US3581804A - Expansion gap compensating system for a die - Google Patents

Expansion gap compensating system for a die Download PDF

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US3581804A
US3581804A US36299A US3581804DA US3581804A US 3581804 A US3581804 A US 3581804A US 36299 A US36299 A US 36299A US 3581804D A US3581804D A US 3581804DA US 3581804 A US3581804 A US 3581804A
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block
impression
die
holding
expansion
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Joseph A Woltering
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Hamilton Die Cast Inc
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Hamilton Die Cast Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/20—Accessories: Details
    • B22D17/22—Dies; Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies

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  • a dies impression block When a dies impression block is fabricated of a metal having a different expansion coefficient than that of the dies holding block crevasses or expansion gaps tend to open between the two blocks upon heating of the die assembly to high temperature from room temperature.
  • the width of these expansion gaps may vary from thousandths of an inch to hundredths of an inch or more, and is mainly dependent on the difference in expansion coefficients of the block metals and on the casting or operating temperature.
  • the system of this invention permits an impression block and a holding block fabricated of, for example, a refractory metal and a steel respectively, (a) to be simply and easily assembled and maintained together as a die in tight and safe operating relation without damage to either, and (b) to be maintained in an exact centered or preset position relative one to another, at all times throughout a casting run.
  • the expansion gap compensating system acts to compensate for expansion gaps that tend to open between related impression and holding blocks as the dieassembly is heated up to and operated at high temperatures, as well as to compensate for the contracting of those gaps as the die assembly cools after the casting run.
  • This invention relates to dies and, more particularly, relates to an expansion gap compensating system that is especially advantageous for dies used when casting high melting point materials.
  • Diecasting is a well-known method of forming cast metal parts; it basically involves injecting a molten metal charge under pressure into a die cavity.
  • the basic components of a diecasting-type machine are a die assembly of two halves or dies that together define a negative impression or cavity of the object that is desired, a chamber for holding a charge of molten metal, and a plunger for transferring the metal charge under pressure from the chamber to the die,
  • the basic functions of such a machine are to close and hold the two halves or dies of the die assembly tightly together for establishing the die cavity; to inject the molten metal under pressure into the die cavity; and then to open the die assembly and eject the finished casting from the cavity.
  • the die assembly for diecasting-type machines basically consists of two separate halves or dies, each containing a part of the casting impression, plus cores if needed for the part to be cast.
  • the die halves are mounted on the diecasting machine and are so arranged that one is stationary (called the cover die) while the other is movable (called the ejector die).
  • the two halves of the die assembly are locked tightly together in precise register, after which the molten metal is injected from the injection apparatus under pressure into the die cavity so formed through a gate in the assembly. Subsequently, the two die halves are drawn apart to allow ejection of the casting.
  • Proper means for rapidly ejecting the casting from the die as" sembly is provided in the form of ejector pins mounted to an ejector plate reciprocably assembled with the ejector die.
  • the movable or ejector die usually contains, in addition to a portion of the casting impression, movable elements such as cores, slides, and ejector mechanism.
  • the material from which the die cavity is formed is one factor in determining the commercial success of the diecasting process. Dies are, of necessity, expensive and the money expended in fabricating them must be justified by good service life as measured by number of castings produced. Since the molten metal is forced into the die cavity under pressure the die must be capable of withstanding impact and mechanical shock, and because the metal is molten and at a relatively high temperature the die must be capable of withstanding thermal shock as well. Also, and very importantly, the die must be able to resist washing or erosion of the cavity configuration by the metal being cast. The combination of these three factors, plus others, means that the die cavity must be constructed of very good quality steels.
  • the problem of securing a long life for the die at an economical per casting cost is not so acute.
  • the higher melting point alloys for example, magnesium, aluminum, gray iron, and copper-zinc alloys
  • the die steel must be of the best possible grade tool steel and must be produced to quite rigid specifications to overcome, in particular, the cavity erosion or wash problem.
  • the ejector die half and the cover die half is each comprised of an impression block and a holding block mated or nested together.
  • the impression block is usually friction fit into the pocket of its related holding block, i.e.,'the outer periphery of the impression block is substantially equal to the periphery of the holding block's pocket.
  • both blocks have been formed from steel.
  • the system of providing an impression block-holding block structure for a die half admits of substantial economy because only the impression block need be replaced, and not the entire die, when the cavity configuration becomes so eroded or washed out that an undesirable percentage of castings being produced is out of tolerance limits.
  • expansion coefficients of the normal steels from which holding blocks are usually fabricated are substantially greater, for example, up to three or four times greater, than the expansion coefficients of the refractory metals from which the impression blocks are fabricated.
  • Such expansion crevasses or clearances or gaps created between the impression block and associated holding block at high dieoperating temperatures may cause alignment or registry difficulties for the cover and ejector impression blocks during repeated openings and closings of the die halves because of slippage or movement of one or both impression blocks within their holding block pockets, thereby rendering out of tolerance a substantial percentage of the castings produced by the die assembly.
  • the expansion gaps created between the impression block and the holding block of the ejector die half at high die temperatures may, even be great enough so that the ejector impression bloclc will actually be ejected from the ejector-holding block by the ejector pins, after the die halves have been opened, during ejection of the formed casting.
