CA1107030A - Die-casting machine - Google Patents

Abstract

DIE CASTING MACHINE
Abstract of the Disclosure A die casting system comprises a machine of the balanced, dual movement type wherein the part is cast and trimmed without any lateral movement. Both halves of the molds or dies are moved equal distances to and from the part plane. The machine incorporates a system of metal injection on the mold parting line with a runner-drain provision;
provision for supporting the part at a plurality of points after the die opening; hydraulic fluid volumetric flow reduction; various nozzle configuration options and a heat transfer system for the dies. In addition, a part trimming machine is disclosed together with a cable transfer for moving the part from the casting machine to the trimming machine.

Description

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BACKGROUND OF q~HE INVENT:I:ON
This invention relates to die casting machines and in particular to a system includlng a die casting machine ~f the balanced, dual movement type that incorporates two pairs of spaced, parallel cylinder assemblies each of which support a mold half, the pistons of the cylinders being secured to the machine frame and the cylinders moving thereon.
In a conventional die casting machine a frame is provided and a fixed or stationary plate upon which one-half of the mol~ for making the part is mounted on the frame. The other half of the mold is mounted upon a moving plate which allows the cast part to ~all out of the machine when in the open position and the moving plate is clamped shut with su~ficient force to con~ain the molten metal while the mold is being filled. In operation, the part separates from the half mold on the fixed plate (the covex half) ana is ratained on the hal mold of the moving plate ~the ejector half) as it moves open following solidification of the molten metal which was injected into the mold cavity. The part which was retained on the moving or ejector half of the mold must then be ejected from it to fall out or be transferred out of the machine. The one-sided motion described a~ove is one of the major causes for the various and complicated types of auto~
matic part-transfer mechanisms a~sociated with conventional casting machines which have been retrofitted with some sort o part-trans~er. The same problem then arises as the part is indexed to a ~econdary operation such as tr~mming wherein a similar one-sided machine is us~d. The part-transfer carrier is required to have both an ~ndexing unction and ~ la~eral movement to match the plate closing and opening stroke as the part is brought into a fixed posltion for the desired operation.
Thi~ conventional ~orm of machine was greatly Lmproved 37~3~

upon by the machine shown in the U.S. Patent to Perrella, 4,013,116 which issued on March 22, 1977. This machine is much simpler than conventional devices in that the part was cast, indexed and removed from the machine for trimming without any lateral mov~ment o the paxt. During processing the part is in a fixed plane and iæ ~rans~erred in that plane. The casting machine has balanced forces in which both plates and mold halves or dies are moved equal distances to and from the part plane and this balanced movement of mass cancels out the normal shock of starting and stopping heavy plates and tools, equalizes thermal expansion differences and automatically centers load deflections.

SU~IMARY OF THE INVENTION
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The balanced, cen~red, single plane machine principle of U.S. Patent 4,01~,116 is the basis for ~he present invention but on which numerous improvements and addit~onal features have been added such as a cable conveyor of low mass and simple design for transfer of the parts out of the machine, a simple part carrier finger at the center line of the mold, metal-injection on the mold parting line, one half the normal strokefor plate movement and thus one half the non-productive tlme or machine opening and closure, a top core pin position on the mold parting line to stabiliz~ the part posltion during mold-opening and eliminate the need ~or ejector pins on some types of parts, opportunity to add internal cores in both mold halves, and automatic loading clearance during installation of the mold and trim dies. The machine of the present invention is designed as a total inteyrated c~sting unit which will deliver a quality part cast and trimmed automatically at a pre~ent rate of production. As such it is onP unit incorporating numerous features.
The main machine consists of a frame, mold ~ounting ; plates and hydraulic closing and opening c~linders having a simple deceleration system to eliminate closing shock. A
standard and uni~orm ~asic mold con~lgur~tion is provided and is adaptable to a large variety of part styles and is of pre-de~ermined registry in the machine plates so as to eliminate mold miss-match because of ~hermal expansion or poor die set practices. Metal-injection of the machine is provided with an infinitely varia~le control capable of presetting to any desired speed or pressure, together with a self-contained molten metal supply with electric resistance heaters therein.
A self contained hydraulic power system is incor-porated, using fire resistant fluid. Provision is made to pre-heat the molds prior to the first shOtr The machine features a self-contained h~at unit for cooling the molds and eliminating lime deposits in the cooling passages all of which is automatically connected to the mold during installation without hoses or pipes. A cable transfer conveyor is also provided to carry the part on a finger to other secondary operations with adequate time before trimming for natural non-distortion cooling of the part prior to trimming, together with a complementary trim machine and basic trim die designs to push the par~t through the die to a carry-away conveyor.
In accordance with a hroad aspect the invention relates to the combination in a die-casting system of a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being ,,--~7~3al opposed to the othes pair of assem~lies carrying the other mold half~ each cylinder assembly of each pair comprising ~i) a stationary pis~on secured to the frame, (ii~ a piston shaft secured ~o and coaxial with the piston, said shaft extending across to a connection with an opposed piston of the other pair, ~iii) a cylinder mounted on the piston and shaft for reciprocal movement thereon in r~spvnse to incompressible fluid injected therein on either side o~ said piston; tiV) means connecting said c~linder to a said mold half, whereby injection of fluid into the cylinders at the pistons crown ends forces the cylinders and mold halves togethe~ and injection of the fluid at the pistons skirt ends forces the cylinders and mold halves apart with ~he terminal force from opening the cylinders being taken by the piston shaft, and (v) means for deceleration of said cylinders to eliminate closing shock; the improvements comprising ~ ,a) e~aporative heat control means for said mold halves including a closed cooling system in each of the mold halves with passages therein ~or the circulation of liquid throu~h the molds; a ~luid inlet ~alve associated with the passages, a ~ake-up pump for in~ectin~ coolin~ liquid into the`passages o~ the molds via said inlet ~al~e~ and a pre sure responsive l~itin~ yalve'~ssoci~ted ~th'the p~ssa~es for ~eleasing evaporated liquid rum the pa~sa.~es ~hen boilin~
~ccurs. ther'ein at a prede~'er~ned pre~suxei' ~nd ~eans associated with'the pressure resp~nsive l~mitin~ ~al~e ~or di~ect'n~ condensed liqui~ ~ac}: to a supply- source ~hereof;
~nd D

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(b) - a metal injectio~ s~ste~ including ~eans for injecting metal into the molds on the partin~ line of said molds, and means associated with said metal injection system for subsequent drainaye of unsolidifi.ed metal ~rom said runner and a self-contained molten metal supply with heating means for said metal supply.
In accordance with a further broad aspect the invention relates to the combination in a die-casting system of a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair comprising (i~ a stationary piston secured to the frame~ tii) a piston shaft secured to and coaxial with the piston, said shaft extendin~ across to a connection with an opposed piston of the other pair, Ciii~ a cy-linder mounted on the piston and shaft for reciprocal movement thereon in response to incom-pressible fluid injected ~erein on either side of said piston; Ci~ means connecting ~aid cyl~nder to a said mold half, ~hereby injection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and injection of the fluid at the skirt ends of the pistons orces the cylinders and mold halves apart with ~he terminal orce ~rom opening the cylinders being taken by the piston shaft; and C~ means for deceleration of said cylinders to eliminate closing ~hock, the improvements comprising:

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~al evaporative h~at control means for said molds;
(b) a metal injection system including means for in~ecting metal into the molds along the parting plane of said molds and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply; and (c.~ each of said mold halves includes a nozzle engaging insert associated with each mold half and mating on a plane corresponding to said mold parting plane; and a nozzle oriented to feed metal along said mold parting plane, said nozzle having a multi-faceted portion of rectangulax configuration on end view and a neck portion contiguous with said multi-faceted portion; said multi-faceted portion of said nozzle having, in cross section taken along a line normal to said end view, front angulated ~aces diverging from a metal outlet end of said nozzle and rear angulated faces conYerging toward the cylindrical neck portion of said nozzle, said angulated faces adapted to mate with corresponding internal ~aces and surfaces formed in said nozzle~en~aging insert to maintain correct alignment with the mold parting plRne when thb mold halves close; said nozæle including a flash guard comprising~ on the neck portion o~ said nozzle, a portion of reduced surface area on cross secti~n relatiye to the cross sectional sur~ace area of the remaindex of said neck portion, said reduced cross~sectional area portion of said neck portion being contiguous with said rear angulated faces and being provided with a curved shoulder which mates with the remainder of said neck portion, said curved shoulder being concave when viewed in said cross -4b-.

