US1910591A - Air cooled engine cylinder - Google Patents

Description

May 23, 1933. 1R. CHILTON '71,910,591

v AIR COOLED ENGINE CYLINDER Filed Aug. 7, 1931 vlatented May 23, 1933 V UNITED STATES PATENT OFFICE ROLAND cEiL'rON, or RIDGEWOOD, NEW JERSEY, AssrGNoR 'ro WRIGHT AERONAUTI- cAL CORPORATION, A CORPORATION OE NEW YORK `AIB. COOLED ENGINE CYLINDER Application filed August 7, 1931. Serial No. 555,674.

-My invention relates to air-cooled engines and more particularly to improvements in the cylinder head construction thereof.

At the points of mostintense heat low such 5 as the spark plug locations, there is in conventional designs of air-cooled aircraft engines, insuilicient area on which to base the desired amount of finning close to the spark plugs, so that cooling is largely dependent on conduction ofthe heat into the surrounding area of the-'cylinder head.. wall. Also, in air-cooled aircraft engines, the fins are interrupted at the spark plug Openings, to aii'ord wrench room around the spark plugs, where` by the conductivity of heat is prejudiced and the fin area at these critical points reduced.

The object of the present invention is to provide a finning arrangement which will lafford improved air low at the rear of the cylinder head wall and will at the same time augment the cooling of the cylinder head in the hot spot Zone of the one or more spark plug locations. That thismay beV satisfactorily accomplished, the cylinder head wall is provided with hollow integral cylindrical extensions surrounding and coextensive with the spark plugs, and the cylinder coolinglin disposition is such that certain of the fins are 3`0 extended uninterruptedly from the cylinder head wall along the spark plug cooling extensions. In this way a very rsubstantial increase in the area withdrawing heat from the cylinder head wall near the spark plugs f is provided. At the same time the reorganized fin disposition provides good air ow along the fins and to the spark plug extension at the back of the cylinder head by three distinct paths of flow, i. e., over the top 3f and around each side of the engine cyliner. e

In the drawing z` Fig. 1 is a rear view of a cylinder head showing the preferred inning arrangement, and

Fig. 2 is a section on the line 2--2 oi Fig. 1. In the embodiment of the invention selected for illustration the wall of the cylinder head is indicated at 10. It is of more or less conventional design. Formed therein is the usual inlet port 12 and exhaust port 14,

and integral therewith are suitable rocker box housings 16 and 18. Front and rear spark plugs are designated as 20 and 22 respectively and each is surrounded by a cylindrical wall 24 integral with the cylinder wall and extending olil therefrom substantially to the outer ends of the spark plugs. Suitable caps 26 may be provided to connect the spark plug cables (not shown) to the spark plugs 20 and 22, and these caps may be designed to give radio shielding similar to that described in the `co-pending application of R. F. Gagg, Serial Number 472,040,l filed July 31, 1930, and assigned to the assignee herein.

0n the top of the cylinder head a plurality of so-called pompadour ins are provided. 'Ihese fins 28 are vertical ns and they extend uninterruptedly across the top of the cylinder head between the rocker box housings 16 and 18. rIhe cylinder head has also formed thereon a plurality of horizontally extending'circumferential fins 30, the upper of which, designated as 30', merge into the successive pompadour fins 28. The pompadour fins and the circumferential fins which subtend `the width of the spark plug cooling` extensions 24 are carried along said extensions uninterruptedly to points at or near their outer ends (see Fig. 2). By thus arranging the fins 28, 30 and 30 an easy path of air low between the fins over the top of and around both sides of the cylinder head to the spark plug cooling extensions 24 is provided. Moreover, the spark plug cooling extensions, in and of themselves, afford an eliective conductive path to the additional iinning extending longitudinally thereof, Vand the added linnin per se provides additional cross-sectiona area in the path of heat flow. It may also be pointed out that the merging of the pom adour fins withthe upper circumferential I s substantially symmetrical with respect to the ports 12 and 14, gives a shape lconducive to easy air iow around and back ofthe rocker box housings which usually interfere lwith the air ow in conventional inning systems. No interruption of the cooling fins at the juncture of the spark plug cooling extensions 24 and the cylinder Wall 10 exists. Both the pompadour fins and the circumferential fins y which subtend the width of the spark plug extensions, extend without a break in the continuity of theo fins for substantially the full length of the respective extensions. In other words, the cylinder wall and its cooling fins are integral with the cooling extensions and the cooling fins with which said extensions are provided.

