US1719215A - Internal-combustion engine - Google Patents

Description

July 2, 1929 A. FARY ET AL INTERNAL COMBUSTIQN ENGINE Filed Jan. 8, 1927 ..0/ Wg anim f T www Patented July 2, 1929.

PATENTy OFFICE.

ARNE FARY AND OLE STANGLAND, 0F CHICAGO, ILLINOIS.

IN TERNAL-COMBUSTION ENGINE.

Application niea January a, 1927. serial No. 159,767;I

Our invention relates to improvements in internal combustion engines, being more particularly concerned with that type of internal combustion engine known as Diesel or semi- Diesel engines. y

The high operating temperatures attained in the Diesel and semi- Diesel engines have always made the cooling of the cylinder walls and the pistons a matter of considerable difficulty, particularly in the case of pistons. In the larger sizes of engines of this type, itis necessary to provide the pistons with water jackets and pipe connections which include a plurality of joints for the purpose of leading the cooling water to and from the pistons to maintain the pistons at proper operating temperature. Such cooling systems are a source of continual trouble and also dissipate a large amount of heat energy.

As the pistons must necessarily be made somewhat smaller than the cylinders to allow for the great expansion due to the rise in temperature of the pistons, this is a source of leakage of oil and fuel. vWith the iston construction of the prior art, it is allso necessary to make the pistons much heavier in order to provide sufficient strength so that the pistons will be able to withstand the ordinary stresses involved at the temperatures to which they are subjected, but if the pistons can be kept cool, as contemplated by our invention, much excess weight may be eliminated by using lighter pistons.

As approximately 'one-third of the heat energy of the fuel is dissipated and lost by radiation and conduction from the cylinder and piston, and one-third of this loss occurs through the piston and its cooling system, the elimination ofthe latter loss results in a saving of fuel and an increase of power, as well as the elimination of many of the difliculties attended by thc use of inadequatevcooling systems which permit the pistons to become overheated, scoring the cylinders and doing other serious damage to the engine.

One of the objects of our invention is the elimination of all the foregoing difliculties and others, by means ofthe provision of a heat insulating shield for the pistons of internal coinbustion engines.

Another object of our invention is the provision of a heat insulating shield for the pistons of such engines, which is light in lWeight and which can be permanently fixed to the pistons of such engines.

Another object of our invention is the provision of such a heat insulating shield which is capable of withstanding perature gradient between the side exposed to combustion and that side aliixed to the cylinder.

Another object of our invention is the provision of such an insulating shield which will maintain Vthe pistons at lower temperatures so that the pistons may be made lighter in Weight, thereby reducing the weight of reciprocatin parts.

Anot er object of our invention is the provision of such an insulating shield which will elminate the necessityy for artificial cooling of the pistons and which will also prevent the loss of heat to a great extent by radiation and conduction through the pistons.

Another object of our invention is the provision of such an insulating shield which is adaptable both to be used upon pistons and upon valves of a like construction in internal combustion engines.

Another object of our invention is the provision of such an insulating shield which is adapted to be permanently allixed to the pistons but which permits access to the usual tapped bores of the pistons, which are used with a screw eye to lift the pistons.

l Another object of our invention is the provision of such an insulatingvshield which is durable, which is economical to manufacture and which may be easily attached to the pistons of any internal combustion engine.

Another object of the invention is the provision of an insulating shield which may also serve as an ignition device diie to the extremely high temperature at which the exposed side of said shield is maintained, thereby eliminating the necessity for other ignition devices after the engine has attained operating temperature.

This feature of the invention is only important upon semi-Diesel engines where compression temperature is not high enough to ignite thecharge without another ignition device.

Gther objects and advantages of our invention will appear more fully from the following description and the accompanying drawings in which similar characters of reference a very high telli-`- indicate similar parts throughout the several views.

In the drawings, Fig. 1 is an elevational lview in cross section of a cylinder and a pis- 5 'ton equipped with our invention.

Fig. 2 is a partial p an view of our improved insulatlng shield.

Fig. 3 is a bottom view of our insulating shield, having a portion of the cover broken away to show the spacer member.

