US3623692A - Casting mold - Google Patents

Abstract

There is disclosed a casting mold with at least one pouring basin arranged at the top or upper side of the upper part of the mold. This pouring basin is in flow communication with a number of pour-in openings or gates through the agency of channels or troughs. According to an important aspect of the invention, the channel depth is greater than the minimum depth of a channel necessary to prevent overflow during the pouring-in operation, but the channel depth does not drop below the highest location of the mold cavity.

Description

United States Patent l 56] References Cited UNITED STATES PATENTS 1,404,682 1/1922 Barker.1........ 164/363 X 2.147.880 2/1939 Campbell 164/359 X 2.288.661 7/1942 Wadman 1 249/105 2.997.757 8/1961 Buhrer et a1. 164/350 Primary Examiner-H. A. Kilby, .lr. Attorney-Werner W. Kleeman ABSTRACT: There is disclosed a casting mold with at least one pouring basin arranged at the top or upper side of the upper part of the mold. This pouring basin is in flow communication with a number of pour-in openings or gates through the agency of channels or troughs. According to an important aspect of the invention. the channel depth is greater than the minimum depth of a channel necessary to prevent overflow during the pouring-in operation, but the channel depth does not drop below the highest location ofthe mold cavity.

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ATTORNEYS CASTING MOLD BACKGROUND OF THE INVENTION The development of automatic molding and casting installal tions which mechanically activate, by means of appropriate mechanisms, all of the operations necessary for molding and casting, in practice result in the use of increasingly larger and larger mold sizes. The use of larger mold sizes redounds in an increasingly larger operational capacity of such installations, and therefore oftentimes to difficulties in finding sufficient orders to operate such installations. The requirement of practice to improve the accommodatability of the molding and casting installations to markedly different pattern shapes and pattern heights has only been insufficiently satisfied up to now.

It is known to arrange a pouring basin at the top or upper side of the upper part of a casting mold and to connect such by troughs or channels with a plurality of pour-in openings, or gates. In so doing, it is not only the function of the channels, which co not possess any slope or gradient, to connect the pouring basin in flow communication with the pour-in openings, but furthermore, they must, during the casting operation, also take up the difference in the quantity of liquid metal between the supply out of the casting ladle and the outflow through the pour-in openings. Such development allowed for an increase in the size of the shape of a mold cast by means of a single pouring basin. Furthermore, by virtue of these measures, mechanical casting was rendered possible.

However, experience has now shown that with increasing ferrostatic casting pressure during casting or pouring of a mold, the surface of a thus produced casting becomes increasingly coarser. Furthermore, with increasing ferrostatic casting pressure, the snelling" or buckling" of a mold becomes greater. These conditions have, up to the present, resulted in the fact that for the molding and casting of shallow patterns, the castings of which should be accurate and possess a clean surface, it is not possible to achieve these results in high molding boxes or flasks.

SUMMARY OF THE INVENTION Accordingly, it is a primary objective of the present invention to provide an improved casting mold which effectively overcomes the aforementioned drawbacks of the prior art constructions and techniques.

Another, more specific object of the present invention, when shallow patterns, that is to say, patterns of low height, are to be cast in high molding boxes, is to enable casting of these molds with casting pressures accommodated to the pattern heights.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, and, in particular, to provide for the aforementioned accommodation of the casting pressure, the invention contemplates that the channel depth is greater than the minimum depth of the channel necessary to prevent overflow during pouring in of the metal, yet does not fall or drop below the highest location of the mold cavity.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and objects other than those set forth above, will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein:

FIG. 1 schematically illustrates in elevational view a first embodiment of inventive casting mold, as viewed substantially along the line I-I of FIG. 2;

FIG. 2 is a plan view of the casting mold depicted in FIG. 1;

FIG. 3 depicts in side view the casting mold of FIGS. 1 and 2, viewed substantially along the line Ill-Ill of FIG. 2;

FIG. 4 shows in elevational view a second embodiment of inventive casting mold, viewed substantially along the line IV-IV ofFlG. 5;

FIG. 5 shows a top plan view of this second embodiment of casting mold depicted in FIG. 4; and,

FIG. 6 shows a side view of such second embodiment of casting mold, depicted in FIGS. 4 and 5, as viewed substantially along the line VI-Vl of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, in the exemplary illustrated embodiments depicted in FIGS. 1 to 3, inclusive, it will be recognized that reference numeral I designates the molding box, or flask, having the upper mold part or cope la and the lower mold part or drag lb. Furthennore, it will be seen that mold box I is equipped with the patterns 2 and 3. The patterns 2 and 3 to be cast communicate with runners 4. Pour-in openings or gates 5 communicate with the runners 4. The pour-in openings 5 extend from the floor or bottom 8 of the channel or trough means 7 to the runners 4 at the parting plane of the casting mold 1. At the upper side or top of the mold upper part la there are formed, in the molding sand 6, the channel or trough means 7. These bottoms or floors 8 of the channel means 7 are arranged so deeply that they are at least located above the highest raised portion of the patterns 2 and 3.

