US2741006A - Means for delivering charges of molten metal - Google Patents

Description

A. S. KUX

April 10, 1956 MEANS FOR DELIVERING CHARGES OF MOLTEN METAL Filed June 5, 1952 4 Sheets$heet 1 INVENTOR. ALBERT 5 KUX ATTORNEY A. S. KUX

April 10, 19 56 MEANS FOR DELIVERING CHARGES 0F MOLTEN METAL Filed June 3, 1952 4 Sheets-Sheet, 2

.INVENTORQ ALBERT 5. KUX

W M KM ATTORNE Y 4 Sheets-Sheet 3 INVENTOR. ALBERT 5. KUX

ATTORNEY A. s. KUX

MEANS FOR DELIVERING CHARGES OF MOLTEN METAL Filed June 3, 1952 IY YI III April 10, 1956 KUX 2,741,006

MEANS FOR DELIVERING CHARGES OF MOLTEN METAL Filed June 3, 1952 4 Sheets-Sheet 4 *N fQ/BIH T MOLTEN METAL INVENTOR. l2 ALBERT s.Kux

ATTORNEY United States Patent Ofiice 2,741,006 Patented Apr. 10, 1956 MEANS FOR DELIVERING CHARGES OF MOLTEN METAL Albert S. Kux, Chicago, 11]., assignor to Kim Machine Company, Chicago, Ill., a corporation of Illinois Application June 3, 1952, Serial No. 291,370 4 Claims. (Cl. 22-79) My invention relates to improvements in a method and means for delivering measured charges of molten metal to the injection chambers of die casting machines.

Conventional die casting machines of the hot chamber type for use with the lower melting point metals and alloys include a structure popularly termed a gooseneck for delivering and injecting charges of molten metal into the die of the machine, the said structure comprising a cylinder submerged in a pot of molten metal and having ports through which the metal from the pot enters into the cylinder. A piston adapted to reciprocate within the cylinder serves to force the molten metal from within the cylinder to the die of the machine with which it communicates. Such hot chamber types of die casting machines have not been found practical for use with the higher melting point non-ferrous metals and alloys, such as aluminum, magnesium and brass. The higher temperatures required for melting such metals and alloys and the corrosive action of these materials at such high temperatures makes the conventional hot chamber type of die casting machine impractical for use in the die casting of these metals. Since in a hot chamber type machine the cylinder and piston are required to be in intimate contact with the molten metal, if used with higher melting point metals, they would be deleteriously affected by the high temperatures of the metals, as well as by the molten metals themselves, so that the useful service life of the cylinder and piston would be relatively short, requiring frequent servicing and replacement of the parts in order to maintain the parts in suitable condition for efiicient operation. It will be apparent that such servicing andreplacement is costly and in addition necessitates curtailrhent of operation of the die casting apparatus during the servicing interval.

In the processing of the higher melting point nonterrous metals, die casting machines of the cold chamber type have been found satisfactory. However, in such machines the charges of molten metal are manually ladled by an operator from the melt pot and poured into the injection chamber of the die casting machine. From a production standpoint such an operation in in'efiicient, costly, and hazardous to the operator.

In accordance with my invention, I provide means associated with the molten metal pot of a die casting machine for displacing the molten metal within the pot to a predetermined level, so that a measured charge of molten metal may flow to the injection chamber or plunger well of the die casting machine, the injection chamber being disposed at a lower level than that to which the molten metal is displaced in the pot.

One of the objects of my invention is the provision of means which will automatically displace molten metal in the pot of a die casting machine to a predetermined level, regardless of the quantity of molten metal within the pot at any one time.

Another object of my invention is the provision of means synchronized with the operation of a die casting machinefor automatically delivering measured charges of 2 molten metal to the injection chamber of the die casting machine so that continuous and automatic operation of the die casting machine may be efiected.

A further object of my invention is the provision of means for delivering molten metal from the pot of a die casting machine to the injection chambers thereof, the said means having a long service life due to the avoidance of the use of operating parts requiring close dimensional tolerances.

A further object of my invention is the provision of a simple method of transferring and delivering measured charges of molten metal from a supply vessel to a point of use.

