US2975778A

US2975778A - Fabricated cylinder head-en-block

Info

Publication number: US2975778A
Application number: US674090A
Authority: US
Inventors: Orland W Wilcox
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-07-25
Filing date: 1957-07-25
Publication date: 1961-03-21
Anticipated expiration: 1978-03-21

Description

March 21, 1961 o. w. WILCOX FABRICATED CYLINDER HEAD-EN-BLOCK Filed July 25, 1957 4 Sheets-Sheet 1 Fig.1

March 21, 1961 o. w; WlLCOX 2, 75,

FABRICATED CYLINDER HEADENBLOCK Filed July 25, 1957 '4 Sheets-Sheet 2 g 2 INVENTOR March 21, 196] o. w; WlLCOX FABRICATED CYLINDER HEAD-EN-BLOCK 4 Sheets-Sheet 4 Filed July 25, 1957 INVENTOR W [0. 404

FABRlCATED CYLINDER HEAD-EN-BLOCK Orland W. Wilcox, Pasadena, Calif. (3080 N. Fair Oaks Ave., Altadena, Calif.)

Filed July 25, 1957, Ser. No. 674,090

4 Claims. (Cl. 123-195) This invention relates to internal combustion engines and more particularly to a cylinder head-en-block construction and more especially to the design and method of fabricating the same.

The general purpose of the invention is the bringing together, in a hydrogen-atmosphere furnace, of sheet metal stampings and associated steel parts into a permanently unitary structure of cylinder head-en-block configuration and a copper brazing or welding thereof by a heat fusionprocess. A cylinder head-en-block is a configuration embodying a plurality of cylinders, the head and ports associated with each cylinder, and the water jacket surrounding cylinders, cylinder heads, and associated parts. 7 H

Several methods of heat treatment have been in use for some time and these include electric welding, gas welding, induction welding and induction brazing, and furnace brazing. Of these types furnace brazing appears to be the most satisfactory for cylinder head-enblock fabrication, provided, of course, a thorough analysis of the fabrication techniques has been made.

Itis therefore the principal object of the invention to provide a cylinder head-en-block which is made entirely of sheet metal and tubing and which is furnace welded into a unitary structure. a

Another object of the invention is to provide a light weight cylinder head-en-block which is suitable for use where high performance is needed for extendedperiods.

Another object of the inventionis to present an improved method of fabricating a cylinder head-en-block so that warpage and leakage are not encountered.

7 Another object of the invention is to provide a cylinder head-en-block which has greatly improved heat transfer 7 2,975,778 Patented Mar. 21, 1961 ice Figure 5 is a partial view in section of one of the hold-down tube slip joints.

Figure 6 is another view of the same, showing the hold-down bolt tube slip joint after subsequent welding and machining.

Figure 7 is a detail of a staked bushing which houses an O-ring (not shown).

Figure 8 is a perspective view of a cylinder having a modified head unit comprising a stamping, each half stamping making up :a half of each intake an exhaust port, and half of each passageway for the valve guide receptacles, and one-half of the cylinder head.

Figure 9 is a View of a single stampingwhich makes up half of a modified cylinder unit which includes the cylinder, the head, and the intake and exhaust ports, and involved tubes.

Figure 10 is a perspective view of a cylinder head, associated ports, and valve guide receptacles of a nonsymmetrical stamping.

A cylinder head-en-block is a unitary structure comprising the cylinders, the cylinder heads, the communicating ports, or conduits, leading to and from the intake and exhaust manifolds, the valve guide receptacle pas sageways, and the water jacket which surrounds these parts.