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section and diver~ing outwardly toward a metal inlet end of said nozzle; and peripheral pockets formed in said internal faces of said nozzle-enga~ing inserts, said peripheral pockets cooperating to form a circumferential cavity when said inserts mate, being coaxial with but offset form said curved shoulder and cooperating with said shoulder to form a toroid such that leakage of molten metal from said nozzle is directed by said shoulder into said pocket.

In accordance with a further broad aspect the invention relates to the combination in a die-casting system of a a die-casting machine ha~ing a frame ~ith two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair compri~ing (i) a stationary piston secur~d to the frame, (ii~ a piston shaft secured to and coaxial with the piston, said shaft extending across to a connection with an opposed piston o the other pair, ~ a cylinder mounted on th~ piston and shaft for reciprocal movement ~hereon in response to incompxessi~le fluid injected therein on either side of said piston; (iv~ means connecting said cylinder to a sai~ mold half, wherehy in~ection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and in~ection of the ~luid at t~e sklrt ends o~ the pistons forces the cylinders and mold halves apart with the terminal force from opening the cylinders being taken by the piston shaft; and Cv~ means for deceleration of said cylinders to eliminate closing shock; the improvement comprising:

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(al evaporative heat control means for said molds;
(b) a metal injection syst~m including means for injecting metal in~o the molds on the parting line of said molds and means associated with said metal injection system for subsequent drainage of unsolidi~ied metal from said runner and a self-contained molten metal supply with heating means for said metal supply; and ~ c) means or positionin~ and releasiny a casting comprising at least one positioning pin mounted in an ejector plate, a sociated with each mold half, and extending to the die face; means to rotate said pin comprising a tube coaxially mounted on said pin and having helical channels therein; a movable die plate associated with each said mold half, follower members mounted on said mo~able die plate and engaging said helical channels whereby linear movement of said die plate and followers causes rotation of said tube and pin to release the same from said casting; and means resiliently mounted on the pin in said ejector plate w~exeby the opening of the mold plate ef~ects linear mo~ement o~ said pin away rom said casting.

In accordance with a further broad aspect the invention relates to the combination in a die-casting system of a die-casting machine having a frame with two pairs of spaced, parallel cylindex assemblies mounted thereon, each pair of assemblies supporting a mold hal~ and being opposed to the other pair o~ assemhlies carrying the other mold half, each cylinder assembly of each pair comprising (i) a stationary piston secured to the frame, (ii) a piston shaft secured to and coaxial with the piston, said shaft extending across to a connec~ion with an opposed piston of -4d-~q the other pair, (iii) a cylinder mounted on the piston and shaft ~or reciprocal movement thereon in response to incompressible fluid injected therein on either side of said piston; (iv) means connecting said cylinder to a said mold half, whereby injection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and injection of the fluid at the skirt ends of the pistons forces the cylinders and mold halves apart with the termin~l force ~rom opening the cylinders being taken by the piston shaft; and (v~ means ~or deceleration of said cylinders to eliminat~ closing s~ock; the improvements comprising:

(a~ evaporati~e heat control means ~or said mold halves including a closed cooling system in each o~ the mold halves wi~th passages therein for the circulation of liquid through the-molds; a fluid inlet valve associ-ated with the passages, a ma~e-up pump for injecting cooling liquid into the passages of the molds via said inlet valve; and a pressure responsive limiting ~alve associated with the passages for releasing e~aporated liquid rom the passages when boiling occurs therein at a predetermined pressure' and means associated with the pressure responsi~e limiting valve for directing condensed liquid back to a supply source thereof;
(b) a metal injection system including means for injecting metal into the molds on the parting line o~ said molds and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply;

-4e-,~ ,,~;, tc! means for supporting a cast part in a fixed position between said mold halves after said mold halves have been withdrawn there~rom; and (d) a cable type transfer system to carry a casting from the die casting machine to a remotely positioned trimming machine or other secondary operation.

The above and other features will be understood from the ~ollo~ing disclosure and acc~mpanying drawings wherein:
Figure 1 is a plan view of the die casting machine;
Figure 2 is a cross~sectional view of the machine taken along the line 2 2 of Figure 1;
Figure 3 is a schematic, cross-sec~ional view taken along the line 3-3 of Figure ~;
Figure 4 is a schematic layout of the heat transfer system ~or cooling the dies of the machine;
Figure 5 is a cross sectional view of the metal supply pot and heating means;
Figures 6 and 7 are schematic illustrations of the metal injection;
Figures 8a and 8b are cross sectio~al views of the metal injection uniti -4f-.~ `?\

Figure 9 is an enlarged cross sectional view of the valve mechanism of the injection unit;
Figure 10 is a side elevation view o~ the injPction unit;
Figure 11 are elevation and end view of the swan's neck joint;
Figure 12 is a cross sectional view taken alony the line 12-12 of figure 8a.
Figures 13 and 14 are concept illustrations o~ the nozzle arrangement of the invention:
Figures 15 and 16 are views of a preferred nozzle arrangement;
Figure 17 is an elevation view of a typical mold ca~ity;
Figure 18 is a cross sectional view of the rotary ejection mechanism;
Figure 19 illustrates the cam and follower of the ro~ary ejection;
Figure 20 a, b and c show various positions of the rotary ejection during its operation;
Figure 21 is a cross sectional view showing the core pin withdrawal system;
Fi~ure 22 is an elevation view of one end of the part transfer mechanism;
Figure 23 is ~n elevation view of another end of the transfer mechanism;
Figure 24 is a cross sectional view taken along the line 24-24 of Figure 23;
Figure 2S is a sectional view of ~he tr~nsfer finger~
Figure 26 is a cro6s sectionAl view taken along the line 26-26 of Figure 22;

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Figure ~7 is a sectional view of the kicker mechanismi ~igure 28 is an elevation ~iew partly in cross section of the trimming apparatus; and Figure 2~ is a cross s~ctional view taken along the line 29-29 of Figure 28.
Figure 30 is an elevation view of a cast part as it enters the trisnming apparatus;
Figure 31 is a ~lan view o* a punch of the trimming apparatus, and Figure 32 is ~ sectional view of ~he punch and die of the tri~uner.

GENERAL DESCRIPTION
Referring to Figures 1-3 a die casting system according to the invention includes a die cas~ing machine 10 having a frame 12 with two pairs of spaced, parallel cylinder assemblies 14, 16 mounted thereon. Each pair of as~emblies 14 support a mold half 18, as shown in P'i~ure 3, and i5 opposed to the other pair of assemblies 16 which carrie~3 the other mold half .
20. As seen best in the general layout of Figure 3, each cylinder as~embly of each pair comprises a stationary piston 22 secured to the frame 12, a piston shaft 2~ secured .
coaxially at one end to, and axially aligned with the piston 22, the sha4t 24 extend~ng across the aentxe of the machine to a connection at its other end with an oppo3ed piston ~6 o the other cylinder ~s~embly 16.
As illu~trated in Figure 3, each cylinder assembly .
14, 16 comprises cylind~rs 28, 30 respectively mounted on the pistons 22, 26 ~nd sh~fts 24 for reciprocal movement of the cylinders thereon in response to hydraulic fluid injected on the crown or skirt ends 62 9 64 respe~tively of thQ pistons whereby khe asRemblies 14, 16 and their associa~ed ~old halvas are moved to open or closed tas shown) positions.