Still another object of my invention is the provision of means of the foregoing character which are simple in construction, durable in service and highly efficient in operation. 7

Other and further objects and advantages of my invention will become apparent from the following description when considered in connection with the accompanying drawings in which:

Fig. l is an end elevational view of an apparatus in accordance with my invention, showing the same in association with a molten metal pot.

Fig. 2 is a top plan view thereof looking in the direction of the arrows 2-2 of Fig. 1.

Fig. 3 is a side elevational view on an enlarged scale looking in the direction of the arrows 3-3 of Fig. 1.

Fig. 4 is a cross sectional view on an enlarged scale taken substantially on line 4-4 of Fig. 2, and

Fig. 5 is a cross sectional View taken substantially on line 5-5 of Fig. 4.

Fig. 6 is a cross sectional view taken on line 6-6 of Pig. 4.

Fig. 7 is a cross sectional view on an enlarged scale taken on line 7-7 of Fig. 2 and showing the injection or shot plunger at the beginning of its stroke.

Fig. 8 is a similar view showing the injection or shot plunger nearing the end of its stroke.

Fig. 9 is a cross sectional view of a modified embodiment of my invention.

Referring to the drawings the numeral it} indicates generally a furnace of any suitable type in which is contained a melting pot ll of suitable high temperature materiai. As viewed in Fig. 3, the pot is provided with a laterally directed extension 12 inclined angularly upwardly, the extension having a bore 113 communicating with the interior of the pot. A conduit i of suitable material is received in the bore 13 and communicates with the injection chamber 16 of a die casting machine exemplified by the structure identified by numeral 15. Reciprocable within said chamber and operated by well known conventional means is an injection or shot plunger 16a. The conduit extension i4- is secured in position by a series of elongated bolts 1'7 which have their anchored in the lateral extension 12, the bolts passing through ears 13 provided on the outer wall of the chamber iii so that the parts may be drawn together in fluid tight relation. An eiectrical heating element 19 encloses the conduit 14 so as to maintain the metal in molten fluid condition during the operation of the apparatus. A jacket of suitable insulation 21 is provided over the heating element B. As will be seen clearly by reference to Fig. 3, the injection chamber 16 is disposed at a level below the top of the melting pot ii. so that molten metal contained within the pot 11 when at a higher level than the bottom of the injection chamber may flow through conduit 14 to the injection chamber 16, all as will be hereinafter explained.

Arranged for reciprocation within the mleting pot l1 is a plunger or displacement member 22 formed of suitable material, such as silicon carbide, and shaped in cross 3 section substantially like that illustrated in Fig. 6. The displacement member 22 is substantially cylindrical in form and has two diametrically opposed longitudinal recesses Ztlextending-the full length thereof. The diameter of the displacement member 22 is materially less than that of the inside diameter of the melting pot so that substantial clearance is provided between the displacement member and the walls of the pot. The displacement member 22 is reciprocated by a plunger rod 23 which is actuatedby a mechanism presently to be described.

Secured to the outer wall of the furnace as by clamps 24 mounted thereon is a tubular supporting chamber 26 on which is supported the actuating mechanism for the displacement member 22. A bracket member 27 shaped substantially as illustrated in Fig. l is provided with a depending spindle 23 which is received in the supporting member 26 to swivel about the axis thereof. The big ct member 27 is provided with a forwardly extending arm 29 terminating in a bearing guide 3. for guiding the connecting rod 23. Additionally, the said bracket memb r is provided with two upstanding arms 32 disposed in spaced relation, the said arms being pierced at the top to receive a pivot pin 33 which pivotally supports a lever arm 34. The end 36 of the lever arm is bifurcated to embrace the connecting rod 23 and the furcations are slotted as at 37 to engage with a pin 38 extending diametrically through the plunger rod. The rearward end 3) of the lever 34 is reduced in thickness and a pair of link members 4-1 are pivotally connected thereto, the said link members affording a linkage connection to the piston rod 62 of a hydraulic pressure cylinder 43 which is supported in depending relation to the rearward arm 54 of the bracket member 27, the said cylinder being connected to suitabie means, not shown, for delivering pressure fluid tr ereto. The forward portion of the arm is provided with a flange 46 to which are connected three rod members 4'! supporting at their upper end a bearing guide 43 adapted to accommodate the connecting rod A stabilizer member 43a is clamped to the plunger rod 23 and is perforated to receive one of the rod members 47 for sliding engagement therewith. Carried on a bracket arm 49 extending laterally from the supporting member 26 is a spring biased detent pin 51 which is adapted to engage in a recess provided on the underside of the bracket arm 44, the said pin when engaged in the recess locking the bracket member 27 against movement about the axis of the supporting member 26. As will be apparent, reciprocation of the plunger rod 23 and with it the displacement member 22 is effected as a result of actuation of the hy' draulic cylinder 43 which rocks the lever arm 34 and effects reciprocating movement of the plunger rod 23.

