US2401210A - Cylinder head - Google Patents

Description

May 28, 1946. A, v. D. WILLGOOS CYLINDER HEAD Filed May 22,1942 3 SheetsSheet 1 I INVENTOR eflwea'iffl #5259005 May 28, 1946,

A. V. D. WILLGOOS CYLINDER HEAD 3 Sheets-Sheet 2 Filed May 22, 19 42 V w W May28, 1946 A. v. D. WILLGOOS 2,401,210

CYLINDER HEAD Fi'led May 22, 1942 s Sheets-Sheet s INVENTOR This invention relates Patented May 28, 1946 2,401,210 CYLINDER HEAD Andrew Willgoos; West Hartford, Conn., as

sig-nor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application May '22, 1942, Serial No. 444,032

to improvement in intemal-combustion engines and has particular reference-to an improved cylinder head for an air cooled engine. i

i i An object of the invention resides in the pro vision of fan improved engine cylinder head of the character indicated which is easy to manufactureand which can be 1 aforged metal blank.

'Aiurther object resides in the provision of an readily shaped from terial concentration the inner end of the improved engine'cylinder head of the character indicated which is particularly strong and durable and at the same time of a relatively light weight;

these advantages being accomplished by an imprdved distribution of the metal of which the cylinder headis formed. l I I A Iurtherfobject'resides in the provision of an I improved cylinder head of the character indi cated which is symmetrical and'reversible so that y l v it can be made to operate in either one of two or more operative positions'on an engine crankcase.

Other objects and advantages will be more particularlypointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawings, inwhich like reference numeralsare used to designate similar,

' parts throughoutthere is illustrated a suitable mechanical'embodin'ient for the purpose of disclosing the invention. The drawings, however,

I are i'or the purpose of illustration only and are not to be taken as limiting or restricting the invention since it will be apparent to those skilled in the art that various changes in the illustrated embodiment'may be resorted to without in any way exceeding the scope of the invention.

In the drawings; i

Fig. 1 isa top plan view of an engine cylinder head constructed according to the invention.

Fig. 2 is a sid-elevational head illustrated in Fig. 1. o v

Fig. 3 is a longitudinal sectional view on the line 3-3 of Fig. 1.

Fig. 4 is a sectional view on the line 4-4 of Fig. 1, and

Fig. 5 is a transverse sectional view onthe line 5-5 of Fig. 3.

Referring to the drawings in detail, the cylinder head comprises a body portionlo provided with internal threads l2 which are adapted to engage with external threads provided on a cylinder barrel, not illustrated, the end of which projects into the body portion of the cylinder head. Below the threads l2 the body portion In is extended to provide a, skirt portion H of progressively thinner section which fits over the outer end 'of view of the cylinder V construction. Above '4 Claims. (Cl. 123 -171) the cylinder barrel. The absence of any head or portion eliminates any maofstresses in. the barrel at cylinder head and thu in-.) 3 creases the safety and durability of the improved the threads l2 the body porform a dome-shaped combustion chamber provided with annular receptacles Hiand l8 for the intake andexhaust valve seats and with internally threaded spark plug 1:

ange on this skirt tion In converges to apertures, one of which is indicated at 20.

. Projecting from the body portion! arethef :extensions 22 and 24 which are made hollow to :3

constitute rocker boxes for the rocker arms of the valve actuating mechanism. 3

5 These extensions 22 and 24 provide valve guides 26 and 28 which open into thehollowed-out por- 1 tion of the integral rocker arm boxes. From the o inner end of the valvegulde 26 an exhaust port [f 30 opens through the cylinder head between extensions 22 and 24, and an intake port 32 leads of extension 24. Extensions 22 vided in the lower tures 36 and 40 extends from the lower portion of the extension 22 to the body portion l0. A similar web 42 extends from the undersurface of extension 24 near aperture 38 to the body portion In of the cylinder head but this web is somewhat deformed to pass around the boss 34.

While a construction has been shown in which; f one of .the valve ports extends to the exterior of the head through the top portion of the head, it is to be understood that, if desiredfboth ports may open through the top of the head, or both may extend to the sides of the head below the respective rocker boxes, in the manner of the port 34, withoutin any way exceeding the scope of the invention. i

The fins on both the circular and non-circular portions of the head may be out (for example) by providing a forging of proper external shape, by applying a rotary cutter to the forging, and l by so controlling the cutter as to. form separate fins parallel to the ends of 'the head or, if preferred, the fin may be cut inthe form of a continuous helix. Of course, the cutter is controlled" to provide proper predetermined depths to the fins. Discontinuous fins such as those around the o 1 upper part of the head maybe cut by this same p. 8

method.