The preferred embodiment of this invention, shown in Figure 1, is a four-cylinder, in-line engine. A cast camshaft housing is mounted on top of this cylinder head-en-block, and a cast crankcase is secured underneath it. The camshaft housing, cylinder head-en-block, andya cast crankcase are bolted together with ten, long, through bolts which pass through the cylinder head-enblock at positions where the hold-down bolt tubes washers 14 are shown in Figure 1. I l

The water jacket comprises a single sheet 11, folde into seven surfaces resembling an inverted U, a pair of ends 12, and a bottom plate 26. This Water jacket sheet 11 is preferably made from a relatively thin gauge sheet steel. Various steels are suitable for this purpose; however, it has been found that a high strength, highly corrosion-resistant steel, sold under the United States Steel Corporation trademark of Cor-ten, is satisfactory for this water jacket.

characteristics when compared with the conventionalcast head-en-block. 1

Another important object of the invention is to provide unique methods and designs for fabricating a cylinder head-en-block with high turbulence, hemispherical;

or squish type combustion chambers.

A further object of the invention is to provide a cylinder head-en-block construction of basic simplicity.

Other objects and advantages will appear and be brought out more fully in the following specifications, reference being had to the accompanying drawings,

wherein: a

Figure 1 is a perspective view of a fabricated cylinder head-en-block having four cylinders, the view being taken from the side which best shows the intake and exhaust ports to the cylinders.

Figure 2 is an end view of the cylinder head-en-block with the water jacket end plate removed and with appropriate break-out sections to show the engine internal The water jacket has a top plate portion 13 and a bottom plate 26 through which extend hold-down bolt tubes 31, washers 14, a top portion 13., spacers'44, and a cylinder reinforcing ring 24, which rests on bottom plate 26. Valve guide receptacles 32 extend to the top portion 13 of the water jacket and are secured by washers 15. After the cylinder head-en-block has been welded into a unitary structure, the

washers

14 and 15 are machinedto form a flat surface illustrated in Figure 6.

Figures 1 and 2 show exhaust manifold mounting flanges 16 and intake manifold mounting flanges 17 which are disposed on different surfaces of the aforementioned water jacket folded sheet 11. These flanges are provided with the bolt receptacles 21 for securing the manifolds thereto. I

The

numerals

18 and 19 respectively refer to the exhaust and intake elbows, or conduits, and may be referred to just as ports, and these ports, or conduits, extend through the water jacket and are welded into a unitary structure.

A spark plug access tube 33 is provided for each cylinder and extends through a surface of portion 20 of the water jacket which is inclined as shown in Figure 2.

The manifold bolt receptacles 21 have a two-fold pur- A pose, which isto hold the

manifold mounting flanges

16 and 17 and the Water intake mounting flanges 38 rigidly to the water jacket, and also to provide a threaded receptacle for the bolts which will be used to hold the intake and exhaust manifolds (not shown) and the'water-hose flange (not shown) to their respective flanges.

Cylinders which are indicated 22 extend through and are secured rigidly to the water jacket bottom plate 26, there being cylinder reinforcing rings 24, and cylinder staking rings 25, which aid strengthening the water jacket where the cylinder goes through the bottom plate 26. The cylinder bottom lip is rolled or staked to the cylinder staking ring 25.

After the cylinder head-en-block is'filrnace-brazed, this joint efiectively becomes a unitary structure. The upper end of the cylinder 22 fits into a cylinder head 23, as is clearly shown in Figures 2 and 3. A slip joint 30 being provided between each cylinder audits head, must be held to a minimum clearance of substantially 0.0005 inch.

The Water jacket bottom plate 26 is secured to the water jacket 11' with the use of bottom plate holding strips 28 which strips are spot welded to the jacket 11 Similar strips (not shown) are spot weldedto the water jacket end plates 12 to hold the ends of the water jacket bottom plate 26. A copper wire 29 is positioned in these holding strips 28 to provide an ample source of bonding copper at this joint. The joint between the bottom plate 26, water jacket 11, and holding strips 28, is intended to be a slip joint similar to slip joint 30.

