US2358175A

US2358175A - Casting apparatus

Info

Publication number: US2358175A
Application number: US461558A
Authority: US
Inventors: James W Mcgill
Original assignee: Aluminum Company of America
Current assignee: Howmet Aerospace Inc
Priority date: 1942-10-10
Filing date: 1942-10-10
Publication date: 1944-09-12
Anticipated expiration: 1961-09-12

Description

Sept. 12, 1944. J; w. McGlLLY, 2,358,175

'CASTING APPARATUS Fild oct. 1o, 1942 4 sheets-sheet 1 ImENTOR;

Jm'es W. NcGi/l ma( ATTORNEY' J. w. McGlLL 2,358,175 CASTING APPARATUS AFiled oct. `1 0, 1942 4 sheets-sheet 2 Sept. 12, 1944.

' INVENTOR Jmes A W NcGi/,

TTQRNEY vifsv Sept. 12, 1944. J. w. McGlLL CASTING APPARATUS Filed oct. 1o, 1942 4 Sheets-Sheet 3 INVENTOR James M /YCGi/l ATTRNEY Sept. l2, l944 J, w, McGlLL.

CASTING lAPPAMTUS Filed Oct. 10, 1942 sheetssheet 4 .ATTORNEY Patented sept. 12, 1944 UNITED ,STATES PATENT 'ori-*lcs I 2,358,175 v CASTING APPARATUS James W. McGill, Alcoa, Tenn., assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Application october 1o, 1942, serien No. 461,558

e claims.

of ingots of the light metals aluminum and magnesiu'm. I

Tiltmolds usually comprise two cast ironhalves hinged at one side and `pivotally fastened to a xed support at their upper portion. At the beginning of casting operations, they are rotated upon the pivotal support until they are almost horizontally disposed with just enoughslope intheir mold cavities to permit the molten metal to flow quietly and without agitation toward the lower corner of the mold. As the pouring operation proceeds and the level of the molten metal in the mold cavity rises, the mold is gradually f lowered until the mold is in a vertically upright position, at which time the mold cavity is sub'- stantially filled.I

Usually it isdesirable that the mold be at a.v

high enough temperature before the casting operation takes place to prevent the metal from solidifying so rapidly that cavities are formed in the casting. /On the other hand, it is desirable that the molten metal be cooled suliiciently rapidly after entering the mold to prevent segregation of alloying elements and to impari; a fine grain structure to the cast ingot.

In order to accelerate the cooling of the cast or poured metal, water jackets through which cooling water is circulated are commonly provided in lthe walls of molds. Such jackets, however, have heretofore been completely llerll with water and consequently they have the disadvantage that, instead of cooling the walls of the mold progressively as adjacent portions in the mold cavity are filled with molten metal they cool the entire wall of the mold simultaneously, caus- 'ing a heat los-s from=portions of the mold cavity before they are filled during castingoperations.

The present invention has for an object to provide an improvedwater cooled moldv of the tiltl type. r

More particularly, an object of the invention vis to provide a. watercooled tilt mold wherein cool- Aing begins adjacent those areas first lled with molten metal and proceeds throughout themold as 4the mold cavity becomes filled with molten metal,

A further object of the invention'ls to provide an improved tilt type mold having a jacket wherein the rise in the level of a circulatingliquid coolant is synchronized with the rise of molte metal being poured into the mold cavity.

Other objects and purposes will appear in the following description of the invention.-

-5 In accordance with the invention, the side walls of a conventional pivotally supported tilt type moldare provided vwith a water jacket having an inlet preferably near the base of the mold and an outlet adjacent the mouthof the mold and in proximity to the wall of the mold that is lowermost when the mold is in horizontal posiiton. Water or other liquid coolant enters the jacket through the inlet and fills the jacket to the level of the outlet, the overflow of water escaping through the outlet from the jacket. While the casting operation is taking place and the base of the mold is being lowered tofbring the mold to an upright Position, the jacket progressively fills with water, becoming completely fllled when the casting operation is completed. Since'the level of the water in the jacket, as wellas the level of the molten metal in the mold cavity, is determined'by the angle at which the'mold is disposed on its pivotal support, the filling up' of the jacket with water and the filling up of the mold cavity with molten metal proceed apaceand the side walls of the mold are contacted by water in' the jacket at substantially the rsame time as the level of' moltenymetal reaches adjacent portions in thevmold cavity. This provides a uniform rate of cooling throughout the casting operation since the level of coolant in the jacket at all times coincides with the levelof molten metal in the mold cavity, .A preferred embodiment of the invention is illustrated' in the accompanying drawings, in whichz" Fig. 1 isa plan view of`a tilt mold designed `for the casting of ingots and adapted to the o objects of the present invention;

Fig. 2 is a'A side view of the mold shown in Fig. 1;

Fig. 3 is a sectional view of the mold taken on theline III-III of Fig; 21; and

15 Fig. 4 ls a side view partially in section showing the mold during astage in the pouring operation.

In the drawings, wherein like reference numerals identify similar parts, I and 2 represent two mold sections of a mold of cast ironv or other suitable materialenclos-ing a mold cavity 2a. The mold sections are joined by a hinge pin 3 passing through suitable-.aligned vbosses or brackets 4 provided along one side of the sections I and 551. The opposite sides of the two sections are.

latch mechanism B when the mold is closed. lit` the-bottom of the mold, a base plate 8; preferably hollow and water coo1ed, is provided. and a block 1 projects outwardly adjacent the top of the mold.

