US3130461A

US3130461A - Cooling passages in cast aluminum cylinder heads and blocks

Info

Publication number: US3130461A
Application number: US128517A
Authority: US
Inventors: Ferris V Curtis
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1961-08-01
Filing date: 1961-08-01
Publication date: 1964-04-28
Anticipated expiration: 1981-04-28

Description

April 28, 1964 F. v. CURTIS 3,130,461

COOLING PASSAGES IN CAST ALUMINUM CYLINDER HEADS AND BLOCKS Filed Aug. 1, 1961 5 Sheets-Sheet 1 INVENT OR PEER/S V CURTIS April 28, 1964 F. v. CURTIS 3,130,461

COOLING PASSAGES IN CAST ALUMINUM CYLINDER HEADS AND BLOCKS Filed Aug. 1, 1961 3 Sheets-Sheet 2 Li I J I (I 37 I \ao -23 3o 3| 3| EI E: 48

INVENTOR PEER/5 V. CURTIS BY Q 4 1...

g ATTORNEY April 28, 1964 F. v. CURTIS 3,130,451

COOLING PASSAGES IN CAST ALUMINUM CYLINDER HEADS AND BLOCKS I Filed Aug. 1, 1961 3 Sheets-Sheet'3 I so\ INVENIOR ,FERR IS V. CUR 77$ United States Fatent ()fi ice 3,130,461 Patented Apr. 28, 1964 3,139,461 COGL G FASSAGES TN QAST ALUPt HNTM CYLTNDER HADS AND BLGEKS Ferris V. Curtis, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed 1, 1961, Ser. No. 128,517 3 Claims. (Cl. 22-263) This invention relates to an internal combustion engine cylinder head or engine block construction in which there are located cooling fluid passages through which inlet and exhaust passages extend. More particularly, this invention relates to a cylinder head or engine block construction and the process of making these or like objects whereby preformed inserts are used in a mold cavity to provide cooling fluid passages and passages for inlet and exhaust gases.

With the increasing complexity of cylinder heads and engine blocks along with the desire to form a very definite relationship between the parts that cooperate with the cylinder head or engine block, it has become more important to provide intricate passages within such members for cooling these cooperating parts without materially increasing the expense of manufacture. It has previously been known to cast molten metal about a conduit of copper to form a cylinder head having necessary cooling passages. This type of construction does not solve present day cylinder head or engine block requirements wherein there is required a greater intricacy of cooling passages and an association between the cooling passage surface and the poured casting to result in maximum heat conductivity to the cooling fluid.

One of the objects of this invention is to provide an internal combustion engine cylinder head or engine block with cooling passages, wherein the cooling passages are formed or stamped parts, thereby giving greater flexibility in design and intricacy in construction without added expense. It is another object of this invention to use a preform in a mold cavity to provide the cooling passages, the preform being integrally associated with the subse' quently poured cylinder head or engine block, thereby resulting in maximum heat conductivity between the cast member and the cooling fluid passages. It is a further object of this invention to provide a process by which a cylinder head or the like with passages therein, may be reliably and easily formed. A still further object of this invention is to produce a cylinder head by using a stamped preformed conduit placed within the cylinder head mold cavity to provide fluid cooling passages in the cast article. The preform may be made by sheet metal stampings securely fastened together to provide desired intricate and complex cooling fluid passages in the cast cylinder head or engine block. Other objects of this invention will become apparent upon analysis of the following description, reference being made to the accompanying drawings wherein a preferred form of the invention is clearly shown.

In the drawings:

FIGURE 1 is a plan view of the cooling fluid preform.

FIGURE 2 is a cross-sectional view taken along line 2-2 of FIGURE 1.

FIGURE 3 is a fragment of a cross-sectional view taken along line 33 of FIGURE 1.

FIGURE 4 is a cross-sectional side view of an intake liner.

FIGURE 5 is a cross-sectional view of an exhaust liner.

FIGURE 6 is a cross-sectional side view of the cylinder head mold having the cooling fluid passage preform and the inlet and exhaust liners assembled therein.

FIGURE 7 is a cross-sectional side view of a cylinder head with the cooling fluid passage preform and inlet and exhaust gas liners molded therein.

FIGURE 8 is a fragmentary view showing the cylinder head cast about the cooling passage preform as illustrated in FIGURE 3.

The cooling passage preform as shown in FIGURES 1 through 3 includes two

sheet metal members

1 and 2 secured together by crimping or the like, and inlet and exhaust conduits 3 and 4 secured to the sheet metal portion it by means of an enlarged portion 5 and a flange 6 on the inlet and exhaust conduits 3 and 4 cooperating with an upset portion 7 in the sheet metal portion 1. A cylindrical conduit 3 has two upstanding portions 9 and it) that are sealingly secured to the sheet metal portion 2 by a press fit or the like with a flanged aperture 11 in the sheet meal portion 2. Conduit 8 further has a spiral 12 extending between the upstanding portions 9 and It) to direct cooling fluid around an exhaust valve stem, as will be hereinafter described. The spiral 12 may consist of one or more turns depending upon the necessity of cooling of the exhaust valve stem, such being dependent upon the actual operating conditions of a particular engine.

