US2647497A

US2647497A - Cooled cylinder head for internalcombustion engines

Info

Publication number: US2647497A
Application number: US179407A
Authority: US
Inventors: Stump Eugen
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1949-08-15
Filing date: 1950-08-15
Publication date: 1953-08-04
Anticipated expiration: 1970-08-04

Description

Aug. 4, 1953 E. STUMP 2,647,497

COOLED CYLINDER HEAD FOR INTERNAL-COMBUSTION ENGINES Filed Aug. 15,1950

g 5 2 ii i s i /6 A 32 1 1 I 4 1% INVENTOR 25/7 2/ 7 27 2a EUGEN STUMP I WWW (MAG;

AGENTS Patented Aug. 4, 1953 UNITED STATES PATENT OFFICE COOLED CYLINDER HEAD FOR INTERNAL- COMBUSTION ENGINES Application August 15, 1950, Serial No. 179,407 In Germany August 15, 1949 25 Claims. (Cl. 12341.79)

The present invention relates to cooling of l quid cooled cylinder heads of internal combustion engines with valves arranged in the cylinder head and in particular to those having a combustion or precombustion chamber in the cylinder head. This invention essentially consists in that between the thermally highly stressed walls of the chambers arranged in the cylinder head, in particular those of the valves and the precombustion chamber, there are streams of liquid directed in such a manner that the cooling water flows with increased velocity through the intermediate spaces. Preferably the liquid is caused to flow in these streams transversely to the cylinder axis and closely along the bottom of the cylinder head into the intermediate spaces between the chamber walls, the walls of said sham-- bers (e. g. for the intake valve, the exhaust valve and the precombustion chamber) forming free passages throughout the height of the liquid streams, i. e. not having connection in a manner to prevent or impair the flow of liquid therethrough. The number of liquid streams as a rule is in conformity with the number of the passages formed between the chamber walls, the liquid streams preferably being directed radially inwardly from the outer zones through the passages towards a common central point of intersection between the chambers or approximately in the direction towards the axis of the cylinder. The generation of such liquid streams is preferably effected by nozzle-shaped exit openings directed transversely to the cylinder axis and formed, for instance, by deflection walls roofing over the transfer ports which communicate the cylinder casing cooling jacket with the'cylinder head cooling jacket. Furthermore it is advantageous to make the walls for the cylinder head screws separate from the chamber walls.

An internal combustion engine according to the invention therefore comprises a cylinder head containing the precombustion chamber and the valves or only the valves and provided with a liquid-cooling system, the cooling liquid spaces of the cylinder block and of the cylinder head being connected to each other by connecting passages, means being provided in the cylinder head cooperating with the passages, these means being preferably arranged above the mentioned passages and adapted to produce viz. guide streams of cooling liquid towards the hottest spots of the cylinder head. Some ribs of the cylinder head therefore are shaped so that the liquid stream is guided to one or more of the spots in ques tion, or deflection walls are provided, or some of 2 the ribs shaped as mentioned above define nozzle-shaped channels therebetween. Preferably these designs of course are provided near or adjacent to the spots of high thermal stress.

- The construction according to the invention provides the advantage that the chamber walls will be particularly emciently cooled where thermal stressingis highest owing to the heat radiation of the combustion chamber, i. e. above all at the zones of transition to the cylinder head bottom. Furthermore an extremely uniform cooling may be obtained owing to undisturbed cooling passages, lack of excessive wall thickness, and an extremely uniform heat dissipation. Excessive thermal stressing and deformation in the cylinder head casting, such as results in cracking, accordingly can be avoided.

It is furthermore particularly convenient, above all in connection with the cooling arrangement, as described in the foregoing, to design the cross-sections of the intake and exhaust valve passages so as to present nozzle-shaped restrictions adjacent the valves. This permits a further improvement of the cooling effect without diminishing the volumetric efiiciency as it allows the provision of particularly large cooling passages on the one hand and a higher air velocity in the valve channel on the other. The former is particularly important for the exhaust valve, the latter for the intake valve. A further advantage may be realized by arranging the valves countersunk in the cylinder head in order to place the hottest spots of the cylinder head, particularly the valve seats (above all of the exhaust valve), somewhat inwardly so as to be more efiiciently exposed to the cooling effect of the cooling water.