The displacement member 22 is caused to be actuated by the movement of a float operated mechanism indicated generally by numeral 52 and illustrated clearly in detail in Fig. 4. The said mechanism comprises a housing 53 adapted to be mounted on the side of the furnace 10. Pivotally supported on spaced lugs 54 secured to the bottom wall of the said housing is a rocker arm 56 having a laterally directed perforated car 57 from which is suspended a counterweight 59. Aiflxed to the upper end of the rocker arm 56 is an arm member 63, the end of which carries a socket element 64 tor receiving a bent rod 66 rigidly connected to a float member 67. The said float member is adapted to move vertically in the space between the inside wall of the melting pot I1 and one of the longitudinal recesses 20 of the displacement member 22. Since the float member 67, in view of the rigid connec' tions between the rod 66, arm member 63 and crank arm 56 must describe an arc in its vertical movement, ample clearance is provided between the wall of the melting pot and the recess 20 in the displacement member 22 for accommodating the float member 67 without interference. The floatmember 67, of course, is intended to float on the surface of the molten metal within the pot 11 and since it is in contact with the'molten metal is subjected to a high degree of heat. Accordingly, the said float member is preferably formed of a suitable material such as silicon carbide, similar to the material of the displacement member 22. The range of movement of the float member 67 is substantially between the limits indicated by the broken lines B and C. As will be seen by reference to Fig. 4, the rocker arm 56 is adapted to engage at each end of its stroke with a limit switch of conventional construction, the said limit switches being identified by the numerals 63 and 659. The limit switches 68 and 69 are so moaned that they may be adjustably positioned relative to each other to control the maximum and minimum levels of metal within the pot. Switch 63 is connected in circuit with a time delayed relay, not shown, which operates to effect actuation of the injection plunger 16a after movement of the displacement member 22 has been arrested.

Arranged above the housing 52 is a conventional electrical push button control box 70 for starting and stopping the operation of the apparatus.

Positioned over the melting pct 11 is a hood 71 which is adapted to rest on tie furnace on the marginal edges of the melting pot. The hood 71 is provided with a central aperture 71a through which the plunger rod 23 passes and also has a slot 71b to accommodate the arm 63. During the normal operation of the apparatus, the hood 71 is maintained in closure position over the melting pot. However, when it becomes necessary to replenish the supply of metal within the pot, the hood 71 may be readily elevated to render the pot accessible for the introduction of additional metal therein.