  • the molten metal to be cast may squirt out between the interface of the cover and ejector impression blocks and run into and solidify in the expansion crevasses or gaps created, thereby preventing the impression blocks from being removed from the holding block pockets other than by breaking or otherwise cutting out the impression block.
  • die half that adequately retains and prevents movement ofthe impression block in the holding block pocket when the expansion coefficient of the impression block material is substantially different from the expansion coefficient of the holding block material.
  • an expansion gap compensating system for a die comprising, in combination and in preferred embodiment form, (a) a holding block (fabricated of, for example, a steel) with a pocket defined therein, (b) an impression block (fabricated of, for example, a refractory metal) receivable within the pocket, the impression block having a substantially shorter peripheral length than the pocket so that when the two blocks are assembled a continuous fixed gap equal in length to at least one-half the peripheral length of the impression block is created between the impression block and the holding block, (c) a chock positionable in wedging fashion within the fixed gap for maintaining the blocks together as a die, and (d) a key engageable with keyways in the bottom of the pocket and the impression block for establishing and maintaining accurate relative position of the blocks one to the other.
  • Each chock is provided with adjustment means so that it can be tightened or loosened within the fixed gap depending on the relative expansion or contraction of the blocks and the crevasses or expansion gaps between the blocks that tend to be formed thereby.
  • the expansion gap compensating system of this inventions preferred embodiment permits the impression block and the holding block of a die, each of which is fabricated of a material having a different expansion coefficient from the other, to be simply and easily assembled and maintained together as a die in tight and safe operating relation without damage to either, to be maintained in an exact centered or preset position relative one to the other even during repeated adjustments of the system, and to preclude undesirable molten material from filling any expansion gaps that occur between sides of the blocks adjacent the face of the die half, at all times throughout a casting run.
  • FIG. 1 is an axial cross-sectional view of a die assembly incorporating the expansion gap compensating system of this invention'
  • FIG. 2 is an elevational view, partially in cross section, taken along lines 2-2 of FIG. 1;
  • FIG. 3 is a cross-sectional view taken along lines 3-3 of FIG.
  • FIG. 4 is a cross-sectional view of an alternate impression block embodiment useful with the expansion gap compensation system
  • FIG. 5 is a cross-sectional view similar to FIG. 3 of an alternative embodiment ofa die assembly incorporating the expansion gap compensating system of this invention
  • FIG. 6 is a perspective view taken from the front of the alternative embodiment of the die assemblys impression block.
  • FIG. 7 is a perspective view taken from the rear of the alternative embodiment of the die assemblys holding block with the back plate removed;
  • FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG.
  • the principles of this invention are incorporated in a die assembly having an ejector or movable die 10 and a cover or fixed die 11, the die halves being held in operational engagement one with the other so as to define a die cavity 12 by apparatus, not shown, associated with any known type of diecasting machine.
  • the ejector die 10 is comprised of an ejector shoe or holding block 13 (fabricated of, for example, a tool steel) which establishes a rectangular nest or pocket 14 in the front face of block 13.
  • the pocket 14 is sized to receive an ejector impression block 15 and an ejector gate block 16 (both fabricated of, for example, a refractory metal) from the front face of holding block 13, and is defined by vertical sidewalls 17 and a flat bottom 18 parallel to the front face of the holding block 13.
  • the bottom 18 of the pocket 14 provides structural support for the impression block 15 when a charge of molten metal is received in the die cavity 12.
  • the impression block 15 and the gate block 16 are abutted end to end at joint 19 in the pocket 14, and the free end of the gate block abuts gate end 21 of the pocket.
  • the overall length L of the abutted impression block 15- -gate block 16 combination is substantially less than the length L of the pocket 14 so as to create an end gap 23 at one end between the impression block and the pocket end 22, see FIG. 2.
  • the widths W of the impression block 15 and gate block 16 are substantially less than the width W of the holding blocks pocket 14 so as to create side gaps 24, 25 on both sides between the sides of the impression block 15-gate block 16 combination and the related pocket sides 17, see FIG. 2.
  • the abutted impression block 15- -gate block 16 combination has a shorter outer peripheral length than the peripheral length of the pocket 14, thereby creating the fixed gaps 23-25 that establish a single, continuous, fixed gap between the impression block-gate block sides and three sides l7, l7 and 22 of the pockets four sides when those blocks are assembled together.
  • the continuous fixed gap 2325 is preferably equal in length to at least one-half the peripheral length of the impression block l5-gate block 16 structure and, in the figures, is shown as being almost percent the peripheral length of the gate block-impression block structure.
  • the ejector gate block 16 can move from one side to the other between sides 17 of the pocket 14 because very precise positioning of this block 16 within the pocket is not required, that is, if the gate block is off center by some hundredths of an inch this will not ordinarily adversely affect the quality of the castings produced.
  • the ejector impression block 15, however, is positioned within the pocket 14 by a rectangular key 27 extending lengthwise of the pocket, see FIG. 1.
  • the key 27 is received in mating keyways 28, 29 sized to fit key 27, the keyways being cut into the bottom 18 of the pocket 14 and into the bottom of the impression block 15 respectively.
