US3670803A

US3670803A - Chill casting machines

Info

Publication number: US3670803A
Application number: US813663A
Authority: US
Inventors: Willi Dehnhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-08-14
Filing date: 1969-04-04
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20
Also published as: DE1758822B1; FR2015611A1; GB1235774A

Abstract

A chill casting machine wherein chill halves are mounted on the free end of a pivoting, cantilevered arm supported by a column. Pivoting movement of the arm is effective to immerse the chill halves in a bath positioned below the arm. A second pivoting means is provided to tilt the chill during the filling thereof to provide rapid and complete filling.

Description

United States Patent Dehnhard [4 1 June 20, 1972 [54] CHILL CASTING MACHINES [56] References Cited 72 Inventor: Willi Dehnhard, Ander Niers 35, 417 Gel- U1 STATES PATENTS dem, Germany 1,715,418 6/1929 Langenberg 164/343 [22] F1 d A 14 1969 3,429,358 2/1969 Tingquist et a1. ..l8/24X 1 pp No 813 663 FOREIGN PATENTS OR APPLICATIONS 292,787 6/1916 Germany ..164/336 [30] F is A u do Prior Dan. 549,139 10/1956 Italy ..118/425 ore n pp ca n y Primary xaminer-Robert D. Baldwin Aug. 14, 1968 Germany ..P 17 58 822.6 Auomey l ur Schwartz [52] U.S. Cl ..l64/267, 164/336, 164/343, [57] ABSTRACT 164/348, 266/33 R 51 Int. Cl. ..B22d 15/04 A casting machim wherein halves m mounted [58] Field of Search ..l64/343 342 336 348,158, the free end of a pivoting. e ed arm stlpported by a 4 18/22? g 425 30 column. Pivoting movement of the armis effective to immerse l2 l 266/33 R S 5 2 the chill halves in a bath positioned below the arm. A second pivoting means is provided to tilt the chill during the filling thereof to provide rapid and complete filling.

8 Claims, 8 Drawing Figures PATENTEDmzo I972 SHEET 10F .4

IN VENTOR FIG.2

WILLI DEHNHA RD ATTORNEY PATENTEBmzo I972 FIG. 8

SHEET u or 4 &

CHILL CASTING MACHINES The present invention relates to a chill casting machine in which the chill is mechanically opened and closed as well as immersed.

Apart from chill casting, procedures for the processing of copper alloys include sand casting and pressure casting. Although the chill casting method and the pressure casting method are especially suited for the production of comparatively thin-walled and complex parts, while the sand casting method is more suitable for compact parts, frequently the choice of a specific method mainly depends upon economic aspects only in the case of moderately shaped parts. Naturally, limited lots are handled by sand casting. However, with increasing lots the costs of the molds are enormous since a broken mold is required for each shape so that manufacture of a permanent mold such as a chill or a pressure casting mold, will be profitable. Investment costs in chill casting are comparatively low since any expensive machinery will not be required. Optimum performance as to number of pieces is achieved by pressure casting; but its employment is not economically justified in general until lot sizes are in excess of about 5,000 units.

From a merely technical point of view and with respect to structure and surface of the workpiece chill casting is in many cases equivalent to pressure casting. In some instances chill casting is superior to pressure casting, for, as opposed to pressure casting, it is possible to use sand cores in chill casting. And it is not difficult either to insert cast-in parts such as screws, bolts, and similar. A number of materials such as aluminum bronze can only be handled by sand or chill casting, not by pressure casting. Finally, the problem of ventilating the mold upon filling is not as serious with chill casting as it is with pressure casting.

In many applications in which chill casting and pressure casting are to be regarded as technically equivalent methods, chill casting might be preferred due to its lower investment costs unless the numerous steps frequently so far still performed by hand and requiring skill and experience contributed to a reduction in production capacity thus partially limiting the favorable economic features of the chill casting method. This applies to connection of the chill halves, to speedy splashproof casting of the liquid metal, to erection of the inclined chill during filling, to separation of the chill halves and removal of the casting, to immersion and black-washing of the heated chill, and possibly to insertion of cores prior to a new connection.

Consequently, the range of application of chill casting can only be extended as soon as the delaying manual steps are avoided and mechanized as far as possible. Provided that these movements may be accelerated, chill casting has a chance to be equivalent to pressure casting as far as production capacity is concerned, and the purchase of expensive pressure casting machines might be eliminated in numerous cases.