To initiate operation of my apparatus a switch in the control means of the die casting machine is actuated to effect movement of the movable component of the die 73 to closed position. A switch, not illustrated, mounted on the stationary component of the die, is caused to be engaged by an appropriate finger carried on the movable component of the said die. Actuation of the said switch eflects energization of a solenoid valve, not shown, to open the pressure line to the hydraulic cylinder 43 causing the piston rod 42 thereof to rock the lever 34 clockwise, as viewed in Fig. 1, to move the plunger rod 23 and associated displacement member 22 downwardly. This movement effects displacement of some of the molten metal within the pot 11 so as to elevate the level of the molten metal therewithin. Since the structure illustrated in efiect is a U-shapedvessel, in accordance with established physical laws, molten metal will tend to flow from the pot 11 through the conduit 14 until a condition of equilibrium is established. In other words the molten metal will tend to seek its own level until the level of the metal within the conduit and its connecting injection chamber is identical with that in the pot, as indicated by the broken line A in Fig. 3. It will be apparent that transfer of molten metal from the pot 11 to the injection chamber 16' begins at a point where the level of the molten metal in thepot is'just above the level of the bottom of the injection chamber 16 and continues so long as the level of the molten metal in the pot is maintained higher than the level of molten metal in the injection chamber 16 or until the level of molten metal within the chamber reaches the top thereof. A float member 67 buoyantly supported on the surface of the molten metal within the pot correspondingly is caused to rise upwardly concurrently with the upward displacement of the'molten metal to rock through members 66 and 63 the rocker arm 56 in a counterclockwise direction, as viewed in Fig. 4, so as to cause the arm 56 to move into engagement with the limit switch 68. When engagement between the arm 56 and limit switch 68 is eifected, the level of the molten metal in the pot is at a desired maximum point. The switch 68 when actuated by the rocker arm 56 eflects deenergization of-the solenoid valve inthe line to the hydraulic cylinder 43 shutting olf the flow of pressure-fluid to the said'cylinder and arresting movement of the displacement member 22 in a down- 2,741,ooe

ward direction. Thus, the level to which the molten metal may rise within the pot is predetermined and is constant for a particular setting of the limit switch 68. Actuation of the switch 68 also efiects energization of a time delayed relay which then elfects the closing of an electrical circuit to eifect forward movement of the injection plunger 16a which acts to inject the metal from the injection chamber 16 into the closed die 73. The operation of the die casting machine is synchronized with the operation of the apparatus of my invention so that molten metal is delivered to the injection chamber in proper sequence and in timed relation to the operation of the various components of the die casting machine.

It will be apparent that the desired maximum level of molten metal within the pot may be controlled by adjustment of the position of switch 68 relative to a vertical plane through the pivotal axis of the rocker arm 56. Thus, the level to which molten metal 'will rise within the injection chamber may be controlled and thereby the quantity or charge of molten metal desired for each injection shot. Accordingly, the charges of metal delivered to the injection chamber are all of uniform quantity.

As the injection plunger 16a moves forwardly, a finger, not shown, mounted on the rearward end thereof, engages with a switch, not shown, to actuate the same and to close an electrical circuit to a solenoid valve which serves to effect a reversemovement of the piston rod 42 whereby the lever 34 is rocked counterclockwise to move the plunger rod 23 and displacement member 22 upwardly,

thereby causing the level of the molten metal within the pot 11 and the conduit 14 to be lowered. Thus, the molten metal for an interval of time is removed from contact with the injection chamber, thereby avoiding continuous heating of the same and providing a cooling cycle result ing in a reduction in deterioration of the parts and an increase in the service life thereof.

The lowering of the metal level in the pct 11 causes a corresponding lowering of the buoyant float 67 and a rocking of the rocker arm 56 in a clockwise direction so that the said arm engages with the limit switch 69 to actuate the same and operate the solenoid valve associated with hydraulic cylinder 43, whereby to arrest the upward movement of the plunger rod 23 and displacement member 22. Thereafter, the die is caused to be opened and the casting is removed therefrom. This completes one cycle of operations of the die casting machine and the apparatus of my invention. Upon manually pressing the appropriate control button a succeeding cycle of operations, as hereinabove described, is initiated.

It will be apparent that in the operation of my apparatus the level of molten metal is elevated to a predetermined point for each metal injection operation, regardless of the progressive depletion of molten metal in the pot. With each incremental depletion of the metal within the pot, the displacement member 22 is caused to travel progressively further downwardly to compensate for such depletion, so that for each cycle, the molten metal may be elevated to a desired maximum level whereby that it may flow into the injection chamber of the die casting machine. It will be clear that the travel of the displacement member 22 is controlled entirely by the float 67 and its associated structure, the float being responsive to variations in levels of the molten metal within the pot. While in each cycle the float may operate only within the limits permitted by the limit switches 68 and 69, the movement of the float for each cycle being identical, the displacement member with each succeeding cycle moves progressively farther downwardly with each successive depletion of molten metal. When the volume of molten metal within the pot reaches a point where the quantity is such that is it below practical limits, the hood 71 may be elevated by elevating the displacement member 22 above the normal range of travel so that the mouth of the pot is exposed and made available for the intro duction of ingots or other metal stock into the pot. The

hood 71 serves as a guard to prevent splattering of molten metal outside of the apparatus, since such action might occur during the reciprocating movement of the displacement member 22 within the melting pot 11.

