US2003571A - Cylinder head for internal combustion engines - Google Patents

Description

June 4, 1935. D. E. ANDERSON CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed Aug. 15, 1932 2 Sheets-Sheet l June 4, 1935.

- D. E. ANDERSON CYLINDER HEAD FOR INTERNAL COMBUSTIONENGINES Filed Aug.

4 2 Sheets-Sheet 2 INVENTOR BY Q W ATl'ORN s Patented June 1935 i Q UNlTED STATES PATENT OFFICE CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES David E. Anderson, Detroit, Mich., assignor to Bohn Aluminum &; Brass Corporation, Detroit, M1ch., a corporation of Michigan Application August 15, 1932, Serial No. 628,919 t 3 Claims. (01. 123-173) This invention relates generally to internal high tensile strength so as to effectively reinforce combustion engines andrefers more particularly the lower section. By forming the wallsof the to improvements in cylinder head constructions combustion chamber from a metal of high thertherefor. I mal conductivity, the compression ratio may be 5 The present invention contemplates increasing appreciably increased due to the fact that the 5 the efiiciency of internal combustion engines as rate of pressure or temperature rise in the comwell as improving the performance thereof by probustion chamber proper is materially reduced, viding a cylinder head construction embodying and the effect of the latter pressure in building up features which permit obtaining compression the temper ture of the last fuel to burn in the ratios considerably higher than has heretofore portion of re tively-small area of the combustion 10 been considered possible without correspondingly chamber is minimized. However, the formation increasing the tendency of the cylinder head to of the walls of the portions of the combustion detonate. chambers containing the last fuel mixture to burn Another feature of this invention which conof a metal of high thermal conductivity is objectributes materially to the elimination of detonationable since rapid he t transfer through the 15 tion in the cylinder head resides in inclining the walls of this relatively small area is highly ininner surfaces of the portions ofthe combustion ducive to the accumulation of carbon upon the chambers containing the last fuel mixture to burn inner surfaces thereof. Inasmuch as carbon is a in a direction to insure sweeping of the latter sur- D0 o d 0f heat, the accumulation of the faces by the relatively cool charge as it passes sa e upon the Walls Of the p of the 00111- 20 from the major portion of the chamber to the bustion chambers containing the last fuel to burn cylinder. This sweeping action of the fuel not reduces the rate of heat transfer through these only tends to cool the inner surfaces of the walls to a minimumirrespective of the metal quenched areas, but, due to the velocity thereof, m Wh c t e latter are formed, as a also tends to maintain these surfaces clean. sequence, increases the rate of pressure rise in 25 A further advantageous feature of this inventhese areas to such an extent as to cause detion resides in the provision of a cylinder head tonation. Accordingly, both embodiments of the formed of a plurality of relatively simple castings invention are provided means for minimizcapable of being readily fashioned from a permain the tendency for hieto accumulate p nent mold with the result that the manufacture the inner surfaces of the"p0 0f the 0011110115 30 thereof is rendered both expedient and inexpention chambers containing the last fuel mixture sive. This construction as well as other objects to burn by re t ic the rate of heat transfer. will be made more apparent as this description through th e w In a n to the/foregoproceeds, especially when considered in connecing, the inner surfaces of "'foresaid portions of tion with the accompanying drawings, wherein: the combustion chamber 0th modifications 35 Figure l is a perspective view of a cylinder head are inclined in a direction to insure sweepi 0f constructed in accordance with this invention; h m y h in m n f l r n i passage Figure 2 is a longitudinal sectional view taken from t e ajo portions of the combustion chamsubstantially on the line 22 of Figure 1; bers into the cylinder bores. As previously stated, 40 Figure 3 is a, cross sectional view taken on the this latter feature is desirable since the tempera- 40 line 3--3 of Figure l; ture of the incoming fuel is considerably less than Figure 4 is a plan view of a slightly modified the temperature of the walls of the portions of form of cylinder head construction; the chambers containing the last fuel mixture to Figure 5 is a cross sectional view taken on the burn, and, as a c s q serves to 0001 these line 5-5 of Figure 4. walls or prevent any carbon accumulation on the 45 For the purpose of illustration, the several fealette f om reach g a temperature Sufiielently' tures of the present invention are shown in assohigh to Cause detonationciation with two difierent types of cylinder head From the foregoing brief description of the p constructions. The two embodiments of the inent invention, it will be appare that provision vention are broadly similar in that both illustrate is ade n b of the illustrated Constructions 50 a composite cylinder head construction wherein for obtaining maximum coo of the Portions of the lower section containing the combustion the combustion chambers where such action is chambers is formed of a metal of high thermal most desirable and for restricting the rate of coolconductivity and wherein the upper or cap section ing of other portions of the combustion chambers is preferably formed from a metal of relatively to eliminate one of the chief causes of detonation.

