US1615086A - Mold for casting metals - Google Patents

Description

Jan. 18, 1927. 1,615,086

0 JUNKER MOLD FOR CASTING METALS Flled July 23 1925 INVENTOR 1 I BY! T W QRNEC g Patented I 18 19 27.

UNITED STATES OTTO JUNKEB, OF STOLBERG, I

morn non cns'rme METALS.

Application fledjuly 28, 1925, Serial No. 4,468, and in Sweden larch v10, 1924.

This invention relates to chill molds and more particularly to chill molds with water circulation for casting metalplates for use in rolling mills. Y

,Chill molds with water circulation have been known :Eor a considerable time. They have the drawback that the metal plates cast therein are considerably inferior to those cast in sand'mglds, i. e. metal plates cast in a bad heat cohtlucting material. 7 In water cooled chill'n'ields the outer layer of the liquid meta Ibe'co'mes chilled and great dif- -ierences in the grain and consequentl' great stressesoccur during the setting of t e cast )late, which exhibit very harmful effects durits further treatment.

' order to avoid this drawback, it has previously been suggested, to bring the cool'- ing fluid to a comparatively high temperature.

For this purpose, however, not only is it necessary to have recourse to a rather complex arrangement, but the metal molds are liable to wear out rapidly on account of thehigh temperature to which they are continuously exposed.

It has, moreover, been suggested to employ metal chill molds having thin walls rovided with a hollow space filled with san around the thin walls of the mold. I

The cooling in such chill'molds is still 1 slower than in commonsand molds, but the cast, the chilling,

casting, although being free from stresses, ossesses a loose texture'and a rough surace in consequence of too slow a cooling.

The present invention enables these draw-v backs to be avoided and results in the production of metal plates which are free from ,stresses and at the same time possess homo-. geneous and fine grained texture. The invention solves the problem by providing a.

chill 'mold in which the walls-so far as is concernedconsist of water.

. For this purpose, the two walls of the chill mold which contact with the metal plate to be cast, are made of very thin sheet metaland water is brought into contact with their rear sides; In this manner, a chill-mold is obtained, in which the water, being a bad heat conductor, prevents any sudden,.deeply penetrating'chilling of the metal plate to be onthe contrary, taking place as follows':-'-

The thin plates of sheet metal take up the first heat from the liquid metaland produce,

by their heat absorptionan initial skin on the outermost layer of the casting. This 'ing the first thin skin, has loeenheated, the

water cooling of the chill mold commences to i be efiective, that is to say, the continuously renewed water behind the sheet metal causes further heat absorption. The drop of temperature between the material of the chill mold and the'metal to :be cast is ke t constant by said continuous supply 0 fresh water. Dueto thefbad heat conductivity of I the water a casting is thus obtained having a uniform texture of medium gram size over 1ts entire cross section. The outermost sk1n formed on the casting is too thin to enable cracks penetrating deeply into the casting, and stresses in the latter to occur..

One constructional form of the improved chill-mold is illustrated-by way of examwhich:-

Figs. 1 and2 show the chill mold in front and side elevation ,respectively, and

Fig. 3 shows a part cross-section on an enlarged scale on the line A--A of Fig. 1.

The construction shown illustrates a double chill mold in which two metal plates may be cast simultaneously in the spaces a, a; The lateral walls of each casting space are formed by verythin plates of sheet. metal b, for example sheets of cop er. The rear surfaces of these sheets are in contact with flowing water. In this particular example a central'water space c and two lateral water spaces (1 are provided, the latter being situated ,in the two covers e of the chill mold. -The water-tight closure is effected by packings f. In order to revent the. thin sheets I) from bellying un er the pressure of the metal to be cast, they are supported rearwardly by ribs 9 provided on the mold.

Peculiar also is the arrangement. of the water supply and discharge, which are effected by a system of pipes rigidly connectedto the chill mold, 1. e. the'water supply takes place through the pipe h and the water discharge through the pipe i.- The sup- 7 plypipe h terminates in a tubular cross piece is carryin two hollow hinge heads I or the oscillabde covers. e of the mold. The water supply to the middle'space 0 of ple in the accompanying drawings in 80 the mold takes placev by way of the channel m. 011 the other hand, the water supply to the two cover spaces 05 is effected through the hollow hinges Z and the bent tubes n. Each of these latter is provided with an elastic connecting member 0 adapted to yield when the closing of the chill mold is effected by means of the presser screws p.

While the water supply takes place at the lower part of the chill mold, the water discharge is eflected at the upper part of the mold by means of a similar system of pipes, as will be understood from Figs. 1 and 2, in. order to ensure the entire filling of the water spaces.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is A double wall metal mold for casting, metals, comprising in combination thin innerwalls which are smooth on bot-h sides, and thick outer walls provided with ribs on their inner sides, said ribs being disposed in contact with the inner walls thereby to support the latter and prevent outward bulging thereof.

In testimony whereof I have signed my name to this specification.

OTTO JUNKER.

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