  • key 27 is fixed to holding block 13 in keyway 24 by two bolts 31 the heads of which are recessed in the key.
  • the key 27 serves to maintain the impression block 15 in a precise, preset position or registry within the pocket 14 at all times, thereby preventing movement of the impression block within the pocket relative to the holding block 13 in both the north-south and east-west directions even when expansion gaps on the order of thousandths of an inch or hundredths of an inch or more tend to open between the two blocks during use.
  • the ejector die is also illustrated as having two ejector pins 26 that are selectively 'reciprocable into the die cavity 12 by ejector apparatus, not shown, so as to eject castings formed in the cavity when the dies 10, 11 are opened.
  • the cover die 11 includes a cover-holding block 1311 that defines a'cover nest or pocket 14a in the front face of block 130, the pocket 14a and block 13a having substantially the same peripheral dimensions and geometry as pocket 14 and ejector-holding block 13.
  • An impression block 1511 and gate block 16a are abutted end to end at joint 19a in the pocket 14a in mirror relation to the impression block 15 and gate block 16 of the ejector die 10, see FIG. 1.
  • the cover impression 15a and gate 16a blocks are of substantially the same outer peripheral dimensions and outer geometry as the ejector impression 15 and gate 16 blocks.
  • fixed gaps 23a-25a substantially equal in dimension and configuration to fixed gaps 23-25 of the ejector die 10 are also established for the cover die 11 between sides 17al7a and ends 21a, 22a of the cover block's pocket 14a and the sides of the impression block 15a-gate block 160 combination.
  • the cover gate block 16a and holding block 13a are dissimilar from the ejector gate 16 and holding blocks 13 in that they cooperate to define a gate or molten metal inlet 33 for the die cavity 12.
  • the inlet 33 receives the end 34 of a shot tube 35 passing through passageway 36 in-the holding block 13a and gate block 16a.
  • a flange 37 integral with the shot tube 35 is seated on the back of the holding block 13a to position the shot tube relative to the gate 33.
  • the shot tube 35 is part of a diecasting machine, not completely shown.
  • the shot tube 35 serves to maintain the gate block 16a in its preset position within pocket 14a.
  • the cover impression block 15a is positioned within the pocket 14a by means of a rectangular key 27a located in keyways 28a, 29a cut in the bottom 18a of the pocket 14a and the bottom of the impression block 15a, respectively.
  • the key 27a is fixed to holding block 13a in keyway 28a by bolts 31a in the same manner as for the ejector die 10.
  • the two dies 10, 11 are closed into cavity 12 forming relation for receiving a charge of molten metal they meet at their front faces, that is, at die interface 41.
  • the impression blocks 15, 15a cooperate to form the die cavity 12 which, in the figures, is illustrated as that of a standard test bar.
  • the gate blocks 16, 16a cooperate to establish the gate or metal inlet 33 for the molten metal, the gate terminating in an end feeder area 42 that distributes the molten metal into the die cavity 12.
  • Guide pins 38 are mounted to. the cover-holdingblock 13a and are receivable in recesses 39 formed in the ejector-holding block 13 for centering or locating the holding blocks 13, 13a in register when they are closed into operable diecasting position.
  • keys 27, 27a act to ensure that impression block 15, 15a will be in registry by maintaining the preset position of the impression blocks relative to their holding blocks 13, 1311 even if expansion gaps or crevasses occur between the two blocks during the casting operation. Movement of the ejector impression block 15 relative to the cover'impression block 15a only a few thousandths of an inch may, in complex casting configurations, so misalign those blocks 15, 150 when they are closed together that castings produced from them will be out of dimensional tolerance limits.
  • keys 27, 27a play an important part in maintaining the position of impression blocks 15, 15a within their pockets 14, 14a and, in combination with guide pins 38 and recesses 39, maintain the registry of the impression blocks during repeated openings and closings of the die assembly even when expansion gaps between impression and holding blocks occur.
  • Each impression block 15, 15a-gate block 16, 16a combination in each holding blocks pocket 14, 14a, respectively, is maintained in that pocket during use of the die assembly by restraining means or chocks 43,4311 engageable with each die 10, 11 from the front face of that die.
  • the chocks 43, 43a are preferably trapezodial or wedge shaped in cross-sectional configuration, each chock having parallel top 44, 44a and bottom 45, 45a sides, a tapered side 46, 46a and a vertical side 47, 470, the inwardly tapered sides meeting the top sides at an acute angle a, see FIG. 3.
  • the chocks 43, 43a are positioned within and sized to fit in the fixed gaps 23-25,23a-25a created when the impression 15, 15a, gate 16, 16a, and holding 13, 13a blocks are assembled to substantially frame each block 15, 16 and 15a, 16a unit in its related pocket 14, 14a, see FIGS. 1 and 3.
  • the impression blocks 15, 15a are provided with outwardly tapered sides 48, 48a in an abotuse angle B, see FIG. 3.
  • the sum of the angles a and [3 equals
  • the inwardly tapered sides 46, 46a of the chocks 43, 43a are angled to cooperate with outwardly tapered sides 48, 48a of the impression 15, 15a and gate 16, 16a blocks so as to restrain those blocks in their respective pockets 14, 14a.