It will be apparent that for purposes of servicing the apparatus, the displacement member 22 may be withdrawn from the pot and swung about the axis of the supporting member 26 out of interference with the pot.

The modified embodiment illustrated in Fig. 9 provides another means for controlling the charge of metal to be delivered to the injection chamber. Corresponding primed numerals are used to identify parts corresponding to those illustrated and described in the preferred embodiment. Referring to Fig. 9 the conduit 14' is integrally formed with a reverse L-shaped extension 75, the vertical leg 76 of which extends above the top of the injection chamber 16'. A vented cap member 77 is provided to afford a protective closure for said leg 76.

The said cap member is provided with a central apertore through which projects a rod 78 at the lower end of which is mounted an electrode 79, the said electrode being connected to a suitable electrical conductor 80. The electrode 79 is adapted to make electrical contact with the molten metal in vertical leg 76 to complete an electrical circuit through the molten metal to actuate the solenoid valve which controls the downward movement of the displacement member 22, thereby controlling the level to which the metal will be displaced upwardly. The rod 78 is supported on an arm 81 which may be adjusted to the positions illustrated by the broken lines so as to render the electrode 79 adjustable vertically. In use, the electrode 79 is adjusted to a position corresponding to an elevation or level of metal desired within the injection chamber 16'. Thus, when the molten metal within the pot is displaced upwardly, as hereinbefore explained, and is caused to flow into conduit 14', molten metal therein will flow into the conduit extension as illustrated. The level of molten metal within the vertical leg 76 will correspond at all times exactly with the level in the injection chamber 16'. When the metal in leg 76 establishes electrical contact with electrode 79, the desired maximum limit has been-reached and further elevation of molten metal is arrested within the melt pot and correspondingly within the injection chamber.

It will be understood that it is within the contempla tion of my invention to utilize instead of the float mechanism other means responsive to the changing levels of metal within the melt pot for controlling the movement of the displacement member. For example, one or more electrodes of the type illustrated in Fig. 9 may be arranged in the melt pot, the same when contacted closing an electrical circuit or circuits to appropriate means for actuating the displacement member.

Various changes coming within the spirit of my invention may suggest themselves to those skilled in the art. Hence I do not wish to be limited to the specific embodiments described or uses mentioned, but'intend the same to be merely exemplary, the scope of my invention being limited only the appended claims.

I claim:

1. An apparatus for transferring molten metal from a containing vessel to a point of use removed from said vessel and at a level lower than the top of said vessel comprising in combination a vessel adapted to contain molten metal, conduit means aifording substantially direct fluid-tight communication between a lower portion of said vessel and said point of use, said vessel and said conduit means constituting a substantially U-shaped structure, a displacement member movable vertically within said vessel, means for actuating said displacement member to move the same in a downward direction to displace molten metal in said vessel upwardly to a level higher than the bottom of said point of use whereby molten metal in tending to seek its own level is caused to flow freely from said vessel into said point of use, and means 7 responsive to changing levels of molten metal for controlling the downward movement of said displacement member in accordance with the progressive depletion of molten metal in said vessel.

2. In combination with an injection chamber of a die casting machine, said chamber having an orifice in a wall thereof, means for delivering charges of molten metal thereto, said means comprising a vessel adapted to contain molten metal and having a height greater than that of the top of said chamber, a displacement member movable verticallywithin said vessel, conduit means aflording substantially direct fluid-tight communication between a lower portion of said vessel and said orifice, and means for actuating said displacement member to move the same inadownward direction to displace molten metal upwardly in'said vessel to a level higher than the bottom of said injection chamber whereby molten metal in tending to seek its own level is caused to flow freely from said vesselinto said injection chamber, and means responsive to changing levels of molten metal for controlling the downward movement of said displacement member in accordance with the. progressive depletion of molten metal in said-vessel.

