EP3302852A1

EP3302852A1 - Hot runner feed system for a diecasting mould

Info

Publication number: EP3302852A1
Application number: EP16727995.9A
Authority: EP
Inventors: Marc Nowak; Norbert Erhard; Ronny Aspacher
Original assignee: Oskar Frech GmbH and Co KG
Current assignee: Oskar Frech GmbH and Co KG
Priority date: 2015-06-05
Filing date: 2016-06-03
Publication date: 2018-04-11
Anticipated expiration: 2036-06-03
Also published as: HK1245718A1; US10618108B2; CN107848025A; WO2016193458A1; PT3302852T; DE102015210400A1; ES2928758T3; EP3302852B1; US20180354025A1; JP2018520006A; JP6802192B2; PL3302852T3; CN107848025B

Abstract

The invention relates to a hot runner feed system for a diecasting mould, wherein the feed system comprises a manifold-and-feed block construction with an inlet-side feed inflow opening (1), at least one first and one second outlet-side feed outlet opening (2, 3), which open out into a mould parting plane between a fixed mould half and a movable mould half of the diecasting mould, and comprises a branching runner structure (5), extending from the feed inflow opening to the feed outlet openings. According to the invention, at least in an outlet-side block region comprising the two feed outlet openings, the manifold-and-feed block construction is produced as shortened in a transverse direction parallel to the mould parting plane with respect to a prescribed desired operating extent by an amount (B-b) which is predetermined as a thermal transverse expansion of this block region when it is heated from a room temperature range to a comparatively increased, prescribed operating temperature range. Use for example for the diecasting of nonferrous alloys and molten salts.

Description

Hot Runner Angular System for a Die Casting Die

The invention relates to a hot runner gate system for a die casting mold, the gate system comprising a melt distribution and sprue block assembly having an entrance gate mouth, at least first and second exit gate openings formed in a mold parting plane between a fixed die half and a movable die half Die casting mold, and a branching of the sprue mouth opening to the Sprußausmündungen extending Gießlaufkanalmündung includes.

Applicant has marketed a hot runner sprue system called Frech Gating System (FGS) for die casting dies marketed e.g. also in the journal article L.H. Kallien and C. Böhnlein, Die Casting, Foundry 96, 07/2009, pages 18 to 26 is mentioned. Hot runner sprue systems generally have the advantage over other conventional sprue systems that the amount of melt material can be significantly reduced, which is eliminated on the so-called gate or the gate cavity preceded by the mold cavity and must be separated from the cast cast product.

Applicant's EP 1 201 335 B1 and EP 1 997 571 B1 disclose hot runner gate systems, e.g. are of a comb or fan gantry type or independently have sprue block units with integrated melt channel heating which can be used in a respective casting mold.

More recently, there has been an increasing demand for die casting dies and associated gating systems which operate in a relatively high temperature range of up to about 750 ° C. With this elevated temperature, the risk of undesirable oxide formation and the risk of fire in highly reactive, strongly oxidizing melts, such as magnesium, in particular in outlet opening areas of the sprue system also increases. One objective to overcome these problems is to move from comb and fan gating systems to systems with a smaller number of larger sized gullies. The design of the hot runner gate system for said elevated temperature range enhances the difficulties associated with the thermal expansion of the various components of the gate system and surrounding components, particularly the adjacent parts of the fixed mold half and the movable mold half. In particular, differences in the thermal expansion due to the use of different materials for the components in question should be noted. At the same time, a reliable sealing of the sprue system must be ensured in order to prevent melt leaks due to system leaks. Conventional gaskets, such as those used in plastic injection molding hot runner systems designed for a lower operating temperature range, do not lend themselves well to the aforementioned elevated operating temperature range, especially since the seals are not only in the operating temperature range when the melt carrying channels are at liquidus temperature , must reliably seal, but must also survive the cooling process of the casting process, when the system is still filled with melt and this solidifies in the channel during cooling.

