US 3628237 A
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United States Patent  Inventor Kurt F. Ziegler Zion, Ill.  Appl. No. 887,518  Filed Dec. 23, 1969  Patented Dec. 21, 1971  Assignee Outboard Marine Corporation Waukegan, Ill.
 METHOD OF CONSTRUCTING AN ENGINE WITH A PREFABRICATED CYLINDER LINER 3 Claims, 6 Drawing Figs.
 US. Cl 29/527.6,
' 92/222  Int. Cl 823p 17/00, 823p 25/00  Field of Search 29/527.6, 527.5, 156.5; 92/222, 225, 224
 References Cited UNITED STATES PATENTS 3,251,119 5/1966 Kingsbury et a1. 29/527.6
3,402,644 9/1968 Geiger et al. 92/224 3,475,804 11/1969 Geiger et a1. 2 /1566 3,533,329 10/1970 Galli 92/222 ABSTRACT: Disclosed herein is a method of constructing an engine having a cast iron cylinder liner and in which the engine block is die cast around the cylinder liner. The cylinder liner is cast with blind ports or recesses on the exterior surfaces. The outside and inside of the liner are machined to make the surfaces concentric, and the engine block is die cast around the liner by using a two-piece die with fingers which extend into the blind ports to prevent entry of the metal therein.
The recesses are opened after the block is die cast by further machining of the inside surface of the liner.
PATENTED [IEC21 12m 3628-237 m'r-roewavs METHOD OF CONSTRUCTING AN ENGINE WITH A IPREFABRICATED CYLINDER LINER BACKGROUND OF INVENTION SUMMARY OF THE INVENTION The invention provides a method of manufacturing an internal combustion engine having an engine block containing a cylinder liner. The method includes the steps of fabricating a liner with one or more blind ports or recesses in the outer surface of the liner. The inside and outside diameters of the liner are then rough machined to make the surfaces concentric to prepare the liner or sleeve for precise location in a diecasting die. The machining operation leaves a thin web of metal in the ports or recesses to keep them closed for the diecasting opera tion.
In die casting the engine block, the liner is mounted on a locating dowel or center plug and inserted in a two-piece die. The die includes transverse fingers or projections which extend into the recesses or blind ports in the liner to prevent entry of metal into the recesses in the liner and to form through openings in the die-cast material or block registering with the recesses in the liner. In addition, the web of metal across the recesses prevents entry of diecasting metal into the interior of the liner. Subsequent to die casting, the inside diameter of the liner is machined to remove the web portions in the recesses and thereby open the recesses to provide through apertures in the liner.
It is an object of the invention to provide a method of constructing an engine block around a cylinder liner or sleeve by diecasting techniques rather than using conventional sand casting techniques.
It is a further object of the invention to provide a method of constructing an engine by fabricating a cylinder liner with blind ports, machining the inside and outside diameters of the liner, die casting the engine block around the liner using a die having transverse fingers which project into the blind ports to prevent the entry of metal into the blind ports during the casting operation and opening the ports by machining the inside diameter of the liner.
Other objects and advantages of the invention will become apparent from the following disclosure.
DRAWINGS FIG. 1 is a perspective view of a cylinder liner.
FIG. 2 is a sectional view along line 2-2 of FIG. I.
FIG. is a fragmentary sectional view showing the step of die casting the engine block around the liner in accordance with the invention.
FIG. 4 is a sectional view along line 4-4 of FIG. 3.
FIG. 5 is a fragmentary sectional view of an engine block constructed in accordance with the invention.
FIG. 6 is a sectional view along the line 6-6 of FIG. 5.
DETAILED DESCRIPTION Referring to the drawings, FIG. 1 shows a cylinder sleeve or liner which is generally designated 10 and which has a cylindrical wall 12 having an internal surface or bore 14 and a peripheral or exterior surface 16. The sleeve 10 is conventionally sand cast from a suitable material such as iron using projections in the mold to create blind ports or outwardly open recesses 20 in the outer surface 16. The recesses 20 are closed by recess bottoms 21.
The recess margins or edges 22 desirably taper outwardly for reasons hereinafter described.
In accordance with the method of the invention, the inside surface 14 of the liner I0 is machined to a first predetermined radius or diameter as shown b the broken line 23, leaving a small web of material 24 whic keeps the recesses 20 sea ed along the diecasting step, hereinafter described. The outside surface 116 of the liner 10 is then machined concentric with the inside surface 14 to afford precise location of the liner 10 in the die.
As shown in FIGS. 3 and 4, the liner 10 is mounted on a locating dowel or center core plug 28 and inserted in a twopart die 30 having first and second die portions 32 and 34. Both die sections 32 and 34 are provided with projections or finger cores 36 which project into the blind ports or recesses 20 to form ports 38 in a die-cast engine block in registry with the recesses 20 and to prevent entry of molten metal into the recesses 20. The die sections 32 and 34 are provided with passage portions 33 and 35 which completely surround the liner and into which metal is introduced through the opening 41 to die cast the engine block 39 (FIG. 3).
Upon removal of the engine block 39 and liner 10, the inside wall 14 is machined to a second diameter as shown in FIGS. 5 and 6 to remove the web portions 24 in the recesses to provide through openings or ports in the engine block. Any excess metal remaining around the finger cores 36 can be punched out of the ports 38 after removal of the web portions 24. The removal of the excess metal is facilitated by the outwardly tapered excess edges 22.
Various port arrangements and ports locations can be utilized with the method of the invention, and axially aligned ports (not shown) can be utilized with an exterior casting to form a transfer passage to afford communication of a fuel-air mixture from the crank case to the combustion chamber above the piston.
Various of the features of the invention are set forth in the following claims.
What is claimed is:
l. A method of constructing an engine cylinder block having a cylinder liner, said method comprising the steps of fabricating the cylinder liner with a blind recess in the exterior surface of the liner, machining the inside surface of the liner leaving a web of metal closing the recess, die casting an engine block around the liner with a die having a finger projecting into the recess, and machining the inside diameter of the liner to remove the web.
2. A method of constructing an engine cylinder block comprising casting a cylinder liner with an outwardly open blind port on the exterior surface of the liner, machining the inside surface of the liner to a predetermined first radius less than the radius of the bottom of the port, die casting a cylinder block around the liner with a finger in the die extending into the blind port to prevent entry of metal into the blind port to form a port in the block in registry with the blind port in the liner and machining the inside surface of the liner to a second radius greater than the radius of the liner port bottom, whereby to remove the bottom of the liner port.
3. A method in accordance with claim 2 plus the additional step of machining the outside surface of the liner prior to die casting the cylinder block.
my UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION D t December 21, 1221 Patent No. 3 ,628 .237
Inventor(s) Kurt F. Ziegler It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 2, line 11 "along" should be during Signed and sealed this 13th day of June 1972.
ROBERT GOTI'SCHALK EDWARD M.FLETCHER,JR. Attestlng Officer Commissioner of Patents