US1956014A - Wearing part for internal combustion engines - Google Patents

Description

April 24, 1934-. c; K ET AL 1,956,014

WEARING PART FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 22. 1924 IIIIIIIIII m. v F66 42M wwi Patented Apr. 24, 1934 PATENT OFFICE WEARING PART FOR INTERNAL COIWBUSTION ENGINES Colin G. Fink, New York, N. Y., and Charles H. Eldridge, Detroit, Mich, assignors, by mesne assignments, to Chemical Treatment Company, Inc., New York, N. Y., a corporation of New York Application November 22, 1924, Serial No. 751,692

' Renewed December 6, 1933 4 Claims.

This invention relates to improvements in wearing parts, for internal combustion engines. By wearing parts we mean parts that in the operation of the engine are subjected to wear as the result of impact, friction, exposure to the combustion gases, or the like. Thus, we intend to embrace in the term wearing parts such articles as valve parts (including heads, stems and seats), tappets, cam-followers, piston rings, piston pins, channels, pipes, cylinder Walls, etc.

The invention aims to provide, as new articles of manufacture, improved wearing parts, for internal combustion engines, and especially for automotive engines. In accordance with the invention such wearing parts have at least a portion of their wearing surface covered with electrodeposited chromium.

Several embodiments of the invention, by way of example, .are illustrated in the accompanying drawing, wherein Fig. l is a view partly in elevation and partly in section of an automobile valve according to the present invention;

Fig. 2 is a sectional view on the line IIII Fig. l.

Fig. 3 is a view in elevation of a piston pin according to the invention.

Fig. e is a cross-section of Fig. 3 on the line IV.

Fig. 5 is a plan view of a piston ring according to the invention.

Fig. 6 is a view partly in side elevation, and partly in section, the section being on the line VIVI Fig. 5.

Fig. 7 is a vertical cross-sectionof part of an internal combustion engine showing a poppet valve according to this invention, in the exhaust passage of the engine.

Referring to said drawing letter A designates the wearing part, and letter C the chromium electroplated thereon. The thickness of the chromium plate is exaggerated in the drawing.

In-Fig. 7 the poppet valve shown in Figs. 1 and 2, is shown as mounted in a conventional manner in an exhaust passage E of an internal combustion engine, R being the bearing and S the seat.

In accordance with our present invention, the

wearing part A, for example a valve part, has its wearing surface covered to an appropriate extent with a relatively thin layer or film C of electro-deposited chromium. By wearing surface, we

mean that portion of the-wearing part that is sub jected to wear as a result of impact, friction, ex-

posure to the combustion gases, or the like. If desired, the entire surface of the wearing part A may be covered with electro-deposited chromium 0. Where it is not necessary or not desirable to cover the entire surface of the wearing part with chromium, the invention contemplates covering with chromium such portion of the surface as is exposed to the greatest wear.

We have found that wearing parts for internal combustion engines when provided with chromium-plated surfaces in accordance with our present invention possess superior wearing qualities. In particular, such chromium-plated wearing parts have a harder and longer wearing surface, as compared with similar unplated parts and consequently the chromium-plated parts of the invention are found to wear better and last longer.

The sulphur or sulphur compounds contained in oil attack most metals in which they come into contact, but this attack is not ordinarily noticed or accounted a factor in the wear of these parts, as the friction of other parts, of the fluid streams, etc., on such parts is ordinarily regarded as the principal cause of wear, and, moreover, the friction usually keeps the parts bright, so that the cause of deterioration or wear is not readily apparent. Nevertheless, the softening of the surface by corrosion or attack is an important factor in the wear produced by the friction of other parts and of liquid or gaseous streams on such attacked surface. Chromium is unaffected by sulphur or sulphur compounds, and hence chromium surfaced parts, while not only presenting harder surfaces for wear than hardened steel, are resistant to sulphur attack, and therefore give superior wear for both reasons.

Chromium-plated valve parts of the invention have hard surfaces resistant to impact, to friction and to the combined corrosive and erosive action of superheated exhaust gases moving at high velocity and to the corrosive contents of oil, such as sulphur or sulphur compounds. Tappets are used to operate the valves and when chromium-plated, in accordance with the invention, possess a hard surface and are highly resistant to impact.

In making the improved wearing parts A of the invention, the unplated' part may be manufactuned in any appropriate and customary manner. The part is then placed as a cathode in an electrolytic cell containing an appropriate chromium electrolyte and the surface (entirely or partially as desired) of the part is covered with a layer C of electro-deposited chromium of the desired thickness. Where only a portion of the surface of the part is'to be covered with the electro-deposited chromium, appropriate measures well understood in the art of electro-deposition may be taken to inhibit the electro-deposition of chromium, where desired. The wearing part is prepared for chromium plating by cleaning the surface to be plated in any appropriate manner as, for example, by an acid and alkali dip. The wearing part A is then hung as a cathode in a chromium plating bath, preferably a chromic acid bath containing a table catalytic agent, such as a sulphate radical as set forth in the patents to Fink 1,581,188, dated April 20, 1926, and 1,802,463, dated April 28, 1931 and others of Fink and associates. The plate C may be either a grey or a bright plate, as may be necessary or desired, and such plate may be obtained by methods disclosed in said patents.

We claim:

1. In an internal combustion engine the combination of a passage for exhaust gases having a bearing adjacent thereto and a poppet valve arranged to control flow of exhaust gases through said passage and having a portion of its stem supported in said bearing and another portion exposed in said passage, said stemhaving both said portions coated with chromium.

2. A poppet valve for internal combustion engines having a guide bearing for the stem portion, said stem being coated with chromium.

3. A hearing member and a member supported therein for relative movement and frictional engagement therewith, one of said members being

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