3. In combination a vessel adapted to contain molten metal, conduit means affording substantially direct fluidtight communication between a lower portion of said vessel and a point of use removed from said vessel and disposed at a level below the top of said vessel, said vessel and said conduit means constituting a substantially U-shaped structure, a displacement member reciprocably movable vertically in saidvessel, a float member adapted to float upon the surface of said molten metal and move in-response to changes in levels thereof, a pivoted arm operatively connected to said float member, means for actuating said displacement member so that when the sameis moved downwardly molten metal is displaced upwardly, means for controlling said actuating means, an electrical switch in electrical circuit with said controlling means, said switch adapted to be actuated by said arm inresponse to movement of said float upwardly to arrest the downward movement of said displacement member to controlthe level to which said molten metal is displaced in said vessel.

4. In combination a vessel'adapted to contain molten metal, conduit .means afiording substantially direct fluidtight communication between a lower portion'of said vessel and a point of use'removed from said vessel and disposed at a level below the top of said vessel, said vessel and said conduit means constituting a substantially U-shaped structure, a displacement member reciprocably movable vertically in said vessel, means'for actuating said displacement member, said displacement member when moved in a downward direction being arranged to displace molten metal to raise the level thereof within said vessel above the level of said point of use whereby said molten metal in seeking its own level will flow freely to said point of use, a float member adapted to float upon the surface of said molten metal and move in response to changes in levels thereof, a pair of spaced electrical limit switches in electrical circuit with control means for said actuating means, a switch-actuating arm operatively connected with said float and arranged to actuate alternately one of said switches, one of said switches controlling the movement of said displacement member in one direction and the other of said switches controlling the'movement of said displacement member in an opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS l,469,224 Ladd Oct. 2, 1923 1,469,225 Ladd, Oct. 2, 1923 1,736,188 Daesen et al. Nov. 19, 1929 2,195,360 Daesen Mar. 26, 1940 2,363,759 Waldie Nov. 28, 1944 2,582,137 Kux Jan. 8, 1952 FOREIGN PATENTS 384,306 France Jan. 31, 1908 956,228 France July 18, 1949 280,569 Switzerland May 1, 1952 497,389 Belgium Dec. 1, 1950

Claims (1)

1. AN APPARATUS FOR TRANSFERRING MOLTEN METAL FROM A CONTAINING VESSEL TO A POINT OF USE REMOVED FROM SAID VESSEL AND AT A LEVEL LOWER THAN THE TOP OF SAID VESSEL COMPRISING IN COMBINATION A VESSEL ADAPTED TO CONTAIN MOLTEN METAL, CONDUIT MEANS AFFORDING SUBSTANTIALLY DIRECT FLUID-TIGHT COMMUNICATION BETWEEN A LOWER PORTION OF SAID VESSEL AND SAID POINT OF USE, SAID VESSEL AND SAID CONDUIT MEANS CONSTITUTING A SUBSTANTIALLY U-SHAPED STRUCTURE, A DISPLACEMENT MEMBER MOVABLE VERTICALLY WITHIN SAID VESSEL, MEANS FOR ACTUATING SAID DISPLACEMENT MEMBER TO MOVE THE SAME IN A DOWNWARD DIRECTION TO DISPLACE MOLTEN METAL IN SAID VESSEL UPWARDLY TO A LEVEL HIGHER THAN THE BOTTOM OF SAID POINT OF USE WHEREBY MOLTEN METAL IN TENDING TO SEEK ITS OWN LEVEL IS CAUSED TO FLOW FREELY FROM SAID VESSEL INTO SAID POINT OF USE, AND MEANS RESPONSIVE TO CHANGING LEVELS OF MOLTEN METAL FOR CONTROLLING THE DOWNWARD MOVEMENT OF SAID DISPLACEMENT MEMBER IN ACCORDANCE WITH THE PROGRESSIVE DEPLETION OF MOLTEN METAL IN SAID VESSEL.

Images