US3447587A

US3447587A - Method and device for mold casting utilizing sonic energization

Info

Publication number: US3447587A
Application number: US655481A
Authority: US
Inventors: Albert G Bodine Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-07-24
Filing date: 1967-07-24
Publication date: 1969-06-03
Anticipated expiration: 1986-06-03

Description

June 3, 1969 A, a. BODINE, JR 3,447,537

METHOD AND DEVICE FOR MQLD CASTING UTILIZING SONIC ENERGIZATION Original Filed m 10. 1965 Sheet or s FIG.I

FIG.2

INVENTOR BY ALBERTG. B'JOINE, JR.

SOKOLSKI 8 WOHLGEMUTH NTCRIEYS June 3, 1969 A. G. BODINE, JR

METHOD AND- DEVICE FOR MOLD CASTING UTILIZING SONIC ENERGIZATION Sheet Original Filed May 10. 1965 FIG.

INVENTOR ALBERT s aounsm. av SOKOLSKI a WOHLGEMUTH ATTORNEYS June 3, 1969 METHOD AND DEVICE FOR MOLD CASTING UTILIZING SONIC ENERGIZATION Original Filed May 10. 1965 A. G- YBODINE, JR

Sheet 3 01's INVENTOR. ALBERT G. BOOINE JR.

SOKOLSKI a WOHLGEMUTH ATTORNEYS United States Patent M US. Cl. 164-49 6 Claims ABSTRACT OF THE DISCLOSURE Fluid material to be cast is poured into a static mold and while it transforms from a fluid to a solid state is subjected to high-level sonic energy as part of a resonant elastic vibration system. This vibration system is excited by means of an orbiting-mass oscillator which automatcally adjusts its frequency and phase of operation with changes in impedance characteristics of the material being cast as it goes from a fluid to a solid state, thereby maintaining optimum resonant operation at all times, such as to improve the temperature distribution within the large mass of material while changing from fluid to solid state.

This application is a division of my application Ser. No. 454,335 filed May 10, 1965, for Sonic Method and Apparatus for Facilitating Gravity Flow of Fluid Material.

Mold casting in which fluid material is poured into a mold and permitted to solidify as it cools to a solidfying temperature is utilized extensively in forming objects from metal and other materials. Several problems are encountered in this type of casting, particularly large ingots, as accomplished under the prior art. Firstly, the casting often adheres to the sides of the mold, making removal therefrom difficult. Further, in removal, the surfaces of the casting are oftentimes marred. Additionally, the material being cast often does not conform with the shape of the mold as accurately as would be desired. Moreover, in large ingot castings the center cools last, and thus solidifies last, shrinking and tearing from the outer portion, with resulting flaws.

The technique and device of this invention overcome the shortcomings of the prior art by applying high-level sonic energy at the interface between the mold and the static casing and into the casing itself. Such sonic energization acts to free the sides of the mold from the cast to facilitate removal from the mold and operates to remove gas and other impurities from the cast material as well as to stress-relieve the casting, and distirbute the temperature while in the plastic state, to improve its structural characteristics of large ingots.

In carrying out the invention, a resonant elastic vibration system which includes the mold itself and in one embodiment includes a dipstick coupled directly to the casting, is vibrated at a resonant frequency by means of an orbiting-mass oscillator. Fluid material is poured into the mold and then excited by the resonant vibration as it solidifies. The orbiting-mass oscillator utilized is adapted to adjust its frequency and phase with changes in the consistency of the casing material as it goes from a fluid to a solid state, thereby assuring the maintenance of optimum resonant vibration with such changes in the impedance of the casting.

It is therefore an object of this invention to provide an improved technique for mold casting.

It is a further object of this invention to facilitate the removal of a casting from its mold in a mold casting process.

It is still another object of this invention to improve the 3,447,587 Patented June 3, 1969 structural characteristics of castings made by mold casting processes.

It is still a further object of this invention to enable the more accurate conformation of castings to their molds in mold casting processes.