The cylinder head 23 as shown in Figures 2 and 3 is of a configuration to create high turbulence which is popularly known as squish type cylinder head. This head 23 is a sheet metal stamping. The intake port 19 is made of two stampings, spot welded together for preliminary assembly. Figure 3 shows one of the intake port stampings 39. This stamping includes passageways for the valve guide receptacles 32. The mating part to stamping 39 is a mirror image of stamping 39. The intake port 19 is held rigidly to the cylinder head 23 with the threaded valve seat 40. The exhaust port 18 is made of two stampings spot welded'together similar to that for the intake port 19, and the exhaust port 18 is rigidly held to the cylinder head 23 with a threaded valve seat 40 likewise.

A threaded coupling 35 holds each port, either intake 19 or exhaust 18, the associated

manifold mounting flange

16 or 17, and the water jacket 11 together rigidly. Each 'valve guide receptacle 32 is pressed into position, spot welded, and thereafter the top lip rolled onto the valve guide receptacle washer 15, as clearly seen in Figures 2 and 3. The rolled lip of the valve guide receptacle holds the port, the washer 15, and the water jacket'top surface 13 together rigidly.

The spark plug access tube 33 and the cylinder head 23 are held in proper alignment to each other with the spark plug threaded sleeve 34, as shown in Figure 2. The spark plug threaded sleeve 34 has both ends rolled over to hold the cylinder head 23 and the spark plug access tube 33 rigidly together for preliminary assembly. Following the furnace brazing cycle, this sub-assembly is a strong, water-tight, gas-tight, unitary joint, and the threaded sleeve 34 then serves as the receptacle for the spark plug. The top end of the spark plug access tube 33 is rigidly held to the appropriate water jacket surface 20 by rolling the lip of the tube as shown in Figure 2.

The water distribution manifold 36 runs the length of the cylinder head-en-block. It is spot welded to the inner side of the water jacket 11 prior to brazing. A novel feature of this water distribution manifold 36 exists in the nozzles 37 which are essentially punched orifices in the manifold. The nozzles 37 are positioned to direct a stream of water directly at the spark plug threaded sleeves 34. The water is then diverted onto the

valve ports

18 and 19 at approximately the threaded valve seats 40. Thus the spark plugs and valve seats 40 which are particularly subject to malfunction due to heat, are

given the advantage of maximum cooling since the lowest temperature cooling water available impinges directly on them.

Figure 4 illustrates one of the hold-down bolt tubes 31 in its preferred form. It serves in three distinct capacities:

The initial purpose of each hold-down bolt tube 31 is to act as a long, hollow rivet. At the top end it shoulders against the reinforcing washer 50, and when its upper lip is riveted over, the hold-down bolt tube washer 14, the water jacket top surface 13, and the reinforcing washer 50, are held together rigidly. At the lower end it shoulders against the hold-down bolt tube. reinforcing washer 45, and when its lower lip is staked, or rolled, over, the hold-downbolt tube staking washer 43, the water jacket bottom plate 26, the adjacent cylinder reinforcing rings 24, the spacer 44, and the reinforcing washer 45, are held together rigidly. Each hold-down bolt tube 31, when staked over at both ends, acts as a spacer maintaining the distance between the. water jacket top surface 13, and the water jacket bottom plate 26. It also acts as the means for holding the entire assembly together prior to rolling the edge of the water jacket 11 and the water jacket end plates 12, as shown by the rolled edge 27. The rolled edge 27 locks the entire cylinder unit into the confines of the water jacket proper. The rolled edge 27 also stitfens the water jacket 11, and the water jacket end plates 12 at this lower joint.

The second major purpose for the hold-down bolt tubes 31 is to act as a compression member when the camshaft housing (not shown), the cylinder head-en-block, and the crankcase (not shown) are bolted. together. The hold-down bolts are torqued up to provide greater bolt tension than would be experienced in the bolts during operation of the engine. This is done so that the cylinder head-cn-block will not lift off of the crankcase. For high performance operation at high compression ratios and high revolutions per minute the hold-down bolt tension necessary for successful operation would distort the water jacket if the hold-down bolt tubes 31 were not provided. The camshaft housing (not shown) is designed to act as a strong back for the fabricated cylinder headen-block.

