US2268981A - Die - Google Patents

Description

[Jari 6, 1942- A. c. ERlcsN v2,268,981

' DIE Filed oct'. 22. 195e res sheets-sheer 1 Te/cfa Jan. e, 194.2.

A. c. ERlc'soN 2,268,981

` DIEv Filed oct. 22, 19sa'\ e sheets-snede "|Iiu I j wir .fw Il" 5?/ #n 72 ava: "a 2725.5 il y aD-:#111

Ill'lI ll l :#.Lf

l'NvENToR 4er/ C'. 7x2/avvl .EBYh y* l c ATTORNEY Jan. 6,1942. A. c. ERlcsoN DIE Filed Oct. .22. 1958.

6 Sheets-Shes?l 3 INVENTOR AAW/a, C. f/cJa/v BY ATTORNEY A. l C. ERICSON Jan. 6, 1942.

' DIE:

Filed Oct. 22, 1988 fe sheets-sheet 5 Ffa/5.

Jams, 1942. A. EmsowV 2,268,981

' DIE Filed oct. 22, 195s e sheets-sheet 6 ATTORNEY Patented Jan. 6, 1942 DIE Arvidc. Ericson, Toledo, oma, assignmto- Doehler Die-Casting Co., Toledo, Ohio, a corporation of New York Application octoberA zz, 193s, serial No. 236,385

(ci. ca -iss) 11 Claims.

This invention relates to dies for molding arto a slight extent, the

ticles, and more especially to dies for metal die i castings. A l

For good die castings, it is important to control factors such as the pressure of the molten metal, the temperature of the molten metal, the composition of the molten metal, and the temperature of the die. The first three factors have desired temperature equalization inthe die. Thus, some parts kof the die may be fed with a slow water ow, and others with a fast water flow, depending upon examination of the castings being made, with skillful deduction concerning the parts that are overbeen controlled successfully, and the fourth has,

therefore,'become the most important factor at this time, and'has heretofore presented great difliculty. The present invention constitutes an important improvement for-'control .of die temperature.

A die should not be run cold because metal is prematurely chilled against the surface of the die and does not amalgamate perfectly with the remaining metal. 'This produces Aso-called chill marks. The die is, therefore, preferably heated.

It may, for example, be operated at a tempera-` heated and the partsl that are underheated, as manifested by defects of the casting. 'I'his mate. ter is so important that the best machine operatoris frequently the man who can best regulate the water valves.

However, the problem is more complex than l has so far been indicated. Diiliculty arises with 1 the watersupply itself, which frequently'changes tureof about 400 F. for a zinc base alloy, 550

F. for an aluminum base alloy, and 1000 F. for a brass base alloy. At the beginning of a working day, the operator of the die-casting machine usually heats the `die with a torch in order to warm itup before beginning operation. I- have inpressure, thus resulting in changes in the speed of flow ofthe water. The water temperature itself changes from time to time. The temperature equilibrium depends on the rate of operation of the machine, for the primary source of heat is the. molten metal being injected into the die. If the operator leaves the machine for only a few minutes, for some necessary purpose, the continued running lof cold water excessively Y chills the gate or other cooled parts of the die,

so far considered the matter of overall temperature, but further difllculty results because the A die may be overheated at some points, say, at a gate or slender core, yet may be too cool at other` points, say, at the remote end of a long slender casting. To prevent overheating, water cooling has been used. 'I'his introducesmany problems. It is 'diillcult and expensive to make the necessary water connections, and in many cases, thirty or more connections mustbe'made,

' stop because' the oper each with appropriate fittings, and considerable` lengths 'of flexible rubber hose, in order to afford movement of the die. The rubber hose soon dries or burns out because of the heat of the machine.

If water cooling `is confined A to the gate or overhatecl points, it is of no assistance in heat-- ing the remote or underheated points, and in 'fact may further cool the same.

A' really thin or slender core cannot be provided'with water'v cooling because it is not enough to merely drill a hole in the core, but the hole must be large enough to receive a tube or a. partition, for the water must circulate rapidly through the core if it is to be of any help.