10 indicates the cylinder walls of any cylinder of an internal combustion engine, and 11 indicates the piston in said cylinder. The piston 11 is usually made considerably smaller .than the cylinder 1() in the case of Diesel and Y semi-Diesel engines, inorder to permit reciprocationfof the piston after it has expanded, due to the high operating temperature.

The piston 11 may be provided with the usual piston rings 12, consisting of split steel ,rings of substantially rectangular cross section, or otherwise, which are adapted to be received in the grooves 13 and which spring outlward against the cylinder walls lforming, with the aid of an oil ilm, a substantially gas tight joint. The piston is usually provided with a central aperture 14 which is tapped to receive the screw threads of a threaded eyebolt, which is inserted whenever it is desired to lift the piston by inserting a hook therein.

Referring to Fig. 1, 15 indicates, in its entirety, our insulating shield, which may consist of a sheet metal container which is stamped or otherwise constructed in the form shown. In the embodiment which we have chosen to illustrate our invention, the insulating shield 15 consists of a substantially cup shaped member 16 of general cylindrical shape, having a downwardly turned exterior cylindrical wall 22'slightly smaller than the size of the piston with which it is to be used, to provide against the contacting of the shield with the cylinder walls when the shield is expanded under high operating temperatures. The cup shaped member 16 is provided with a central annular `iange 17, registering with the tapped aperture 151 of the piston 11 Y to permit access to the tapped aperture when the insulating shield is fixed upon the cylinder piston.

In order to secure the maximum degree of insulation, the flanged opening 17 in the center of the insulating shield may be eliminated so as to to completely cover the end of the piston, and our invention includes insulating shields which comprise sheet metal containers having no central aperture, but completely covering the end of the piston. In such case, the member 16 may be formed of vcup shape without a central aperture, being closed by a cover plate which is likewise formed without a central aperture. The embodiment shown is preferred as 4it is adaptable to existing means for lifting the pistons.

(i5 The chamber formed by the cuplike member 16 is provided with a cover plate 18 consisting of a substantially flat plate having a central aperture with an upwardly turned annular ange 20 about said aperture and an upwardly turned annular lange 21 about the exterior edge of said cover plate.

The central annular flange 17 is preferably formed in the' shape of the frustum of a cone,

the lower edge of the flange being sloped slightly inward toward the center of the shield, while the exterior wall 22 of the shield is also preferably sloped slightly outwardly toward its lower edge, for a purpose further to be explained.

i The cover late` 18 is preferably of such size that the gauges 20 and 21 form a tight fit with the ianges 17 and 22 when the bottom of the cover plate is flush with the lower edge of the anges 22 and 17. In order to eliminate the bad effects caused by the expansion of the gas within the shield 15 under operating temperatures, we prefer to ill the shield 15 with .a gas under reduced pressure considerably lessthan that of atmospheric pressure and the pressure of the gas within the shield 15 should preferably be such that at the average operating temperature, the pressure within the shield will be substantially the same as the average pressure within the cylinder. The pressure being thus reduced, there is no tendency for the gas within the shield to disrupt the shield and the insulating qualities of the gas or air within the shield are greatly increased by reducing the pressure therein. Our invention also includes thel provision of shields of the type, described in which the interior of the shield has been reduced to such a high vacuum that the interior pf the shield is a practical non-conductor of leat.

The cup shaped member 16 is preferably provided with a plurality of concentric corrugations 23, of semi-circular cross section, terminating in the interiorof the insulating shield in a plurality of equally spaced ridges 24 of equal height.

It will be observed that when the shield is subjected. to operating conditions, the exposed side is subjected to extreme temperatures and, as a result, tends to expand more than the side aixed to the piston. Another important advantage of the corrugations is the fact that they permit the necessary expansion without greatly increasing the size of the shield. This structure is also capable of long service under the widely varying temperature conditions existing in'the cylinders.

Resting upon the ridges 24 within the insulating shield is a division plate 25 consisting of a iiat plate'of metal having a central aperture 26 slightly larger than the annular iange 17 and the plate 25 is of circular shape, adapted to be received within the walls 22, allowing suicient play for expansion of the plate 25. Between the division plate 25 and the cover .start at any side of the container and, being bent backupon itself as at 28,29, 30, etc., may

traverse the interior of the insulating shield a plurality of times after the manner shown in Fig. 3. The exact manner of bending the spacer member 27 is of no particular importance except that the spacer member 27 should provide a plurality of closely spaced lines of support between the division plate and the cover plate 18.