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A more detailed description of the basic concep~ of the machine 10 may be had from the disclosure of U.S. Patent 4,013,116.
Turning to Figure 1, a plan view of the machine 10 shows the mold clamping cylinders 14, 16, pla~ens 32, die .
separation and ejection cylinders 34, interference blocks 36 for preve~ting accidental rylinder movement and the drive means 38 for the transfer mechanism.
Figure ~ illustrates the injeCtor as~en~ly 40 comprising the furnace 42 gooseneck 44 with shot and selector valves 46, 48; and shot valve locking system 50. Nozzle 52 directs the zinc shot into the mold 54 to provide a casting 56 that is oast on~o a carrier finger 5~ on t~e transfer mechanism 60 that transports the cast part to a trimming station.
A die casting machine re~uires only a small, nominal force to advance the molds to their clossd position shown in Figure 3 but this must be followed by a s~rong clamping .
force to retain high internal pressures ~eveloped in the mold when the casting metal is injected therein. Therefore, a cylinder large enough to clamp the die would re~uire an excess volume to fill it duxing the closing stroke. As seen in Figures 1-3, the machine of ~he present invention is of the two-tie bar type with each end of the two shafts 24 .
extending through the hollow centre of the two stationary pistons 22, 26 on each side of the machine~ As seen in Figure 3, the pistons have rod extensions 22a and 26a on their skirt ends but the extensions are of a smaller diameter than ~he crown ends of the pistons and therefore form a slightly different pressure area at each end of the surround-ing cylinders 28, 30 which are the moving memb~rs and which are integral with the ma~hine platens 3~ on each side of the machine centre. Accordingly, by pre~surizing both the crown end 62 and skirt end 64 of each cylinder and proYiding an internal flow passage ~rom the sm~llex pre~sure area 64 to the larger 62, the fluid ~olume that is required for a cylinder stroke in one direction is only the di~ference between ~he tw~ areas 62, 64, times the stroke. When clo~ed ~ in Figure 3, the pressure to the smaller ar~a 64 is dumped to ~ank _ 7 _ `

allowing all the force on the larger area 62 to clamp the die closed.
The above described sy~tem works only for die closing and therefore the ejector cylinder 34 is used for die opening.
Cylinder 34 is also of a double-rod type utilizing a relatively small net forc~ area and thus requiring a minimal hydraulic flow volume. Cylinder 34 pushes against fixed outer stops 35, Figure 3,to open the machine and subsequently retracts to withdraw a stripper pin plate (Fig. 21). We have found that substantial saving in fluid volume is realized from this system.
HEAT TRANSFER
-Die casting in a permanent mold involves the process o transferxing heat ~rom a molten metal alloy to the walls of the die cavity and from the cavity to a heat exchange medium. Accordingly, certain specific parameters must ~e maintained to attain the heat 1OW rate desired.
In the system of the present invention, the heat exchange medium is water and electric immersion heaters are used only to preheat the die to operating temperature and t~ereafter the temperatures above the boiling point of water are reached by controlling the internal pre~sure of the die cooling cavity, the actual heat removal being accomplished ~y evaporation of the water as it flowg through the system in a metered quantity.
The system is shown sch~matically in Figure 4 which shows immersion heaters 66 situated in the mold manifold 68 adjacen~ the cavi~y face 70 and where they preheat the die to operating temperature, say 400F. The water passages 72 in which the heaters are i~mersed are in communica~ion wi~h cooling passageways 74 which interconnect inlet and outlet valves 76, 78 respectively.

The surface area in the die cavity that is exposed to the molten metal casting alloy is in proportion to the area of cooling surface exposed to the water and the distance ~etwPen the two surfaces is sized according to the heat-transfer rate of the die cavity matexial.
The heat transfer from the die block to the water is by evaporative cooling only. The temperature of the water within ~he cooling passa~es 7~ of the die is maintained at an elevated point which is conductive to making good casting finishes during the metal injection. Subsequently, when the part is cast the excess heat is carried away as boiling occurs only where an overtemperature condi~ion exists. ~herefore, no cixculation or flow of water is required within the die passages 72. As steam is generated in direct proportion to the heat removed from the molten metal it is only necessary to inject a make.-up water volume slightly in excess of the steam 0scaping through the pressure relief valve 78.
As shown schematically in Figure 4, water from a holding tank 80 is injected by pump means 82 into the cooling passa~e 72 through the inlet valve 76 at a pressure slightly in excess of the water being evaporated. As the heat trans-~erred to the passages 72 from the die 70 cause the water in the passageway 72 to boil, the valve 78 opens under the pressure of the steam to allow it to escape via a manifold passageway 84 and line 86 where the steam condenses and xeturns to the tank gO.
It will be appreciated that the heat transfer system is an integral part of the mold design and function and provides for preci~ion flow adjustment built for and adaptable 30 in design to a variety of mold requirements. It ~ompletely eliminates the use of hose attachments and has the feature of flow adjustment retention from one run to the next.

_ g _ METAL INJ~CTION UNIT
I
The metal injection uni~ of the present invention~
indicated at 40 in Figure 2 is different in principle in numerous ways from conventional systems and which efect both performance and safety aspects. I~ effect, the only similarity to conventional systems is that it employs a force to drive a piston which in turn creates an hydraulic pressure to fill the mold cavity.
The injection unit 40 is suspended in the supply pot 42, Figure 5, which comprises a double steel wall construction having an inner wall 106 and outPr wall 108 spaced by webs 110.
This structure gives the strength e~fect of a continuous large H-beam to resist the internal force of the molten metal and also provide an air-space form of insulation. The interior of the pot 42 is lined with a suitable insulator such as vermiculite board 112 to which a castable refractory lining 114 is applied.
The temperature of the molten metal in the pot 42 is maintained at the desired level by a plurality of electric immersion heaters 116 (as shown also in Figure 8a) spaced tl~oughout ~he pot 42. Each heater 116 comprises an element 118 encased in stainless steel tubing 120 to protect the heaters against corrosion, enlarge the surface area exposed to the casting alloy and thus reduce the watt-density.
The injection o~ casting metal into the die cavity is efected by the injection assembly indicated generally at 40 in Figure 2. As shown in detail in Figures 8a, 8b and 10, the assembly 40 compri~es a ~teel body 122 suspended within the confines of the furnace pot 42 by means of arms 88 which support the crown 90 of the assembly from the machine frame 12, the crown 90 being connected to the body 122 by long ~tuds 92.
The body 122 incorporates a large diameter cylinder 124 to accommodate the piston 128 of the shot valve a~sembly 46 ` `` ~ ~ 7 ~ 3 and a small diameter cyli~der 126 to accommodate the valve 130 of the selector assembly 48~
As shown conceptually in Figur~s 6 and 7, piston 128 intensifies the pressure of casting metal going to the die and valve 130, depending on its vertical positioning, selects a flow path fxom the pot supply to fill the pressure intensifier chamber 132 at the bottom o~ cylinder 125 (Figure 6) or selects a flow path to the ~ie from the piston 128 (Figure 7)~
Chamber 132 is connected to the selector cylinder 126 by a passageway 134 and conduit 136 in tha gooseneck 44.
As shown in large scale in Figure 9, selector valve 130 has an uppex head 100 and a lower head 102 interconnected by a stem 104 of reduced diameter. Upper head 100 mates with valve seat 140 and lower head mates with seat 142, depending on the .
operative m~de. It will be noted that the spindle has upper and lower arms 144, 146, which slidably engage the portions of the cylinder 126, thereby leaving ample room between the cylinder wall and the spindle body for passage of casting metal thereby.
Durin~ the interval between machine cycles, selector valve 130 is maintained in its shut-off posi~ion to the no~zle conduit 136 but open to the pot 42. This position would be that at the top of its stroke "S" with head 100 angaging seat 140, or the "hold and re~11" position indicated in phantom line in Figure 9. In this shut-off position, valve 130 con~titutes a positive safeguard against accidental flow to the machine nozzle. At the next cycle - sequence ~ignal, the valve 130 is shifted to its bottom position shown in Figure ~ and the shot mod~, arrow A, is ready.
Valve 130 is vert~cally actuated by a ram 148 connected to the valve through a irsme comprislng a pi8~:0n rod 150 7i~ 3 ~