The cooling eifectof the water is'regulated by appropriate valves. Often, separate valves are used on every water line for each of thecooling passages, in order to help approach, at least and the castings made after his return are defective until the die has again become heated up to normal temperature. Theqwater lmight b'e shut down, but this is seldom done for a short a'tor dislikes to lose the relative adjustment of the valves which ,he has finally worked out in order to obtain good castings. Similar dimculty arises at noon time, though it is then more customary toshut the water off, but even in such case there is a waste of timeand castings before bringing the die to optimum temperature. The temperature equilibrium, even lif snccessfully worked out with water cooling. is critically related to the rate of casting, and applies to only one particular speed, say, onehundred shots an hour in one case, or two hundred shots an hour yin another case, and so on." A change in the casting rate, as, for example, if the operator speeds up or' slows down his operation'of the machine, will upset the desired temperature balance;

It has already been mentioned thatwater cooling works only one way, that is, to cool the die. It cannot be used to heat up a cool part of the die. In order to heat up a cold spot, it is necessary to have overflow passages for 4the molten metal to flowinto, which, of course, is wasteful of metal and troublesome in operation. Sometimes, an electric heater or a torch is kept continuously burning at the coldpart of the die, thus presenting the double difllculty of making water Asometimes a large number of ejector pins and surface of the copper.

cooling connections at one part, and heating connections at another part of the die. In accordi ance with the present invention, both of these` are eliminated, and the excess heat of an overheated part of the die is transferred to and itself used to heat a cold part of the die.

Another and important disadvantage of water cooling remains to be mentioned. This arises out of the necessity for providing leak-proof passages for the water. Frequently, a cooling passage cannot be put where it is wanted and needed because it will cross or interfere with a reciprocable ejector pin or core pin, thus causing leakage of water. In a complex mold, there are core pins, and it becomes increasingly 4"difficult to nd clear space for the drilling of water passages. Even skilled die makers occasionally slip up and nd that a water passage has intersected or contacted an ejector pin passage or the like, whereupon it becomes impossible to use water cooling in the die. The die must either be discarded, or, as is sometimes done, it may be operated without water cooling but at very slow speed, say, one-third the normal speed of prolduction, until a new die can be made up. I'his same difliculty frequently occurs because a thinductive metal such as copper. The inserts are 35k usually in the form of round b'a-rs. but. as is` later explained, in special cases may take other shapes -and may even be flat plates or a combination of intersecting bars or intersecting bars and plates.

The copper is disposed outside the mold cavityv40 and does not come into direct surface contact with the molten metal. This is desirable to prevent the metal from alloying with the copper, for it has a much greater affinity to copper than to the steel die surface. The die thus remains 4B.

all-steel surfaced, as is anyway desirable in .order in complex dies, a single die would often employ many hundreds of feet of rubber hose, and a large number of connections and ttings.: To

merely mount the die in the machine, or to re' move the'same from the machine, would consume much working time because of the neces-l sity for making so many water connections.-I

Even more important, however, is the extreme exibility land freedom obtained in locating the inserts. They may cross ejector pins, core pins and the like, without diiiiculty. Simple, straight passages may be drilled through the di'e at desired points. With water cooling alone, I frequently encountered a hot spot in the die which was inaccessible to cooling water, so that the die `had to be operated at reduced speed. I have as yet never encountered a hot spot which is inaccessible to the addition of a copper rod or strip to prevent erosion by themolten metal. Excel. V

lent heat transfer between the die body and theA inserts is desirable, and to this end, the inserts are preferably soldered to the die, thus making an excellent union for heat transfer, and preventing air nlm and possible oxidation of the l. Copper has ten times the heat conductivity of steel, which helps explain the benefit obtained 5l.

without using overflow metal or heating devices at the cold spots. Cores are readily drilled and filled with a highly conductive insert. A '.core only one-eighth inchy in diameter, for example,

vthe die. temperature is satisfactorily equalized 00 can be provided with a copper insert, although it 65 would not be feasible to provide water cooling. Any metal having a-high temperature coeiilcientl of conduction may be used. Silver, for example is even better than copper, and while itwould be expensive for large inserts, it would not be at V'I0 all prohibitive for thin inserts -in slender cores.-

The present improvement minimizes and -in some cases even eliminates water passages, water connections, rubber hose, and valves, and to appreciate this fact, it lshould be kept in mind that 7 for cooling the hot spot.