Suitably secured to the block 1, as by screws I, is ahorizontally disposed channel member l provided at each of its extremities with a laterally turned member I0.. Each member I is provided with a trunnion II, the trunnions being disposed in axial alignment and journalled in iixed pedestals or supports I2. This arrangement permits the entire mold to swing about zontal axis of the aligned trunnions II.

Preferably anvexternal lug I3 is provided on base plate 6 having an aperture I4 by means of the hori-l 2,353,1"75 adapted to be clamped together by aconventional heated the desired temperature, from the upright position shown in Fig. 2 to a position but slightly inclined from the horizontal. Before lifting the mold, the drain cocks 22 are opened to empty the water chambers Il. A pouring crucible, not shown, filled with molten metal then is supported upon the pins II and the crucible is tilted to pour the metal into the mold cavity. The molten metal flows with a minimumGof turbulence down the slight slope formed by the inclined wall of the "mold cavity to thev lower portion of the mold. As the lower portion of the mold cavity becomes filled. the metal backs up toward the open mouth of the tilted mold, whereupon the which a vertical hoisting cable I5 (Fig. 4) can be attached for liftingV or swinging the mold to bring the mold from its normal upright position to its inclined position for initial reception of the molten metal therein. 'I'he top of the mold is provided with bosses I6 having projecting pins I 'I coaxial with the trunnions I I and upon which a pouring crucible, not shown, *may be supported during casting operations:

Each of the mold sections. I and 2 is provided mold is gradually lowered about its pivotal support until the cavity isl lled, with themold returned to its upright position.

While the casting operatloniis taking place,

water is delivered constantly through the supply line 24` to conduit 24a and pipe 28 and thence through the

hose connections

21 and 29 to the base plate 6 and the distributing pipes 2l in the in its side wall with a. water jacket or chamber y the jacket away from the' mouth of the mold.

The lower portion of `each jacket isprovided with an inlet 20, tothe inner end of which is connected a distributor pipe 2I that extendsr across the lower end of the chamber I8. A series or row of perforations 2Ia is formed in the wall of the pipe 2| through which jets of water issue into the jackets. Preferably the jets of water are directed against the inner wall of the chamber I8. Each jacket also is provided at its lower portion I with a pipe having a drain cock 22joutsi1de the mold adapted to be actuated by a rod 23.

In the apparatus illustrated.. a water supply' line 24 passes centrally through one of the nxed supports I2 and its trunnion Il. ply line 24 connects with a downwardly extending conduit 24a, the lower end of the latter being l provides a means The water supconnected to an inlet- 25 leading into the hollow base plate 6. Watery entering-into base plate C discharges through drain pipe 2l, emptying there- 'from into a suitable open draintrough `(not shown) below the mold. 'A' flexible hose 21 con- I8 whilel the apparatus is being used for casting mold section 2' operations, and reference numeral .denotes the body of metal being cast in' the mold cavity 2a.

d In the operation of the apparatus, hoisting cable IB is lifted by a crane or other`device, notshown, to swing the mold. the cavity of which is jackets I8. With the mold in the near horizontal position at the beginning of the pouring operation, the jets of water' issuing from the perfo-l rated distributing pipes 2| strike the inner side walls of the mold section and form a pool 30 (Fig. 4) in the lower portion oi the jackets I8, the overflow of water from the'pool 30 escaping out of the slotted discharge openings. I 9 as is clearly shown in Fig. 4. The pools Voi.water 30 in the respectivechambers I 8 nil a progressively greater area in the jackets asthe mold is lowered to upright position and the level of the water rises in the jackets. Hence, during the kentire casting operation, the level of the water within the jackets automatically synchronizes or corresponds with the level of the metal within the mold cavity, andthe mold wall is progressively contacted by the -water coolant in the jackets simultaneously with the rise of molten metal in the adjacent mold cavity. V

The circulation of water through the base block for cooling the bottom of the mold. l

If it is desirable that the coolant contact each portion of the'mold wall before or after, instead ofat the same time as `the level of molten metal arisesto adjacent portions in the mold cavity, the mold illustrated herein is susceptible of modification whereby the level of water in the jacket is higher or is lower, as predetermined, throughout the casting operation than the level of `the molten metal being poured into the mold. By positioning the lower portion of the discharge opening so that it is closer to the upper side of the mold when the mold is plvoted to'horizontal position, the

level assumed by the water in the jacket before it vovelows through the discharge opening becomes higher with respect to the level of molten metal in the mold cavity. Likewise the lower portion of the discharge opening may be advanced toward the lower side c: the substantially horizontally f The .lischarge opening should be suiiiciently* large to permit escape of .avolume of water equal to that being 'admitted into the jacket through the inlet pipe 2li. An opening of such size perf mits escape of the entire overil'ow of water from the jacket, no matter what the inclined position of the mold might be, and prevents the jacket from becoming filled with water abovethe level of the lowermost portion of the opening.