secured to a frame made up of upper and lower horizontal cross arms 152, 154 and vertical arms 156O
The shot cylinder 96 and in particular piston 94 therein is actuated by an external supply, infinitely variable pneumatic pressure volumetrically sized to the underside of piston 94. sriefly~ the shot cylinder 124 is cycled so as to fill the mold cavity and instantaneously withdraw the pressure.
Because the gate thickness of a casting mold is thinner than the casting cross-section, the gate thickness is the first to solidify and doe~ so in a fraction of a second. Therefore, an instantaneous reversal of the pressure does no ha.rm to the casting but does permit the unsolidified metal in the large inlet runner sections to drain out and thereby leave only a slush-molded tubular runner section attached to the partl as will be illustrated further on. There are several advantages to this runner-drain principle of operation. Firstl valuable cycle time is not lost waiting for heavy runner sections to solidify. Secondly, the t~bular seation of the casting is very stron~ and pxovides a light frame for tran~er of the part out of the mold; the runner and part emerge a~ ~he same ~emperature which ~avors dimensional stability prior to trimmi~g; much less heat is imparted to the runner area of the mold and the hollow runners cost less ~o remelt. Al~o, the casting metal drained from the runner is held at a point just inside the nozzle tip thus minimizing ~he volume of air to be expelled from the mold cavity.
Turning to Figure 8a, piiston 128 is shown at its maximum shot position at the bottom of its stroke "S" of the ram rod 96. ~hen a casting is completely illedj, piston 128 will stop, the flow of mol en metal having passed through ~he open port of valve 130, arrow A, Figure 9. A fractioD of a second after the injectlon is completed and the cast~ng gates are solidified, piston 128 is displaced upward by pxessure on the unaerside of piston 94. This supply is volumetrically equal to the amount of metal contained in the runner system of the casting die to a point just inside of the nozzle tip.
At this moment, piston 128 is arres~ed in its upward movement long enough for selector valve 130 to shift and hold the column of metal in the nozzle and gooseneck conduit 136 in a static position and simultaneously open the val~e 130 to the "hold and refill" position of Figure 9 so that there is communication rom the supply in the pot 42 into the chambex 132. Piston 128 is then signaled to return to its topmost position enabling the cylinder 124 to fill.
A pressure accumulator may be provided for the shot cylinder 98 to include a variable pressure pneumatic pre-charge system to provide a constant source of pressure to the cylinder 98 but being infinitely variable as required for the particular casting being made. A casting shot is made when the opposing, hydraulic pressure is released to drain and the piston 94 is returned to its starting position of Figure 8a when the hydraulic pressure is re-applied, However, the first movement of the shot-return action is accomplished by an auxiliary hydraulic displacement cylinder having an adjustable stroke to inject a controlled amount of fluid into the shot-return circuit. This action serves to withdraw the shot piston 128 and in turn provides space for the unsolidified casting metal in the runners of the die to drain out leaving a shell molded hollow section as mentioned previously.
An accumulator type receiver is provided to accept th~ !
fluid discharged from ~he shot cylinder. The fluid so discharged is in the order of 500 g.p.m. and the receiver su~sequently discharges the fluid slowly to drain to tank during the machine cycle period.

7B;3~3 .
A safetv restraint or ~scotch" system is shown generally at 141 in Figure 8a and in detail in Figure 12. This apparatus prevents actuation of the shot when making machine adjustments and when the 'shotl mode is not selected.

Ram rod 96 is provided with a cammed flange 143 adapted to engage and momentarily displac~ a pair of locking collars 145, 147 when the ram g6 and piston 94 are on thelr upward stroke so that ~lange 143 then nests in the socket 149.
Collars 145, 147 are main~ained in their closed position of Figure 12 ~y a spring 149 and are openea against the spring pressure by the upward movement of the flange 143. Once ~n the socket 149, pi~ton 94 and ram 96 cannot progress downward as the closed collars engage the underside of the flange 143. As shown in Figure 12, collars 145, 147 are pivotally mounted on pins 151 snd geared together by teeth 153.
Collar 147 has a wing 155 held to the closed position by the spring 149 on a pin 156 ~lidably positioned in a member 157.
An actuator 158 has a rod 159 acting on the other side of wing 155. It will be appreciated that when act~ator 158 displaces rod 159, collars 145 and 147 will be opened to allow th~ ram rod 96 to progress downwardly.
The entire injection aYsembly i5 ~u~pended and supported by a ca~tilever ~rame made up of the arms 88 and cross plate 89 bolted to the fr~me 12 of the casting m~chine.
Alignment ad~u~tment o~ the assembly is accomplished by screws 160 ~or linear mov~ent along the axis or cen~reline of the gooseneck 44, and by screws ~62 for vertical and 164 ~or hori~ontal right and left movement. For alignment of th~ ~ozzle tip to the casting die ~n the plane of x-x, Flgure 8b, the ball and 80cket pivot 166, ~hich i8 slightly loo~en~d durlng ~ 117030 the alignment procedure, permits a 3-axis movement to be made to locate the nozzle tip in line and square with the casting die.
It will be seen from Figure 10 that c~ntilever arms 88 have surfaces 168, 169 which when extended to lines A .
and B are parallel to the centre line of the gooseneck 44.
Crown 90 has shoes 170 that ride on surfaces 168 and 169 so that .
adjustment o the screws 160 moves ~he assembly linearly correct.
The ~equential operation of the metal injection system is as follows.
A signal from the mold clamping ac~ion causes the shot selector valve 130 to move to its downward position of Figure 9 and thereby contact a positional sensor.
The positional sensor in turn signals the restraint system to withdraw, effecting movement of the actuator 159 and releasing the collars 145, 147 from the ram flange 143.
The restraint sensor gives signals to activate the metal injection shot piston 94 and to initiate a timer which signals the partial retract system af~er a fraction o a second delay to give tLme for the metal in the mold gates to solidi~y and thereafter drain out the r~nner cores. ~t the completion of the time delay the shot s lector valve 130 returns to it~
upward position.
~he up position of selector valve 13~ then signals the shot cylinder 94 to return to its top position and ~g~ln the restraint ~ystem moves to its locke~ position.
NOZZLE
As shown in Figure 8b a nozzle extension i~ provided to bridge the dlstance from the pressure intens~fier 128 to the casting di~ 54 (F~gure 2). Re~erxing to Figure 11, the ext~n~ion includes an adjustable joint coupl~ng lndicated generally at 184 whlch connects the termlnal end 186 of the 3 ~