The final and obvious reason for the hold-down bolt tubes 31 is to provide a water-tight passage for the holddown bolts.

A step-by-step description of the forces involved during the heating half of the brazing cycle will show how this simple, clean design accommodates the distorting forces which could be caused by severe temperature differentials within the cylinder head-en-block. When the mechanically assembled cylinder head-en-block is transported into the furnace, which is maintained at 2100 F., the Water jacket heats very rapidly. Assuming that the water jacket at one given instant is 1000 F. hotter than any of the internal parts, it can be understood why provisions for this temperature differential must not be ignored. Two pieces of steel 12 inches long, at ambient temperature, would measure of an inch difference in length, should one piece be heated to 1000 F. hotter than the other. The stress necessary to restrain the heated piece, or to elongate the cooler piece of steel would be approximately 120,000 p.s.i. The yield strength of suitable stamping sheet steel ranges from 20,000 p.s.i. to 80,000 p.s.i. Thus it is explained why permanent distortion may beexperienced during the brazing cycle.

The cylinder units are independent of one another (they are not internally connected to one another in any manner) and are essentially floating in the water jacket as the water jacket expands lengthwise. The water jacket also expands heightwise very rapidly. This heightwise expansion is taken up two ways: The hold-down bolt tubes31 expand slower than the water jacket 11; consequently the bolt tubes 31 force the water jacket bottom plate lip 26 to enter deeper into the slip joint at the holding strip 28. The hold-down tubes 31 heat up faster than the cylinders 22, because the cylinders are of heavier material. Assuming that all parts reach furnace temperature before the cylinders 22, we find that slip joint 30 has allowedthe cylinder 22 to pull out of the cylinder head 23 a short way. When the cylinder 22 reaches furnace temperature also, it slips all the way back into the cylinder head 23. 7 Thus the slip joint 30 relieves anticipated stresses. 7 g i The cooling-01f half of the brazing cycle is relatively simple. The cylinder-head-en-block cools evenly and slowly as it drops in temperature 300 F. The slow, even cooling gives the copper a chance to solidify and to bond all the parts together into a unitary structure. The brazed joints are stronger than the parent metal by the time the structure has cooled to 1550 F.; so it is then safe rapidly to air-quench the structure in order to refine the grain size of chrome-molybdenum steel cylinders. One design precaution must be observed before attempting the air quench from a high temperature of 1550 F. This precaution is that the cylinder uni as a unitary structure must be stronger in column loading than the water jacket surrounding it.

Figure 5 shows the hold-down bolt tube 31 held in a slip joint formed by a slide bushing 41. The slide bushing 41 is staked over the hold-down bolt tube washer 14. This design would allow the water jacket to be made in some configuration wherein the bottom plate 26 would not be able to move. Figure 6, as previously explained, is primarily to show a rolled (or staked) joint after it has been machined to provide an accurate surface.

Figure 7 is a detail of a staked bushing 42, which houses an O- ring (not shown). The application of'this type of bushing would be where a hold-down bolt tube 31 was not needed. The staked bushing 42 would allow a hold-down bolt (not shown) to pass through the water,

jacket 13 and the O ring would effect a Water seal be-' tween the bolt and the bushing .42.

cylinder head stamping 46,- shown as the mating stamping 46a, also. The combination symmetrical cylinder head stamping 46 makes up half of each port (intake and exhaust), half of each passageway for the valve guide receptacles, and half of the cylinder head. Two

of these stampings are spot welded together and accomplish the same purpose as the five individual stampings in Figure 2. The symmetrical feature of this stamping 46 makes it unnecessary to have more than one set of stamping 'dies.

