screws 6 and 1 lead from the interior oi the gas conveying channels 4 afd 5 to the crank case. In order to prevent the screws or bolts and 1 from decreasing or impedin'g' the free' passage' of the gaseous media through said channels i and 5, recesses II' are' provided inv the interior surfaces of said channels or passages 4 and 5 for receiving the' heads or', if desired, the nuts oi the connecting screws or bolts. In o'r'der to cover up the heads or nuts of the' screws or bolts 6` and 1, caps 2z are provided which are arranged in said recesses and arev retained therein in any convenient manner, e. g. by a clamp fitting. If desired', also clampingscrews, accessible from the outside of the cylinder head may be used for retaining the caps 22 in the recesses II. When the cylinder head is made of light metal, it is particularly advantageous' to form the base surface of said recesses II by strong steel rings or washers I2 which are' preferably cast into the cylinder head'. In: this way, the specific stress of the cylinder' head caused by the' forces exerted by the screws or bolts 6 and 1 is materially reduced. It is p vrti'c'uiarly advantageous to arrange the channels or passages 4 and 5, as shown with the channel 4, so that the axis of their openingsr toward the outside substantially registers with the longitudinal axis of the respective screw or belt 6, 1. The screws or bolts are thus easily accessible after removal of the connecting pipes normally connected to,r said channels. It', however, as shown with the outlet channel or passage 5, the channel or passage' has its opening toward the' outside transverse' to the central axis of the connecting screw or bolt, it is convenient, in order tov make the screw or bolt easily accessible, to provide an aperture I4 in the channel wa-ll facingthe head or nut of the screw or bolt This aperture may be closed by a threaded stopper I3 or the like.-

-A further improvement in the passage of cooling air between the gas conveying channels 4 and 5 may be obtained by arranging thevalves 2 and at an angle with regard to each other, the apex of said angle being located toward the cylinder pertaining to the cylinder head. In this way, the space between the gas conveying channels is still further increased. The Acylinder head illustrated in the drawinghas additional advantages dueto the fact that the inlet passages 4 and the outlet passage 5 are so arranged as to be associated with two connectingV screws 6 and 'I respectively, while the combustion chamber I is located approximately between the other two connecting screws or bolts 8 and 9. In this way, the access of air to the space between the two gas conveying channels 4 and 5 is improved. This is the case when the cooling air is blown against 4 the cylinder head from that side at which the combustion chamber is located, asv well as when the cooling4v air is' blownE from' the opposite side against the cylinder head.

In some instances it may be advantageous to pass the connecting screws through the gas conveying channels' toward the outside as illustrated in Fig. 4. In such an instance, that portion of the connecting screws which extends through the said channels is preferably surrounded by a cover 25 which may be cast into the cylinder head. This cover is preferably shaped according to aerodynamic principles. It may also be mentioned that, if the occasion should call for, also: more'y than one connecting screw may be passed through one gas conveying channel.

The arrangement according to the present invention is of advantage also in such instances in lwhich the cylinder head together with the cylinder pertaining theretois in a manner known per se' suspended' on a plate arranged above the cylinder head, said plate' being tied upv toA the crank case'. With th'e internal combustion eng'i'nes of this type, it was always` necessary heretoiore', to provide additionalmaterial from the cylinder lid' upwards laterally of the gas conveying channels into which ,material the connecting screws are screwed. The arrangement according to' the' present invention rnakes the provision' of such additional material unnecessary so that the' space heretofore taken up by the said additional material will become' available forv the gas conveying channels. I

The invention is applicable not only to four stroke' cycle internal combustion engines' but also to' two stroke cy'c With the last mentioned type of engines, the diic'ul'ties described in the opening paragraphs o' this specification occur toA an increased extent when the cylinder h'ead comprises twoI outlet valves arranged side' by side. The reason for this consists in' that in such an instance, the' web located between the said two outlet valves is heated to a far greater extent. For such a web it is, therefore, particularly important to be cooled from the' outside by cooling air.