  • each impression block-gate block unit is restrained and, thereby, retained, in its pocket because of the wedging action of the chocks 43, 43a between the impression 15, 15a and gate 16, 16a blocks and the holding blocks 13, 13a.
  • each chock 43, 43a is of a thickness T substantially less than the depth D of the pockets 14, 14a so they can be adjusted downward when required, as is more fully explained hereinafter.
  • the top side 44, 44a width of each chock 43, 43a is preferably about equal to or a little less than the width at interface 41 of the fixed gaps 23-25, 23a-25a that the chock is to serve when the die is at room temperature.
  • the top sides 44, 44a of the chocks are substantially parallel with the front faces of the die halves 10, 11, see FIG. 3, and substantial clearance 49, 49a is established between the bottom side 45, 45a of the chocks and the bottom 18, 18a of the pockets 14, 14a.
  • the chocks 43, 43a are maintained in operating position, and are adjustably positionable within fixed gaps 23-25, 23a- -25a during heat up, operation, and cool down of the die, by adjustment means in the form of threaded bolts 50, 50a spaced along'their length in mirror relation for the ejector die 10 and the cover die 11; the bolts are available to an operator for adjustment from the front face of each die.
  • the bolts 50, 50a are engageable with the holding blocks 13, 13a by threads 52, 52a that pass through, without threadedly engaging the chocks 43, 43a.
  • Each bolthead 54, 54a cooperates with a recessed shoulder 53, 53a in each chock 43, 43a for forcing the chock down toward the bottom of its related pocket 14, 14a when the bolts 50, 50a are tightened into the holding blocks 13, 13a.
  • the chocks 43, 43a in the fixed gaps 23-25, 23a- 25a between the tapered sides of the impression-gate block units and the sides 17, 17a, 22, 22a of the holding block pockets 14, 14a (the pressure of which can be varied or adjusted by bolts 50, 50a) the impression blocks 15, 15a and gate blocks 16, 16a are easily and simply assembled and, thereafter, can be maintained together in tight and safe assembly during casting operations even when expansion gaps tend to occur due to different block material expansion eoefficients and high temperatures.
  • the geometry of the chocks in cooperation with the impression blocks and holding blocks also precludes undesirable molten metal or flashing from filling any expansion gaps between sides of the blocks adjacent the faces of the blocks that might normally be caused by the difference in the blocks coefficients of expansion because those expansion gaps are never allowed to open through operation of adjustment means 50, 50a for the restraining means 43, 430. Thus, no molten metal flashing runs into expansion gaps.
  • the chock 43, 43a structure is substantially the same for the chocks used with both the ejector die 10 and the cover die 11, except that the depth of the working shoulder 53 from the chock's top side 44 for the ejector die chocks 43 is substantially deeper than that depth for the cover die chocks 43a. It is preferred that shoulders 53a of the chocks 43a be recessed to a depth substantially less than the height of the boltheads 54a, and it is preferred that the shoulders 53 of the chocks 43 be of substantially greater depth than the height of the boltheads 54.
  • the chock 43, 43a structure of this invention admits of a method of use which is unique and novel in that it easily and simply permits the impression block 15, 15a to be changed with its related holding block 13, 13a. That is, the necessity for a tight friction fit between the impression block 15, 15a and holding block 13, 130 has been eliminated by the method and structure of this invention, thereby lessening the practical problems that obtain when handling, for example, refractory metal impression blocks which are relatively brittle at room temperature.
  • the impression block 15, 15a and gate block 16, 16a are placed in the holding blocks pocket 14, 140 from the front face of the die 10, 11, those blocks and pocket being formed so as to create fixed gaps 23-25, 2311-250 between the sides of the impression block 15, 15a and the sides 17, 17a, 22, 22a of the holding block pocket 14, 14a.
  • the key 27, 27a is positioned in the keyways 28-29, 28a- 29a provided in the bottom 18, 18a of the pocket 14, 14a and the bottom of the impression block 15, 15a, thereby centering the impression block in the holding blocks pocket. Because the impression block-gate block unit is formed with a peripheral length less than the peripheral length of the holding block's pocket 14, 140 the impression block 15, 15a can be easily and gently set down into the holding block's pocket.
  • the chocks 43, 43a are positioned within those gaps 23-25, 23a-25a from the front face of the die 10, 11 in a wedging fashion so as to maintain the impression block 15, 15a immobile relative to the holding block 13, 13a.
  • the chocks 43, 43a are tightened in position from the front face of the die 10, 11 by tightening the bolts 50, 50a and, thus, the impression block 15, 15a is tightly and safely restrained in operating assembly with the holding block 13, 1311.
  • chocks 43, 43:: are tightened with unequal pressure on either side of the impression block 15, 15a, those blocks still maintain their preselected alignment because of the key 27, 27a and keyways 28-29, 28a-29a.
  • Such a method and structure has been found to substantially reduce the amount oftime required by an operator to change imprcs sion blocks in a holding block.
  • the impression block does not expand as much as the holding block to maintain the tight friction fit; therefore, expansion gaps or crevasses on the order of thousandths of an inch or hundredths of an inch or more are formed during high-temperature operation between the impression block and the sides of the holding blocks pocket when the prior art method of holding the two blocks in operating engagement is used.