Chill casting machines have been developed in which only the chill halves are automatically opened and closed. There are machines of the horizontal mold closing type and of the vertical mold closing type. As a rule opening and closing is effected by hydraulic cylinders in which event, as is the case with the pressure casting method, one of the two chill halves is frequently stationary while the other half is moved to be opened and closed. With these machines the chill cannot be tilted prior to filling and raised again during filling. In this case the chills cannot be readily immersed and black-washed after each casting cycle either.

For brass and copper chill casting in which both chill halves will have to be immersed into a blacking bath after each cast, machines with a horizontal mold closing movement are frequently used. A machine is known, for instance, in which on opposite sides of a trough containing a cooling and blacking bath, two substantially identical means are provided to receive the clamping jaws of the chills, to hydraulically move the same towards each other in a horizontal direction, and to immerse the chill halves in the trough by tilting.

As to its construction this embodiment is rather expensive. Insertion of cores is complicated and often only possible by the aid of additional equipment. In practical casting it is, however, a severe drawback that the chill has been built into the machine too far. The operator does not have free access to the chill so that uniform emptying of the ladle is seriously obstructed resulting in the risk of casting faults due to slow and splashing filling.

It is the object of the present invention to provide a simple casting machine for chill casting which may be produced economically and by which the most essential steps are effected automatically, while the chill grants free access to the operator for filling.

According to the present invention the chill casting machine comprises a pillar column to which a freely projecting arm adapted to be inclined around a horizontal axis has been attached, the front end of said arm supporting a chill closing and holding means moving the chill halves towards and away from each other.

Provision of the closing and holding means at the free end of the projecting arm grants absolutely free access to the chill so that the operator will not be required to forward the ladle via machine elements into the inside of the machine. Construction costs are considerably reduced as compared to units already known due to the fact that the mold closing movement is efiected by a means which is common to both chill halves.

In a preferred embodiment the closing and holding means comprises guides parting in front in the direction of the arm in a V-shape and adapted to guide the clamping jaws for the chill halves; the guides are approaching or departing from each other by a movement in the direction of the arm.

The guides may be designed as dovetail guides.

When the clamping jaws are displaced in the guides, means for the drawing of cores or ejectors may be actuated simultaneously.

It is a most favorable feature if the closing and holding means of the chill may be turned around an axis extending along the arm so that the machine will be able to perform the mold closing movement horizontally and vertically in which case the vertical mold closing movement facilitates the operation with inserted cores or actually enables such operation.

More particularly, the chill closing and holding means may be attached to a tube supported in the arm and adapted to turn around the longitudinal axis. With respect to the inclined movement upon filling the front end of the tube may be provided with a fork, while the closing and holding means may be inclined around a journal in said fork located in the vicinity of the guides for the chill halves with respect to the tube or the arm respectively.

It is true that the chill will be inclined when the total arm is inclined, but the operators ladle would have to follow the filling opening along a considerable path. By providing a second axis of inclination adjacent to the guides containing the chill halves the displacement of the chill aperture caused by the required inclination of the chill will be remarkably reduced.

Favorably inclination of the arm in the column and of the closing and holding means in the tube is effected hydraulically.

With some alloys and shapes it may be necessary to submit the chill in the closing and holding means to a vibration during casting in which case such vibration may, for instance, be produced via the hydraulic means for the inclination of the closing and holding means.

To immerse and black-wash the chill halves after casting a bath may be provided below the arm in which the chill halves in the closing and holding means may be immersed by inclination of the arm.

In a further automated embodiment of the present invention the arm may be provided with a filling means to feed liquid metal from a melting furnace into the filling aperture of the chill located in the closing and holding means.

Favorably, the filling aperture of said embodiment comprises a ladle located at the end of a rod which is attached to the arm which is parallel to said arm, while it may be displaced in its longitudinal direction and turned around its axis.

Construction of the unit is preferably such that the column may swing around a vertical axis and that the ladle by inclination of the arm into one of the swinging positions may be inserted into the melting furnace, while in the other swinging position the closing and holding means together with the chill may be immersed in the bath.

According to this feature the machine can be located very near to the furnace so that the path to be described by the liquid metal in the open filling means submitted to the oxygen in the air is limited to a minimum. Displacement into the bath which is immediately following results in fast operation.

When the individual movements occurring with chill casting have been mechanized in the manner described above, it is recommended, especially with embodiments featuring automatic mold filling, to submit all steps to programmed control.

The device according to the present invention is not only suited for iron or non iron metals but also for any other castable substances such as resin, and for the production of any shapes whatsoever.