The geometry and temperature profile of the hot runner gate system are selected to overcome these problems such that the melt outlets are preferably arranged in ascending order and that a temperature gradient from a hotter upstream region, e.g. is formed by a melt distribution region and at an operating temperature of depending on the used melting material e.g. 380 ° C to 700 ° C is set to a less hot, downstream region adjacent to a contouring portion of the mold formed by the fixed and movable mold halves with an operating temperature range of about 120 ° C to 300 ° C. The described temperature conditions increase the problem of the thermal expansion of different, adjacent system components.

Patent specification DE 102005 054 616 B3 discloses a permanent casting mold having a mold body at least partially surrounding a mold cavity and a mold insert which has an upper side associated with the mold cavity, a main body seated with play in a receptacle of the mold body in a cold mold, and a support collar which positively in a transition into the mold cavity Paragraph of the recording sits. An overall height of support collar and base body is smaller than a depth of the receptacle by an undersize, which is at least equal to a height dimension by which the base body expands when casting in the height direction.

The patent DE 840 905 discloses an injection mold in which a part of a mold cavity is arranged in an insert which is displaceable in the direction of mold division, so that it can automatically center to a Auswerfform, for which it has a recess into which one end fits the insert.

The invention is based on the technical problem of providing a hot runner-gate system of the type mentioned, which is process-reliable even for relatively high Druckgießtemperaturen in an advantageous manner.

The invention solves this problem by providing a hot runner gate system having the features of claim 1. In this gate system, the melt distribution and sprue block assembly is at least in an outflow block containing the two or more sprue outlets shortened in a transverse direction parallel to the mold parting plane with respect to a predetermined operating distance by an amount of expansion which is referred to as thermal transverse extension of that block area when heating one Room temperature range is predicted on a contrast, increased, predetermined operating temperature range. Therein, the transverse thermal expansion is meant as relative size, i. relative to any lower transverse thermal expansion of adjacent system components, such as, in particular, an adjacent region of the solid mold half.

This measure according to the invention takes into account the longitudinal expansion of the melt distribution and runner block structure in the particularly relevant, exit-side area in a controlled manner, which includes a predetermination of the associated thermal expansion. The prediction can be carried out experimentally and / or by means of computational simulation, as known per se to the person skilled in the art, wherein the respective influencing parameters represent input variables of this prediction and represent the respectively considered die with its parts relevant for this purpose. When the melt distributor and sprue block assembly is heated from room temperature to the operating temperature, it expands precisely to the extent to which it is made shortened, so that it is gap-free and sealing to the adjoining system components, for example, with its outlet-side block area containing the sprue outlets fixed mold half fits. The sufficient tightness at the contact-A / connection points is preferably achieved by suitable material pairings such that the thermally different coefficient of expansion seals the system stronger with increasing temperature. For this purpose, depending on the application, suitable temperature-dependent biases can be calculated in advance and used and / or conical sealing surfaces can be used in the temperature range of the tool. Thus, the invention enables the provision of a pressure-cast-tight connection, ie a relation to the Druckgießschmelze sufficiently tight connection of Schmelzeverteiler- and sprue block construction on the one hand and solid mold half on the other hand, without necessarily mandatory sealing elements must be used.

In one development of the invention, the melt distributor and sprue block assembly has a one-piece distributor and sprue block comprising the runner channel structure from the sprue mouth to the sprue outlets, comprising the exit-side block region. This refinement is of constructive advantage, in particular for systems with comparatively smaller dimensions and / or lower operating temperatures. Due to the one-piece design, sealed contact points between a melt distribution area and a downstream adjoining Angusssystembereich.

In one embodiment, the exit-side block region forms an elongate oval in this one-part distributor and sprue block, in whose two end regions there is one sprue outlet each.

