US2619078A - Cylinder head assembly for internal-combustion engines - Google Patents

Description

Nov. 25, 1952 J. E. WlTZKY ETAL 7 CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES Filed June so, 1947 6 Sheets-Sheet 1 WOLFGANG S. LANG ICHARD i208 3331 Nov. 25, 1952 J. E. WlTZKY ETAL 2,619,078

CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES Filed June 30, 1947 6 Sheets-Sheet 2 WOLFGA N6 3. LANG ICHARDJ. KOB

Nov .2 5, 1952 J. E. WITZKY ETAL 2,619,078 1 CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES 6 Sheets-Sheet 5 Filed June 30, 1947 v avwenfom JULIUS E WITZKY WOLFGANG S. LANG a mg VZICHAZL J. E. WITZKY ETAL 6 Sheets-Sheet 4 CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES Nov. 25, 1952 Filed June 30, 1947 Elnocmrom II JULIUS E. WITZ KY 61 H'ornur Nov. 25, 1952 J. E. \NlTZKY ETAL CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES Filed June 50, 1947 6 Sheets-Sheet 5 anon Tom JULIUS E. WITZKY WOLFGANG S. LANG 12 RICHA 59%,, 3'

RD J. AKOB @m Nov. 25, 1952 J. E. WlTZKY ET AL 2,619,078

CYLINDER HEAD ASSEMBLY FOR INTERNAL-COMBUSTION ENGINES 6 Sheets-Sheet 6 Filed June 30, 1947 0 ME 9 1 w S .r G u .5 umm L wmA F 1 F mmw 77. JW R/ m E Q J 2 2 45% I Z V lilllll 2 J W] Patented Nov. 25. 1952 CYLINDER HEAD ASSEIHBLY FOR INTER- NAL-COMBUSTION ENGINES Julius E. Witzky, Stuttgart-Cannstatt, and Wolfgang S. Lang and Richard J. Jakob, Wendlingen-Neckar,

Germany,

assignors to the United States of America as represented by the Secretary of War Application June 30, 1947, Serial No. 758,030

1 Claim.

This invention relates to internal combustion engines, more particularly it is directed to a cylinder head assembly for diesel engines wherein fuel is injected into very highly compressed air within a combustion chamber, the air having its temperature raised to a point where it will spontaneously ignite the fuel.

The principal object of the invention is to provide a cylinder head assembly for diesel engines, which is simple and easy to manufacture and maintain, and which meets the highest requirements of reliability, light weight and compactness, with minimum overall dimensions and yet readily accessible for inspection, maintenance and repair.

Another object of the invention is to provide a cylinder head assembly for diesel engines having a water-cooled removable precombustion chamber for preventing detonation in the combustion of the fuel by partially burning it in the precombustion chamber, and releasing the partially burned fuel into a main combustion space, together with a novel arrangement of intake and exhaust ports, valves and their guides and cooling water ducts in combination with the precombustion chamber.

Another object of the invention is to prevent cooling water from heating the incoming air of diesel engines by eliminating the cooling ducts around the upper sides of intake ports and which permits recesses to accommodate valve springs, whereby the length of intake valve stems may be reduced, thus reducing the height and weight of the cylinder heads of the engine.

Another object of the invention is to provide a cylinder head assembly including an improved thrust mechanism on rocker arms of a diesel engine for actuating the valves thereof.

With the above and other objects and advantagesin view, the invention consists of certain features of construction and operation of parts which will hereinafter be described and shown in the accompanying drawings, in which-- Fig. 1 is an enlarged fragmentary vertical sectional view through the cylinder head assembly;

.Fig. 2 is an enlarged fragmentary vertical sectional view through the intake and exhaust valve mechanism and its associated parts of the cylinder head assembly;

Fig. 3 is a plan view of a cylinder head assembly, parts being in section;

Fig. 4 is a horizontal cross-sectional view taken on line IV-IV of Fig. 1, looking in the direction of the arrows;

Fig. 5. is a vertical detail sectional view taken on line VV of Figs. 3 and 4, looking in the direction of the arrows;

Fig. 6 is a horizontal sectional view taken on line VIVI of Fig. 1, looking in the direction of the arrows;

Fig. '7 is a detail vertical sectional view taken on line VII-VII of Fig. 4, looking in the direction of the arrows;

Fig. 8 is a vertical sectional view taken on line VIII-VI1I of Figs. 3 and 4, looking in the direction of the arrows;

Fig. 9 is a vertical sectional view taken on line IX-lX of Figs. 3 and 4, looking in the direction of the arrows;

Fig. 10 is a vertical sectional view taken on line X--X of Figs. 4 and 6, looking in the direction of the arrows; and

Fig. 11 is a detail vertical sectional view of a precombustion chamber removed from the cylinder head assembly.

