US2042015A

US2042015A - Apparatus for casting sleeve-like bodies

Info

Publication number: US2042015A
Application number: US743376A
Authority: US
Inventors: Thomas A Moormann
Original assignee: Forging & Casting Corp
Current assignee: Forging & Casting Corp
Priority date: 1934-09-10
Filing date: 1934-09-10
Publication date: 1936-05-26
Anticipated expiration: 1953-05-26

Description

May 26, 1936, 'r. A. MOORMANN APPARATUS FOR CASTING SLEEVE LIKE BODIES.

Filed Sept. 10, 1934 INVENTOR. 70 7745 /7. M00 27274 I727.

A TTORNEYS.

Patented May 26, 1936 UNITED STATES PATENT OFFICE APPARATUS ronicasrma SLEEVE-LIKE BODIES Thomas A. Moormann, Pleasant Ridge, Mich assignor to The Forging & Casting Corporation, a corporation of Michigan Application September 10, 1934, Serial No. 743,878

2 Claims.

by which passages may be formed in the wall of a. cylindrical hollow article during centrifugal casting thereof.

A still further object of the invention is to provide for the formation, in the wall structure of a hollow centrifugally cast article, of passages which would present 'difllculties in machining such, for instance, as passages which extend at diverse and selected inclinations to the axis, with respect to which the molten metal is revolved during the centrifugal casting operation.

Other objects of the invention are to provide, in a centrifugal casting mold, a destructible lining element having its inner surface complementary to the outer surface contour desired on a centrifugally cast article; to provide an irregular or undulated contour on the inner surface of a centrifugal casting mold lining for forming complementary undulations and irregulations in the outer surface of a centrifugally cast articler'to provide a self-sustaining lining of this character which is adapted to be formed externally of the mold and stored for use in subsequent casting operations; to provide a lining of this kind which is conveniently insertable in the mold and. adapted to be placed therein immediately after completion of a casting operation and without waiting for the mold to cool; to provide a destructible centrifugal casting mold lining element which 40 an article cast therein has solidified; and to provide a removable partial end closure for the mold which has a substantially central charging opening therein that is adapted to admit molten metal to the interior of the mold during rotation of the latter at a comparatively high speed.

A further object of the invention is to provide for the formation of passages through, or 11npression in, the wall of a centrifugaily cast article without the aid of a nold lining.

Still further objects .of the invention are to provide individual passage-forming cores in a mold of this character and means for holding the cores therein in predetermined position; to provide passage-forming cores of this kind which is conveniently removable from themold aftermay be positioned at divers inclinations with respect to each other and with respect to the axis of rotation of the mold; ,.to' provide an improved method of forming composite cylinder liners by a centrifugal casting operation which may be con- 5 ducted in either ofthe foregoing lined or unlined molds; to provide a method of this kind by which the particles of the different metals'forming the composite cylinder liner are thoroughly comingled at the junction of the different portions thereof; and to provide for the introduction of a. non-oxidizing or reducing gas into theinterior of the mold during operation thereof so as to prevent excessive oxidation of the metal or metals.

An additional object of the invention is to provide improved centrifugal casting method and apparatus which are particularly adapted for formation of sleeves such as cylinders.

A still further object of the invention is to provide an improved integral, centrifugally cast, hollow metal article having passages in its wall structure and having an irregular or undulated exterior.

The above being among the objects of the pres-' g5 ent invention, the same consists in certain novel features of construction, combinations of parts and steps of operations that will hereinafter bedescribed with reference to the accompanying drawing and then claimed, having the above and other objects in view.

In the accompanying drawing which illustrates suitable embodiments of the present invention, and in which like numerals refer to like parts throughout the several different views, I

Fig. 1 is a side elevational view of a centrifugal casting apparatus showing the improved mold thereof in longitudinal vertical section.

Fig. 2 is a side elevational view of a cylinder liner of the type used in Diesel engine cylinders, 40 illustrating a specific article which may be advantageously cast in the improved apparatus and in accordance with my improved centrifugal casting method.

Fig. 3 is a horizontal sectional view of the cyl- 5 inder liner taken on the line 8-3 of Fig. 2.

Fig. 4 is a fragmentary view, similar to Fig. l, but showing a modified form of the invention.

Fig. 5 is an enlarged fragmentary sectional view taken through the wallof a preferred type of engine cylinder 'liner which maybe advantageously formed by use of the apparatus disclosed in either Fig. 1 or 4.

