US2202838A - Internal combustion engine piston - Google Patents

Description

Patented June 4, 1940 UNITED STATES INTERNAL COMBUSTION ENGINE PISTON Charles W. Dake, Grand'Haven, Mich.'

Application March 9, 1938, Serial No. 194,827

Claims.

My present invention pertains to internal combustion engine pistons which have to do principally with internal combustion engines wherein there is a cylindrical bore in which a trunk type 5 piston is caused to move longitudinally thereof in response to pressure generated by combustion of an explosive mixture of gases.

The objects of improvement of my piston are: first, to provide a piston having great strength coupled with lightness; second, to provide a piston for internal combustion. engines having an improved heat conduction; third, to provide a piston wherein the head will have great resistance against burning through; and, fourth, to provide a piston for internal combustion engines of improved heat transfer to thev engines cylinder walls.

I attain these named objects by the structure hereinafter described with the assistance of the accompanying drawing, in which Figure 1 is a plan view of my piston as looking at the head end thereof, and

Figure 2 is a longitudinal sectional view of my piston taken on line V-V of Figure 1 looking inI the direction the arrow thereon indicates.

Referring to the drawing, similar numerals refer to similar portions of the piston as follows:

Numeral I refers to the piston as a wh le; 2 the head thereof, 3 the skirt portion; 4 the beginning of the skirt portion or thevjuncture of the skirt portion and the head portion 5; 6 the upper land; 'I the piston ring separating land; 8 pressure sealing ring grooves; 9 wrist pin accommodating bosses; I0 an inwardly extending reinforcing flange; II head reinforcing or stiffening rib at the under side of the pistons head. I2 designates a thickness of metal highly impregnated with copper or other metal having a higher heat conduction factor than the ferrie base metal or other 40 metal from which the piston may be composed.

Expert internal combustion engine engineers have 'long recognized the necessity of improving the transfer of the intense heat generated within the combustion spaces of internal combustion engines by combustion to the cylinder Walls, but until applicants present inventionlittle or no improvement has been made in the said heat transfer which not only causes pre-combustion of the gaseous fuel within the engine, but also causes'rapid deterioration of the internal portions of the engine that the intense heat contacts and which attacks the pistons 4head most severely with the result that the head soon cracks or ruptures, which is commonly termed burning through, which is due primarily to .the'pistona not having a suiiiciently high heat conduction or ability to transfer heat of combustion to the cyl- "'inder wall and therethrough to be absorbed by the cooling fluid within the cooling fluid chamber vsurrounding the cylinder wall.

In my present improved piston, .which is preferably produced by the method disclosed in my application for Letters Patent Serial No. 194,826 bearing even date hereof for Method of casting internal combustion engine pistons, the piston is preferably cast from a ferric base metal having as its principal constituent iron, either in its iron state or as when converted into steel, to which is added during its molten state, a non-ferrie base metal such as copper, and as this cast metal con- 15 tains copper or some other metal having a higher specific gravity than the ferrie base metal, and because of themethodof casting the portion of the pistons head designated by I2 which represents the portion of the piston consisting of almost all 20 copper, which is herein employed for ease of description, or very highly impregnated with copper, which amount or density of impregnation because of the method of casting gradually diminishes with the distance of the portion of the piston separated from the said portion I2. That is, the portion I2 of the pistons head will contain the greatest density or amount of copper with the portion 5 containing less copper, the portion 4 still less and the skirt 3 still less, with the ange I0 containing little or no copper. Therefore the copper or non-ferrie base metal content of the ferrie base metal of my piston will gradually diminish from a maximum density at the head portion I2 to the ange I0 at the opposite end of the skirt from head 2, which flange will contain little or no copper.

Having described my present improved piston, the rights thereto I desire to secure are set forth in the claims as follows:

1. An internal combustion engine piston having as its principal constituent, ferric base metal impregnated with a non-ferrie metal having a higher heat conduction than the ferrie base metal thereof with the greater density of impregnation at the pistons head portion exposed to combustion during the engines operation.

2. An internal combustion engine piston having as its principal comstituent ferric base metal impregnated with a non-ferrie base metal, the 50 degree of impregnation being greatest at the surface of the piston exposed to combustion during the engines operation.

3. An internal combustion engine piston having as its principal constituent a ferric base metal impregnated with a metal or metals having a higher heat conduction factor than the ferrie base metal thereof, `the degree of impregnation being greatest within the pistons head.

4. An internal combustion engine piston having skirt and head portions of which the heat conduction resistance coecient increases from the head portion to the skirt portion.

5. An internal combustion engine piston having as its principal constituent a ferrous metal having therein a non-ferrous metal so distributed throughout the ferrous metal that the heat conduction will have less resistance to ow in the head portion than in the skirt portion.

CHARLES W. DAKE.

Images