US1788668A - Piston for internal-combustion engine - Google Patents

Description

H. FORD PISTON FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 1 Filed May 51, 1924 39.17 INVENTOR. 71 M.

ATTORNEY.

Jan. 13, 1931. H, F 1,788,668

PISTON FOR INTERNAL COMBUSTION ENGINES Filed May 31, 1924 2 Shgets-Sheet 2 5i 1 I /l2 14 f'T.-9 [3 .10 j M E? 'WIINESS: INVENTORY WW 95M.

TTORNEY.

Patentecldan. 13, 1931' IQPATE NT OFFICE v HENRY FORD, OF DEARIBORN, MICHIGAN, ASSIGNOB '10 FORD MOTOR COMPANY, OF

DEARBORN, MICHIGAN, A CORPORATION OF DEAWABE PISTON. FOR INTERNAL-COMBUSTION ENGINE Application filed Kay 81, 1924. Serial Ili'o. 716,989.

The object of my invention is to provide new and useful improvements in a piston for internal combustion engines of simple, durable and inexpensive construction. A further ob'ect of my invention is to provide a piston w ich may be constructed from steel as distinguished from cast iron or aluminum. It will be understood that heretofore pistons for internal combustion engines have ordinarily been made from cast iron but that such pistons are objectionable from the fact that the weight is very considerable and of course the effect ofweight is much multiplied.

in connection with a reciprocating part such as a piston. It has been proposed to use aluminum and various other white metal alloys of relatively light Weight for pistons and in fact a considerable number of such pistons have been used. Heretofore, however, such pistons have been objectionable from the fact that their coeflicient of expansion is much higher than the coefiicient of expansion of the cast iron from which the cylinders are made, so that it is necessary to have such pistons fit very loosely when the engine is cold in order that they may not bind when they expand from the heating of the engine after the engine has been in operation for some time. Such pistons, therefore, give relatively poor compression and oil sealing at the time the engine is cold so that while they are more satisfactory from a weight standpoint, still they are not so satisfactory from other standpointsl It has also been proposed to use steel pistons and I have been informed that a large number of expert engineers have attempted to solve the problem of using the steel piston as the steel would have substantially the same coefiicient of expansion as the cast iron cylinder and yet the weight would be a fraction of that of the cast iron piston. A piston is a rather complicated construction due to the fact that it is necessary to provide relatively strong bosses to receive the sleeves which support the wrist pin and it is also necessary to provide grooves for the piston rings and to brace the head so that it will not cave in or otherwise alter-under the force of impact of the explosions in the cylinder. Further, it is difiicult to make the.

skirt of a steel piston of sufliciently thin material so that it will be light enough and yet at the same time hold its circular shape.

With the foregoing explanation in mind,

it is the further object of my invention to provide a piston which may be formed from steel and which may have a sufficient rigidity in the skirt to keep it from losing its circular form, which may have suificient material and rigidity in the dome to permit of the forming of'ring grooves and to withstand the shock of the explosions and which may have suflicient strength in the skirt and its connection with the dome so that bo sses may be struck up to receive the wrist pm sleeves.

A further object of my invention is to so form the parts of my improved piston that they may be readily and satisfactorily welded together to withstand the necessary duties of a piston.

A further object ofmy invention is to rovide a piston having a forged head and a 'rt of pressed steel of substantially tubular form which may be butt welded to the forged head.

A further object of my invention is to provide a skirt of substantially tubular form V which may if desired be made initially in two halves which may be butt welded together.

A further object of my invention is to provide a sheet metal skirt of substantially tubular form which may have ring grooves formed therein and bosses struck up therefrom to' receive the wrist pin sleeves.

A further object of my invention is to provide bosses to receive the wrist pin sleeves which are so arranged that a satisfactory welding job may be readily made in connection therewith. r

With these and other objects in view, my invention consists in the arrangement, combination, and construction of the various parts of my, improved device, as described in the specification, claimed in my claims, and

has been constructed in accordance with my mventlon.

,Figure 2 shows a bottom pla nview of the;

piston illustrated in Figure 1.

Figure 3 shows a verticalcentral sectional view taken on the line 33 of Figure 1.

