US2600529A - Engine cylinder construction for cooling valve seat inserts - Google Patents

Description

2,600,529 N FOR TS A T. GREGORY ENGINE CYLINDER C0 COOLING VALVE FilOd Juno June 17, 1952 NSTRUCTIO SEAT INSER INVENTOR. ALFRED I GREGORY BY 2' .43., TTORNEYS.

Patented June 17, 1952 ENGINE CYLINDER CONSTRUCTION FOR COOLING VALVE SEAT INSERTS Alfred '1. Gregory, Mas'sapequa, N. Y., assignor to Fairchild Engine and Airplane Corporation, Farmingdale, N. Y., a corporation of Maryland ApplicationJune 19, 1946, Serial No. 677,887

11 Claims. 1

This invention relates to engine cylinder constructions, and has particular reference to exhaust valve seat constructions for cylinders of internal combustion engines, although the invention is not limited to that use.

The dissipation of. heat from the seat of the exhaust valve of an internal combustion engine is always a problem, and in the case of cylinders comprising a steel liner encased in aluminum, the liner intervenes between the highly conductive aluminum and the exhaust valve seat. Accordingly, although the cylinder as a whole is eli'ectively cooled by reason of the high heat-conductivity of the aluminum, the exhaust valve seat still retains an excessively high temperature because the intervening liner metal has lower conductivity than the aluminum and acts as a heat dam. In addition to the liner, the joint between it and the press or shrunk-fitted valve seat provides a space which, although exceedingly small, nevertheless'causes a temporary drop between the outside surface of the valve seat and the inside surface of its socket in the liner, so that heat conduction from the valve seat to the aluminum is further retarded.

In accordance with the present invention, a cylinder construction for the exhaust valve seat of an internal combustion engine cylinder is provided which afi'ords a direct heat-conducting path between the valve seat and the aluminum casing or mufl of a unit cylinder of the type described, whereby the heat dam occurring in previous constructions is avoided and substantial improvement in the cooling of the exhaust valve seat is obtained.

In one embodiment of the invention, the exhaust valve seat socket is formed in the wall of the head of a unit cylinder and the wall of this socket is pierced radially with spaced openings, so that when the aluminum casing or mufi is cast around the liner, the aluminum flows into the openings in the valve seat socket and becomes cast against the exposed outer surface of the steel valve seat, which has been previously pressed or shrunk into the socket in the liner. Preferably. the external surface of the valve seat is coated with a material which bonds readily with aluminum in accordance with a known process, such material being chromium, for example, or a ferrous metal selected to unite with aluminum at the temperature at which the liner unites with aluminum during the bonding of the liner with the aluminum casing or mufi.

In another embodiment of the invention, the head of the unit cylinder liner is provided with bronze or other material not uniting with aluminum at the bonding temperatures between aluminum and the steel cylinder liner, the outside surface of the socket liner is preferably coated with chromium, so that when the aluminum,

forming the casing or muff of the cylinder liner is cast in place thereon, the aluminum becomes bonded with the chromium-plated surface of the socket liner through the access openings in the wall of the valve seat socket. Ii the valve seat socket liner is of aluminum or other material uniting readily with the casting aluminum, no separate coating of chromium or the like is necessary. Alternatively, instead of providing a separate valve seat socket liner, it may be cast of aluminum by providing an annular space between the valve seat and the interior surface of the valve seat socket, into which the aluminum flows through the openings in the latter when the aluminum is cast around the cylinder liner as a whole.

It will be seen that the engine exhaust valve seat construction of this invention affords a direct heat-conducting path of aluminum or other high heat-conducting material directly from the outer surface of the steel valve seat through the openings in the wall of the cylinder liner to the heatconducting and dissipating casing or mufl surrounding the cylinder, which may be provided with conventional cooling fins.

For a more complete understanding of the invention, reference may be had to the accompanying drawings, in which:

Figure 1 is a view of the upper portion of a typical unit cylinder encased in aluminum and provided with the exhaust valve construction of this invention;

Fig. 2 is a cross-section through the exhaust valve seat as seen along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary axial section of a modified form of the invention, and

Fig. 4 is a fragmentary axial section of a modification of the arrangement of Fig. 3.

Referring to the drawings, numeral l0 designates a cylinder liner of steel, preferably formed in one piece, either by being drawn or machined of one piece of metal, or formed of a tubular barrel portion II and a dome or cap I: welded 3. together at it, the barrel having proper wearing qualities for cooperating with the piston and the dome l3. having the high strength necessary for resisting combustion gas pressure within the cylinder.

Formed in the wall of the cap or dome l2 are sockets l4 and i5 for receiving the valve seat inserts l6 and ll of the intake and exhaust valves, respectively. Although the invention is also applicable to intake valve seats, the problem of cooling the latter is not as acute as with exhaust valve seats, and consequently the latter will be described.