For convenience of descri tion the invention has been described wit specific refer'- ence to the cooling of the hot spots generated around the spark plugs. Obviously the invention can be applied to any other;v point on the cylinder head where additional cooling is desirable. To mention one instance only, compression ignition engines have an injection valve which could be substituted for one of the spark plugs illustrated without departin from the spirit of the invention.

at I claim is:

1. In an air cooled internal combustion engine; a cylinder having formed in its side wall an opening, said opening being ada ted to receive a spark plug; a laterally projecting solid wall integral spark plug cooler extension formed on said cylinder around said opening, said extension having an overall length substantially coextensive with the rojecting length of the spark plug when Etted in said opening; and fins for cooling said c linder and said extension formed integral y therewith and with each other upon the exterior wall of said cylinder and said extension respectively, said fins throughout a portion of their length being extended lengthwise of said extension.

2. In an air cooled internal combustion engine; a cylinder having formed in its side wall an opening, said opening being adapted to receive a spark plug; a laterally projecting solid wall integral spark plug cooler extension formed on said cylinder around said opening, said extension having an overall length substantially coextensive with the rojecting length of the spark lug when tted in said opening; and fins or lcooling said c linder and said extension formed integrally therewith and with each other upon the exterior wall of said cylinder and said extension respectively, said fins throughout a portion of their lenglth being extended uninterruptedly across t e top of said cylinder and throu hout the remaining portion of their lengt being extended lengthwise of said extension.

3. In an air cooled internal combustion engine; a cylinder having formed in its slde wall an opening, said opening being adapted to receive a spark plug; a laterally projecting solid wall integral spark plug cooler extension formed on said cylinder around said opening, said extension having an overall length substantially coextensive with the projecting length of the spark plug when fitted in said opening; and fins for cooling said cylinder and said extension formed integrally therewith and with each other upon the exterior wall of said cylinder and said exv tension respectively, said fins throughout a 4portion of their length being extended substantially uninterruptedly circumferentially around said cylinder and throughout the remaining portion of their length being extended lengthwise of said extension.

4. In an air cooled internal combustion engine; a cylinder having openings formed in its forward wall and in its rearward wall respectively, each said opening being adapted to receive a spark plug; solid wall integral spark plug cooler extensions formed on said cylinder, one each around each said opening to project laterally out from said cylinder at substantially diametrically opposite points, each said extension having an overall len h substantially coextensive with the projectmg length of its associated spark plug; and fins for cooling said cylinder and both said extensions formed integrally therewith and with each other, said fins being extended substantially uninterrllptedly across the top of said cylinder and lengthwise of said extensions to respectively terminate at or near the. outer extension ends.

5. In an air cooled internal combustion engine; a cylinder having openings formed in its forward wall and in its rearward wall respectively, each said opening being adapted to receive a spark plug; solid wall integral spark plug cooler extensions formed on said cylinder, one each around each said opening to project 'laterally out from said cylinder at substantially diametrically opposite points, each said extension having an overall length substantially coextensive with the projectlng length of its associated spark plug; and fins for cooling said cylinder and both said extensions formed integrally there` i with and with each other, said fins being extended substantially uninterruptedly circumferentially around said cylinder and lengthwise of said extensions to respectively terminate at or near the outer extension ends.

In testimony whereof I ,hereunto alx my

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