One preferred embodiment of the invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, in which Fig. 1 is a horizontal section of the cylinder head taken on line l-! of Fig. 3,

Fig. 2 is a transverse section of the cylinder head taken on line 22 of Fig. 1,

Fig. 3 is a longitudinal section of the cylinder head taken on line 3-3 of Fig. 1.

Fig. 4 is a diagrammatic illustration of the cross-sectional shape of the inlet and exhaust valve ports.

To the cylinder casing l with the cylinders 2 there is secured the cylinder head 4 by means of screws 3. Cylinder casing and cylinder head are liquid cooled, for instance water cooled, and have cooling jackets 5 and 6, respectively. The cylin der head accommodates the intake valve 1, the exhaust valve 8 and a precombustion chamber 9, the latter being constituted by inserts Ill which are either closely fitted into the surrounding wall l l or spaced from the latter for insulating purposes and connected through a passageway l2 with the cylinder space 2. Fuel is injected by the injection nozzle l3 in the direction of the axis of the passageway l2 into the precombustion chamber. If desired, a bore l4 may be provided in the cylinder head casing for the starting glow plug preferably at the side of the precombustion chamber remote from the valves. The inlet port l5, for instance, is open at the top of the cylinder head, while the exhaust port opens through a side wall thereof. The valve seats I1, it are countersunk and the two walls 19, for the valve chambers of the intake and exhaust valves or of the inlet and outlet passage are restricted inwardly at 2| and 22, respectively (Fig. 3), adjacent to the valve seats in the form of a nozzle, so that a reduction of cross section of the inflowing air and of the effluent products of combustion will result. The wall II of the precombustion chamber and the walls l9 and 20 for the intake and exhaust valve chamber being so arranged that wide connecting

passages

23, 24 and 25 are formed between the three walls extending outwardly in the form of a star from a central point of intersection 26 (Fig. 1).

Radially outside these

passages

23, 24 and 25 and extending substantially in horizontal direction over the bottom 21 of the cylinder head there are provided connecting passages 28, 29 and 30 connecting the cooling water jacket 5 of the cylinder casing with the cylinder jacket 5 of the cylinder head. Above the orifices of these connecting passages in the cylinder head there are U- shaped or pocket-like deflection walls 3|, 32 and. 33 cast integral with the cylinder head. The defiection wall 3| in this case is positioned between two cylinders and accordingly opens at its opposite sides, each opening beingapproximately radial with respect to the corresponding cylinder axis and also in the direction of the passage 23. The pocket-like deflection walls 32 and 33 open in the directions of the

passages

24 and 25, respectively, and towards the pointof intersection 26. The cooling liquid overflowing from the cylinder jacket 5 through the connecting passages 28, 29 and 30 into the cooling water jacket 6 of the cylinder head therefore will be radially deflected by the deflection walls 3|, 32 and 33 acting as nozzles in the direction of the passages 23, 2d and 25 so that as a result there will be a more intense flow through these passages in the direction of the central point of intersection 2B of the aforementioned three passages from which central point the cooling water then flows upwardly for discharge from the jacket. In this way the thermally highest stressed walls I], l 9 and 20 are particularly eficiently cooled above all at the point of junction with the cylinder head bottom 21.

The connecting passages 28, 29 and 30 as well as the corresponding connecting passages associated with the remaining cylinders of the en gine may be provided as unique connections between the cooling water jackets of the cylinder casing on the one hand and of the cylinder head on the other. In this case a particularly high passage viz. outlet velocity of the flow of the cooling water will result, thus providing efficiently cooled areas. If the cross sections of these cooling passages alone are not wide enough for the passage further connecting passages, such as at 34, may be provided.

