US2404348A - Internal-combustion engine piston - Google Patents

Description

Jul 23,1946. L, B, BOYD 2,404,348

' INTERNAL-COMBUSTION ENGINE PISTON Filed Dec. so, 1943 .INVENTOR. I

fatented July 23,1946 I Applicamn December 1943,-seria1 No.1516t134? Claims, (Cl. 123 193 I Mypresent invention I in pistons, and particularly to pistons for internal combustion, engines having a cylinder block structure and a cylinder cover; and the objects of; improvement are: first, to provide an internal .combustion engine piston that will cause-improved combustion of the fuel .charge in fuel spaces. of the engine; second, to provide an internal combustion engine piston having a thin layer of substantially pure copper forming a heat radiant,extending-throughout its head for refleeting heat of combustion back into ,thecombustion; chamber; third, to provide aninternal combustion engine, piston. having. a, ,member I of copper extending throughout its head portion thatdoes-rnotg act ,as a-heat transferv member;

. fourth, to provide an internal combustion. engine piston havingless heat transfer to the wall of the cylinder in which the piston reciprocatesthan veither pistons composed of non-ferrous metal or such other piston having copper or other nonie'rrous metal at their heads; fifth, to provide an internalicom 'bi stion engine piston that can operate on its reciprocative excursions with less main substantially free from' carbon accumulation under its deckan'd'onthe .t'op'of the piston;

' 'seventh, to provide 'an' internal combustion engine piston of whichthe pressure sealing rings 'will not become carbon bound eighth, to provide an internal combustion engine piston whereby the horse power output of the engine will be I greaterthan'th'at of internal combustion engines o'fqthfe same horse power rating and using the same quantity and quality fuel ninth, to provide an internal' combustion e'nginefpiston that will "causea minimum of fuel consumption for a given horse pown'devempe'd by the engine; tenthfto provide: an [internal combustion engine piston that will cause a minimum consumption of lubri- I eating oil; eleventh, toprovide aninternal' combustion enginepiston that will be more efficient thanl such pistonsat present employed.

I attain these'named objects'andsuch other objects as'appe'ar from a perusalof the following description and the structure illustrated in the accompanying drawing, in which:

ternal combustion engine cylinder block having ela est fim ov m ,the crank pm of the engines crankshaft, and

' 2' Figurez is an elevation view of my pistonln part section. I 3 I Figure 3 is an enlarged cross-sectional view of a portion of an internal combustion engine piston illustrating the application of copper or other metals by other than my preferred method. I

Throughout the three views of the drawing, similar numerals refer to similar parts and portionsof my piston, as mounted 'in an internal combustion engine, and referring to the drawing: Numeral I refers to my present internal combustion engine piston, comprising a skirt portion Z with inwardly extending wrist pin bosses 3, each havin a bore 4 for recei'ving'the wrist pin 5, 'to which is swingably connectedrod 6 connected to whereby the crank shaftjis turned by the piston on its power excursion and the piston is moved longitudinallyby power stored in the crank shaft and; associated members I, on its compression excursion; a

. The skirt portion z ia'sjriar itslower endt annul ar ring slot I, having loosely mounted ther'ein outwardly springable 'oil film" regulating ring 8, and near its upperenda thickened portion I9 having a plurality of annular slots l0, each hav ing. therein an outwardly springable pressure sealing ring lll and outwardly'exte nding annular fiange of slightly lessdiameter than the skirt portion and the lands separating .thefpressure sealing ring slotsQf I At the topof the thickened portion 9 and forming a portion of the outwardly extending annular, flange H is the piston head or deck' l2, having secured to its side nearest to the combustion of thefuel charge a thin ferrous. ,metal plate l2 having a higher resistance to heat transfer than the metal of the said deck l2, secured to the deck I I2 preferably by brazing with a high temperature melting point solder, and has at its side opposite the side from the said head deck a smooth heat reflecting. layer l3 having high heat reflecting characteristics such as copper.' Both the plate 12- and heat reflecting layer l3 are shown extending throughout the top surface of the head deck I2 and with the heat reflecting layer extending 'beyond the periphery of the annular flange I I. with a thinbeveled edge l3 lightly ena cylinder cover extending over its top and a piston is caused to reciprocate.

gaging the wall of the cylinder bore in which the 5Q Figure 1 is a vertical sectional view of an in- I Numeral [4 refers to a cylinder block or frame of an internal combustion engine provided with a cylinder sleeve 15 having outwardly extending annular flange [6 at its top resting on annular ledge ll of the cylinder block or frame, having cylinder cover [8 secured to its top surface with a suitable high pressure heat resisting packing interposed between the cylinder block and cover.