The invention is particularly good for castings which must have a perfect finish suitable for chrome plating, and without preliminary grinding, either because of the intricate shape of the casting, or because of highly competitive conditions in the manufacture of the item in question, making grinding prohibitive in expense. A common example of this situation is the numerous die castings on automobiles, which should be given a. smooth, perfect finish directly from the die, and ready for chrome plating, without surface grinding.

' The invention is also invaluable in connection with multiple cavity molds. Heretofore, it was seldom that the various cavities could all be brought to the same temperature. With my invention, pyrometers have been inserted at the various cavities, and equal temperatures have been obtained. If necessary, this may even be done by trial and error after building the die, and while making a few preliminary castings. Any hot spots or cold spots discovered by examination of the surface texture or condition of the castings are corrected, by adding appropriate heat distributing inserts. The invention is also readily applied to old dies heretofore arranged for water cooling. .I have beneficially changed over many such older dies, and the change may be madel with ease because the'passages for the copper inserts may be drilled through the die body (after first removing the ejector pins, core pins, etc.) without paying any attention to water passages and the holes for ejector pins and core pins.' 'After the inserts have been secured in place, the holes for the ejector pins and core pins are rebored to cut through the copper at any points where the copper may have intersected these holes. The pins are then replaced.

To the accomplishment of the objects generally outlined above, and such other objects as will hereinafter appear, my invention consists in the die elements and temperature distributing and regulating elements, and their relation one to the other, as hereinafter are more particularly described by way of a number of specific illustrative examples showing a variety of ways in which the invention may be applied. The examples are illustrated by drawings, in which:

Fig.' 1 shows the parting face of the cover half of a single cavity die embodying the heat distributing inserts of the present invention;

Fig. 2 is a plan View of the ejector half of the die;

Fig. 3 is a section taken in the plane of the line 3 3 of Fig. 2, with the die closed;

Rig. 4 isa plan view of the ejector half of a multiple cavity die section` intended to be used in'a sectional die;

Fig. is a side elevation of the cover half of the die of Fig. 4;

Fig. 6 is a partiallysectioned side elevation ofthe ejector half of the die taken .in'theplane of the line 6-6of Fig. 4;

, Fig. 7 is a plan view of the ejector half of .a section for a sectional die, utilizing intersecting Fig. 12 is a section through the die in closed condition taken in the plane of the line l2-l2 of Fig. l1;

' Fig. 13 is a parting face view of the cover half of the diearranged to combine both water cooling and the heat distributing inserts ofv the present invention; v

Fig. 14 is a section through'the die in-closed condition taken in the plane of the line I4--I4 of Fig. 13; and

Fig. 15 is a partial showing 4of a transverse section taken through the same die in the plane of the linev |5-l5 of Fig. 13.

. Referring first to Figs. l, 2, and 3, the dieV comprises an ejector 4part I2 anda cover part I4. The casting being made is a comparatively slender, curved ornamental product. 4The die parting face iis', therefore, curved and irregular,

as is indicated at I8 in Fig. 3. Metal is supplied through the cover die in the usual manner', the cover die being provided with the approximately of inserts 36 and 38 may be extended to `form heat radiating members '40 and 42. It is significant, and it should be noted, that ejector pin 44 passesdirectly through insert 36. The same applies to ejector pins 46 and 48, except that these passl through insert 38. Ejector pins 50 pass partially through insert 36. There is no need to-avoid these ejector pins, nor to displace the inserts sidewardly, merely to avoid the ejector pins. Instead, the inserts are located in the best possiblemanner for vpurposes of heat distribution and temperature regulation. This situation is to vbe contrasted with that arising .with water cooling, .for the moment a water cooling passage intersects an ejector pin Vpassage, the die is spoiled because of leakage of water around the ejector pinand into the mold cavity.

It wm be understood by those skilled in the art that in the present case, the ejector pins,

, other than pin 44, are located outside the casting,

pin to help eject the casting.

hemispherical recess 28 for the nozzleA of the die-casting machine. The ejector half of the l Vdie is provided with a mating gate post the seat forY which is indicated at 22 in Fig. 2. This is 'adapted -to receiveY a gate post of the type described in greater detail in connection with Fig.