In other words, the present invention provides for obtaining efiicient operation of a high compression cylinder head, and this operation is accomplished herein by a relatively simple construction about to be described.

Referring now more in detail to the specific embodiment of the invention illustrated in Figures 1 to 3, inclusive, it will be noted that this modification features a composite cylinder head I0 comprising a lower section I 1 adapted to seat upon a cylinder block I2 and an upper or cap section I3 for clamping the lower section to the block. The clamping action is accomplished herein by a plurality of stud bolts I 4 having head portions engaging the upper section and having threaded shank portions extending through aligned stud bosses in the aforesaid sections for threaded engagement with the cylinder block. The lower section II is formed with a plurality of combustion chambers I5 in the bottom surface thereof corresponding in number to the number of cylinders IS in the block and is preferably, although not necessarily, formed from a metal of high thermal conductivity such as aluminum or an aluminum alloy.

In the event the lower section I I is formed from aluminum or some metal having similar characteristics, the cap section I3 is preferably formed from a metal having relatively high tensile strength so as to reinforce the aluminum section in the assembled relation of the head. The upper walls of the combustion chambers are effectively reinforced by forming depression I! in the cap section in such a manner that the lower wall portions I8 thereof abut the top surfaces of the combustion chambers. In this connection, it is to be noted that the lower walls of the depressions are apertured in alignment with suitable threaded openings I9 in the upper walls of the combustion chambers for receiving suitable spark plugs or other fuel igniting devices (not shown). As will be observed from Figure 3, the cap section l3 cooperates with the lower section II to form a space 20 for the circulation of a cooling medium over the combustion chambers. The cooling medium is introduced into the space 20 from the cylinder block through suitable openings 2I formed in the lower section and is permitted to flow back into the heat exchange unit (not shown) through a suitable opening 22 in the cap section.

The particular shape of the combustion chambers I5 forms no part of the present invention except for the fact that they are of the high compression type having major portions 23 for receiving the charge of incoming fuel and having other portions 24 extending over the cylinders of the engine. The latter portions of the combustion chambers have a large surface to volume ratio as compared to the portions 23, and the inner surfaces 25 thereof are inclined in a direction to insure sweeping of the same by the fuel passing from the major portions 23 of the combustion chambers into the cylinders IS. The above feature not only provides for cooling the inner surfaces 25 of the portions 24 to prevent any carbon accumulation on the latter from reachinga sufficient temperature to cause detonation, but in addition tends to dislodge any small particles of carbon adhering to these surfaces due to the extremely high velocity of the fuel.

While the sweeping of the surfaces 25 of the portions 24 by the incoming fuel reduces the effect of carbon accumulation to cause detonation, nevertheless, the present invention contemplates minimizing the tendency for carbon to adhere to the surfaces 25. As explained above, rapid transfer of heat through the walls of the combustion chambers is highly inducive to carbon accumulation upon the inner surfaces of these walls. Inasmuch as the surface to volume ratio of the portions 24 of the combustion chambers is considerably greater than the portions 23 of the latter, the accumulation of carbon upon the former appreciably reduces the volume thereof, and, as a consequence, increases the pressure -or temperature rise to such an extent as to cause detonation. The rate of transferpf heat through the walls of the portions 24 of the combustion chambers is restricted in the embodiment shown in Figure 3 by preventing the circulation of the cooling medium in the space 20 over portions of the Walls of the portions 24. This is accomplished in the present instance by forming projections 26 upon the upper walls of the portions 24 in the manner illustrated in Figure 3. As shown in this latter figure, the projections extend upwardly from the upper walls of the portions 24 and engage depressed wall portions 21 on the cap or upper section I3 of the cylinder head. The above construction not only provides for obtaining the desired restriction in heat transfer through the upper walls of the quenched areas, but in addition serves as a reinforcement for the portions of the combustion chambers where the compression pressures are the greatest.