Numeral l9 refers to the combustion chamber 7 of the engine which should be of suitable form for the engine in which the piston is to be used, as different designs of engine require differently formed combustion chambers. Numeral 20- refers to the fuelintake valve operated by the valve stem 2i for admitting gaseous fuel to the combustion chamber I9 from fuel intake passage 22; numeral 23 designates the ignition spark plug V and 24 the chamber containing the cooling fluid I of the cylinder block or frame. v

Referring to Figure 3 therein is shown a meth- 0d of securing copper directly to the top of the pistons head by the metal being melted into a, recess extending over the deck of the piston, and into annular grooves 26 machined into the said of the present application, the View merely shows ,a method whereby copper or other metal having a lower melting temperature than ferrous metal can be app-lied to the head of a piston.

Applicant isaware thatprior to his present invention copper of considerable thicknesshas been attached to the head .portion of internal combustion engine pistons for the express purpose of uniformly transferring heat caused by combustion in the combustion spaces above the piston :30 I I fer tothe piston skirt and cylinder wall with its dissipation by a cooling medium.

to the head of the piston to be dissipated by air circulated within the piston against the under side of the head, and also conveyed by the head to the surrounding skirt -portion and therefrom to a p the cylinder wall, which" of most internal combustion' engines'is surrounded by a cooling fluid circulated through cooling fluid chambers and air 'cooled radiators, all making it necessary to provide suffi'cient metal throughoutthe piston 7 structure to carry the heat of' combustion to the" 40 ciableamount; also, the copperlayer I3 or other satisfactory n'onferrous metal that might be employed having similar heat characteristics, is being secured to the felTOlls metal plate l2" having-" a higher resistance toheat transfer than the metal of said deck 12 and which in turn is'secured to the head deck of the pistons, forms a resistance to coin'bustion heat transfer from the copper to the head deck of the piston and to the oil and atmosphere circulating within the piston; all of which contribute to producing higherroperating eiiicien'cy'of the enginein whole, as the thin layer of copper being smooth at its combustion exposed surface acts as a radiant to reflect or deflect and throwback iiito'thecombustion spaces-of the engine heat to'cause'uniform heating of the sucneeding gaseous fuel charges'draw'ninto the combustion spaces of the engin'e and thereby more nearly perfect and uniform; combustion of the 2,404,348 r j ii? T1.

fuel is obtained; further, the thinness of the copper metal layer l3 approximately one sixty-fourth prevents accumulation of carbon within the pis- "ton'g as where the lubricating oil is splashed against the under side of the head deck of a piston when heated, as it is in internal combustion engines having assisted heat transfer by a heat transfer means, form, a deposit of carbon throughoutmost of the interior of the piston,

' and also in the pressure sealing ring grooves, thereby preventing free action of the rings. This formation of carbon in the piston contributes to excessive oil consumption and the prevention of pressure sealing ring free action contributes to 7 high fuel consumption. 1 V

"In-my internal combustion engine piston there 'is the layer of substantially pure copper metal of approximately one-sixty-fourth inch thickness, -which acts as a radiant to divert'or throw back intothe combustion spaces of the engine, heat caused by 'combustion, and to the means of at taching the copper to the ferrous metal plate, and the ferrous metal .plate to the head deck, together with the ferrous metal plate, dampens heat trans- Having described my present invention claim: I 1.-"An internal for reflecting back into the'combustion spaces heat caused by'combu'stion of, fuel in said combustion'spaces.

:2. In anjinternalbombustion engine piston having a skirt with'a head deck associated therewith,1machined 'atfits top side exterior of the piston, a ferrous metal plate jo ned to the ma-' ,chined side of the head deck of the piston, and 1 having, at its opposite side from the head deck a heat radiant'surface forirefiecting heat of combustion back into the combustion spaces of the engine.

"3. In,an internal combustion engine. piston having askirt and a head deck the head deck having witha machined side external of the pistongi'a steel plate having a copper metal "layer notexceeding one sixty-fourth inch thick joined to .one'of its'flat sides, with the steel plate fused to the mac'hined'side of vthe head deck. 4. Inan internal combustion engine piston, the

combination of ahollow, piston'body having a head deckclosing' one of its ends with a ferrous metal plate having a fused joinder with"the head decjk-exteriorofthe piston,'and,hav,ing a I nonferrou'slmetal layer integral with the ferrous nietaiplate at the opposite side thereof," from the headdeck.-, i" f t 1 LANDONBL'BOYD.

relating'to; internal combustion enginepistons, I

combustion engine piston havinga' copper metal layer forming a heat reflector head, ,and fastened thereon by a ferrous metal plate secured t the head deck of thepiston-and having a-lesser heat conduction factor 'th'anjthe heat 'conduction'factor'of thecopper

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