In another embodiment, the outlet-side block area of this one-part distributor and sprue block can be inserted into a receptacle of the fixed mold half, wherein the receptacle has a transverse extent that corresponds to the operating distance of the outlet-side block area. In one development of the invention, the melt distributor and sprue block assembly includes a melt distributor block containing the inlet-side sprue orifice and, subsequently, a first sprue block containing the first sprue orifice and a second sprue block containing the second sprue orifice. At each of the first and the second sprue block, a sprue insert is arranged, which is displaceable on the fixed mold half in a transverse direction parallel to the mold parting plane and fixable thereto. Thus, the system components in question can be shifted in a not yet heated to operating temperature and non-fixed state against each other, to then fix them to each other when reaching the desired operating temperature range. Thus, the length expansion effects caused by the heating process can be absorbed. By fixing the tightness in the operating temperature range can be secured. Possibly existing gaps can optionally be covered or sealed by an associated cover plate. In one embodiment of this measure, each of the sprue inserts is assigned a wedge plate for wedging the sprue inserts to the fixed mold half. This represents a structurally advantageous method for fixing the sprue inserts to the solid mold half. In a further embodiment, the sprue inserts are displaceable along a connecting line of the first and the second sprue orifice and can be braced by the wedge plates in a transverse direction perpendicular thereto.

In a further development of the invention, the melt distribution and sprue block assembly includes a melt distribution block having a first exit nozzle associated with the first gate and a second exit nozzle associated with the second gate, and an intermediate plate having nozzle attachment mouthpieces for centering the exit nozzles. In this case, the intermediate plate is manufactured with a spacing of its nozzle attachment mouthpieces from one another, which corresponds to a Betriebsstempe- ratur distance of the outlet nozzles from each other, while the melt distribution block is made with a distance of its outlet nozzles, which corresponds to a relation to the operating temperature distance less room temperature distance. This represents a structurally advantageous realization especially for systems with comparatively larger dimensions and higher operating temperatures and an alternative to the realization with displaceable and fixable sprue inserts. The intermediate plate represents with its nozzle attachment mouthpieces the dissolved position of the system in the so-called Abgefahren position of the die. After heating to operating temperature, the intermediate plate can be driven onto an existing heating package and on the outlet nozzles of the melt distribution block, whereby it can clamp and seal the outlet nozzles. Thereafter, the intermediate plate can be locked, after which the tool operates in this configuration until the operating temperature range is exited.

Advantageous embodiments of the invention are illustrated in the drawings and will be described below. 1 is a perspective view of a one-piece distributor and sprue block of a

Hot runner sprue system

Fig. 2 is a fragmentary schematic plan view of a solid mold half of a

Die casting mold with a hot runner gate system with the distributor and sprue block of FIG. 1 in a room temperature state, FIG. 3 is a sectional view along a line III-III of FIG. 2, FIG.

FIG. 4 shows the view of FIG. 2 in an operating temperature state, FIG.

5 is a sectional view taken along a line V-V of Fig. 4,

6 shows a schematic top view of a solid mold half with a hot runner gate system attached thereto, which has slide-on contact inserts on the outlet side, in a room temperature state,

7 shows the view of FIG. 6 in an operating temperature state, FIG.

8 is a schematic sectional view along a line Vl-Vl of Fig. 7,

Fig. 9 is a schematic perspective sectional view of a melt distribution and sprue block assembly with exit side intermediate plate in front of a movable mold half in a room temperature condition and Fig. 10 is the view of Fig. 9 in an operating temperature state.

FIGS. 1 to 5 show, partially in part, a hot runner sprue system for a diecasting die of a die casting machine with only its components of relevance here. Incidentally, the sprue system and die have any of the configurations familiar to those skilled in the art, which need no further explanation here. The hot runner runner system includes a melt distribution and runner block assembly having an entrance-side gate mouth 1, first and second exit-side gate openings 2, 3 opening into a mold parting plane between a fixed mold half 4 and a movable mold half 20 of the die and one In the example shown, the Gießlaufkanalstruktur 5 includes two fluidically parallel running channels 5a, 5b, which depart from the Angußmundöffnung 1 and one of which to a pour spout 2 and the other to another sprue 3 leads. To the sprue mouth 1 can be applied in a conventional manner a mouthpiece of an upstream part of the Angusssystems, such as a casting chamber or a riser.