gooseneck with the extension 18B. The end 186 of the gooseneck riser is machlned to provide a peripheral ~lange 190 and adjacent groove 192. The extension 188 terminates in a spherical end 194 and, when the end 194 and the end 186 are properly aligned the conduit 136 is completed. The two end~
are held in alignment by means of a pair of clamps 196, 198 secured together by bolts 200 as shown. The clamping blocks 196, 198 are also provided with a plurality of car~ridge heaters 202 to maintain the proper temperature level in the connection.
As mentioned in the preamble of the present disclosure, the die casting machine of the present invention utilizes a "parting line" injection where the entry of the molten casting metal into the dle pas~es through the conduit 136 which ~s centred with the parting line o~ the mold and at the periphery thereof on one side. There must o~ cour~e be a leak-proof fluid tight seal with the nozzle when the mold is closed and yet there must be freedom for the mold to open without dragging or sticking. With known nozzle ~ips o~ circular shape, the mold has to have two half round shapes to close about it whereby a condition exists of zero clearance angle at the parting line where the two corners of the half circle are tangent to the diameter and, since a leakproo~ seal requires an lnterferen~e fit, it is impossible to not have some opening friction. To obviate this and other associated problems, a square, di~mond shaped nozzle is utilized as ~hown conceptually in ~igures 13 and 14. A similar configuration is used for the carrier ~inger 58 (Figure 22~ the purpose o which will be subsequently disclosed.
A~ shown in Figure~ 13 ~nd 14, the mold h~lve~ 68 are provided with ~nserts 206 and whil~ not illustr~ed, the ~qu~re nozzle 204 iB sllghtly l~rger ~h~n the ~quare hnle that is ~ormed for i~ when ~he mold halv~s 68 are closed about the 7f~3~

nozzle. ~he parting line variations ln the nozzle to machine alignment might be in the area of plus or minus 0.20-0.30 inch and these dimensions are absorbed by the elastic movement of the injection assembly. The inserts provide opportuni~y for precision fitting of the parts concerned. It will be appreciated tha~ all of the surfaces of the nozzle and the mold will be subjec~ to the same unit force upon closing as well as pro~iding a very accurate camming means to bring the two mold halves into proper alignment.
A preferred embodiment of the nozzle having a multi-faceted design is shown in Figur~s 15 and 16 where the nozzle 208 has slightly rounded or cut off corners 210 but does have flat surfaces 212 ~or lateral alignment by inserts 206 provided on both mold halves 68. In addition, as shown in Figure 16 the nozzle has angulated faces 214 and 216 in side view which mate with similar faces in the mold half inserts 206 to effect the proper linear allgnment.
Figure 16 also illustrates a cross-sectional view o~ a flash-guard 236 which is formed by surface 220 of reduced diameter and the adjacent curved shoulde~ ~22 in cornbination with the pocket 226 and its ofset surface 228~ If for any rea~on molten metal ~hould leak under pressure ~rom the nozzle tip, the re~ulting flash would ~ollow the arrow F, ~eing directed into the pocket 226 by the shoulder 222.
~he de~ired temperature of the noz~le 208 is maintained by a nozzle cover 248 enclosing ~uitable insulation 250 which in turn ~urrounds electric heaters 252.
MOLD

Figuxe 17 illuskrates the mold of the present ma~hine~ ¦
One of the bas~c ad~antage~ of the pra~ent mach~e over the prior art is the nearly perfect thermal b~lance between the mold halves 68 coupled wlth die ~ep~r~tion ~imultane~usly Away fr~m the casing. In situations having no core pins and adequate draft angles, part~ can be produced without any stripper pins.
However, either with or without stripper~ the part is supported at three points around the periphery of the fri~me in which it is cast. These three points form a plane o reference from which the part i~ subsequently transferred out of the machine.
As shown in Figure 17, the nozzle has made a casting in the mold and the inlet runner 254 extends between the gate araa 255 and that portion o~ the mold 258 which will provide a casting around the transfer finger 58 shown in Figure 22. Further gates 260 extend from the inlet runner into ~he casting proper ~62 (in this case a logo DBM and frame therearound) and an outlet runner extends upwardly to surround a top core slide 264.
Therefore when the die halves 68 are simultaneously separated the casting is held by a) the top core slide 2S4, b) the nozzle entry 256, and c~ thie txansfer inger 258, the part 262 subsequently being tran~ferred out of the machine by finger 58 as will be subsequently described in relation to Figure 22.
In addition, when the top supporting core 264 becomes a coxe ~0 for forming a section o~ the casting, i~ also serves as the third point of support during opening of the dies and virtually eliminates the need for any stripper pins.
EJECTOR PIN RELEASE AND RETRACT MECE~NïSl!![
In convent~onal die casting mi~chines t~e cast part usuall~ follows the ejector half of the mold as it pulls away from the cover half. Then, upon nearing the end of the opening strokes, ejector pins extend and push the par~ away from ~he mold face. In order to en5ur~ th~t the part is relea~ed from the p~n faces a further devic~ i~ used to disturb lts tendiency to stick on the pin~ and thi~ device is ~::ornmonly ~alled a "quick e~ec:tor" and it actually tip5 the part out of the original working plane.

A "quick ejector" arrangement cannot be used with the machine of the present invention as the part must be re~ained in its original working plane. Addition~lly, the part must be held in a fixed plane as both halves of the mold are opening.
Accordingly, the die casting machine of the present invention requires a compl~tely dif~erent type of part ejection device to loosen the part ~rom the mold and hold it in this desired, fixed position. Therefor~, means are provided to both loosen and retract the pins to leave the part retained at the centre line of the machine and attached to the carry-out inger 58 at one edge and the nozzle impression at the other.
Figure 18 is a cross~sectional view of th~ ejector plate and i~s associated mechanism for rotating the eje~tor pins.
Such mechanism is provided from both sides of the cavity.
The ejector pin 228 is mounted at one end in the ejector plate 230 and extends through to the die ~aae 232. To this end, the pin 228 has an extension piece 234 ~cured in coaxial alignment with pin 228 by means of a tube 238 ha~ing a pair of helical channels 240 formed therein as showm in Figure 19. Pin 228 and extens~on 234 are welded to the tu~e 238 and ~s free end is t~readably engaged in a ~ushing 242 yieldably mounted against rotation in a pocke~ 246 under press~r~ o~
bellville wa~her~ 266.
The mold pla~e 268 is provided with a shouldered sleeve 270 having a pair of di~metrically opposed pin followers 272 thereon ~nd which ride in the hel~cal channels 240 as shown in Figure 18. Sleeve 270 i8 provided with a spline 274 (see inset) which engages a spli~e 276 on a tubular spring lock 278 when a release pin 280 i~ retracted.
As the machine clo~e8 the mold halves tog~thex, pin 228 i~ in the posi ion of F~gure 20a, its te~minal ~nd extenaing iust beyond the die p~rting l~ne. A~ ~he molds ~lo~e~ Figure .