  • the chock 43, 43a structure ofthis invention is utilized by the method steps of periodically tightening the chocks 43, 43a from the front face of the die 10, 11 as the die heats up to operating temperature by means of adjusting bolts 50, 50a to take up any expansion gaps or crevasses created, thereby maintaining the impression block in tight and safe operating assembly with the holding block 13, 13a and preventing expansion gaps from opening in the first instance.
  • This step drives the wedge-shaped chocks 43, 43a deeper into the fixed gap 23-25, 230-2511, but the original clearance 49, 49a between the bottom 18, 18a of the pockets 14, 14a and the bottom 45, 45a of the chocks permits such limited movement to be achieved.
  • Such tightening of bolts 50, 50a also can be performed by an operator from the readily accessible front face of each die 10, 11 when the die halves are momentarily parted for ejecting a casting at the end of one casting cycle during a casting run, that is, the die does not have to be dismounted from the casting machine or disassembled to make the required adjustments.
  • this method easily and simply permits that expansion gap to be recreated or Opened as the die assembly is cooled down and the impression 15, 15a and holding 13, 13a blocks contract back to normal room temperature configuration, thereby preventing cracking of the impression block on cooling that may occur if intolerable pressures are created on the brittle refractory metal impression blocks.
  • the impression block 15, 15a is fabricated of, for example, a refractory metal and the holding block 13, 13a is fabricated of, for example, a tool steel it is preferred that the chocks 43, 4311 be fabricated of that tool steel and the key 27, 27a be fabricated of that refractory metal. 1n the case of the chocks 43, 43a, they must usually be made of steel so they can withstand the stresses placed on them by tightening of the bolts 50, 50a. ln the case of the key 27, 270, it is desirably fabricated of the same material as the impression block 15, 15:: so that no slippage or gaps occur between the key and its related impression blocks because both expand and contract at equal rates. Even if small gaps occur between the key 27,
  • impression blocks 15, 15a illustrated in FIGS. 1-3 have been shown as defining a single die cavity. However, an
  • the impression block is one having one-half 61 of a first die cavity on its front face 62 and one-half 63 of a second die cavity on its back face 64.
  • This alternative embodiment can be flipped over in a holding blocks pocket when a casting configuration change is required.
  • Such an impression block admits of substantial economy particularly when that block is formed of a high-cost material such as a refractory metal in that two castings, instead of just one, can be cast from it.
  • the cross-sectional angle [3 defined by each face 62, 64 with the tapered sides 65 of the impression block is an obtuse angle, thereby making such a block configuration useful with the expansion gap system of this invention.
  • FIGS. 5-8 An alternativeembodiment of a die assembly incorporating the expansion gap compensating system of this invention is illustrated in FIGS. 5-8.
  • the alternative embodiment of a die half 70 basically differs from the embodiment illustrated in FIGS. 1-3 in that (a) impression block 71 is inserted from the rear of holding block 72 instead of from the face of the holding block as with the preferred embodiment, and (b) the impression block 71 is automatically adjustable during use of the die assembly's alternative embodiment to compensate for expansion gaps that tend to open between sides of related impression and holding blocks at their face as the die assembly is heated up to operating temperature, as well as to compensate for contraction of the gaps as the die assembly cools after a casting run.
  • each die half 70 of the alternative embodiment is comprised of a holding block 72, an impression block 71, and a rear plate 73.
  • the casting cavity 69 illustrated is that same type of test bar as illustrated in the preferred embodiment of FIGS. 1-3.
  • the holding block 72 is provided with a specially configured pocket 74 that extends completely through the holding block.
  • the pocket 74 is configured to provide a seat 75 or recess in the rear surface 76 of the holding block 72, the seat being defined by'verticalsidewalls 77 perpendicular to the rear surface and a bottom wall 78 substantially parallel to the rear surface of the holding block.
  • the holding blocks pocket 74 is further defined by angulated cam walls 79 which extend from the bottom wall 78 of the seat 75 to the face 81 of the holding block 72.
  • the angulated walls 79 define a hole more or less in the shape of a'truncated tetrahedron, the minor face of the tetrahedron being at the face 81 of the holding block and the major face of the tetrahedron being at the bottom wall 78 of the seat 75 in the holding block 72, that is, the periphery of the hole at the face of the holding block is substantially less than the periphery of the hole at the bottom wall of the seat in the holding block.
  • This configuration i.e., the cam walls 79, provides wedgelike surfaces for that portion of the pocket 74 adjacent the face 81 of the holding block 72.
  • the impression block 71 is especially configured to cooperate with the pocket 74 in the holding block 72.
  • the impression block 71 is comprised of a base 84 which is of a width A and of a length B substantially less than the width A and length B ofthe seat 75 in the holding block 72, see FIG. 8.
  • This configuration allows fixed gaps 85 to be established between the sides 86 and ends 87 of the base relative to the sidewalls 77 and bottom 78 of the seat 75 when the impression block 71 is operationally engaged with the holding block 72, see FIGS. 5 and 8.