Other objects of this invention will become apparent as the description proceeds in connection with the accompanying drawings, of which:

FIG. 1 is a cross-sectional view in elevation of a first embodiment of the device of the invention;

FIG. 2 is a perspective view of the first embodiment of the device of the invention;

FIG. 3 is a cross-sectional view in elevation of a second embodiment of the device of the invention;

FIG. 4 is a cross-sectional view in elevation of a third embodiment of the device of the invention;

FIG. 5 is a cross-sectional view of an oscillator which may be utilized in the various embodiments of the device of the invention;

FIG. 6 is a cross-sectional view taken along the plane indicated by 6-6 in FIG. 5; and

FIG. 7 is a cross-sectional view taken along the plane indicated by 7--7 in FIG. 5.

Referring now to FIGS. 1 and 2, the utilization of the device of the invention in ingot mold casting is illustrated. Here, molten material 62 which may be aluminum to be cast is poured into ingot mold 63. Ingot mold 63 is supported on metallic base plate 64, which in tum is supported on suitable isolation supports 65. Base plate 64 is sonically energized by means of orbiting-mass oscillator 16 which is mounted thereon, which is pneumatically driven by air fed thereto through line 19. Oscillator 16 is preferably of the type illustrated in FIGS. 5-7. Orbiting-mass oscillator 16 resonantly vibrates base plate 64 to produce standing waves 67 therein and these vibrations are fed to mold 63 and the bottom of the molten material 62, and appear at the interfaces between the mold and the material 62 being cast. The sonic energy acts to stress-relieve the cast material 62, removes gas and other impurities therefrom, provides for more uniform tempera ture, obtains better crystal structure, and thus generally improves the characteristics of the final end product. The active sonic condition established at the interfaces between material 62 and the sides of mold 63 prevents the cast material from adhering to the mold, and thus enables easy removal therefrom when the casting process has been completed. The sonic mechanical oscillator operates at maximum efiiciency by automatically adjusting its frequency with changes in the characteristics of the cast material as it solidifies.

Referring now to FIG. 2, the utilization of the device of the invention in a gravity mold in which excitation is provided through a dipstick directly to the cast material, is illustrated. Molten material 72 is poured from hopper 79 into mold 71. Dipstick 74 is suspended in the material being cast from resonant bar 76, which is supported by pulley mechanism 78. Orbiting-mass oscillator 16, which is driven pneumatically through line 19, is attached to resonant bar 76 and is oscillated to cause bar 76 to vibrate resonantly with standing waves 80 formed therealong. The material being cast 72, which may be plastic or a metal such as zinc, forms part of the resonantly vibrating system. As already mentioned in connection with the other embodiment, orbiting-mass oscillator 16 adjusts its frequency as the material being cast hardens and changes in its density and elasticity, so as to maintain optimum resonant vibration throughout the casting process. As explained in connection with the other embodiment, the sonic energization prevents the casting from adhering to the mold and imparts superior characteristics to the final end product, removing impurities, gas bubbles, and providing for a better overall structure having greater density, and in the case of metallic castings, superior crystal structure.

Referring now to FIG. 3, the device of the invention is shown as utilized in conjunction with an injection molding process. Plastic or molten condition material 96 is injected through mold injector 92, press 95 pushing down on the top of mold 94 to hold the mold in place. Sonic energy is provided to mold 94 from sonic oscillator 16, which is pneumatically driven through line 19. Sonic oscillator 16 is attached to resonant bar 90 to provide high Q resonant vibration, and bar 90 is attached to mold 94 at piston portion 94a thereof. Here again, as in the other casting processes described, the molding process is enhanced by the resonant sonic vibration to remove impurities and to provide a denser, better formed end product which can readily be removed from the mold.

Referring now to FIGS. 5, 6 and 7, a preferred embodiment of the pneumatically driven orbit ing-mass oscillator which may be utilized with the device of the invention is illustrated. This orbiting-mass oscillator has the unique characteristic of adjusting its frequency of operation with load changes, in effect locking in with a resonent load to maintain such resonant operating condition.

Mounted within case 150 is rotor member 18 which includes a central circular portion 151 and an outer circular portion 152 joined together by a web portion 153. Extending inwardly from case 150- are a pair of C-shaped

portions

154a and 154b. Pressurized air is fed through inlet port 157 to the interior of casing 150. Disc-shaped members 159a and 15% are held between the ends of C-shaped portions 154a and 15% respectively. Disc-shaped members 159a and 15% are held so that they are free to rotate and to move radially and at the same time provide a divider which prevents any significant amount of the inlet air from passing directly from one side thereof to the other. An air outlet is provided from the interior of casing 150 by means of outlet aperture 160.