20b, pin 228 is linearly retracted ayainst washers 266, under pressure of about 300 lbs. Release pin is retracted allowing spring 282 to slide lock 278 forwardly, engaging the splines 274, 276, preventing rotation of sleeYe 270. As the mold plate 268 is pulled back towaxds the position of Figure 20c, the follower pins 272, acting in the channels 240~ rotate the tube 238 and pin 22~, the extension 234 threading itself into bushing 242. When the plate 268 reaches the position o~
Figure 20c, the pin is then linearly retracted against ~he washers 266 to about a 400 lb. load, pulling the pin 228 back from the casting by a distance "B"p about .008 inch.
Returning the plate 268 to its closing position of Figure 20a the tube 238 is rotated back to its Figure lg position, release 280 disengaging the splines 274, 276.
Rotation of the pin face in relation to the casting disturbs its attachment thereto caused by the pressure of the casting process. Secondly~ as shown in Figure 20, it withdraws thQ pin a preci~e distance depending upon the chosen design of the helix 240 on the tube 238. Thus, pin 228 is both ~0 loosened and withdrawn leaving the cast part completely free but still contained within the small clear~nce between pins extending from both halves of the mold.
CORE PIN WITHD~AWAL
~ eans ~re provided ~or primary core pin withdrawal prior to opening of the die and lmmediately following the solidus condition of the cast metal. Thi~ Permits a true stripping action without distortio~ of the casting a~ well as for less strain on the core pin itself because the casting has not had time to cool and shrink tight sround the core.
As cores are to have at least ~0005 inch per inch taper per side lt is only necessary to withdxaw the core enough to exc~ed the amount of casting ~hrink~ge during the brief lnterval -- 2~ --between the solidus ~ime and wi~hdrawal time. ~he ad~antage is significant in respect to scrap reduction, pin breakage and lack of di~tortion ~n the casting ~ecause the cores are entirely free of the casting when the die is open.
Reerring to Figure 21, the machine ejector plate 284 supports an air ~ylinder 286 which linearly actuates a rod 288 that is coupled at i~s terminal end to further plates ~90 that retain a plurality of core pins (only 1 of which i~ shown), each core pin being positioned within a tubular strippex pin ~94.
Actuation of air cylinder 286 serves to advance or retract piston xod 288, plates 290 and pin 292 within the stripper 294.
~RAN5FER MECHANISM
As indicated generally in Figure 2, the finger 58 of the part transfer mechanism 60 carries the cast part from the die cavity to secondary operations such as trimming~ When a part is cast from molten metal in a permanent mold it must remain in the mold after solidification for a long enough period ~o a~tain sufficient streng~h to be self supporting from its own weight. ~owever it is of co~rse also desirable to open the mold as soon as po~sible ~n the intere~t of a short cycle .
time and to minimi~e shrinXage onto the male cores. In pra~tice, the casting emerges several hundred degrees above amhient temperature and if cooled by the conventional practice of water ~uenching, severe strains are built up in the part which can make it dimensionally un~table, particularly in regions where heavy sections are adjacent to thin sections.
In the system according to the present invention, a conveyor is provided which transfers the part which has been cast onto a finger 58 out of tha mold 60 and through a ~e~uence of indexes until it h~s been a~r Gooled ~lowly to near ~mb~nt temperat~re. The slow co~ling greatly reduces ~train in th~
part and presents it to ~econ~ary machining operations ~lth ll~S}~O
greater accuracy.
In the illustrated embodiment o~ the present invention the cast part is transferred from the molds 60 to a ~rimming operation, Figure 22 illustrating the "casting" end of the transfer mechanism and Figure 23 illus~rating the "trimming"
end of the transfer mechanism.
Referring to Figures 22 and 23, the transfer mechanism generally indicated at 60 comprises a frame 29~ whic~ carries sprockets 298 and 300 on the casting end o the mechani$m and sprockets 302 and 304 on the trimming end. The sprockets are interconnected wi~h upper run side plates 306, 308, sprockets 302 and 304 having their own side plates 310 for a purpose which will be described. Other ~ide plates 312 are provided between but are not connected wi~h sprockets 304 and 298 for the return lower run of the txansfer mechanism~
As shown clearly in Figures 25 a~d 2~, a multi~strand wire cabla 314 is provided around the sprockets and cable 314 has much greater tensile stren~th than is re~uired for the working load. Cable 314 forms the basis o~ the transfer system 60 and to that end is provided with a plurality of me~al fingers 58 which are loosely attached ~o the cable 314 to carry the casting 56 from the mold 6~. As described in rela~io~ to Figure 17, the casting or "part sho~'l consists of ~he cas~ing supported within the rame which includes the metal inlet runners 254 and 260r the part 262 and the gates, overflows stripper pads etc. and the socket end 258 which is cast o~to the conveyor transfer finger 58 a~ well a~ th~ ~ocket 264 ~hich may be cast onto the oentre mold. As shown in Figure~ 25 ~nd 26, finger 58 consists of an upper body member 316 termi~atlng in ~ ~quare, diamond sh~pe tapered e~d 318. Body 318 has a lower so~ket 320 for th~ r~c~ption of plug 3~2 whic~ i detachably secured to the a~bl¢ 314 by a ~et screw 324. Plug 3~2 locates the body of the finger on the cable which is attached thereto by end retainers 3260 It will ~e seen from Figure 25 that there is sufficient clearance provided between the interior socket of the finger and the plug 322 to provide for finger movement. ~he cable 314 is also provided wi~h a plurality of links 32 8 which are movably secured to the cable by set screws 330, each end of the link 328 having a tapered bore 332 to allow fox flexibility in cable mo~ement when training the links around the sprockets of ~he mechanism.
It will also be noted from the full view of the finger 58 in the right-hand portion of Figure 25 that the body member 316 has flat portions providing lower and upp~r track engaging shoulders 334 and 33fi respectively, the function of which will subse~uen~ly be described.
The sprocke~s 298 and 300 are rotatably mounted within side plates 338 which in turn are interconnected to the side rails 306 by connecting plates 340 so that the plates 338 and side rails 306 are co-planar and ~o-extensive with respect to one another. Additionally, the side rails 306 support spaced track members 342 as shown in Figure 26 and which support the finger 58 and specifically the shoulders 334 thereof. It will be noted that the track members 342 are spaced to receive the side surfaces 335 of fingers 58 as shown in the right hand side of Figure 25 and Figure 26. Moreover, the sprockets also include an arcuate member 344 which i8 co-extens~ve wi~h the trac~ member 342 on the rails 306 80 that the fin~r 5B ~nd spacers 328 i8 continuous both in the straight sections and around curves ~o as not to present any ~hear points or w~dge entries where debris could be trapped and 8top the indexing movement.
It will alo be seen from the bottom portion of F~gure 22 that on its return run, the aable 314 carries the figure 58 3 ~

along the lower run 312 where the upper shoulders 3~6 of the finger engage track members 342.
It will also be noted from the upper l~ft hand portion of Figure 22 that sprocket 300 has spaced indentations 346 to receive and drive the spacers 328 and f~rther inden~ations 348 which are provided with contours to receive and drive the lower shapes of the fingers 58.
As seen in Figure 26, rail 306 is secured to the frame 12 of the die casting machine by means of a plate 350 a~d cap screws 352.
Looking now at Figuxe 23, the finger ~a which would carry a cast part is indexed along the upper run 308 of the track to its position at a trimming mechanism as shown generally at 354 and after the trimming opera~ion, the cable 314 draws the finger over sprocket 302 onto track 310. Track 310 together wi~h the sprocket 302 which lt carries is pivoted a~out the centre of lower sprocket 304 and track 310 (which is in ef~ect :
a long arm) is used as a fulcrum about tha cen~re of sprocket 304 to maintain the cable 314 in proper tension through ~he action of a spring tension~ng member 356 which is connected at one end 358 to the arm 310 and at its other end 360 to the frame 296 of the transfer mechanism. ~ take-up spring 36~
applies outward pressure on ~he arm 310 which is allowed to pivot about the centre o~ ~ sprocXet 304 through tha ~lidable .
connection between the upper portion 364 of the arm be~ween s~de plates 366 secured ~o the upper tr~ck 308. The eon~an~ .
load on the cable 314 also ~erves to maint~in a const~nt ovesall lengt~ to ~he cable in re~pect to lts elastic ~tretch properties and any minor dif~renceæ in position o~ ~he f~ngers 58 from one to ~nother ~e ~bsoxbed ~y ~h~ purpos~ul loosenes~
of those fingers plu8 or ~lnus of the position of lts f~xed nttachment to the cable ~6 sh~n in the relationship to lts ~ 24 ~