15.. The metal flows from the gate passage to the die cavity by means of a passage or gate 24 clearly shown in Fig. 1.

In accordance with the present invention, the

y die temperature, is equalized by copper inserts or bars. Specifically, the cover die yis provided with copper bars 26 and 28. 'I'hese are disposed at an angle, as shown in Fig. 3, in order to more closely approach the d-ie cavity. In' Fig. 1, vit

there being a special-web or overflow at each It will also be understood that the ejector half I2 of the .die is mounted on a suitable mechanism for providing the desired movement of the ejector pins even though they are disposed at an angle. In-

asmuch as the ejector half of the die may be increased in bulk because of its angular disposition, the die impression itself may be formed on a special hardened steel insert 52 which is in. serted in the die body, as shown in Figs-2 and 3. The copper inserts 36 and 3 8 vpass through the part 52 as readily as they pass through the remainder of the die body.

A good t between the copper and the die, and l a clean surface contact therebetween, are essential for best results. The copper may be ldriven into the die with a snug or even a force t. If desired, a shrink fit may be used, as by treating the copper in "Dry Ice (solid carbon dioxide) or by heating the die before `forcing the copper into the die. If desired, the copper bars may be made oversize and may be provided with slits,

will b-e seen that inserts 26 and 28 are disposed between the gate passage 30 and the mold cavity i6. In this way, heat is transferred from thegate passage to the ends of the comparatively slender casting. This tends to equalize the tem-4 perature of the die. For further cooling of the die', the inserts 26 and 2B are preferably prolonged or extended outwardly, as is shown at 32 and 34, thus providing a substantial amount of radiation'or air cooling. In the specific case here shown, the bars were extended 'about ten inches.

The ejector half l2 o f the die is providedwith inserts 33 and 38. .These are disposed at an angle, as shown in Fig. 3, in order to conform to the curved shape ofthe mold cavity. TheV inserts are located directly'beneath the mold cavity, as is clearly shown inFig. 2. The ends affording a springy fit of the copper inthe die. v

Also, the copper bars may be soldered to the die, thus insuring a clean surface, but the fit of the copper within the die should, nevertheless, be kept close, say, with a few thousandth of an inch -at the most. Ind that it is better clearance not to-permit the use of solder` at all if it becomes merely an excuse for poor fit, the die maker tending to rely on the solder to fill up even large spaces, which must not be done. In fact, the die operating temperature is such that the solder may melt and run out or run to the end of a passage, thus leaving air spaces between the copper and the die.' When soldering is used, the copperbars are,

of course, cleaned and tinned, and the die passages are tinned, or a supply of solder is placed therein, followingwhich the copper bars areV in.

serted while hot. An advantage of solder is in eliminating air 4film and oxidation of the metal surface, which otherwise might reduce the desired heat transfer. In referring hereinafter to the use of solder, it will be understood, first, that its use is optional, and second, thatit should not 'be substituted for a good't, the latter being essential with or without solder.

Attention is now directed'to Figs. 4 through 6 of the drawings. These show one section intended to be detachably inserted in a large sectional die, as will be understood by those skilled in the art. The ejector half 54 of the die is shownin'FigA, and the single section has mulmobile window regulators.

tiple cavities therein, there being four cavities 56, 58, 60, .and 62 for forming handles for auto- Cavity'56 is supplied with metal through gate 64; cavities 58 and 60 through gate 66; and cavity 62 through gate 68. These gates are at the inner end of the die section for registry with the master gate extending lengthwise down the middle of the main die receiving a substantial number of die sections, such as that here shown. The die sections are slid into the master die with the gate ends foremost. When water cooling is provided, the water connections must all be disposed at the outer or left-hand end of the die section, as viewed in Fig..4; Various complex passages would have to be formed by intersecting numerous drilled holes and then plugging the outer or exposed ends of these holes in an effort to form water circulating passages having inlet and outlet connections, all concentratedA at one end of the die section.. 'I'hese passages could not be used to heat up the ends of the cavities remote from the gates, and, on the contrary, would cool the same. Moreover, comparatively slender retractable cores and 12 are provided at the ends of each cavity, and it would be very diiiicult to provide satisfactory water cooling of these cores, first because they are small, vand second, because they are reciprocably mounted for movement by means of al core plate schematically indicated at 14.