Referring more specifically to the drawings and more particularly to Figs. 1 and 2, the cylinder head assembly includes a head I which is an individual casting and cored out to form water ducts at 2, intake port 3, exchaust port 4, a central cylindrical bore 5, and an exit opening or port I including a threaded portion 8 for removably receiving a threaded lower end 9 of a casing in of a removable precombustion chamber II, which is in direct thermal contact with water ducts 2.

Cooling water is adapted to flow up in the jacket [2 into the water ducts 2 through ports [3 and i3 formed in the cylinder and cylinder head I, respectively. From the ducts 2, the water enters a chamber M immediately contacting the lower end of the precombustion chamber l I, and after circulating around the walls surrounding the intake and exhaust valves 3| and 32, respectively, the water enters the vertical ducts I5 leading to a. chamber [6 immediately contacting the upper end of the precombustion chamber, whence the water enters a port I! leading to the manifold l8. In order to provide an intensive cooling of the exhaust valve seats, the lower part of the cooling water space in the cylindrical head is provided with guides or ribs. The amount of cooling of the precombustion chamber It attained relative to the cooling of the cylinder head is regulated by the size and shape of the upper and lower chambers l4 and I6 immediately contacting the precombustion chamber H. The exit opening or port I from the precombustion chamber ll communicates with the main combustion chamber or space 53 and is provided with a burner or insert 54 consisting of an upper part and a lower part 55 and 55, respectively. The upper part 55 is threaded on its periphery to engage an internal thread 56 on the lower end 9 of the casing ID and carries an inner heat storing core piece 57 by means of a disc having apertures 58 therein. The disc not only presents a relatively fiat or planar surface to the interior of the pre-- combustion chamber so as to receive the full impact of the expanding gases from combustion but serves to locate the heat storing core piece 51 as closely as possible adjacent to the center. of the precombustion chamber to more easily receive heat from the combustion therein and to aid maintenance of vaporization of the mixture passing from the precombustion chamber to the main combustion chamber. The lower part 55' is in the form of an inverted cone with the conical wall having slightly rounded edges which gradually join the exist opening 1, thereby forming a conical nozzle for directing the contents of the precombustion chamber it against a cone having point l9 formed on the piston 23, with the boundary surface surrounding the point 19 being formed with an annular depression 24, so that the mixture ejected from the precombustion chamber is distributed evenly throughout the main combustion chamber or space 53, formed by the upper crown of the piston and the lower portion -22 of the cylinder head. The central location of the precombustion chamber l! and the short compact structure of insert 54 reduce the distance the fuel must travel to a minimum and therefore cause a complete utilization of the air present in the engine cylinder, with a minimum of air remaining. The upper end of the casing I is slida-bly fitted in the bore 5, and a portion of the wall of the casing l0 forming the precombustion chamber II is slidably fitted in the bore adjacent to the walls of the intake and exhaust 3 and 4, respectively. A casing 23 including a fuel opening 25 is provided, in which casing 23 is supported a fuel nozzle 25 preferably of the pintle type which is adapted to discharge fuel through the opening 2 2 into the precombustion chamber, it being understood that the fuel nozzle 25 is connected to'a source of fuel supply by any suitable means such as by the tubes 25. The casing IE] is held in engagement with the precombustion chamber ll by means of a threaded collar or bushing 27.

The nozzle 25 atomizes and sprays the fuel with an injection pressure of a predetermined amount in pounds per square inch into the hot compressed air trapped in the precombustion chamber. Due to partial combustion in the precombustion chamber, the entire fuel is vaporized. The pressure rise in the precombustion chamber blows the fuel vapor and carbon monoxide gas violently into the main combustion space 53, where the dispersing cone l9 on the crown of the piston 20 causes the jet to mushroom and mix thoroughly with the hot air. In this procedure the proportions of the precombustion chamber H, the shape of the burner 5 and the area of the orifices are of great importance as they can be changed to meet various con.-

ditions and requirements of operation.