In Fig. 4 the cross sectional area (q) for the intake valve (Q6) and of the exhaust valve (qa) for instance has been plotted against the distance (1) from the valve cross section. As appears from the drawing a nozzle-shaped design has been provided. As experience has shown, restrictions of cross section up to 30% can be made without impairing the volumetric eificiency.

The invention may find application to internal combustion engines of any type, i. e. both to carburetor engines a well as diesel and other enines but is of special importance for the thermally highly stressed diesel engines with combustion chambers arranged in the cylinder head, such as pre-combustion chambers, turbulence and whirl-chambers, so-called air storage cells or the like. The invention may be applied also for instance to such cylinder heads in whichwith or without pro-combustion chambers-three, four or more valves are arranged in the cylinder head for each cylinder and it is, of course, not limited to water-cooling but permits the use of any other coolant, e. g. glycerine.

An especially advantageous arrangement of the deflection walls is one which results in deflectin the cooling liquid in directions towards the passages between the valve and combustion chamber walls in the cylinder head, said deflection walls being so arranged as to permit, if desired, deflection of the cooling liquid leaving a connecting passage into two or more directions, e. g. for cooling the chamber walls of adjacent cylinders.

Having now particularly described the nature of my invention what I claim is:

1. A liquid cooled internal combustion engine having a cylinder block and a cylinder head containing a pro-combustion chamber and valve chambers extending in the cooling jacket thereof the cooling liquid jackets of the cylinder block and of the cylinder head being connected by channels, means being provided in the cylinder head cooling jacket above said channels adapted to direct cooling liquid streams from said channels towards the hottest spots of the cylinder head, the means for directing the cooling liquid streams consisting in deflection walls, the deflection walls being provided thus positioned so that said streams of liquid are directed from outer zones radially inwards at least approximately towards a common central point of intersection between the chambers.

2. An internal combustion engine with cylinder head containing the combustion chamber and the valves and with liquid cooling, the cooling liquid spaces of the cylinder block and of the cylinder .head being connected by channels, means being provided in the cylinde head cooperating with the mentioned channels and adapted to produce cooling liquid streams towards the hottest spots of the cylinder head, the means for producing the cooling liquid streams consisting therein that some of the ribs of the cylinder head are nozzle-shaped, these nozzle-shaped exit openings for the cooling liquid passing from the cy1- inder easing into the cylinder head being directed at least approximately transversely to the cylinder axis.

3. A-liquid cooled internal combustion engine having a cylinder block and a cylinder head formed with a precom-bustion chamber and valve chambers for each cylinder in the cooling jacket thereof, the cooling liquid jackets 0f the cylinder block and of the cylinder head being connected bychannels located between adjacent cylinders. means being provided in the cylinder head cooperating with said channels and adapted to direct cooling liquid streams from said channels towards the hottest spots of'sa-id cylinder head, the means for directing the cooling liquid streams consisting in deflection walls, the deflection walls forming part of the cylinder head casting and formed to deflect the cooling liquid in directions towards the passages defined between the valve and precombustion chamber walls in the cylinder head cooling jacket, said deflection walls being so arranged as to deflect the cooling liquid leavin a connecting passage into a plurality of directions for cooling the hottest spots of the two adjacent cylinders.

4. A liquid cooled internal combustion engine according to claim 3, the walls for the cylinder heeld screws being separated from the chamber wa s.

' 5. A liquidcooled internal combustion engine comprising a cylinder block and a cylinder head. each formed with a liquid cooling jacket, the cooling jacket of the cylinder head containing a precombustion chamber and intake and intake and exhaust port chambers having valves therein, the cooling liquid jackets of the cylinder block and of the cylinder, head being connected by channels between adjacent cylinders, means being provided in the cylinder head above the mentioned channels adapted to direct cooling liquid streams towards the hottest spots of the cylinder head, the means for directing the cooling liquid streams consisting in deflection walls, the deflection walls forming part of the cylinder head casting and deflecting the cooling liquid in direction towards, the passages between the valve and combustion chamber walls in the cylinder head cooling jacket, said deflection walls being so arranged as to permit deflection of the cooling liquid leaving a connecting passage into a plurality of directions toward the axes of the two adjacent cylinders, the walls for the cylinder head screws being separated from the chamber walls, the cross sections of the liquid cooled intake and exhaust port chambers being restricted adjacent the related valves in the form of nozzles.