Figure 4 shows a horizontal central sectiona view taken on the line 44' of Figure l, and Figures to 14 inclusive show V8.1l1S schematic or diagrammatic views to illustrate the various steps in the formation of the sheet metal skirt for my improved piston. Figures to 17 inclusive show a somewhat diiferent forgin being a cup-shaped mem er as is indicate above the dotted line 10 in Figures 1 and 3. It will be seen that this forging may be readily for ed out of a disc of steel in an ordinary orging machine. The ring grooves 11 are cut into the head A after it has been-for ed and of course they are suitably groun or otherwise shaped to the proper dimensions to receive the desired piston ring.

The'skirt B of the piston is, as may be noted from the Figures 3 and 4 especiall of, generally speaking, tubular cylindrical orm.

In Figures 5 to 14 inclusive I have illustrated one manner in which this skirt may.

be formed.

Referring to these figures it will be noted that in Figures v5 6' and 7, I have illustrated an. end, lan, an edge view, respectivel of the blan from which one-half of the s 'rt may be formed. This blank may be placed in a suitable die so that it is formed to substantially semi-cylindrical form as is illustrated in the elevation plan and section of Figures 8, 9 and 10. It will be noted that this blank has an o ening 12 formed therein by this operation w ich forms the pilot opening for the punch which latter will form the boss in the blank to receive the wrist pin sleeve. The blank also has a ring receiving groove 13 formed near the bottom edge thereof and a stiffening rib 14 formed at the bottom thereof by this same operation. Adjacent to the lower edge of the ring groove 13 I provide a struck in portion 15 which termi- 'nates in a flange 16 at the lower edge of the ring oove 13 whereby I perform the double function of stren hening the skirt to keep it round and of ormin a combined flange and groove for wipin t e oil from the surface of a cylinder. hen the blank has been formed, as shown in Figures 8,9 and 10, it'

is then again placed in a press and the wrist pin receivingboss 17 illustrated in Figures 11 and 12 is struck up, the pilot 0 nin 12 being used to locate the punc mem r w 'ch forms the boss 17 and to permit the edge of the boss to be relatively smooth and unbroken. This wrist pin receiving boss is of substantially cylindrical section in all vertical planes and straight section in all horizontal planes.

-.After the boss has been struck up, as illustrated in'Figures 11 and 12 then the wrist pin receivin sleeve 18 is forced into the boss with a press no play between the sleeve 18 and the boss 17, I prefer to use a encil' arc weld or line weld at 19 and 20 to her secure the boss and sleeve together. After this has been accomplished a pair of the skirt sections, such as is shown in Figure 13, are placed with their lateral edges together and these lateral edges butt welded together at 20 to form the tubular skirt illustrated in the plan view in Figure 14.

It is ossible to form a skirt heretofore described by drawing same from asingle perforated disc or tube to tubular form and then t. In order to be sure that there is striking up'the bosses and ring grooves and reinforcing flanges or ribs after the member has been so drawn.

The'skirt B when formed, as heretofore described is then butt welded on the dotted formed with an up-set outwardly extending flan e intermediate of its ends, which is butt wel ed to the edges of the perforation in the disc portion of the skirt. It will be noted that the dished in portion may be said to be of conical shape and the up-set flange on the sleeve is also of somewhat conical shape so that when these parts are forced together in the presence of a welding current then the heat' of the metal will break the metal down so t at a continuous weld or joint between the two parts will be insured. Many advantagm arise from the use of my improved piston and among these advantages it should first be pointed out that the piston here described is thoroughly practical as it has actually been made and run on test in engines with thoroughly satisfactory results. Further, the weight of the iston is very small as compared with that o the cast iron piston so that the well known advantagw of a light weight piston are secured by usin the construction herein disclosed without t e disadvantages of the light weight pis tons which have heretofore been used with regard to the fitting. ofthe cylinder under various engine conditions.

Another advantage resulting from the use of this improved piston is that it may be relatively cheaply manufactured and that the manufacturing operations are of themselves of such a nature that they may be readily adapted for cheap and large production.

I claim as my invention:

1. A piston for internal combustion engines having a for ed head with ring grooves therein, a cylindr ical sheet metal skirt integrally united with said forged head, said skirt having a pair of diametrically opposite 'dished in portions formed therein, a pair of wrist pin receiving sleeves, and radial flanges extending from substantially the longituditransverse dished in portions havin an openand radia ing formed at substantially the middle part thereof, alpair of wrist gin receiving sleeves,

y extending anges disposed substantially at the lon tudinal center of said sleeves, said flanges eing integrally united with the edges of the openings in said dished in portions of the skirt.

' HENRY FORD,

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