One example of the manner of bending the spacer member 27 is shovvn in Fig. 3, and While the embodiment chosen shows a rod which has been used for the spacer member` 27, our invention also includes the use of strips of flat metal, or metal of other shapes which may be bent as shown, or in the form of a spiral spring, or in other irregular shapes,

the essential thing being that the spacer member should support the spacer plate 25 and the cover plate 18 in spaced relation Without providing a substantial area for heat conduction between these parts.

All parts of the insulating shield 15 are preferably formed of nickel steel or chrome vanadium steel, as these materials are capable of withstanding for long periods the conditions of service existing Within the cylinders of the engines above mentioned.l After the division plate 25 has been placed in the cup shaped member 16 andthe spacer 27 has been placed upon the plate 25, the cover 18 is put in place and the edges between the cover 18 and the Walls 22 and flange 17 are Welded together, as shown at 31 and 32, with the exception of a single small aperture Which may be usekli for reducing the atmosphere within the she l. i

rlhe atmosphere Within the shield may then be reduced by exhausting the air therefrom by pumps and sealing the aperture, but a very convenient methodbf securing the reducedl pressure Within the shield is that of heating the shield to a very high temperature, substantially that of the average operating temperature Within the cylinder. Theshield may be kept at such temperature for a sufficient length of time to heat and expand the airV Within the same, driving out the excess air through the aperture which has been provided as described above. While the insulating shield is still at high temperature,4 the aperture may be sealed by Welding and upon cooling the shield the gas Within the same will be reduced to the pressure desired.

While our insulating shield may be attached to exhaust pistons of internal combustion engines Without altering the size of the pistons, suchprocedure would necessarily reduce the space Within the cylinder. However, the beneficial results attained by our insulating shield justifies its use even under such conditions.

We prefer, however, to reduce the thickness of the upper piston Wall an amount sufficient to -permit the addition of our insulating shield Without reducing the space Within the cylinder, and as the piston is no longer subjected to the extreme heat of the interior of the cylinder, We find that such a reductionv in the size of the piston does not reduce its strength below that required. Our insulating shield may be affixed tothe piston by spot Welding at a plurality of points about the outside edge of the Walls 22 and when once aliixed to the piston requires no further attention.

The insulating shield described may also be used to equal advantage upon the ends of tappet valves Where they are subject-ed to extreme temperatures and it is desirable to protect them from the same to eliminate the bad effects of overheating as Well as the necessity forvcooling. In such case theshield may be made Without a central aperture and of such size as will conveniently cover the exposed end of the valve.

In the case of very large pistons, We-prefer to change the typeof corrugations used as follows. Instead of concentric circles as shown in Figure 2, star shaped corrugations may beused, theistars having substantially parallel sides, rounded corners and from eight or more points. Such corrugations may be used with or Without a central aperture and the cross-section of a single corrugation may be semi'oircularas shown. We find that the latter construction readily permits the uneven expansion of the parts occurring in unusually large shields of the class described.

We desire it also to be understood that our i shield may be either pressed from sheet metal or forgedand We do not limit ourselves to either method of construction. I

It Will thus be observed that We have invented an improvement in internal combustion engines comprising an insulating shield for pistons which eliminates'overheating of the pistons as Well as the necessity for Water cooling, prevents over expansion of the pistons, saves oil and fuel, increases power due to the saving of heat usually dissipated by the piston cooling system, and successfully prevents the sticking of the pistons due to overheating.

While We have shown and described a specific embodiment of our invention, many modifications may bemade Without departing from the spirit of the invention, and We do not Wish to be limited tothe precise details set forth, but desire4 to avail ourselves of all changes Within the scope of the appended claims.

Having thus described our invention, what We claim as new and desire to secure by Letters Patent of the United States is:

1. In an article of manufacture, a heat insulating shield forI pistons and valves of internal combustion engines comprising a metal container having a plurality of corrugations in one side providing a plurality of lines of support for the Walls of said container, said container being filled withv gas under reduced pressure.