The air entering through inlet 157 enters

crescentshaped cavity portions

163 and 164 and tangentially drives both inner portion 151 and outer portion 152 of the rotor in a conuterclockwise direction. Such counterclockwise rotation of the rotor on its axis results in a clockwise rolling of the rim of outer rotor portion 152 around the raceway formed by the inner wall 168 of casing 150. In view of the eccentricity of the rotor in this rolling action, case 150 is vibrated in accordance with the rotor rotation frequency.

The oscillator just described is relatively simple and highly reliable in its operation and is capable of producing a high-amplitude sonic output which automatically locks in at the resonant vibration frequency of the load being driven.

The device and method of this invention thus provide sonic means for enhancing the molding of fluid material in which the adhesion of such material to the flow defining member is minimized. In addition, the sonic action improves the structure of the material and facilitates the forming process for same.

While the device and method of this invention have been described and illustrated in detail, it is to be clearly understood that this is by Way of illustration and example only, the spirit and scope of this invention being limited only by the term of the following claims.

I claim:

1. A method for mold casting such as for large ingots, comprising the steps of: V

pouring casting material into a static mold;

coupling the output of an orbiting-mass oscillator to said casting material and said mold; and

driving said oscillator at a frequency such as to produce resonant elastic vibration of the resonant vibration system comprising said casting material and said mold, said oscillator operating to automatically adjust the frequency and phase of its output to maintain resonant vibration of said vibration system as said fixed mass of casting material transforms from a liquid to a solid state.

2. The method of claim 1 wherein a dipstick is placed in said material and said sonic oscillator is connected to said dipstick.

3. The method as recited in claim 2 wherein said resonant vibration system includes a resonant bar attached to said dipstick, said oscillator being attached to said resonant bar.

4. In a device for casting fluid material,

a mold for forming said fluid material;

an orbiting-mass sonic oscillator;

means for coupling the vibration output of said oscillator to said mold and said material, said mold and said material forming a resonant elastic vibration system; and

means for driving said oscillator at a frequency such as to cause resonant elastic vibration of said system, said oscillator being adapted to automatically adjust its frequency and phase to maintain resonance with changes in the impedance of said system,

whereby said resonant vibration prevents said material from adhering to said mold and improves the qualities of the casting.

5. In a device for the casting of fluid material,

a mold for forming said fluid material;

a dipstick partially immersed in said fluid material;

an orbiting-mass sonic oscillator;

means for connecting the vibration output of said oscillator to said dipstick; and

means for driving said oscillator at a frequency such as to cause resonant vibration of the elastic vibrating system including said dipstick and said material, said oscillator being adapted to automatically adjust its frequency and phase to maintain resonance with changes in the impedance of said system,

whereby said resonant vibration prevents said material from adhering to said mold and improves the qualities of the casting formed.

6. The device as recited in claim 5 wherein said means for connecting the output of said oscillator to said dipstick includes a resonant bar having high Q characteristics attached to said dipstick, said oscillator being attached to said bar.

References Cited UNITED STATES PATENTS 2,549,179 4/ 1 Delamare-Deboutteville 264-23 3,363,668 1/1968 Petit et al. 164-83 3,326,787 6/1967 Jacobs 26423 X 2,419,373 4/1947 Schrumn 264-83 2,116,367 5/1938 Smith 164260 X 2,535,596 12/1950 Peterson 164260 X 3,233,012 2/1966 Bodine 26423 3,371,703 3/1968 De Wilde 16449 FOREIGN PATENTS 644,189 7/1962 Canada.

OTHER REFERENCES Ultrasonic Vibrations Refine Grain Size by D. H. Lane, I. W. Cunningham and W. A. Tiller, Metal Progress September 1959, pp. 108-110.

I. SPENCER OVERHOLSER, Primary Examiner.

V. RISING, Assistant Examiner.

US. Cl. X.R.