However, the problem of temperature regulation is easily handled by means of the present invention. Ejector die 54 is provided with three suitably disposed copper bars or inserts 16, 18, and 80. These transfer heat from the gate end to'the remote or cool ends of the mold cavities. They further transfer heat to the die and cause it to act as a large heat radiating body. Moreout consideration of the fact that ejector pins or cores may have to pass through the same.

Moreover, the cores themselves may be cooled by 'inserts of highly conductive metal. Specifically, core 10 is hollowed and provided with a copper insert 92, and core 12 is similarly cored with copper, as is indicated at 94. These copper inserts effectively remove the concentration of heat around the end or tip of the core, and Aeifec g tively distribute it throughout the length ofthe core, and this provides adequate cooling for the core. v l

Another example of the invention is shown in Figs.,7 through 10 of the drawings. This also constitutes one section of a sectional die, and inthe present case, the die is intended to mold an ornamental box cover. 'I'he ejector part |00 of the die is raised to form a iixed core |02 conforming to the inside of the box. The cover die of the box.- I'he parting face |08 is, of course, disposed at the edge of the box. Molten metal is fed to the die cavity through a'gate- ||0 which, as is usual with sectional dies, terminates at the end of the section for registration with the main gate paages in the master die receiving the sections. The molded -box cover is ejected by means of side ejector pins ||2 and end ejector pins 4 and ||6. These ejector pins are half cut away, as shown, in order to provide a broad vbearing surface against the comparatively thin y The core |02 is cooled by two massive copper' inserts A| |8 and |20, which are disposed at right angles to the parting face of the die. In Fig. 9,

it will be seen that the inner ends of these inserts come well into the core |02, and thus function to carry heat away from the core.l Moreover, the

ejector die |00 is provided with additional insertsv helps radiate, but also helps equalize the die temating body.

|04 has a cavity |06 conforming to the exterior perature. Referring to Fig; 7, it should be observed that the inserts |22 vare preferably so -disposed that they contact with or partially intersect the sides of the inserts ||8 and |20. I'his helps carry heat away from the core and helps maintain the entire die at a uniform temperature. Moreover, it helps transfer heat from insert ||8, which is near the gate, to insert |20, which is relatlvely remote from the gate, thus helping keep the entire core at a uniform temperature. l

In this case, the inserts are not only soldered to the die, but are soldered to one another, in order `to insure an eifective heat transfer union therebetween. The method of constructing the die is practically self-evident, it being merely necessary to insert some of the inserts before drilling the .holes for the transversely related Iinserts, or, if all of the passages are preliminarily made, it is merely'necessary to rebore some of the passages after putting into place the transversely related inserts. l,

'I'he cover die |04 is also provided with transversely related inserts in order to effectively distribute heat over the entire area of thedie. Specifically, there are transverse inserts |24 and |26 which are disposed beyonds the ends' of the die cavity. These insertsare crossed by longitudinal inserts |28, the inserts |28 being disposed outside the top of the die cavity. The inserts are all suitably tinned and soldered-'to vone another and to the cover die. They function to transfer heat from the hotter or gate endv of the die to the cooler or remote end of the die, thus equalizing. the die temperature, and they also function to dissipatehcat by makingv the entire diera heat-radi- It will be noted that, inthe present case, the inserts Ado not project outside the die. jections are used only if greater heat dissipation is needed. For example, inthe sectional die of Figs. 4-6, the'inserts were projected about eight inches beyond the die. This depends :to a large extent on the speed of operation of the die and the character Iof the metal being cast. The necessityfor further heat radiation is readily determined upon beginning operation of the die. In practice, long inserts may be initially provided, and the projecting ends may later be-shortened o r cut off altogether if it is found desirable to reduce the heat dissipation in order tdbring the die temperature up to desired value. It will also be understoodthat additional passages may be bored, and additional inserts provided, if it is l Such profound necessary to increase the heat radiation or pins v|82 which are so positioned as to act on an ornamental plate having a cored boss at the three end points |40. Fig. 12 is a section through the die in closed condition, there being a cover die I|80 disposed over an ejector die |32. A Fig. 11

shows the ejector die with its seat |34 and pas-" sage |36 for the gate post. The nozzle passage through the cover die |30 is schematically indicated in broken lines at |88.