The provision of fins in the upper portion of to an annular boss 34 provided in the side of the 5 cylinder head just below andslightly to one side and 24 are proa portions thereof with aper- 38 through which enter the valve push rods.- From aperture 36 a reinforcing Web valve ports.

the head is particularly illustrated in Fig. in which the elongated core portion 46 is shown provided along'each side thereof with continuous fins, as indicated at 48 and 50. This figure shows, in broken lines, the path of the cutter while forming fins on the non-circular portion of the head. It will 'be noted that the core portion 46 provides a. relatively thick web 5| between the This core portion, together with the integral web 40 extending to the side of the head and the relatively thick walled port 32, provide a bridge of relatively tirely across the cylinder head thus adding 'materially to the head strength. v

Both the upper and lower ends of the cylinder head are substantially flat, as indicated in Fig. 3, and are parallel to each other. This shape greatly facilitates the machining of the head blank and also results in a considerable reduction in the height from threads l2 to the upper surface of the head. The provision of the exhaust valve port 3|] opening through the top of the cylinder head between the rocker boxes 22 and 24 also is an ad'- vantage in that the hot exhaust gas is kept entirely away from the finned portion of the cylinmetal bridge extending diametrically across the top of said combustion chamber portion and having its longitudinal axis adapted to be positioned in alignment withvthe cooling airflow over said head, a pair of elongatedflat topped valverocker boxes carried by said bridge at opposite sides of the top thereof, said boxes extending outwardly in opposed relationship from said bridge and havheavy metal extending env der head and there is, therefore, little transfer of heat from the exhaust gases back to the cylinder head.

The improved rocket box and fin arrangement also insures a maximum cooling. effect with a minimum pressure loss in the coolingair flow past the cylinder heads since a substantially straight line flow of cooling air across the cylinder and around the valve rocker arm boxes can be obtained. M

It is to be understood limited to the specific embodiment herein illustrated and described, but may be used in other by the following claims:

1. In an aircooled integral cylinder head having a combustion chamber portion, a pair of elongated valve rocker boxes having their longitudinal axes aligned and adapted to be positioned in alignment with the cooling airflow over said head,

said boxes extending oppositely and being positioned in spaced relationship along the line of their longitudinal axes, a metal bridge extending across the top of said combustion chamber porthat the invention is not ing their longitudinal axes aligned and extending in the directionfof the longitudinal axis of said bridge, a web connecting the under side of one of said boxes with said combustion chamber at one side thereof, and a fluid passage extending underneath the other of said-rocker boxes and having a wall constituting a web connecting said rocker boxxwith the other side of said combustion chamber.

3. A one-piece forged cylinder head for radial aircraft engines comprising, a dome shaped combustion chamber portion having intake and ex haust valve ports symmetrically disposed on opposite sides thereof, valve supporting portions projecting outwardly-at opposite sides of said dome portion and having valve stem receiving bores therein disposed at acuteangles with respect to the longitudinal axis of the cylinder, a valve rocker box extending laterally, in a direction normal to said longitudinal cylinder axis and at an angle with respect to the axis of the corresponding valve'stem bore, from each of said valve support- .ing portions adjacent the top of said valve stem tom wall of each of said boxes.

' ways without departure from its spirit as defined 4. In an aircooled integral cylinder head having a combustion chamber portion,-a pair of elongated valve rocker boxes having theirlongitudinal axes aligned and adapted to be positioned in alignment with the cooling'airflow over said head, said boxes extending oppositely and being positioned, in spaced relationship along the line of their longitudinal axes, a metal bridge extending across the top of said combustion chamber portion between said boxes and supporting the adjacent ends of said boxesa push rod aperture in -the outer end of each of said boxes and a valve stem aperture in theinner end of each of said boxes, and spaced parallel cooling fins substantially completely covering saidcombustion chamber portion and said bridge, said fins forming cooling air passages adapted to receive a cooling airstream flowing in the'direction of the longitudinal axes of said rockerboxes.

D. wnmoos. 1

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