Figure 9 shows a single stamping 47 which is intended to serve as half of ,the cylinder as well as half of all the other functions which stamping 46 accomplishes. The half cylinder unit stamping 47 can be made of chrome-molybdenum steel sheet stock, or it can be cast or forged from some of the other appropriate steels. Made of the proper steel, the valve seats can be ground out of the parent stamping 47. Two stampings, such as 47, may be welded together by higher temperature means than copper brazing and maybe done prior to brazing thus simplifying the water jacket brazing process.

The cylinderhead. depicted in Figure 10 shows the use of two non-symmetrical combination cylinder head stampings 48} and 49. Each stamping makes up half of each port (intake and exhaust), half of each passageway for the valve guide receptacles, and half of the cylinder head. The design features of Figure 10 include maximum and unrestricted induction porting, and the possibility of using different size intake and exhaust valves.

Figures 8, 9, and 10 show a bridging strip 51 between the intake and exhaust ports." This bridging strip 51 adds considerably to the dome strength of a hemispherie cal combustion chamber.. Thebridging strip, and the ports form a triangle which stifiens the dome, reducing I r .35 The hemispherical combustion chamber is very often conduits, and a web extending between the inlet and exhaust conduits.

References Cited'in the file of this patent UNITED STATES PATENTS 1,113,124." Jacobs Oct. 6, 1914 1,133,531 Breath "Mar. 30, 1915 1,270,044 Murray June 18, 1918 1,402,695 Wall Jan. 3, 1922 1,621,521 Cappa Mar. 22, 1927 2,011,642 Loefiler Aug. 20, 1935 2,199,423 Taylor May 7, 1940 2,275,478 Taylor Mar. 10, 1942 2,337,577 Taylor Dec. 28, 1943 2,341,488 Taylor Feb. 8, 1944 1 2,444,963 Taylor July 13, 1948 2,578,079 Meinertz Dec. 11, 1951 the flexing caused by the' compression stroke and the I. 1

power stroke of the gas charge in the cylinder.

Having described my invention what I claim is:

adaptation to an internal combustion engine consisting of a plurality of cylinder units, each cylinder unit comprising as components a tubular cylinder, a head, inlet, exhaust, valve guide, and spark plug conduits communicating with said head, and 'a sheet metal water jacket through which all of said'components exclusive'of said head, extend, all of said components and said Water jacket being secured together by a heat fusion process, each said head comprising a sheet metal stamping having a peripheral portion transverse to the cylinder axis adjacent the top of the cylinder so formed as to provide high turbulence of a fuel charge in said cylinder.

2. A fabricated cylinder head-en-block structure for adaptation to an internal combustion engine consisting of a plurality of cylinder units, each cylinder unit comprising as components a tubular cylinder, a head, inlet, exhaust, valve guide, and spark plug conduits communicating with said head, and a sheet metal water jacket through which all of said components exclusive of said head, extend, all of said components and said water jacket being secured together by a heat fusion process, said water jacket including top and bottom plates for mounting respectively a cam shaft housing and crank case, and

a plurality of bolt hold-down tubes extending through and secured to said top and bottom plates.

3. A fabricated cylinder head-en-block structure for adaptation to an internal combustion engine consisting of a plurality of cylinder units, each cylinder unit com prising as components a tubular cylinder, a head, inlet,

exhaust, valve guide, and spark plug conduits communicating with said head, and a sheet metal water jacket through which all of said components, exclusive of said head. extend, all of said components and said water jacket being secured together by a heat fusion process, each said cylinder head comprising a pair of half stampings, jointly forming said conduits, eachcylinder unit including a pair of mirror image stampings, each of said stampings forming one-half respectively of a head, inlet, ex-

haust, and valve guide conduits, and a web extending between the inlet and exhaust conduits.

4. A fabricated cylinder head-en-block structure for adaptation to an internal combustion engine consisting of aplurality of cylinder units, each cylinder unit comprising as components a tubular cylinder, a head, inlet,

exhaust, valve guide, and spark plug conduits communi- 2,817,327 Brenneke Dec. 24, 1957