  • the depth C of the impression blocks base 84 is substantially less than the depth C of the seat 75 in the holding block 72.
  • the impression blocks base 84 is formed integral with a truncated tetrahedron 91 which presents a face 92 having an outer periphery 93 that is substantially identical with the periphery 94 of the hole defined by cam walls 79 at the face 81 of the holding block 72 at room temperature.
  • the truncated tetrahedron 91 is of the same cross-sectional configuration as is the hole defined by cam walls 79, but the depth D of the truncated tetrahedron is substantially greater than the depth D' of the hole defined by cam walls 79 in the holding block 72.
  • the overall depth (C +D) of the impression block 71 is equal to the overall depth (c+D) of the pocket 74 in holding block 72.
  • the impression block 71 is made from a material having a different expansion coefficient than that of holding block 72, as in the case of the preferred embodiment, and it is preferred that the impression block be configured during manufacture so that, when assembled with the holding block at room temperature, the face 92 of the impression block is substantially flush or in the same horizontal plane with the face 81 of the holding block.
  • the impression block 71 is held in operative engagement with the holding block 72 by means of the backplate 73 which is fixed to the holding block by means of threaded bolts 102 (shown only in FIG. 5).
  • the backplate 73 cooperates with the impression block 71 to maintain 'same in fixed or wedged engagement with the cam sides 79 of the holding blocks hole pocket 74 at room temperature.
  • the backplate 73 is preferably made of the same material as the holding block 72.
  • the backplate 73 is provided with a key 103 which cooperates with a keyway 104 in the impression block 71 to maintain same in exact position or registry during use of the die assembly.
  • the key 103 is comprised of an elongated bar that is fixed by bolts 105 to the backplate 73, and the key is made of the same material as the impression block 71.
  • One of the holding blocks 72 is provided with a series of recesses 110 of a depth substantially greater than the depth of the boltheads 111. Those recesses 110 are aligned relative to the periphery of pocket 74 so that a further hole 112 may be bored completely through ledge section 114 of the holding block 72 in alignment with. a hole 113 through base section 84 of the impression block 71, the ledge section 114 and base section 84 overlapping as seen in cross section in FIG. 5. The diameter of holes 112, 113 is such that bolts 108 are not threadedly engaged therewith.
  • the bolts 108 are inserted through the holes 112, 113 in the impression block 71 and holding block 72 and are each provided with heavy spring or disc washer 109 interposed between nut 116 and the rear 76 of the impression block.
  • Seats 117 are provided in the baseplate 73 to receive the nutted end of the bolts 112.
  • the springs 109 cooperate with the bolts 108 to continually pressure the cam sides 106 of the impression block 71 against, and to insure that the cam sides of the impression block are held in engagement with, the
  • the holding block 72a of the other mold half 70a is provided with bolt holes 110a of a depth substantially less than the height ofthe boltheads Illa, and the holes 110a are positioned in mirror relation to the boltholes H of the die half 70.
  • boltheads 111a are received in recesses 110 in the holding block 70 so as to essentially seal off that space 121 between boltheads ll], 111a and prevent molten metal from freezing the bolts in position.
  • a method of compensating for expansion gaps in a die wherein each die halfis made up ofa holding block and an impression block, and wherein the coefficient of expansion of said holding block is greater than the coefficient of expansion of said impression block comprising the steps of providing a pocket in said holding block providing said impression block with an outer periphery configured such that said impression block can be established in nested position within said holding block's pocket, said impression block thereafter being nested in said holding blocks pocket, providing restraining means associated with said impression and holding blocks that maintains said impression block in nested position with said holding block, and that precludes undesirable molten material from filling any expansion gaps between sides of said blocks adjacent the face of said die half that might normally be caused by the difference in said blocks coefficients of expansion, as the temperature of said die half rises during use thereof,
  • a method as set forth in claim 1 including the further steps of returning the temperature of said die toward ambient temperature
  • a method as set forth in claim 2 including the further step of providing registration means associated with said holding and impression blocks for maintaining desired registry of each of said die halfs impression blocks to each other during adjusting of said restraining means.
  • step of providing registering means includes keying said impression block to said holding block.
  • An expansion gap compensating system for a die assembly having two complimentary die halves, at least one die half comprising, in combination,
  • impression block established in nested position within said holding blocks pocket, the impression block material having a lesser expansion coefficient than the holding block material
  • adjusting means associated with said impression and holding blocks for adjusting said restraining means as required to compensate for the differential expansion of said impression and holding blocks as the die halfs temperature rises during use, thereby alleviating the formation of an expansion gap between the sides of said impression and holding blocks adjacent the face of said die half during the use thereof.
  • An expansion gap system as set forth in claim 11 including registration means associated with said impression and holding blocks for maintaining desired registry of said impression block with a cooperating impression block of another die half during use of said adjustment means.
  • An expansion gap compensating system as set forth in claim 12 wherein the periphery of said impression block is substantially less than the periphery of said holding blocks pocket, said dissimilar peripheries resulting in a preformed gap between the sides of said blocks equal to at least about one-half the peripheral length of said impression block being disposed between the sides of said impression block and said holding block's pocket, and wherein said restraining means is positioned within said preformed gap.