The accompanying drawing shows examples of a construction according to the present invention.

FIG. 1 is a side view of the chill casting machine.

FIG. 2 is a plane view and FIG. 3 is a view from the left side according to FIG. 1.

FIG. 4 is a side view illustrating erection of the chill during casting.

FIG. 5 is a corresponding side view upon immersion of the chill.

FIG. 6 is a side view in which the closing and holding means has been turned such that the partition plane of the chill is approximately horizontal for the insertion of cores.

FIG. 7 is a view from the left side according to FIG. 6.

FIG. 8 is a lateral view of a casting machine supplemented by a filling means and adapted to swing around a vertical axis between melting furnace and bath.

The casting machine comprises a ground plate 1 and a column 2 having journal bearings 3 in which the arm 5 is supported by means of the horimntal journals 4 such that said arm may be inclined. Inclination is effected by means of a hydraulic cylinder 25 attached to the ground plate 1 at 24 and to the arm 5 at 23. In the am 5 there is a tube 6 which may be turned by means of a motor 7 and a gear pinion 8. The front end of the tube 6 is provided with a fork 9 in which a closing and holding means as a whole identified as 10 for the chill 13, 13' is suspended to be inclined around an axis 22.

The closing and holding means 10 includes a V-shaped dovetail guide 11, 11' in which the clamping

jaws

12, 12 for the chill halves 13, 13' may be displaced. Said clamping jaws are connected via joints 14, 14' to the piston rod 15 of a hydraulic cylinder 16. When the piston rod 15'is retracted, the clamping jaws 12, 12' together with the chill halves are withdrawn from their opened position shown by interrupted lines in FIGS. 1 and 2 into their closed position shown by full lines. The chill halves are at the same time moved and approached to each other in a straight line. After closing the chill may be filled. When the piston rod 15 is drawn out, the chill halves depart from each other and the casting may be removed from the chill. Practically on occasion of the opening movement cores are drawn and ejectors are actuated, features which have not been illustrated in detail.

As may especially be seen from FIG. 4, another hydraulic cylinder 18 is joined to a journal bearing 17 at the end of the hydraulic cylinder 16 not facing the chill, the other end of said cylinder 18 being fixed inside the tube 6 at 19. Both the tube 6 in its turned position in which the filling aperture 20 of the chill 13, 13' is directed upwards, and the arm 5 surface are provided with recesses 21 through which the end of the cylinder 16 may project upwards upon actuation of the hydraulic cylinder 18 so that the entire closing and holding means 10 may be inclined downwards in the fork 9 prior to filling in of the liquid metal. By inclining the arm 5, that is to say, by actuation of the hydraulic cylinder 25 the chill halves 13, 13' may be immersed into a bath 26 below the arm after removal of the solidified casting with the clamping jaws 12, 12' drawn out.

FIG. 8 shows a further automated embodiment according to the present invention in which the entire chill casting machine may be turned around a vertical axis 27 and in which the bath 26 has been located separately. A melting furnace has been defined as 28 from which liquid metal 30 may be withdrawn via an aperture 29. This step is also automatically effected by the chill casting machine shown in FIG. 8. The closing and holding means 10 is provided with a flange 31 supporting an hydraulic cylinder 32 extending approximately into the direction of the axis of the arm 5. The extension of the piston rod 33 of said cylinder has been provided with a ladle 34 which, upon displacement of the piston rod 35, immerses into the molten material 30, and which, upon withdrawal of the piston rod 33, is placed in front of the filling aperture 20 of the chill, while, upon erection of the arm 5, it is feeding its contents into the aperture 20. To completely discharge the ladle 34, the piston rod 33 may be turned as illustrated by 34'. After the chill has been filled, the chill is swung around the axis 27 into a position in which immersion of the opened chill halves into the bath 26 can take place.

All movements described above such as tilting, swinging, turning, are automatically controlled by a suitable program the structure of which depends upon the requirements of any particular case. Operation is, therefore, no longer to be governed by the operator. With the machine according to FIG. 8 which is also automatically filling the mold, this results in an almost fully automatic cycle.