In the modification illustrated in Figures 4 and 5, I have shown a combined water and air-cooled cylinder head 30. In general, maximum cooling of the major portions of the combustion chambers in the head 30 is effected by passing water over the same and restriction of the rate of heat transfer through the relatively small area portions is accomplished by air cooling the same. In detail, the head 30 is similar in general construction to the head I!) in that it is of the composite type having a lower section 3| and a cap section 32. The lower section is formed with a plurality of combustion chambers 33 in the bottom surface thereof corresponding in number to the number of cylinders 34 in the block 35 and is preferably, although not necessarily, formed from a metal of high thermal conductivity such as aluminum or an aluminum alloy. The combustion chambers 33 are of the high compression type having major portions 36- for receiving the charge of fuel and having portions 31 extending over the cylinders 34 in the block.

The upper or cap section 32 corresponds in width to the length of the major portions 36 of the combustion chambers and cooperates with the top walls thereof to form a chamber 38 for a cooling medium. The cooling medium is circulated over the top walls of the major portions of the combustion chambers 33 from a heat exchange unit (not shown) in the same manner as hereinbefore set forth in connection with the first described form of the invention. As in the first described modification, the cap 32 is preferably formed from a metal of high tensile strength for reinforcing the lower section and serves to clamp the latter to the cylinder block by means of the stud bolts 40.

The upper walls of the portions 31 of the combustion chambers extend laterally from the corresponding walls of the major portions of the chambers beyond the cap 32 so as to be exposed to the atmosphere and are formed with a plurality of laterally spaced upwardly extending ribs 39. The ribs 39 not only provide for obtaining the desired rate of cooling of the portions 31 of the combustion chambers, but also serve to reinforce the upper walls of the latter areas. The side of the lower section projecting beyond the cap 32 is clamped directly to the cylinder block by means of a plurality of stud bolts Ill extending through stud bosses 4| formed on the lower section and threaded for engagement with the cylinder block 35.

By virtue of the foregoing construction, mafimum cooling of the major portions or the combustion chambers 35 is not only secured, but the desired restricted cooling of the portions 37 of the combustion chambers is obtained. In connection with the embodiment of the invention illustrated in Figure 5, it will be noted that by reason oi the specific construction thereof set forth above, the effective area of the passage 3t for the cooling medium is appreciably less than in cylinder heads now commercially produced, with the result that the cooling medium will flow over the major portions of the combustion chainbers at a considerably higher velocity, and the efficiency of cooling will be correspondingly increased.

While in the description of the foregoing modifications particular stress has been placed upon the association of this invention with a composite cylinder head, nevertheless, it is to be understood that the same may be advantageously employed in connection with different types of cylinder heads formed of various kinds of metals, and, accordingly, reservation is made herein to make such changes as may come within the purview of the accompanying claims.

What I claim as my invention is:

1. An internal combustion engine cylinder head formed with a combustion chamber therein and having a wall spaced above the top wall of the combustion chamber to form with said top wall a space for a cooling medium, said combustion chamber having a portion for receiving a charge of fuel and having another portion of relatively large surface to volume ratio adapted to register with a .cylinder of an engine, and

cooperating registering projections extending ini to the space aforesaid from the top wall of the second named portion of; the combustion chamher and the above mentioned wall of the head to prevent the flow of the cooling medium in said space over a portion of the top wall of the second named portion of the combustion chamber.

2. An internal combustion engine cylinder head having a lower section formed from a metal of relatively high thermal conductivity and having a combustion chamber therein, an upper section removably secured to the top surface 'of the lower section and cooperating therewith to form a space for a cooling medium above the combustion chamber, said combustion chamber having a fuel receiver portion and having a communicating portion of relatively large surface to volume ratio adapted to register with a cylinder of an engine, and cooperating means extending into the space from both of said sections and forming a column above the top wall of the second named portion of the chamber fior preventing the fiow of cooling medium over a portion of said wall.

3. An internal combustion engine cylinder head having a lower section formed with a combustion chamber therein and having an upper section removably clamped to the lower section forming with the latter a space above the combustion chamber for a. cooling medium, said combustion chamber having a fuel receiving portion and having a communicating portion adapted to register with a cylinder of an engine, and a projection of predetermined cross sectional area extending into the space aforesaid from the top surface of the second named portion of the chamber and engaging the upper section to prevent the fiow of cooling medium over a portion of the upper wall of said second named portion of the chamber.

DAVID E. ANDERSON.

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