It will be apparent that the cooling "jacket described herein may be employed not only with molds of the specific construction illustrated but also with other types of tilt molds known to the art as well. Also, the apparatus specifically described is susceptible to various modifications, and it will be understood that the variouschanges and modications that `will be suggested to those skilled in the art are within the scope of the in.- vention as dened in the lappended claims.

I claimz' v l..The method of cooling a cast article at a I progressive and uniform rate during the casting thereof in a tilt mold, which comprises passing a liquid coolant through a jacket in the side wall of said tilt mold during the casting operation as the mold is pivoted from the horizontal to the upright position, and effecting discharge of said coolant from the jacket at a point near the mouth of the mold and adjacent the side of the mold .thatis lowermostwhen the mold is in the horiz ontal position ata rate to cause the level of' liquid coolant in said jacket to occupy progressively a greater volume and to rise apace with the rise in the level of the 'molten metal being cast in the mold cavity as the mold is moved from a tilted to upright position. Y

2. A tilt'mold comprising a body vhaving a -cavity therein open at the top for receivingv molten metal, means for pivotally supportingr said body adjacent to an upper edge thereof, said body having a cooling chamber in at least one side thereof substantially coextensive. in area with Athat of the mold cavity, and an inlet in said mold cavity, and an inlet in said chamberforthe chamber for the admission of a liquid coolant and an outlet adiacent the pivotal supportL of the mold body and vof a size suillcient to discharge the coolant at least at substantially the same rate as. that' at which it is admitted to the chamber whereby the rise in level fof the coolant in the'chamber substantially coincides withthe rise in level of molten metal in the mold cavity as the mold body moves from the initial poiiring'position to an upright position.

3. A tilt mold comprising a body having a cavity therein open at the top for receiving molten metal, means for pivotaily supporting said body adjacent to an upper edge thereof, said body having coolingchambersin opposite side walls j thereof' substantially coextensive in area with that of the mold cavity, and inlets near the bottom of each of said chambers for the admission of a' liquid coolantandan outlet from each of -said chambers adjacent the pivotal support of the mold body and oi, a size suilicient to discharge the coolant at least at' substantially the Vsaine rate as that at which it is admitted to the chamber whereby the rise in level of the coolant in thechamber substantially coincides with the rise in .level oimolten metal in the mold cavity as the mold body moves from the initial pouring position t0. an upright Position.

4. A tilt mold`comprising a body having a cavity` therein open at the top for receiving molten metal, means forpivotallysupporting said b'ody adjacent t an upper edge thereof, said bodyy having a cooling chamber in at leastone side thereof substantially coextensive in area with that of the mold cavity, and an inlet in said chamber for the admission of a liquid coolant and an outlet consisting o'f va slot extending across the top of the chamber with one end adjacent the pivotal support of the mold body, said slot being of a size suillcient to discharge the coolant atl ing a cooling chamber' in at least one side thereof substantially coextensive in area with that of the admission of a liquid coolant and-an outlet conslstingof a slot extending' across the 'top of the chamber with one end adjacent the pivotal support of the mold body, said slot being of a sizeV sufficient to discharge the coolant at least at substantially the same rate as that at which it is admitted to the chamber whereby the rise in level of the coolant in the chamber substantially coincides with the rise in level of molten metal in the mold cavity as the 4inoldbody moves from the initial pouring position t0 -an upright position, said mold body having an outwardly proas that at which it is admitted to the jecting ledge across the side and above the youtlet slot in the cooling chambery-said ledge overlying the slot whereby any coolant is prevented from splashing upwardly from the outlet.,

8. A tilt mold comprising -a body having a cavity, therein open at the top for .receiving molten metal, means for pivotally supporting said body adjacent to an upper edge thereof, said body having a coolingchamber inat least one side thereofsubstantially coextensive in area with that of the mold cavity, andan inlet in said chamber for the admission/6ta liquid coolant and an outlet adicent the pivotal support ofthe mold body and of a size suillcientto discharge the coolant at least at substantially the same rate amber whereby the rise in level of the cools in the chamber substantially coincides with the rise-in level of molten metal in themold cavity as the mold body moves from the initial pouring position. to an upright position. said chamber having valve means at the bottom thereof for draining it when the mold is in an upright position.

JAMIE W. MOGILL.