The casting is ejected by ejector pins |42 disposed beneath the moldedA piece. An ejector pin |44 is disposed beneath the gate. Additional outside ejector pins |48 are employed, as is well understood in the art, these acting upon webs of overowmetal intentionally provided for that purpose. The extensions, Vand any excess flash or iin, may be all simultaneously trimmed off in a trimming die.

In the present case, each half of the ldie is provided with two lo'ng, diagonally disposed inse'rts |48. These inserts are disposed on opposite sides of the gate and extend to the remoter parts of the mold cavity, specifically, the e'nds |50 and |62. In this way, heat is transferred from the overheated or gate portion of the dieto the cooler remote parts of the same. The die temperature is thus equalized, and the entire massive body of the die helps radiate and thereby dissipate heat. In the present'case, no extensions of the weblike spokes of the casting. The sectional elevation of Fig. 15 is taken at'right angles to Fig. 14, and consequently, the inserts |80 show up clearly in Fig. 15, while the ejector pins |82 show up clearly in Fig'. 14, It will be understood that the lower ends of the six inserts|80are .received in copper plate |16, just as was previy ously described in connection with the cover die, and that the parts are all preferably soldered together to insure good heat transfer.

The core |84 of the cover die is here shown as water cooled. For this purpose, it is hollowed at |86 and provided withwater inlet and disthe inserts 48 beyond the ends of the die proved necessary. Before ending the discussion of this die', it may be pointed out that a substantial f' 'number of the ejector pins pass through the copper inserts, and-that one of the cores passes through a copper insert. This will be evident on inspection of Fig. 1l.

Attention is next directed to the die illustrated in Figs. 13 to 15 of the drawings. This die is intended to mold a steering wheel hub. In Fig.

"i4, it will be seen that there is a cover die |60 and an ejector die |62 fitting together on parting face |64. Fig. 13 is a vparting face view of the cover die, and illustrates the gate passage |66. yThis passage, as well as the nozzle opening |68, are clearly shown in Fig.' i5. The casting beingl made is a cup-shaped member with a cored hub and web-like spokes between the shell and hub. Passages |10 and |12 are provided for sidewardly movable plates which have to do with the forming of spoke openings for the steering wheel. It is suflicient for the present purposes to consider the same as sidewardly pulled cores. The present-die is illustrated as an exam` ple of how the copper inserts of the present invention may be combined with water cooling, if desired. The present die also illustrates the use of copper inserts in plate form instead of rod form. Specifically, cover die |60v is provided with a comparatively-flat circular plate of copper |14, while ejector die |62 hasthe iiat circular plate of copper |16. Short rods or inserts |18 are disposed in the cover die, there being six such rods,

as is clearly shown in Figs. 13 and 14. The upper ends 'of these rods intersect and are received in plate |14. Rods |18 are preferably soldered to the die and to plate |14, all as was previously described. Similarly, the ejector die |62 is provided with six copper rods or inserts |80 (Fig. l5). These l are rotatably displaced, however, relative tothe rods |18, in order to come between six` ejector charge pipes |88and |90 leading into the pasl sage |86. The outer end of passage |86 is stop- Such water cooling is often desirable for a.

gate post or sprue post,but even that may', if

desired, be copper cooled. The practice to be followed in such cases may be illustrated by the copper cooled gate post best shown' in Fig. 15.

lAdequate cooling at this point is essential in order to insure solidiiication of the metal at the sprue so that it will be carried out of the cover die and along with the ejector die as a part of the casting. Referring to Fig. 15, the gate post 200 is formed at the upper end of a cylindrical enlargement 202. This is in accordance with standard practice, the enlargement 202 being received in a mating seat formed in the ejector die |62. The post 200 is hollowed as far as practicable and is provided with a comparatively thin wall, as is shown in the drawings. -This wa1l may, for example, be lone-eighth of an inch in thick-' ness.. The gate post is provided with a copper insert 204, the upper end 206 of which is preferably turned to accurately fit the hollow in the gate post. The parts are preferably soldered together, as was previously described. For additional cooling, the outer end 208 of insert v204 may be projected well beyond the die. This projeotion may be a matter of ten or twelve inches, if desired. No inconvenience is caused by extension of the insert in this fashion because the gate post is located on the ejector die, whichis anyway mounted on a large die base having ejector plate and core plate mechanism. This gate post construction may be standardized in accordance with conventional practice, so that in making new dies, it is merely necessary to provide the necessary standardized seat for the gate post. Such a seat is shown at 22 in Fig. 2, and at |34 in Fig. 11. r