As shown particularly in Fig. 2, the lateral, wall of the exhaust valve socket I5 is pierced by a series of relatively large spaced holes l8, preferably circular, as shown, although they may have any other desired shape. The hardened steel valve seat is normally directly pressed or shrunk within this socket, as indicated in the case of the intake valve seat It, but in the case of the exhaust valve seat l1 its exterior surface, where it abuts the interior surface of the socket I5, is provided with a thin coat of chromium 20, preferably applied by electro-plating. Instead of chromium, the coating maybe some othermaterial which unites with aluminum casing material at the temperature at which the liner bonds with aluminum, such as copper, a ferrous metal, aluminum, and the like.

During casting of the aluminum casing or mull 2| around the cylinder H), the aluminum or aluminum base alloy casting material forms a chemical bond with the steel of the liner ill, the operation being conducted to secure that effect, preferably according to the process disclosed-in Patent No. 2,396,730, issued March 19, 1946, to Whitfield and Sheshunofi. The molten aluminum accordingly comes into intimate contact with the exterior coated surface 20 of the exhaust valve seat l1 through the openings 18, and bonds therewith under the conditions described in the aforesaid patent.

constituting the mud! or casing 2|, and thence to the cooling fins 22', as described.

Alternatively, the valve seat socket liner 25 shown in Fig. 3 may be cast in place with aluminum during the operation of casting the casing or muff 2i, by spacing the valve seat H from the inner wall of the socket 15, so that the casting aluminum flows through the openings 18' into the annular space between the seat l1 and the socket Hi to form the valve seat socket liner 25' or aluminum, as is shown in Fig. 4. The outer end of the annular space is, of course, sealed to prevent the aluminum from flowing out. In case the socket liner 25 of aluminum is so cast in 'place, it is preferred that the exterior surface of the valve seat ll be coated with chromium, copper, aluminum, or the like, so as to bond with the casting aluminum in the manner and for the purpose described in connection with Figs, 1 and 2.

Although certain preferred embodiments of the invention have been illustrated and described herein, it is to be understood that the invention is not limited thereby, nor is it limited to internal combustion engine cylinders, but may be employed with equal facility for valve seats in other engines, pumps, turbines, or the like, all within As illustrated particularly in Fig. 2, the aluminum of the casing 2i extends through openings la in intimate contact with the valve seat H so that heat is conducted from the latter directly through the aluminum casing 21 to the cooling fins 22 formed at and adjacent the exhaust valve passage 23, which is cored in the casing H or may be formed'by a sheet metal exhaust passage liner 24, as shown in Fig. 3, for example.

In the modified form of the invention illustrated in Fig. 3, the socket iii in the liner I0 is formed with the lateral openings It as before, but a valve seat socket liner 25 is interposed between the valve seat l1 and the inner surface or the socket IS. The liner 25 is preferably aluminum, bronze, copper, or some other good heat-conducting metal, into which the valve seat I1 is pressed or shrunk, either before or after the liner 25 is likewise pressed or shrunk into the socket l5. II of bronze or other material not uniting or bonding chemically with the aluminum or aluminum base alloy metal iorming the mufi or casing 2|, the outer surface of the valve seat liner 25 is coated with aluminum, chromium, or

.other metal which bonds under those conditions and temperatures with the molten casting aluminum or aluminum base alloy. As before, the casting metal of the mufi or casing 2| flows into the openings l8 and unites with the exterior surface of the valve seat socket liner 25 to form a continuous heat-conducting path from the latter through the openings I! to the aluminum mass the scope of the appended claims.

I claim:

1. A valve seat construction for engine cylinders and the like, comprising a metal cylinder liner, a casing for said cylinder of different metal having higher heat-conductivity than said liner metal, a valve seat insert mounted on said liner, heat-conducting means of metal of higher heatconductivity than said liner on the outer surface of said insert, and metal of higher heat conductivity than said insert extending substantially radially through said liner from said casing to said valve seat insert and united with said casin and said heat conducting means to conduct heat from said valve seat insert to said casing.

2. A valve seat construction for engine cylinders and the like, comprising a metal cylinder lin'er, a casing for said cylinder of diflerent metal having higher heat-conductivity than said liner metal, a valve seat insert mounted on said liner, said liner having spaced openings opposite said valve seat insert and extending substantially radially thereto, and heat-conducting means of metal of higher heat-conductivity than said liner extending through said openings in saidlinei, said heat conducting means being united with said casing and bonded to said insert whereby heat is conducted from said valve seat insert to said casing.

3. A valve seat construction for engine cylinders and the like, comprising a metal cylinder liner, a casing for said cylinder of difierent metal having higher heat-conductivity than said liner metal, a valve seat insert mounted on said liner and having on its outer periphery a layer of metal capable of bonding to said casing metal, said liner having spaced openings opposite to the outer periphery of said seat insert and extending substantially radially thereto, and heat-conducting means of metal of higher heat-conductivity than said liner extending through said openings in said liner from said casing to said valve seat insert and united with said layer of metal and said casing metal, to conduct heat from said valve seat insert to said casing.