  • An expansion gap compensating system as set forth in claim 15 wherein the thickness of said chock is substantially less than the depth of said fixed gap so that a clearance is established between the bottom of said chock and the bottom of said pocket when said chock is positioned within said gap at ambient temperature, and wherein the top side of said chock is substantially flush with the front face of said impression block when said chock is positioned within said gap at ambient temperature.
  • An expansion gap compensating system for a die assembly having two die halves comprising, in combination,
  • first and a second impression block each receivable within one of said pockets, the impression blocks material having a lesser expansion coefficient than the holding blocks material and said impression blocks each having a substantially shorter peripherallength than its related pocket so that a fixed gap is created for each pair of blocks,
  • first series of bolts adjustably interconnecting a first chock and said first holding block from the front face of said first die half, the first boltheads being substantially recessed below the top side of the first said chock
  • a second series of bolts adjustably interconnecting a second said chock and said second holding block, the second boltheads extending substantially above the top side of the second said chock and being gositioned in mirror relation to said first bolts, and the eads of said second bolts being received in the deeper recesses formed for said first bolts after said die halves are positioned in operable die assembly, t
  • both said series of bolts adapted to be turned to periodically adjust the position of the respective chocks within the respective fixed gaps to compensate for widening or narrowing of said fixed gap as the die temperature increases and decreases, respectively, from and to ambient temperature during use.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Casting Devices For Molds (AREA)
US36299A 1970-05-11 1970-05-11 Expansion gap compensating system for a die Expired - Lifetime US3581804A (en)

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US3629970A 1970-05-11 1970-05-11

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US (1) US3581804A (OSRAM)
JP (1) JPS5214209B1 (OSRAM)
CA (1) CA931726A (OSRAM)
DE (1) DE2120358A1 (OSRAM)
GB (1) GB1352639A (OSRAM)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4100962A (en) * 1977-02-28 1978-07-18 James H. Housman Casting die
US4390057A (en) * 1979-12-11 1983-06-28 Mecan Arbed S.A. Curved continuous-casting mold and method of reestablishing the internal dimensions thereof
EP0233452A1 (en) * 1986-01-10 1987-08-26 Akio Nakano Die casting machine
DE10033207C1 (de) * 2000-07-07 2001-12-06 Peter Derksen Einsatzanordnung für ein Formwerkzeug sowie Formwerkzeug mit einer solchen
US20060034973A1 (en) * 2002-11-05 2006-02-16 Hoogland Hendricus A Apparatus and method for manufacturing holders, in particular crates
US20070169685A1 (en) * 2006-01-20 2007-07-26 Bp Corporation North America Inc. Methods and Apparatuses for Manufacturing Geometric Multicrystalline Cast Silicon and Geometric Multicrystalline Cast Silicon Bodies for Photovoltaics
US20070269545A1 (en) * 2006-05-16 2007-11-22 Graham Packaging Company, L.P. Magnetic quick change mold
US20100193031A1 (en) * 2007-07-20 2010-08-05 Bp Corporation North America Inc. Methods and Apparatuses for Manufacturing Cast Silicon From Seed Crystals
US20100197070A1 (en) * 2007-07-20 2010-08-05 BP Corproation North America Inc. Methods and Apparatuses for Manufacturing Cast Silicon From Seed Crystals
US20110158887A1 (en) * 2008-08-27 2011-06-30 Amg Idealcast Solar Corporation Apparatus and method of use for casting system with independent melting and solidification
US20110233378A1 (en) * 2010-03-24 2011-09-29 Bales Daniel A Die inserts for die casting
US20130105435A1 (en) * 2010-09-27 2013-05-02 Lg Hausys, Ltd. Mold for forming 3-dimensional pattern and method of manufacturing exterior material for home appliance using the same
US8591649B2 (en) 2007-07-25 2013-11-26 Advanced Metallurgical Group Idealcast Solar Corp. Methods for manufacturing geometric multi-crystalline cast materials
US8709154B2 (en) 2007-07-25 2014-04-29 Amg Idealcast Solar Corporation Methods for manufacturing monocrystalline or near-monocrystalline cast materials
CN108941498A (zh) * 2018-08-17 2018-12-07 镇江汇通金属成型有限公司 用于蜗轮铸造的离心模具
CN109689330A (zh) * 2016-11-29 2019-04-26 东和株式会社 压缩成型装置、压缩成型方法、及压缩成型品的制造方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016123495A1 (de) 2016-12-05 2018-06-07 Schuler Pressen Gmbh Werkzeug zum Gießen und/oder Umformen eines Bauteils, Gießvorrichtung, Presse und Verfahren zur Spaltkompensation

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US2366475A (en) * 1942-06-25 1945-01-02 Doehler Die Casting Co Die for die-casting