In connection with this die, it will be seen that the inserts |18. and |80 tend to convey the heat outwardly from the parting face wherethe ing and interconnect the rods so that heat is distributed from hotter rods-near the gate to cooler rods lremote from 'the gate. The rods in the coverv die surround the outsideof the molding cavity, and the rods in the ejector die are disposed within the shell and between the shell and hub of the casting. Together, the rods and plates form a' cage of highly .conductive metal which intimately surrounds allparts of the casting 'despite the-intricate nature of the casting. The temperature of the die cavityis thuslmade uniform. The water cooling helps dissipate heatV `from the copper inserts of the cover die, 'and this ably extended beyond vthe die, as shown at 2M.

It willv be clear that in this case, Athe sole function of the insert is to provide additional cooling of the gate passage. 4 A y It is believed that the present invention, and the method of applying the same to many conditions arising in molding practice, as Well as the numerous advantages of the invention, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described my invention in preferred forms, many changes and modifications may be made in the structures disclosed without departing from the spirit of the invention dened the following claims.

I claim: l

1. A die for die casting metal, ejector pins in said die, and means to redistribute heat in said die, said means consisting of elongated cylindrical rods made of a highly heat conductive metal, the die being bored with cylindrical holes which are disposed inside the die and close to but outside the die cavity, the rods being forced into said holes to iill the same, and one or more of said ejector pins passing slidably through the rods at points of intersection located inside the die body.

2. A die for die casting metal, core pins in said die body, and means to redistribute heat in said die, said means consisting of elongated cylindrical rods made of a highly heat conductive metal, the die being -bored with cylindrical holes which are disposed inside the die and close-to-but outside the die cavity, the rods being forced into said holes to ll the same, one or more of said core pins passing slidably through the aforesaid rods at points of intersection located inside the die y body.

`3. `A die for die casting metal, the body of said close to but outside the die cavity, the rods being forced into said holes to fill the same with a tight t, the metal of the die surrounding the metal of the rod all around the periphery of the rod.

5. A die for rapidly repeated pressure casting. said die having solid steel parts of generally conventional configuration and separable on a parting face to open a die cavity formed inside said die, said cavity being small relative to the die parts, thereby leaving a substantial body of steel around the die cavity, and means to redistribute heat in said die, said means consisting of elon. gated cylindrical solid copper rods, the solid metal of the die beingv bored with cylindrical holes which are disposed wholly inside the solid metal of the die and close to but outside the die cavity, the copper. rods being inserted in said holes to iill the same and being soldered to the die in order to insure excellent heat* conductivity therebetween, the metal of the die surrounding the copper rod all around the periphery of the rod.

' 6. A die for 'rapidly repeated pressure casting, saiddiehaving solid metal parts of generally conventional configuration and separable on a parting face to open a die cavity formed in said die, said cavity being small relative to the die parts and thereby leaving a substantial body of solid metal around the die cavity, and heat distribution means to cool a part of the die cavity which is apt to become overheated, and to simultaneously heat a part of the die cavity which would otherwise be too cool, by transferring heat thereto from the overheated part oi' the die, said heat distribution means including an elongated cylindricalinsert of highly heat conductive metal, said insert being located with a tight fit in a cylindrical hole disposed within the solid metal of the die body and outside the die cavity but inside the Vouter walls of the die and so located that a part of the insert is disposed near the overheated part of the mold cavity and another part of the insert is disposed near the cool part of the mold cavity.

7. A die forrapdly repeated pressure casting, said die having steel parts of generally conventional' configuration and separable on a parting face to open a relatively long die' vcavity and a tapered gate passage formed in and passing through the solid metal of said die, said cavity and gate passage being small relative tothe die die being made of steel, core pins and ejectorv at least a substantial part of the length of thev4 copper rods being forced into said holes to fill the holes, said rods being soldered to the die in order to insure excellent heat conductivity therebetween, and one or more of' said pins passing slidably through the aforesaid rods at points of intersection located inside the die body.