4. A valve seat construction for engine cylinders and the like, comprising a. metal cylinder liner having a recess for a valve seat insert, a

casing for said cylinder of different metal having higher heat-conductivity than said liner metal, a valve seat insert mounted in said liner recess, said liner having spaced openings, substantially radial in the peripheral wall' of said recess, and heat-conducting means of metal of higher heatconductivity than said liner extending through said openings in the wall of the recess in said liner between said casing and said valve seat insert and united with said insert and said casing, whereby heat is conducted directly from said valve seat insert to said casing.

5. A valve seat construction for engine cylinders and the like, comprising a metal cylinder liner, a boss on said liner forming an internal recess for a valve seat insert, a casing for said cylinder of diflerent metal having higher heatconductivity than said liner metal, a valve seat insert mounted in said liner recess, and having on at least its outer periphery a metal layer capable of uniting with said casing metal, said liner having space'd openings in the peripheral wall of said boss extending substantially radially to said insert, and heat-conducting means of metal of higher heat-conductivity than said liner extending through said opening and united with said layer and the metal casing to'conduct heat from said valve seat insert to said casing.

6. A valve seat construction for engine cylinders and the like, comprising a metal cylinder liner, a casing for said cylinder of different metal having higher heat-conductivity than said liner metal, a valve seat bushing of higher heat conductivity than said liner mounted on said liner, a valve seat insert in said bushing, and heatconducting means of metal 'of higher heat-conductivity than said liner extending at spaced points substantially radially through the wall of said liner between said casing and said valve seat bushing and bonded to said casing and bushing, to conduct heat from said valve seat insert to said casing.

7. A valve seat construction for engine cylinders and the like, comprising a metal cylinder liner, a casing for said cylinder of difierent metal havinghigher heat-conductivity than said liner metal, a valve seat bushing of higher heat conductivity than said liner mounted on said liner, said liner having spaced substantially radial openings opposite said bushing, a valve seat insert in said bushing, and heat-conducting means of metal of higher heat-conductivity than said liner extending through said openings in said liner and united with said casing and said valve seat bushing for conducting heat from said valve seat insert to said casing.

8. A valve seat construction for engine cylinders and the like. comprising a ferrous metal cylinder liner, 9. boss on said liner forming an internal recess for receiving a valve seat insert, said boss having spaced peripheral openings extending substantially radially therethrough, and a casing of metal of higher heat-conductivity than said liner metal enclosing said liner at least at said boss and extending through said openings therein into engagement with a valve seat insert in said recess.

9. A valve seat construction for engine cylinders and the like, comprising a ferrous metal cylinder liner, a boss on said liner forming an internal recess for a valve seat insert, said boss having spaced peripheral openings extending substantially radially therethrough, a valve seat insert in said recess, a casing of metal 01' higher heat-conductivity than said liner metal enclosing said liner at leastat said boss and extending through said openings therein into engagement with a valve seat insert in said recess, and a layer of metal on the outer peripheral surface of said valve seat insert uniting with said casing metal at the molten temperature thereof.

10. A valve seat construction for engine cylinders and the like, comprising a ferrous metal cylinder liner, 2. boss on said liner forming an internal recess for a valve seat insert, said boss having spaced peripheral openings extending substantially radially therethrough, a bushing in said recess, a valve seat insert in said bushing, and a casing of metal of higher heat-conductivity than said liner metal enclosing said liner at least at said boss and extending through said openings therein and bonded to the valve seat bushing in said recess.

11. A valve seat construction for engine cylinders and the like, comprising a ferrous metal cylinder liner, a boss on said liner forming an internal recess for a valve seat insert, said boss having spaced peripheral openings extending substantially radially therethrough, a bushing in said recess, a valve seat insert in said bushing, a casing of metal of higher heat-conductivity than said liner metal enclosing said liner at least at said boss and extending through said openings therein into engagement with said bushing, and a layer of metal on the outer surface of said bushing opposite said openings united with said casing metal.

ALFRED T. GREGORY.

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

UNITED STATES PATENTS Number Name Date 1,165,339 Moench Dec. 21, 1915 1,168,752 Seidler Jan. 18, 1916 1,233,964 Birkigt July 1'7, 1917- 1,562,555 Harley Nov. 24,1925 2,112,232 Stoll Mar. 29, 1938 2,134,250 Heintz Oct. 25, 1938 2,136,690 Jardine Nov. 15, 1938 2,191,485 Jensen Feb. 27, 1940 2,275,503 Brown Mar. 10, 1942 2,280,660 Newcomb Apr. 21, 1942 2,331,554 Irgens Oct. 12,1943 2,362,622 Fischer Nov. 14, 1944 2,369,025 Cummings Feb. 6, 1945

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