AT186785B (de) * 1953-07-24 1956-09-10 Leopold Wittmann Kokille
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US2912730A (en) * 1956-11-01 1959-11-17 Nat Lead Co Positioning or locking guides for dies
FR1316838A (fr) * 1962-03-05 1963-02-01 Perfectionnement aux moules
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US1370191A (en) * 1919-02-05 1921-03-01 Walter W Crate Mold for making artificial teeth
US2366475A (en) * 1942-06-25 1945-01-02 Doehler Die Casting Co Die for die-casting
AT186785B (de) * 1953-07-24 1956-09-10 Leopold Wittmann Kokille
US2848771A (en) * 1955-03-03 1958-08-26 Buehler Ag Geb Apparatus for closing and locking of die casting machines and the like
US2912730A (en) * 1956-11-01 1959-11-17 Nat Lead Co Positioning or locking guides for dies
FR1316838A (fr) * 1962-03-05 1963-02-01 Perfectionnement aux moules
US3335459A (en) * 1965-02-12 1967-08-15 Allied Chem Cartridge heater constructions including extrusion dies
US3380121A (en) * 1965-07-30 1968-04-30 American Can Co Mold with replaceable inserts
US3357058A (en) * 1966-10-31 1967-12-12 Gronemeyer Erich W Apparatus for injection molding a bristled product

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4100962A (en) * 1977-02-28 1978-07-18 James H. Housman Casting die
US4390057A (en) * 1979-12-11 1983-06-28 Mecan Arbed S.A. Curved continuous-casting mold and method of reestablishing the internal dimensions thereof
EP0233452A1 (en) * 1986-01-10 1987-08-26 Akio Nakano Die casting machine
DE10033207C1 (de) * 2000-07-07 2001-12-06 Peter Derksen Einsatzanordnung für ein Formwerkzeug sowie Formwerkzeug mit einer solchen
US20060034973A1 (en) * 2002-11-05 2006-02-16 Hoogland Hendricus A Apparatus and method for manufacturing holders, in particular crates
US20070169684A1 (en) * 2006-01-20 2007-07-26 Bp Corporation North America Inc. Methods and Apparatuses for Manufacturing Monocrystalline Cast Silicon and Monocrystalline Cast Silicon Bodies for Photovoltaics
US8951344B2 (en) 2006-01-20 2015-02-10 Amg Idealcast Solar Corporation Methods and apparatuses for manufacturing geometric multicrystalline cast silicon and geometric multicrystalline cast silicon bodies for photovoltaics
US20070169685A1 (en) * 2006-01-20 2007-07-26 Bp Corporation North America Inc. Methods and Apparatuses for Manufacturing Geometric Multicrystalline Cast Silicon and Geometric Multicrystalline Cast Silicon Bodies for Photovoltaics
US8048221B2 (en) 2006-01-20 2011-11-01 Stoddard Nathan G Methods and apparatuses for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics
US8628614B2 (en) 2006-01-20 2014-01-14 Amg Idealcast Solar Corporation Methods and apparatus for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics
US20070269545A1 (en) * 2006-05-16 2007-11-22 Graham Packaging Company, L.P. Magnetic quick change mold
US8440157B2 (en) 2007-07-20 2013-05-14 Amg Idealcast Solar Corporation Methods and apparatuses for manufacturing cast silicon from seed crystals
US20100193031A1 (en) * 2007-07-20 2010-08-05 Bp Corporation North America Inc. Methods and Apparatuses for Manufacturing Cast Silicon From Seed Crystals
US20100197070A1 (en) * 2007-07-20 2010-08-05 BP Corproation North America Inc. Methods and Apparatuses for Manufacturing Cast Silicon From Seed Crystals
US20100203350A1 (en) * 2007-07-20 2010-08-12 Bp Corporation Noth America Inc. Methods and Apparatuses for Manufacturing Cast Silicon from Seed Crystals
US8709154B2 (en) 2007-07-25 2014-04-29 Amg Idealcast Solar Corporation Methods for manufacturing monocrystalline or near-monocrystalline cast materials
US8591649B2 (en) 2007-07-25 2013-11-26 Advanced Metallurgical Group Idealcast Solar Corp. Methods for manufacturing geometric multi-crystalline cast materials
US20110158887A1 (en) * 2008-08-27 2011-06-30 Amg Idealcast Solar Corporation Apparatus and method of use for casting system with independent melting and solidification
US20110233378A1 (en) * 2010-03-24 2011-09-29 Bales Daniel A Die inserts for die casting
US8814557B2 (en) * 2010-03-24 2014-08-26 United Technologies Corporation Die inserts for die casting
EP2371469A3 (en) * 2010-03-24 2016-03-02 United Technologies Corporation Configuration of die inserts for high temperature die-casting
US20130105435A1 (en) * 2010-09-27 2013-05-02 Lg Hausys, Ltd. Mold for forming 3-dimensional pattern and method of manufacturing exterior material for home appliance using the same
CN109689330A (zh) * 2016-11-29 2019-04-26 东和株式会社 压缩成型装置、压缩成型方法、及压缩成型品的制造方法
CN108941498A (zh) * 2018-08-17 2018-12-07 镇江汇通金属成型有限公司 用于蜗轮铸造的离心模具
CN108941498B (zh) * 2018-08-17 2024-02-02 镇江汇通金属成型有限公司 用于蜗轮铸造的离心模具

Also Published As

Publication number Publication date
DE2120358A1 (de) 1971-11-25
GB1352639A (en) 1974-05-08
CA931726A (en) 1973-08-14
JPS5214209B1 (OSRAM) 1977-04-20

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