The two valves 6' and 1 are actuated byl rocker arms I5 which are arranged above the cylinder head in a cup or pan I6 integrally cast with the cylinder head. The cup' or pan I6 is covered toward the outside by a protective cap I1. The push rods I8 for actuating the' rocker arms I5 extend froth below the cup or pan I6 into the latter through corresponding' apertures'. In order t provide for easy accessieiiity of the' connecting screws or bolts 6 and 8", the bottom I9 above the screws or bolts 8 and 9 is provided with two openings respectively, which are adapted in 'a leak-proof manner to be closed by threaded s toppers 2| to prevent oil from leaking therethrough.

It is,- of course, understood that the present invention is, by no means,- limited to the particular constructions shown in the drawings but also comprises any modifications within the scope of the appended claims.

What we claim is:

1. In an air cooled cylinder head for internal combustion Verig'ir'ies,y channel means extending through said head for conveying gaseous media therethrough,- passag'e' ineans extending freni each of said channel rneans' to the bottoni of said cylinder head for receiving andI passing enneet ing screws therethrough to connect said cylinder head to the cylinder pertaining theret, said e internal combustion engines.

up said heads or nuts.

' 2. An air cooled cylinder head according to claim 1, in which the top surface of said closure means is substantially ush with the bottom of the adjacent channel means.

3. An `air cooled cylinder head `according to claim 1, which includes steel ring means respectively arranged at the bottom of said recesses and cast into said cylinder head.

4. In an air cooled cylinder head for internal combustion engines, channel means extending through said cylinder head and adapted to convey gaseous media therethrough, passage means extending from the interior of said channel means to the bottom of said cylinder head for receiving and passing screws therethrough to connect the cylinder head to the cylinder pertaining thereto, said channel meansand said passage means being arranged so that at least a portion of that end of each channel means which is remote from the bottom of the cylinder head is in alignment with passage means, each of said channel means provided with a recess at the entrance to said passage means for receiving the head or nut of said screws, and cap means inserted in said recesses for respectively closing said recesses with regard to said channel means.

5. In an air cooled cylinder head for internal combustion engines, channel means extending along a curved path from the bottom area of said cylinder head to one side thereof to convey a gaseous medium through said cylinder head, passage means extending along a straight path from the bottom area of said cylinder head upwardly so as to intersect with said `channel means and adapted to allow the passage of screw means therethrough for connecting said cylinder head to a cylinder, said channel means being provided with a recess at the intersection of said channel means with said passage means to receive the head or nut of said screw means, said cylinder head being provided with additional passage means accessible from the outside of said cylinder head and substantially registering with said first mentioned passage means, closure means detachably mounted in said additional passage means to close the latter toward the outside of said cylinder head, and cap means inserted in said recess for closing the latter with regard to said channel means.

6. An air cooled cylinder head for internal combustion engines which comprises in combina- `therethrough tion, a combustion chamber spaced from the bottom of said cylinder head, an intake channel,

a discharge channel, said channels being arl ranged to convey gaseous media therethrough, a first pair of passage means respectively intersect'- ing with said channels and extending from the interior thereof head, said rst pair of passage means being adapted to receive and pass therethrough connecting screws for connecting said cylinder head pertaining thereto, each of said being provided with a recess at with the adjacent passage means to receive the head or nut of the respective screw to be passed through the adjacent passage means, cover means respectively inserted in said recesses to close the same with regard to the adjacent a second pair of passage means outside said channels for receiving and passing combustion chamber being located substantially between the passage means of said second pair of passage means.

'7. In an air cooled cylinder head for internal combustion engines, especially diesel engines having a combustion chamber spaced from the bottom of said cylinder head: gaseous media conveying means extending through said head, said head also being provided with passage means respectively branching off` from said conveying means and leading to the bottom of said head to allow the passage of connecting screws therethrough for connecting said cylinder head with the cylinder pertaining thereto, said gaseous media conveying means respectively having their walls at the branching 01T points of said passage means provided with recesses for receiving the head or nut of the respective connecting screw, and cover means respectively detachably retained in said recesses for completely covering up the upper portion of said heads or nuts and. having their outer contour conforming to the contour of the adjacent wall portion of said conveying means toi thereby protect said heads or nuts against heat while reducing to a minimum the now resistance adjacent said recesses.

References Cited in the le of this patent UNITED STATES PATENTS to the bottom of said cylinder additional connecting screws, said`

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