6. A liquid cooled internal combustion engine according to claim 5, the valves being arranged countersunk inthe cylinder head.

7. An internal combustion engine comprising a cylinder block formed with at least one cylinder therein, a cylinder head formed with a cooling jacket for a cooling medium, a plurality of chambers formed in said head and opening into each cylinder, thewalls of said chambers being separated from each other to define passageways therebetween for the cooling medium inside said jacket, means introducing a plurality of streams H of cooling medium to said jacket, and means directing said streams separately into said passageways between the chamber walls with increased velocity of flow.

8. An internal combustion engine as set forth in claim 7; wherein said chambers are disposed as a circularly arranged series, and said directing means are arranged radially outside said series of chambers and have outlet openings directed radially inward toward the passageways between said chambers.

9. An internal combustion engine as set forth in claim 7; wherein at least three chambers are provided in the cylinder head opening into each cylinder, at least one of said three chambers be ing a precombustion chamber and at least an other of said three chambers being a valve port chamber.

10. An internal combustion engine as set forth in claim 7; wherein said directing means guide the cooling medium streams to points directly above the bottom of said cylinder head so that the cooling medium is guided into said passageways along the bottoms of the latter.

11. An internal combustion engine as set forth in claim 7 wherein at least three of said chambers are provided disposed in a circularly arranged series, at least one of said chambers being .a precombustion chamber and at least another of said chambers being a valve port chamber, and wherein said directing means are disposed radially outside of said series of chambers and have outlet openings directed radially inward toward the passageways between said chambers and constructed and arranged to direct the cooling medium streams at points just above the bottom of said cylinder head so that the cooling medium is guided into said passageways along the bottoms of the latter.

12. An internal combustion engine comprising a cylinder block formed with a cooling jacket for a cooling medium, a cylinder head formed with a cooling jacket for the cooling medium and separate from the jacket of the cylinder block, a plurality of chambers in the cylinder head defined by walls separating said chambers from the interior of said jacket of the cylinder head, said walls defining the chambers being spaced apart to define passageways therebetween for the cooling medium in the cylinder head jacket, a plurality of connecting channels communicating the cylinder block jacket with said cylinder head jacket and opening into the latter outside of said passageways, and deflecting walls extending across the openings of said channels into said cylinder head jacket, each of said deflecting walls opening laterally in the direction toward at least oneof said passageways for directing a stream of cooling medium entering said cylinder head jacket from said cylinder block jacket into said one passageway.

13. An internal combustion engine as set forth in claim 12; wherein said walls are arranged so that said passageways converge at a central point, said connectingv channels opening into said cylinder head jacket at locations disposed radially outside of the outer ends of said passageways and the lateral openings of said deflecting walls facing radially inward with respect to the related passageways to direct streams of the cooling medium radially inward through said passageways and along the bottom of said cylinder head so that the cooling medium streams meet at a point between said chambers.

. 14. An internal combustion engine as set forth in claim 12; wherein said cylinder block has at least .two cylinders therein and said cylinder head has a plurality of said chambers for each of said cylinders and arranged above the related cylinder in said block, and wherein certain of said connecting channels are disposed between adjacent cylinders and said deflecting walls cooperating with said certain channels open laterally in opposite directions toward one passage defined between the chambers associated with each of two adjacent cylinders.

15. An internal combustion engine as set forth in claim 7; wherein said cylinder block has a plurality of cylinders therein, and wherein certain of said means introducing cooling medium to said jacket open into the latter at locations disposed between adi cent eyhnders. and said i ctin means associated with said certain intnoducing mean are con truc ed n arranged to ui the medium laterally in opposed directions into a passa eway between the chambers associated with each of said adjacent cylinders.