4. A die for'rapidly repeatedpressure casting,

said die having solid metal parts of generally conventional coniiguration and separable on a parting face to open a die cavity formed inside said vdie, said cavity being small relative to the die parts, thereby leaving a substantial body of metal around the die cavity, and means to redistribute heat in said die, said means, consisting of elongated cylindrical rods made of a metal having high heat conductivity, the sclid metal of the die being bored with cylindrical bales which are disposed wholly inside the solid metal of the die and in said die, water cooling connections to said parts and thereby leaving a substantial body of steel around the die cavity and gate passage, and heat distribution means to cool thejgate passage which is apt otherwise to become overheated, and to simultaneously heat the remote end of the cavity which would otherwise be too cool, by

transferring heat thereto from the gate passage, said heat distribution means including a tightly Iitting insert of solid copper, said insert being located within the solid steel of the die body and outside the die cavity but inside the outer walls of the die and being so located that a part of the.

insert is disposed near the gat'epassage and another part of the insert is .disposed near the remote endof the mold cavity. l

8. A die for rapidly repeated pressure casting, said die having solid metal parts of generally conventional configuration and separable o'n a parting face to open a die cavity formed inside said die, said cavity being small `relative to the die parts, thereby leaving a substantial body of metal around the die cavity, a water cooling passage passage to cool the die, and additional heat distribution means to relatively cool apart ofthe die which is apt to become overheated despite so located in the solid metal of the the solid metal of the die being the aforesaid water' cooling, and to simultaneously heat a part of the die which would otherwise be too cool, said heat distribution means including an insert of highly conductive metal die body that a part of the insert is disposed near the overheated part of the mold, and another part of the insert is disposed near the cool part of the mold,

'whereby the water cooling functions to remove in order said die having solid metal parts of generally conventional configuration and separable on a parting face to open a die cavity formed inside said die, said cavity being small relative to the die parts, thereby leaving a substantial body of metal around the die cavity, and means to redistribute heat'in said die and to cool the same, said of elongated cylindrical rods having high heat conductivity, bored with cylin-l are disposed wholly inside means consisting made of a metal drical holes which the die and close to but outside the die cavity,

said holes opening onto an outside wall of 'the die, at least a substantial part of the vlength of the rods being forced into said holes to iill. the

with a tight fit, the metal of the die surrounding the metal of the rod all around the periphery of the rod, the outer ends of said rods projecting well out of the die body for added -heat radiation.l

10. A diefor rapidly repeated pressure casting.

-solid metal parts of generally said die having conventional configuration and separable on a parting face to open a relatively long die cavity and a tapered gate 'passage formed in and passing through the solid metal of said die, said cavity and gate' passage being vsmall relative to tions'to redis bute heat f is'disposed vnear the gate the die parts' andthereby leaving a substantial body of rnetalv around the die cavity and gate passage. and heat distribution means to cool the gate passage `which is aptto. otherwise become to simultaneously heat the remote end of the cavity which would otherwise be too cool, by transferring heat thereto from the gate pa'ssage, said heat distribution means invcluding an elongated cylindrical insert of highly heat conductive metal, said insert being received with a tight fit in a cylindrical hole disposed within the solid metal of the die body and outside the die cavity but inside the outer walls of the die and being so located that a part of the insert passagev and another part of the insert is disposed near the remote end of the mold cavity.

11. A die for rapidly repeated pressure casting, said die having solid metal parts of generally conventional configuration and separable on a parting face to open a die cavity formed inside said die, said cavity die parts. thereby leaving a substantial body of metal around the die cavity, a water-cooling passage in said die,watercooling connections to said passage to cool the die. and additional heat disvtributionmeans to redistribute heat in the mold,

which are disposed in the solid ,metal ofthe die and close to but outside the die cavity, andthe rods beingreceived in said holes with a tight fit, the water-cooling functioning to remove heat from the mold at a desired rate in order to maintain the mold at a desired average temperature, while the heatdistribution means or insert funcf in the mold in order to'maintain individual parts ofthe mold at a desired relative temperature.

being small relative to the

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