2. In an article of manufacture, a heat insulating shield for pistons and valves of internal combustion engines comprising la sheet metal container of a size and shape adapted to substantially cover the end of a piston, and means Within said container for supporting its opposite walls under pressure, comprising metal Wires bent to traverse said container between its Walls at spaced intervals.

3. Inan article of manufacture, a heat insulating shield for pistons and valves of internal combustion engines comprising a sheet metal container of a size and shape adapted to substantially lcover the end of a piston, and means Within said container for supporting its opposite Walls under pressure, said container comprising a cup shaped member having a central annular flange, and a cover member Welded thereto, one of said members having concentric corrugations.

4. In an artlcle of manufacture, a heat 1nsulating shield for pistons and valves of internal combustion engines comprising a sheet metal container of a size and shape adapted to substantially cover the end of a piston, and means Within said container for supporting its opposite walls under pressure, said container comprising a cup shaped member having a central annular flange, and a cover member welded thereto,'one of said members havingv concentric corrugations, a division plate in said container lying against said corrugations anda spacer member between said division plate and the opposite Wall of said container.

5. Inan internal combustion engine of the Diesel type of sufficient size as to require a piston cooling system, the combination of a piston with an insulating member secured to the end of said piston, andsubstantially cov-V ering the end thereof', said insulating member comprising a sheet met-al container filled with a gas under reduced pressure.

6. In an internal combustion engine, the combination of a cylinder with a movable part having an exposed surface in said cylinder, and means for insulating said part from the heated gases in said cylinder, comprising a gas-tight metal container substantially covering said exposed surface and carried by said v movable part.

7. In an internal combustion engine, the combination of a cylinder with a movable part having an exposed surface in said cylinder, and means for insulating said part from the heated vgases in said cylinder, ycomprising a gas-tight metal container` substantially covering said exposed surface and carried by said movable part, said container having one wall lying againstsaid movable part and a second Wall exposed in said cylinder and spaced from said first wall.

8. In an internal combustion engine, the combination of a cylinder with a movable part having an exposed surface in said cylinder, and means for insulating said part from the heated gases in said cylinder, comprising a gas-tight metal container substantially covering said exposed surface and carried by said movable part, said container having one Wall lying against said movable part and a second wall exposed in said cylinder and spaced from said first wall, and a plurality of points of support for said second wall upon said first Wall to maintain said Walls in spaced relation under operating pressures in said cylinder. f

9. In an article of manufacture, a heat insulating shield for pistons and valves of iuternal combustion engines comprising a gastight metal container of sufficient size to substantially cover said piston or valve and having one Wall lying against said piston or valve and a second wall spaced from said first wall.

10. In an article of manufacture, a heat insulating shield for pistons and valves of internal combustion engines comprising a gastight metal container of sufiicient size to substantially cover said piston or valve and having one Wall lying against said piston or valve anda second Wall spaced from said first Wall, said container being filled with gas under reduced pressure at normal temperature to prevent bulging under operating temperature.

. 11. In an article of manufacture, a heat insulating shield for pistons and valves of internal combustion engines comprising a gastight metal container of sufficient size to substantially cover said piston or valve and having one Wall lying against said piston or valve and a second Wall spaced from said first Wall, said second Wall being corrugated to permit its expansion under operating telnperature Without excessive strain.

12. In an internal combustion engine, an ignition device comprising a closed metal container having one Wall lying against a piston, valve 0r the like and carried thereby and having a second wall spaced from said first wall and exposed to be maintained at ignition temperature by combustion in said engine.

13. In an internal combustion engine, an ignition device comprising a closed metal container having one Wall lying against a piston, valve or the like and carried thereby and having a second Wall spaced from said first Wall and exposed to be maintained at ignition temperature by combustion in said engine, said container being filled with sufficient gas to attain substantially average operating pressure in said container at operating temperature.

14. In an internal combustion engine, an

ignition device comprising a, closed metal permit expansion under operating temperacentniner having one Wall lying against n ture Without excessive strain.

piston, valve or the like and carried lthereby In Witness whereof, We hereunto subscribe 10 and having a second Wall spaced from saidI our naines this 28th day ofDece1nber,1926.

irst wall and exposed to be maintained at i 1- ignition temperature by combustion in said ARNE FAROY.

engine, said second wall being corrugated to OLE STANGLAND.

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