15. An internal combustion engine asset forth in claim '7; wherein at least one of said cham= hers is a valve port chamber having a valve seat formed at the end thereof opening into the associated cylinder, the cross-section of said valve port c amber being reduced above said valve seat so that the cross-section of the passageway for the cooling medium defined by the wall of said valve port chamber is increased.

17. An internal combustion engine as set forth in claim 16; wherein said valve seat is counterand said directing means guide the cooling medium streams toward points directly above the bottom of said cylinder head so that the coolin medium is guided into said passageways along the portions of increased cross-section of the latter.

iii. A liquid cooled cylinder head for an internal combustion engine, comprising a cooling jacket having spaced walls therein defining separated valve chambers and a preoombustion chamber for each cylinder, said chambers being oircularly arranged and defining free passa ways between the Walls thereof immediately above the bottom of said jacket, said bottom having a cooling medium supply opening eX tending therethrough for each of said passageways.

19. A liquid cooled cylinder head as set forth claim 18; wherein said passageways converge towards a central and common discharge space between said chambers, and said supply openings ar di po d dia ly outside of the r lated pos sageways.

29- A liquid oo ed cylind r h ad as set forth in claim 19; including deflecting means disposed above each of said supply openings and defining a jet orifice opening toward the related passageway and parallel to said bottom. of the jacket for receiving the cooling medium from the assoi ed pp y p nin and discharging the medium in the form of a jet guided along the related passageway.

21. A liquid cooled cylinder head as set forth in claim 20; wherein aid bottom of the jacket has further supply openings for the cooling meium o eely i tribute the latter throu ho th ja k t space outsi e of said chamber 2- In an internal combustion engine h v ng a pl ral y o j xtapose cylinders and a ommon cylinder head therefor includin a Jacket fo a cooling medium; spaced Walls in said. jacket defining valve port chambers and a precombustion chamber for each of said cylinders circularly arranged above the related cylinder, said chambers defining free passageways therebet-ween immediately above the bottom of said jacket and converging toward a common discharge space between the chambers tor each cyh-nder for admitting cooling medium radially inward toward said central discharge pace. the bottom of said jacket havin supply openings extending therethrough between adjacent cylinders for admitti g cooling medium to said jacket at the bottom of the latter at locations registering with the radial axes of opposed passageways defined by chambers associated with the two adjacent cylinders, and deflecting means disposed above each of said supply openings and defining oppositely directed jet orifices opening toward said opposed passageways defined between the chembers associated with the two adjacent cylinders and parallel to said bottom of the jacket for receiving the cooling medium from the associated supply opening and discharging the medium in the form of jets guided along said opposed passageways.

23. In an internal combustion engine; the combination set forth in claim 22 wherein said supply. openings are disposed radially outside of said opposed passa eways. and each of said deflecting means includes a channel member open ing downwardly for communication with the reted supply opening and at its opposite ends in directions facing radially inward toward said opposed passageways.

24. A method of cooling the cylinder head of a liquid cooled internal combustion engine having valve port chambers and a precombustion chamber in the cooling jacket of the head for each of the'cylinders comprising passing independent and separate streams of a cooling medium along the bottom of the cooling jacket and throu h the passageways defined between the chambers, the number of independent and sep arate streams being the same as the number of passageways defined between the chambers.

25.. method as set forth in claim 24; wherein said streams are directed through said passagewaysto oonverge above the center of the related ylinder and are given an increased velocity durins ravel through s passag ys.

EUGEN STUMP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,107,946 Hesselman Aug. 18, 1914 1 ,479,129 Feilner Jan. 1, 1924 1,556,338 Marigold. Oct. 6, 1925 1,793,713 Mo rrill Feb, 24, 1931 1,391,638 Gadoux Dec. 20, 1932 2,085,810 Ljunsst-rom July .6, 19.37 2,216,802 Easter 1 1 Oct. 8, 1940 2,456,951 ,Klctsch Dec. 211, 1,948 2,493,532 Foden et a1. Jan. 3, 1950 FOREIGN PATENTS Number Country Date 192,464 Germany of 1930