Sheet metal portions

1 and 2 have

apetrures

13 and 14 extending therethrough, such apertures being necessary to accommodate intake and exhaust valves.

Similar apertures

15 and 16 can be incorporated in the preform for a plurality of spark plugs or other accessories, if desired. These apertures are formed by having upstanding flanges on the lower sheet metal portion 1 engaging the upper sheet metal portion 2. More particularly, as shown in FIGURE 2, the

upstanding flanges

17 and 18 of the sheet metal portion 1 form the intake and exhaust passages respectively and upstanding

portions

19 and 29 on the upper sheet metal portion 2 provide a press of fused fit with the

portions

17 and 18 to form a secure enclosed assembly. Additionally, the upper sheet metal portion 2 is crimped around its outer edge about the lower sheet metal portion 1 in a well known manner. Similarly, the upper sheet metal portion 2 can be crimped at 21 and 22 about the lower sheet metal portion 1.

Inlet and exhaust conduits 3 and 4 provide means for introducing and removing cooling fluid to and from the cooling passages formed by the preform. The actual location of the inlet and exhaust conduits 3 and 4 will depend upon a specific assembly and in particular, the type of engine in which the preforms are to be used. Since engine cylinder heads take any one of a number of shapes, it should be appreciated that likewise, the applicants preform may take any one of a number of shapes to adapt to the particular cylinder head arrangement. Although the embodiment disclosed and described in this specification discloses a preform adapted only to a single cylinder, use of this invention could obviously involve and include provision of a preform for a multiple cylinder engine. Likewise, the preform could be used in the type of engine wherein each cylinder is separately cooled. Dirnples or depressions 23 may be provided in the lower sheet metal portion 1 to increase the flow characteristics of the cooling fluid and the surface area of sheet 1 so that a greater amount of fluid is warmed thereby obtaining a more rapid cooling characteristic. These dimples 23 could be formed in the upper sheet 2 alone or in the lower portion 1 as well as to increase the rigidity of the preform and aid in securing the preform to the poured molten cylinder head casting.

FIGURES 4 and 5 show intake and exhaust liners, respectively. These liners consist primarily of a stamped sheet metal tube, the specific design of which will be dependent upon the actual cylinder head construction. The intake liner 24- has an aperture 25 extending through a portion 26 that is offset from the regular curvature of tube 24. The aperture 25 is provided for the conventional intake valve stem. The exhaust liner 27 similarly has an aperture 28 in offset portion 29 for the exhaust valve stem.

The assembly of the fluid passage preform and the intake and exhaust liners in the mold cavity is shown in FIGURE 6. Fingers 3t) are spot-welded or otherwise secured to the preform to support the preform within the mold cavity upon shoulder 31 of lower mold piece 32. A permanent core 33 of steel or the like is inserted in the lower mold cavity. This permanent core 33 has two upstanding portions 34 and 35 which extend upwardly beyond the lower mold cavity 32. Tapered

portions

36 and 37 on these upstanding portions are slightly tapered and provide the surfaces upon which the intake and exhaust liners are assembled prior to the molding operation. The upstanding portions 34 and 35 further have shoulders 38 and 39, respectively, that engage the liners

adjacent apertures

25 and 28, while upstanding portions 34 and 35 extend through these apertures and seal off the flow of molten cylinder head metal to the intake and exhaust passages. A helical conduit 8 extends around the upstanding portion 35 so that cooling fluid can be circulated around the exhaust valve stems during operation of engines utilizing cylinder heads and engine blocks incorporating the previously described casting preforms. The exhaust valve gets considerably hotter than the intake valve and the heat problems with this valve are somewhat more difricult and require the necessity of additional cooling means around the efiaust valve stem, such as provided with the helix coil 8.

An upper mold portion 4% has a cavity which determines the external dimensions of the cylinder head therein. This upper mold 40 has extensions 41 and 42 that engage respective outer edges of the intake and exhaust liners. Extensions 41 and 42 prevent flow of molten metal into the intake and exhaust passages.

Apertures

43 and 44 are provided in this upper mold to vent hot exhaust gases from the intake and exhaust passages to atmosphere. The upper mold 4% may necessarily have to be composed of a plurality of pieces due to the relationship of the upper mold with the intake and exhaust liners. For example, this upper mold could be divided into two pivotally associated halves, the halves mounted to be pivoted into association with the intake and exhaust liners subsequent to their being placed within the mold cavities.

After the upper mold 40 is positioned upon the lower mold 32 and the preform and the intake and exhaust liners are assembled in the mold cavity, mold cap 45 is assembled upon the upper mold 4i? so that cap 45 engages the upstanding portions 34 and 35 to complete the molding cavity for an internal combustion engine casting.

Referring now to FIGURES 7 and 8, molten metal is then poured into

passage

46 or 47 to form the cylinder head H and to associate the preform and the intake and exhaust passages with the cylinder head. The poured cylinder head may be associated integrally with the cylinder, such being formed between the lower mold 32 and the permanent core 33 in space 48 shown in FIGURE 6. Special passages, not shown, are provided in the lower mold 32 through which the inlet and exhaust conduits 3 and 4 extend.