In the form of the invention illustrated in Fig. l, the improved centrifugal casting apparatus includes a base or support it upon which a driving member I I is mounted, the driving member being shown, for the purpose of illustration,

as an electric motor although any suitable drivsuitable type such as is employed for baked cores in usual foundry practice. The lining sleeve i9 is self-sustaining in shape and is preferably formed externally of the mold l4 so that sleeves --of this character may be produced in any desired numbers and stored for use in future casting operations. This sleeve is insertable into the .interior of the cylinder through the open end l3 thereof and its outer periphery conforms with and closely fits the inner periphery of the cylinder. In the form shown, the bore of the cylinder tapers outwardly from the closed end l1.

thereof, but this tapered relation of the cylinder wall, while usually desirable, is not essential and the latter maybe straight if desired.

The inner surface of the sleeve I3 is formed to a contour complementary to that desired on the exterior of the final product. In the illustration shown in Figs. 1, 2 and 3, the article is a cylinder liner sleeve, generally designated by the numeral 20, of the type used in Diesel engines and it has aradially extending external flange 2| on one extremity and spaced radially extending external flanges 22 intermediate its extremities. Located between the flanges 22 of theliner sleeve 23 is a series of circumferentially spaced exhaust ports or passages 23. The

-exhaust ports 23 extend in diverse inclinations to each other and with respect to the axis of the cylinder liner sleeve and it will be understood that. such ports would ordinarily present difliculties where necessary to machine them out of a solid sleeve.

The internal side of the mold lining sleeve I3 is provided with spaced grooves 24 and 25 which are complementary to the flanges 2| and 22, respectively, and inwardly extending

radial flanges

26 and 21 are provided on the opposite extremities of the mold lining sleeve is for defining the of the closure 23 abuts against the outer side of the flange 26 of the mold lining sleeve is and holds the latter against unintended displacement from the mold and also retains the inner extremity of the mold lining sleeve in contact with the end wall II of the cylinder It. This closure is releasably held against displacement from the open end of thecylinder. it by any suitable means,- that shown by way of illustration comprising wedges 3l which are fitted in slots formed in the wall of the cylinder it, as illustrated in Fig. l.

The shaft I2 of the driving member ll, fixture l3 and the end wall I! of the cylinder l3 are provided with communicating passages 32 5 through which a reducing, it non-oxidizinggas may, if desired, be conveniently supplied to the interior of the mold to prevent excessive oxidation of the molten metal during solidification thereof. The left end of the passage 32 in the 10 driving member shaft I2 is connected by a tube 33 with a suitable source of either non-oxidizing or reducing gas (not shown).

In operation-of my improved centrifugal casting apparatus the lining sleeve ll and closure 2315 are assembled in the cylinder It in the relation illustrated in Fig. l, and the cylinder is then rotated by the motor ll while the charge of moldable material, such as ferrous metal, nonferrous metal, alloys, or any suitable metallic or non-metallic moldable material, is introduced into the interior of the mold through the charging opening 30. On the other hand, if desired, the charge may be introduced into the mold while the latter is at rest and in this case the mold is promptly rotated after the charging operation. The mold is rotated at a speed sufliciently high to centrifugally evenly distribute the metal around the interior of the mold lining sleeve l8, thereby causing the metal to flow into the grooves 24 and 2i and around the cores, which are preferably of slightly greater length than the thickness of the wall structure of the article. The mold is thus. rotated until the metal solidifies and then the wedges 3| are knocked out and the closure 23 is removed so as to permit the cast article to be removed from the cylinder It by axial move ment with respect thereto. In the particular construction shown the mold lining sleeve may be removed with the cast article and then broken 40 away from it. On the other hand, the mold lining sleeve I! may stick in the mold, in which case during removal of the finished article the cores 28 and the flange 26 will be sheared oil and in some instances the entire lining sleeve broken down, thereby permitting free and easy removal of the article. The cylinder it may then be completely cleaned and a new lining sleeve may be inserted immediately after removal of the article and while the mold is still hot. In the form of the invention illustrated in Fig. 4, the main parts of the centrifugal casting apparatus are substantially identical to those shown in Fig. 1 and corresponding parts of the structures are designated by the same numerals. The cylinder of the mold, generally designated in Fig. 4 by the numeral i3, is provided with a closed .end wall l1 and an open opposite extremity l8. Formed on the open end portion of the cylinder 16' is an oflset cylindrical portion 34 which is coaxial with the main body portion of the cylinder. The closure 23 in the open end of the cylinder I8 is normally located in spaced relation to the inner extremity to the offset portion 34 so as to provide a groove 33 which is comv mediate its ends with a thickened circumferential portion 33, in registration with which internal recesses 39 are formed for receiving individual cores 4!! which are so constructed and arrangedas to provide a series of circumferentially spaced 7 exhaust ports or passages 4| in the finished casting. Also, in using this form of apparatus, before the casting operation the interior of the mold is preferably washed, sprayed orv painted with a thin coat 42 of suitable refractory material of the nature sometimes used in connection with casting in permanent molds of conventional construction. ,In addition, this may be followed by a thin coating of lam'pblack also in accordance with conventional practice in permanent molds.