~L~37~3~3 moun~ing in Figure ~5.
As the finger 58a is drawn along arm 310 wi~h the frame of the casting r~maining after the trimming operation, it reaches a kicker sta~ion 368 where the part-shot frame is kicked off the ~arrier finger 58 onto a belt conveyor ~not shown) for return to ~he casting metal melting pot.
The kicking ~tation sh~n in cross-section in Figure 27 incluaes a pair of slippers 370 mounted on either side of the track or arm 310 and which are connected by bolts 372 acting in slideways 374 wi~h a plate 376 connected to ~ linear actuator 380. As ~een in Figure 24, finger 58 with the remainder of the casting frame is drawn downwardly between the confines of the arcuate end~ 382 of the slippers 380 which effectively lie undex ears 384 on the casting as shown ~n Figure 30. When finger 58 and the casti~g frame reaches the position of Figure 27 by indexing r ~he linear actuator 380 is activate~
which moves the plate 376, bolts 372 and slippers 370 outwardly (to the left in Figure 23 or Figure 27) thereby kicking off the remainder of the cast on part which will drop down onto the conveyor and be returned to the melting pot. The finger 58 ~hen returns to the casting end of the transfer meehani~ along the lower run of track 312 as shown in Figure ~3.
TRIMMING MACHINE
Referring to Figures 28 and 29, khe ~rimming machine 354 provides ~ location mldway between ~he two platens for support o~ the ~ransfer conveyor track 308 which carries the parts ~o the tr~m die and on through as required. In effect, as shown in Figure 28 the trimming machine straddle~ the conveyor 308 ~nd finger 58 and the part that it carri~6.
The concept of the trimming machine feature~ two mov~ng platens 386 ~nd 3~8 which carxy the tr~m die 390 t~t i~
c~rried on platen 386 and ~ trim punch 392 thAt is c~rxi~d by ~ ~5 -7 ~ 3 ~

platen 388. ~he two platens advance towards one another to close a~out the 8tat~0nary, pre-positioned casting 394 within the carrier frame. The timing o~ the two movements is such that the die 390 reaches its final positlon while the punch 392 is still advancing and accordingly it acts as a back-up to the preliminary advance of final-po~ition locators 396 just before the punch encounters the part to shear it from the carrier frame.
The trim machine 354 is a two tie bar type with upper and lower prestxessed bars 398 and 400 mounted within tubular c~mpression members 402, 404 to provide s~bstantial rigidity. As seen in Figure 29c bars 39Z and 400 are tilted :
off a vertical line to facilitate loading of the die while suspended from an overhead li~t. A pair of short stroke hydraulic shock absorbers 406, 408 are positioned in 180~
opposite to one another and on a plane of the machine centre line and serve to ab~orb the unloading shock when the punch 392 breaks through the sheared section of the part.
One form o~ the trimming machine utilizes a ~ingle hydraulic cylinder 410 and 412 driving each of the pl~te~s 388 and 386 resp~ctively along the centre llne of the machine axis.
Another form of the machine fe~tures hydraulic cyllnders 414 and 416 which oper~te as an integxal part of the platen bearing supports whi~h permits having ~n open aperture through the die platen for ~u~omatic receip~ of the part as i~ is pu~hed through the die in a subsequent transfer.
~he punch 392 ~nd ~ie 390 ~re self-align~ng.
Re~erring to Figure 30, ~ cast part 394 has a pair of apertures 420 the~eln -and pexiph~ral fl~sh 422. ~he part is carried by ~ing~r 58 into tr~mming apparatus a~ 5hown in Figure 28. ~h~ d~e 390, afi shown in Figure 32, h~s a - ~6 -peripher~l collar 424 which surrounds the part and supports it behind the flash.
Die 390 is secured to the platen 386 b~ a pair o~
cap screws 426 and spring washers 428. While only one cap screw is shown in Figure 32, a pair of these screws are provided and are located diagonally from one anot~er. The die 39û
ha~ a bore 430 for each cap screw 426, the diameter of the bore being ~lightly larger than the body of the cap screw to thereby allow limited movement o~ ~he die 390 on its mounting beneath the spring washers 428.
As shown in Figures 31 and 32, punch 392 is similarly mounted ~o a rise~ 432 by cap screws 4~4 and spring washers 436, the bore 436 being slightly larger than the diameter of the cap screws 434 to allow movement of the punch 392 on its .
mounting. The punch 392 and die 390 can therefore "float~ on their mountings and with respect to one another. .
Punch 392 is provided with a pair of diagonally poR~tioned locator pins 396 for engagement in apertures 438 of the die 390 and platen 386. Punah 392 also includes a second pair of locating pins 440 which ~orrespond to the apertures 420 in the part 394.
In operation, the conveyor 308 and finger 58 carry part 394 to its Figure 28 position. The die 390 i8 advanced to its Figure 32 pos~tion to ~upport the par~, the floating die adjusting to it~ pos~ion on the part in re~ponse to the contour~ thereo~. The punch 392 is then advanced toward the die 390 and part ~94, the apertures 420 in the part receiving the pins 440 of the punch and effectin~ aligning movement o~
the punch on its ~p sCrews 4 3 4 so that, as ~he punch and d~e ~lose, lo~ators 3g6 uill be re~ei~ed in apertures 438, While the invention has been described in connection with a specific embodiment thexeof and in a specific use~
various modification~ ~hereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.
The texms and expressions employed in this disclosure are used as ~er:ns of description and not of limitation and there is no intention in theix use to exclude :
any equivalents of the features shown and described or lQ poxtions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a die-casting system of the type comprising, in combination a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair comprising (i) a stationary piston secured to the frame, (ii) a piston shaft secured to and coaxial with the piston, said shaft extending across to a connection with an opposed piston of the other pair, (iii) a cylinder mounted on the piston and shaft for reciprocal movement thereon in response to incompressible fluid injected therein on either side of said piston; (iv) means connecting said cylinder to a said mold half, whereby injection of fluid into the cylinders at the pistons crown ends forces the cylinders and mold halves together and injection of the fluid at the pistons skirt ends forces the cylinders and mold halves apart with the terminal force from opening the cylinders being taken by the piston shaft, and (v) means for deceleration of said cylinders to eliminate closing shock; the improvements comprising (a) evaporative heat control means for said mold halves including a closed cooling system in each of the mold halves with passages therein for the circulation of liquid through the molds; a fluid inlet valve associated with the passages; a make-up pump for injecting cooling liquid into the passages of the molds via said inlet valve; and a pressure responsive limiting valve associated with the passages for releasing evaporated liquid from the passages when boiling occurs therein at a predetermined pressure; and means associated with the pressure responsive limiting valve for directing condensed liquid back to a supply source thereof and (b) a metal injection system including means for injecting metal into the molds on the parting line of said molds, and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply.

2. The die-casting machine of claim 1 including means for supporting a cast part in a fixed position after the mold halves have been withdrawn therefrom comprising a frame integrally cast with and connected to the part, said frame having portions cast to surround the nozzle entry, a transfer finger and a core slide to thereby support said part at three locations when the mold halves are moved away from it.