An important feature of the applicants invention is the use of aluminum as a material for both the intake and exhaust liners and for the fluid passage preform members l and 2 as well as for

conduits

3, 4 and 8. Use of aluminum members in association with a conventional aluminum cast cylinder head, allows the preform and liners to become integrally associated with the aluminum engine castings during the casting process resulting in a continuous integral aluminum composite body. The preform and liners are properly cleaned and treated by a flux in a well known manner prior to the casting operation so that there will be a rigid integral association between the preform, liners and the casting.

The use of aluminum liners and preforms with an aluminum casting provides a cylinder head construction functionally equivalent to those castings which do not use preforms or liners. Among the important advantages of this use of preforrns and liners are that a more reliable casting is produced and a process which avoids the com plexity of sand cores, such as the cleaning thereof, is provided. Additionally, an integral aluminum cylinder head and preform construction avoids any relative expansion problems or bonding difiiculties that may exist where unlike materials are used. However, should any difficulty in bonding the airtight preformed inserts to the molten aluminum or casting metal arise, the inserts can be specially coated to facilitate the desired adherence. It is recognized that casting aluminum about an aluminum preform or liner presents certain problems in that the heat conductivity of aluminum could possibly result in the molten aluminum metal excessively melting the aluminum preforms and liners. This can easily be avoided by proper selection of the preform and liner alloy material.

While the embodiment above described is the preferred form it should be understood that this invention could take many forms depending upon the type of construction in which preform and liner passages are found necessary. Therefore, it is to be understood that the invention is not to be restricted to the above disclosure but that the invention should have the scope as determined by the following claims.

What is claimed is:

1. A method of casting an aluminum internal combustion engine cylinder head comprising the steps of positioning a permanent core within a lower mold cavity, positioning and fastening upstanding support members on the top surface of said permanent core, welding supporting tabs to a hollow preformed aluminum alloy insert, placing said hollow insert over said upstanding support members so that said support tabs rest upon a shoulder in said lower mold cavity, placing aluminum alloy tubular intake and exhaust gas liners upon said upstanding support members, attaching fluid inlet and outlet ducts to said hollow preformed insert, positioning an upper mold portion upon said lower mold, inserting a mold cap member within said upper mold portion, and pouring a molten aluminum alloy within said assembled mold cavity causing an integral bond with said preformed insert and said gas liners upon solidification of said molten alloy.

2. A method of casting an aluminum internal combustion engine component comprising the steps of positioning a permanent core within a mold cavity, inserting a hollow aluminum alloy preformed insert within said mold cavity, placing aluminum alloy tubular gas passage liners upon said permanent core, connecting fluid inlet and outlet means to said preformed insert, positioning an upper mold portion upon said mold cavity to form a complete mold cavity, and pouring a molten aluminum alloy within said mold cavity whereby an engine component comprising an integrally bonded hollow preformed insert 7 and gas passage liners is formed.

3. A method of forming an aluminum internal combustion engine component comprising the steps of placing a hollow preformed aluminum alloy insert within a lower mold cavity, positioning a first end of an aluminum alloy gas duct liner Within said preformed insert, placing an upper mold portion upon said lower mold, attaching a second end of said gas duct liner upon an extension of said upper mold portion, inserting a mold cap member Within said upper mold portion to form a mold cavity, and pouring a molten aluminum alloy within said cavity causing integral bonding of said gas duct liner and said preformed insert with said engine component upon solidification of said molten alloy.

References Cited in the file of this patent UNITED STATES PATENTS Dietz Feb. 20, 1940 Towler Dec. 24, 1940 Irgens Oct. 12, 1943 Stevenson Mar. 1, 1949 George Apr. 18, 1950 Watson June 28, 1955 Douglas Sept. 25, 1956 Atchison Feb. 19, 1957 Burrows et a1. Nov. 4, 1958 Rarey et al. June 21, 1960

Claims

2. A METHOD OF CASTING AN ALUMINUM INTERNAL COMBUSTION ENGINE COMPONENT COMPRISING THE STEPS OF POSITIONING A PERMANENT CORE WITHIN A MOLD CAVITY, INSERTING A HOLLOW ALUMINUM ALLOY PREFORMED INSERT WITHIN SAID MOLD CAVITY, PLACING ALUMINUM ALLOY TUBULAR GAS PASSAGE LINERS UPON SAID PERMANENT CORE, CONNECTING FLUID INLET AND OUTLET MEANS TO SAID PREFORMED INSERT, POSITIONING AN UPPER MOLD PORTION UPON SAID MOLD CAVITY TO FORM A COMPLETE MOLD CAVITY, AND POURING A MOLTEN ALUMINUM ALLOY WITHIN SAID MOLD CAVITY WHEREBY AN ENGINE COMPONENT COMPRISIG AN INTEGRALLY BONDED HOLLOW PREFORMED INSERT AND GAS PASSAGE LINERS IS FORMED.