Continuing, it will be recognized that at the locations 9 there are provided the pouring basins into which liquid metal is poured. The cross section of the channel or trough means 7 is narrow at their bottom or floor region and widens upwardly in chalice or trumpetlike fashion. The cross section of the trough or channel means 7 can be, of course, also trapezoidal shaped or rectangular. Moreover, the cross section of the channel means 7 should be dimensioned such that, during the casting or pouring operation, the channel means 7 at least can take up the difference of the quantity of liquid metal between the supply drain, the casting ladle and the out of or outflow from the pour-in openings 5. As best seen by referring to FIG. 1, the bottom portions or floors 8 of the channel means 7 possess a slope or gradient in the direction of the pour-in openings 5, so that with correct calculation of the quantity of liquid metal, the bottoms of the channel means also empty. Thus, only metal is present in the pour-in openings 5 at the end of the solidification process.

FIGS. 4 to 6, inclusive, depict a second embodiment of the invention incorporating a mold box or flask 11 consisting of the upper mold part or cope 1111 and the lower mold part or drag 11b within which are formed two patterns 12 and 13 possessing different height. More specifically, reference numeral 12 represents a pattern which makes almost full use of the height of the mold 11, as shown, so that the trough or channel means 17 are only fonned slightly beneath the top or upper side of the upper part Ila of the mold 11. The channel bottoms or floors 18, in this arrangement, will be seen to be located, however, above the highest raised portion 19 of the pattern 12. Channel bottoms I8 communicate with the pourin openings or gates 15 opening into the runners 14.

On the other hand, the pattern 13 is raised only slightly above the parting plane 20 of the mold 11 and, therefore, when using channels of known dimensions and arrangements, will be cast with too large a static pressure of the molten metal. It is for this reason that a channel system 21 designed according to he teachings of the invention is used for the pattern 13. However, it will be observed that the channel bottoms or floors 22 are still located above the highest raised portion 23 of the pattern 13. At locations 26 there are disposed the pour-in basins into which there is poured the liquid metal from the casting ladle into the troughs or channels 21. This liquid metal moves from channels 21 into the pour-in openings or holes 24 and the runners 25.

The casting mold according to the present invention renders it possible to also form in high molds shallow patterns and to cast such by a deep course or runner system without exceeding the static pressure of the molten metal accommodated to these patterns. Therefor, with automatic casting installations, it is possible to form in uniformly high molding boxes both high patterns as well as low or shallow patterns, and to cast such under favorable foundry conditions.

Castings formed by the use of channels designed according to the invention possess improved quality of the surface. The prevention of the swelling" or mold wall movement" of the molds during casting improves the tolerances in the dimensions of the cast pieces.

The accommodation of the upper course depth to the momentary height of the mold cavity results in an improvement of the metallic recovery or yield since the pour-in openings or gates are of shorter length, as a result of which the gate plugs are less heavy.

it should be apparent from the foregoing that the objects set forth at the outset to the specification have been successfully achieved.

I claim:

1. A casting mold comprising a mold upper part and a mold lower part, at least one pouring basin means arranged at the top of said mold upper part, a plurality of pour-in openings, channel means for communicating said pouring basin means with said plurality of pour-in openings, said channel means being dimensioned such that during casting said channel means can at least take up the difference in the quantity of liquid metal between the supply out of a casting ladle and the outflow from said pour-in openings, but with said channel means possessing a channel depth greater than the minimum depth of a channel necessary for the taking up said difi'erence and for preventing overflow during casting, yet wherein such channel depth does not fall beneath the highest location of the mold cavity and is located at least in close proximity to such highest location, the bottoms of said channel means sloping downwardly in a direction towards said pour-in openings.

2. A casting mold as defined in claim 1, further including a plurality of said pouring basin means only connected with their associated pour-in openings via said channel means, said mold being divided into a number of mold portions commu nicating with an associated pouring basin means.

3. A casting mold as defined in claim 1, wherein said pouring basin means together with the associated channel means possess different depths accommodated to the corresponding highest location of the associated mold cavity.

I I II 1B

Claims (3)

1. A casting mold comprising a mold upper part and a mold lower part, at least one pouring basin means arranged at the top of said mold upper part, a plurality of pour-in openings, channel means for communicating said pouring basin means with said plurality of pour-in openings, said channel means being dimensioned such that during casting said channel means can at least take up the difference in the quantity of liquid metal between the supply out of a casting ladle and the outflow from said pour-in openings, but with said channel means possessing a channel depth greater than the minimum depth of a channel necessary for the taking up said difference and for preventing overflow during casting, yet wherein such channel depth does not fall beneath the highest location of the mold cavity and is located at least in close proximity to such highest location, the bottoms of said channel means sloping downwardly in a direction towards said pour-in openings.

2. A casting mold as defined in claim 1, further including a plurality of said pouring basin means only connected with their associated pour-in openings via said channel means, said mold being divided into a number of mold portions communicating with an associated pouring basin means.

3. A casting mold as defined in claim 1, wherein said pouring basin means together with the associated channel means possess different depths accommodated to the corresponding highest location of the associated mold cavity.

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