The coating 42 may last for several casting operations but the lampblack is renewed for each casting operation. -It may be noted that a knock out hole 48 may be provided for each recess 88 so as to permit the corresponding core 48 to be displaced easily after each casting operation.

The centrifugal casting apparatus illustrated in Fig. 4 is employed in identically the same manner in making a cast article as'the apparatus pre viously described, that is, after the interior surfaces of the mold have been suitably provided with a coating 42, the cores 40 have been inserted inplace and the dam 28 secured in position, the mold is set in rotation and suificient molten metal is introduced through the opening 88 to provide the desired article, or, as previously explained, the molten metal may be introduced through the opening while the mold is at rest and then the mold immediately set in rotation to cause proper distribution of the molten metal around the interior walls of the mold. After the metal has solidified and becomes suificiently cooled the dam 28 may be removed and the cast article pulled out of the mold shearing the cores 48 during their removal operation. 0n the. other hand the cores 48 may be knocked out by inserting a suitable tool through the various openings 48 prior to removal of the cast article.

Both forms of the apparatus disclosed in the drawing may be advantageously employed for the production of cylinder liners of a composite nature such, for instance, as those having an outer layer of metal having desired characteristics of toughness, rigidity or the like, and an inner wall portion of metal having suitable characteristics to resist the wear and abrasion oi the piston which will reciprocate therein or the chemical reaction of the gases and/or liquid with which it will come into contact during operation in an engine. A section through a wall of such composite cylinder liner is illustrated in Fig. 5 in which it will be noted that the liner includes a relatively thick outer portion 48 and a relatively thinner inner portion 48, differentiated from the portion 45 by stippling, although, as will be apparent to those skilled in the art, the relative thicknesses of the two portions may vary as desired. As a matter of illustration it may be assumed that the portion 48 is formed from east grey iron and the portion 48 formed from a type of metal which may, for instance, readily lend itself to a nitriding treatment.

.In forming a cylinder liner of the composite type illustrated in Fig. 5 by the apparatus shown, the same methods as hereinbefore described are followed for forming the outer portion 48, and

sufiicient metal is introduced into the rotating or rotated mold to provide the required thickness of the portion 48. In this case it is particularly important that a reducing or non-oxidizing gas is introduced into the mold through the 5 opening 82 to prevent oxidization of the exposed surface of the liner being cast; The mold is rotated and as soon as the metal forming the portion 45 has solidified sumciently to retain its shape, additional molten metal of a composition required to form the portion 48 is introduced into the mold where, because of the relatively greater heat of this second charge of metal and the still relatively high temperature of the first charge of metal and because the exposed surface 15,

of the first charge has been kept from oxidizing, the contacting surface layers of the two charges will intimately commingle throughout their entire areas and be fused together in such a manner that there will be no distinct line of separation between the twvoportions 48 and 48 when the liner is completed. This insures that in the finished article there will be perfect heat conducting bond between the two portions of the liner and that there will be no danger of one of the portions separating from the other during.service. The bond is also such that, regardless of subsequent heat treating 'or other operation upon the liner, the two portions will retain their intimate bond with one another.

With either of, the foregoing centrifugal casting apparatuses and methods high speed production of centrifugally cast cylindrical articles having passages in their wall structures located intermediate their extremities may be economically conducted. By employment of the mold linin sleeve l9, illustrated in Fig. 1, it is possible to centrifugally cast the exterior of an article to substantially any desired irregular contour.

Although but several specific embodiments of the invention have been herein 'described,.it will be apparent to those skilled in the art that various changes may be made therein without departing from the spirit and substance of the broad invention, the scope of which .is commensurate with the appended claims. p

I claim:

1. In centrifugal casting apparatus including a hollow casing having an open extremity, a lining sleeve comprising core material insertable in said'casing and including an integral core extending inwardly of said sleeve for forming an opening in the wall structure of an article cast in said casing.

2. In centrifugal casting apparatus, a mold including a hollow cylindrical casing having a core recess in its interior and having an opening registering with said recess and extending through the wall of said casing, and a destructible core replaceably mounted in said recess and extending :toward the central portion of said casing, the portion of said core disposed in said recess being removable therefrom by insertion of a suit--' able instrument into said opening from the. exterior of said casing.

' THOMAS A. MOORM ANN.