Referring to Fig. 2, which is an enlarged fragmentary vertical sectional view through an date valve springs 29, which saves distance in the length of the stems of the intake valves 3!. The cylinder head is also provided with a return 53 which extends diagonally from the recess 28 to a chamber 60.

The head of the cylinder is provided with thrust mechanisms for actuating the intake and exhaust valves 3| and 32, which thrust mechacontact with the valve stems.

nisms are providedon the ends of double rocker arms 33 and 33' for the intake and exhaust valves.

The rocker arms at their outer ends 34 are drilled and threaded, and support adjustable hollow studs 35 held in adjustable locked position by lock nuts 36. The studs 35 are hollowed at their lower ends to accommodate spheroidal balls 31 which have a fiat portion 31' at the top and a fiat portion 38 at the bottom in The lower rims of studs 35 are crimpedv at 39 to hold the balls 3? in place. Small tubes 4! are press-fitted into the studs 35 and present a flat face 43 to the fiat portion 31 but allow a small clearance therebetween. This arrangement permits limited turning of the balls 31 so that they can accommodate themselves to theflat surface of the valve stems 3i) and is of the intake and exhaust valves 3| and 32, respectively, throughout the limited swing of the rocker arms 33, while'tubes ll prevent turning of the balls far enough for them to get out of line with the valve stems. Studs 35 and tubes ti, being hollow, permit oilto accumulate and run through to lubricate the balls 35 in their sockets.

By using a removable precombustion chamber l l, a single casting may be made of thecylinder head, machining of the spherical inside of the precombustion chamber can be made on a small piece by an inexpensive turning operation, the size and shape of the precombustion chamber may be made readily adaptablefor diii'icult applications without alteration of the cylinder head, the outside surface in contact with the cast cylinder head allows many possibilities of cooling and insulating the precombustion cham her, the water flow may be so directed that certain parts are more cooled to a greater extent while other parts of the precombustion chamber are insulated to remain hot.

It will thus be seen thatthere has herein beenprovided a novel and efficient cylinder head assembly for internal combustion engines of the diesel type which is well adapted for the purpose intended. Even though there has herein been shown the device as comprising certain features of construction and operation of parts, it is nevertheless to be understood that various changes may be made therein, without departing from the spirit or scope of the claim.

Having thus described our invention, what we claim as new and wish to secure by Letters Patent is:

A cylinder head assembly for a diesel engine comprising a cylinder head having internal ducts for a liquid coolant; a bore extending through the head and communicating with said ducts, said bore opening at the center of the.

portion of the head that will cover a main combustion chamber when the head is mounted on an engine block; and a precombustion chamber unit including a bulbous precombustion chamber having a substantially smooth spherical interior and an open stem, a fuel injecting nozzle opening into said precombustion chamber opposite said stem, and a substantially cylindrical insert removably mounted in said open stem and extending exteriorly thereof; said unit being removably mounted in said bore with the stem directed toward said portion of the head that will cover a main combustion chamber and with said cylindrical insert terminating in said bore in the plane of the exterior of the head; said cylindrical insert including an inner portion and an outer portion; said inner portion being substantially disk shaped and externally threaded to engage the interior wall of the stem of the precombustion chamber; said inner portion also having a planar surface presented to the interior of the precombustion chamber, and having a plurality of passageways extending therethrough spaced around a center portion which forms a heat storing core piece extending from said planar surface of said irmer portion and protruding from the exterior side thereof; said outer portion being substantially cylindrical and having a tapered longitudinal bore therethrough; said bore communicating with said passageways of said inner portion and converging toward the outer end of the insert whereby said insert with its bore and passageways forms a nozzle through which must pass the gaseous mixture resulting from partial combustion of the injected fuel in the precombustion chamber and whereby heat may be retained in the heat storing core piece which is substantially insulated from the engine coolant by said plurality of passageways while the major portion of the precombustion chamber is cooled by direct contact with the coolant.

JULIUS E. WITZKY. WOLFGANG S. LANG. RICHARD J. JAKOB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Ser. No. 368,293, Von Mallinckrodt (A. P. 0.), published May 11, 1943.

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