The machine according to FIGS. 1 to 5 operates as follows when casting of cores is not required: The black-washed and cooled

chill

13, 13 is brought into its closed position which, in FIG. 2, has been shown by full lines, and the closing and holding means 10 is slightly tilted forward which, in FIG. 4, has been shown by full lines. While the liquid metal is filled in, the closing and holding means 10 is steadily raised into a substantially horizontal position which, in FIG. 4, has been shown by interrupted lines, while the end of the cylinder 16 is retracted into the tube 6. This results in perfect, splashproof casting in which case the filling aperture 20 of the chill is merely slightly changing its position due to the vicinity of the axis of inclination thus enabling the operator to easily follow and permitting a fast and uniform filling step. After casting has been completed, the chill halves are advanced according to FIG. 2 when the casting which is solidified in the meantime, is ejected. The arm 5 is then inclined into the bath 26, according to FIG. 5, in which the chill is cooled and at the same time black-washed again. After erection of the arm 5, closing of the chill, and tilting of the closing and holding means 10 the machine is ready for another casting cycle.

If it is required to insert sand cores or other parts to be cast in into the chill, the closing and holding means 10 is turned at about prior to closing of the mold, as shown in FIGS. 6 and 7, to bring the partition plane of the chill into a horizontal position so that the inserted parts are not liable to be dropped.

With the casting machine according to FIG. 8 the arm 5 is raised after the ladle 34 has immersed into the molten material 30 and has then been brought in front of the filling aperture 20, and upon erection of the arm 5 the liquid metal is fed into the chill. Any residues in the ladle which are more or less oxidized and cooled and which, in any case, would spoil the next cast, are emptied by tilting the ladle into the position 34'. Although the movement of inclination required for casting is effected by itself with the machine according to FIG. 8 upon erection of the arm 5, even this machine has been provided with the cylinder 18 for tilting the closing and holding means 10 so that, if necessary, filling by hand will be possible and the machine will be suitable for any operating conditions. After the chill has been filled, the machine swings around the axis 27 immersing and black-washing the chill 13, 13' in the bath 26 in the usual manner.

What I claim is:

l. A chill casting machine comprising:

a. a column;

b. a cantilevered arm mounted on said column for pivotal movement about a first horizontal axis;

0. said arm having two ends, one end being a free end located more remotely from said column than the other end;

d. a chill divided into halves;

e. means mounted on said free end of said arm for closing and holding said chill halves;

f. means on said casting machine for pivoting said arm about said first horizontal axis;

g. a bath located below said arm, the pivotal movement of said arm being effective to immerse said chill halves in said bath;

h. means associated with said arm for tilting said closing and holding means relative to said arm about a second horizontal axis, the tilting movement being effective during filling of the mold to achieve a full and uniform filling.

2. A chill casting machine as defined in claim 1 wherein said pivoting means includes an hydraulic cylinder.

3. A chill casting machine as defined in claim 1 wherein said tilting means includes a hydraulic cylinder.

4. A chill casting machine as defined in claim 1 including a tubular element rotatably mounted in said arm, said closing and holding means being mounted on said tubular element, whereby rotation of the tubular element is effective to rotate said chill.

5. A chill casting machine as defined in claim 4 wherein said tubular element is provided with a fork on one end thereof, said closing and holding means being mounted in said fork for tilting movement about said second horizontal axis.

6. A chill casting machine as defined in claim 1 including means in said arm for vibrating said chill as said chili is being filled with molten material.

7. A chill casting machine as defined in claim 1 wherein said closing and holding device includes a guide along which said chill halves are reciprocated to effect opening and closing of said chill halves.

8. A chill casting machine as defined in claim 1:

a. including a melting furnace associated therewith;

b. wherein said column is rotatable;

c. including a means for rotating said column;

d. including a means on said arm for filling said chill with molten material from said furnace.

Claims

1. A chill casting machine comprising: a. a column; b. a cantilevered arm mounted on said column for pivotal movement about a first horizontal axis; c. said arm having two ends, one end being a free end located more remotely from said column than the other end; d. a chill divided into halves; e. means mounted on said free end of said arm for closing and holding said chill halves; f. means on said casting machine for pivoting said arm about said first horizontal axis; g. a bath located below said arm, the pivotal movement of said arm being effective to immerse said chill halves in said bath; h. means associated with said arm for tilting said closing and holding means relative to said arm about a second horizontal axis, the tilting movement being effective during filling of the mold to achieve a full and uniform filling.

6. A chill casting machine as defined in claim 1 including means in said arm for vibrating said chill as said chill is being filled with molten material.

8. A chill casting machine as defined in claim 1: a. including a melting furnace associated therewith; b. wherein said column is rotatable; c. including a means for rotating said column; d. including a means on said arm for filling said chill with molten material from said furnace.