3. A die-casting machine according to claim 1 wherein said metal injection system comprises a steel body including a first cylinder having a pressure intensifying piston and shot chamber therein for a) filling said shot chamber with molten metal from said supply and b) effecting an injection of said molten metal from said chamber into the cavity of said mold halves of said machine and to instantaneously withdraw shot pressure to permit unsolidified metal in the inlet runner section of the mold halves to drain out to provide a tubular runner attached to the part; and a second cylinder in said body including a selector valve adapted in one position to a) open a first passageway from said metal supply to said shot chamber of the intensifying piston while b) simultaneously closing off a second passageway to the nozzle of the injection system and in another position to c) close off said first passageway and simultaneously open the second passageway, said selector valve being situated between the shot chamber of the intensifying piston and the second passageway.

4. A die-casting machine according to claim 1 wherein each of said mold halves include a nozzle-engaging insert on the mold parting line; and a multi-faceted nozzle of rectangular configuration on end view, the nozzle being oriented diagonally with respect to said mold parting line and having front and rear angulated faced adapted to mate with adjacent faces and surfaces in said inserts to maintain correct alignment therewith when the mold halves close around the nozzle.

5. In a die-casting system of the type comprising, in combination a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair comprising (i) a stationary piston secured to the frame, (ii) a piston shaft secured to and coaxial with the piston, said shaft extending across to a connection with an opposed piston of the other pair, (iii) a cylinder mounted on the piston and shaft for reciprocal movement thereon in response to incom-pressible fluid injected therein on either side of said piston; (iv) means connecting said cylinder to a said mold half, whereby injection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and injection of the fluid at the skirt ends of the pistons forces the cylinders and mold halves apart with the terminal force from opening the cylinders being taken by the piston shaft; and (v) means for deceleration of said cylinders to eliminate closing shock;
the improvements comprising (a) evaporative heat control means for said molds;
(b) a metal injection system including means for injecting metal into the molds along the parting plane of said molds and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply; and (c) each of said mold halves includes a nozzle engaging insert associated with each mold half and mating on a plane corresponding to said mold parting plane; and a nozzle oriented to feed metal along said mold parting plane, said nozzle having a multi-faceted portion of rectangular configuration on end view and a neck portion contiguous with said multi-faceted portion; said multi-faceted portion of said nozzle having, in cross section taken along a line normal to said end view, front angulated faces diverging from a metal outlet end of said nozzle and rear angulated faces converging toward the cylindrical neck portion of said nozzle, said angulated faces adapted to mate with corresponding internal faces and surfaces formed in said nozzle-engaging insert to maintain correct alignment with the mold parting plane when the mold halves close; said nozzle including a flash guard comprising, on the neck portion of said nozzle, a portion of reduced surface area on cross section relative to the cross sectional surface area of the remainder of said neck portion, said reduced cross-sectional area portion of said neck portion being contiguous with said rear angulated faces and being provided with a curved shoulder which mates with the remainder of said neck portion, said curved shoulder being concave when viewed in said cross section and diverging outwardly toward a metal inlet end of said nozzle; and peripheral pockets formed in said internal faces of said nozzle-engaging inserts, said peripheral pockets cooperating to form a circumferential cavity when said inserts mate, being coaxial with but offset form said curved shoulder and cooperating with said shoulder to form a toroid such that leakage of molten metal from said nozzle is directed by said shoulder into said pocket.

6. In a die-casting system of the type comprising, in combination a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair comprising (i) a stationary piston secured to the frame, (ii) a piston shaft secured to and coaxial with the piston, said shaft extending across to a connection with an opposed piston of the other pair, (iii) a cylinder mounted on the piston and shaft for reciprocal movement thereon in response to incompressible fluid injected therein on either side of said piston; (iv) means connecting said cylinder to a said mold half, whereby injection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and injection of the fluid at the skirt ends of the pistons forces the cylinders and mold halves apart with the terminal force from opening the cylinders being taken by the piston shaft; and (v) means for deceleration of said cylinders to eliminate closing shock; the improvement comprising (a) evaporative heat control means for said molds (b) a metal injection system including means for injecting metal into the molds on the parting line of said molds and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply; and (c) means for positioning and releasing a casting comprising at least one positioning pin mounted in an ejector plate, associated with each mold half, and extending to the die face; means to rotate said pin comprising a tube coaxially mounted on said pin and having helical channels therein; a movable die plate associated with each said mold half, follower members mounted on said movable die plate and engaging said helical channels whereby linear movement of said die plate and followers causes rotation of said tube and pin to release the same from said casting; and means resiliently mounted on the pin in said ejector plate whereby the opening of the mold plate effects linear movement of said pin away from said casting.

7. A die-casting machine according to claim 6 including means for withdrawing core pins from said a casting comprising a plate member associated with at least one mold half and supporting at least one core pin, a tubular stripper tube surrounding said core pin, and hydraulic means associated with the mold half for withdrawing said plate and pin within said stripper tube.

8. In a die-casting system of the type including, in combination a die-casting machine having a frame with two pairs of spaced, parallel cylinder assemblies mounted thereon, each pair of assemblies supporting a mold half and being opposed to the other pair of assemblies carrying the other mold half, each cylinder assembly of each pair comprising (i) a stationary piston secured to the frame, (ii) a piston shaft secured to and coaxial with the piston, said shaft extending across to a connection with an opposed piston of the other pair, (iii) a cylinder mounted on the piston and shaft for reciprocal movement thereon in response to incompressible fluid injected therein on either side of said piston; (iv) means connecting said cylinder to a said mold half, whereby injection of fluid into the cylinders at the crown ends of the pistons forces the cylinders and mold halves together and injection of the fluid at the skirt ends of the pistons forces the cylinders and mold halves apart with the terminal force from opening the cylinders being taken by the piston shaft; and (v) means for deceleration of said cylinders to eliminate closing shock; the improvements comprising:

(a) evaporative heat control means for said mold halves including a closed cooling system in each of the mold halves with passages therein for the circulation of liquid through the-molds; a fluid inlet valve associated with the passages; a make-up pump for injecting cooling liquid into the passages of the molds via said inlet valve; and a pressure responsive limiting valve associated with the passages for releasing evaporated liquid from the passages when boiling occurs therein at a predetermined pressure;
and means associated with the pressure responsive limiting valve for directing condensed liquid back to a supply source thereof;
(b) a metal injection system including means for injecting metal into the molds on the parting line of said molds and means associated with said metal injection system for subsequent drainage of unsolidified metal from said runner and a self-contained molten metal supply with heating means for said metal supply;
(c) means for supporting a cast part in a fixed position between said mold halves after said mold halves have been withdrawn therefrom; and (d) a cable type transfer system to carry a casting from the die casting machine to a remotely positioned trimming machine or other secondary operation.

9. A die-casting machine according to claim 1 including a cable type transfer system comprising an endless conveyor cable trained between the mold halves of the die-casting machine and a remotely positioned trimming machine; a plurality of fingers adjustably mounted on said cable for sequential positioning between said mold halves to receive a casting therearound; sprockets for driving said cable; and adjustable link means on said cable for engagement by said drive sprocket.

10. A die-casting machine according to claim 9 wherein said cable type transfer system comprising an endless conveyor cable trained between the mold halves of the die casting machine and said remotely positioned trimming machine;
a plurality of fingers adjustably mounted on said cable for sequential positioning between said mold halves to receive a casting therearound; sprockets for driving said cable; and adjustable link means on said cable for engagement by said drive sprocket.

11. A die-casting machine according to claim 10 wherein said trimming machine comprises a pair of movable platens carrying a trim die and a trim punch and adapted to receive the conveyor cable, finger and casting therebetween; the die being adapted for movement into position before said punch to act as a backup to the punch; means for absorbing shock from the action of said punch; and hydraulic means for actuating said punch and die.