In the exemplary embodiment of FIGS. 1 to 5, the melt distributor and sprue block assembly has a one-piece distributor and sprue block 6 containing the runner channel structure 5 from the sprue mouth 1 to the sprue orifices 2, 3. An exit-side block portion 6a of the manifold and sprue block 6 is formed as an elongate oval, with the two sprue outlets 2, 3 being at opposite end portions of the oval as shown. The distributor and sprue block 6 is arranged on the solid mold half 4 in such a way that it lies with its outlet-side oval 6 a in a shape-identical, oblong oval receptacle 7 of the fixed mold half 4. Each of the sprue outlets 2, 3 corresponds to a respective inlet region 25, 26 of the movable mold half 20 or of the mold cavity formed by the two mold halves 4, 20.

Characteristically, the distributor and sprue block 6 with its exit-side oval block area 6a in a transverse direction perpendicular to the mold-parting plane is opposite to a predetermined operating distance B by an extent of extension Ab made to an extent b = B-Ab shortened. The expansion measure Ab is characteristically controlled as a thermal transverse extension of this oval block area 6a when heating from a room temperature range to a comparatively elevated, predetermined operating temperature range in advance. 2 and 3 show the built-in oval block portion 6a in its fabricated, shortened extension b, as it is at room temperature. Depending on the melt material to be cast and the other parameters which have an influence on the thermal expansion behavior of the system components relevant here, the expansion measure Ab is experimentally predicted experimentally, as by corresponding experiments or series of experiments, and / or by computer simulation, as is known to those skilled in the art other problems known per se. As melting materials are mainly metal melts of non-ferrous alloys, such as those based on magnesium, aluminum, zinc, tin, lead and brass, but also called molten salts. In this case, the hot runner sprue system can also be designed in particular for comparatively high operating temperatures of over 600 ° C. and in corresponding applications also up to 700 ° C. or 750 ° C. Corresponding to the extent of expansion is a deviation measure by which the position of the sprue outlets 2, 3 at room temperature deviates parallel to the mold parting plane from the position of the inlet regions 25, 26.

The advance determination of the expansion dimension Ab of the distributor and sprue block 6 and in particular of its exit-side oval block portion 6a makes it possible to achieve a tight fit between adjoining parts without the risk of melt leaks, whereby customary seals can be dispensed with in whole or in part. When the distributor and sprue block 6 is brought from room temperature to the predetermined operating temperature, it expands more in the transverse direction than the surrounding area of the fixed mold half 4 in accordance with the anticipated extent of extension Ab. In keeping with this, the corresponding receptacle 7 is fixed Form half 4 to the expansion dimension made of greater than the recorded oval block portion 6a, ie in the example of Fig. 2, the receptacle 7 has in the transverse direction along a connecting line 8 of the two sprue outlets 2, 3 a width B, which is larger by the expansion amount Ab as the extension b of the oval block portion 6a in this direction. In most cases, the thermal expansion change of the fixed mold half 4 and especially of its recess 7 is practically negligible compared to that of the oval sprue block area 6a. Otherwise it understands itself, that it is always the difference of the thermal expansion changes of the opposing system components or components in the pre-determined expansion Ab.

FIGS. 4 and 5 show the system in the view of FIGS. 2 and 3, respectively, after the heating of the distributor and sprue block 6 to the predetermined, desired operating temperature range has been completed. The oval block area 6a has expanded by the heating by the anticipated expansion dimension Ab and thereby fills its associated receptacle 7 in the solid mold half 4 fitting and sealing, ie it presses by its thermal expansion on all sides parallel to the mold parting plane gap-free and sealing against the edge his corresponding recording 7. In particular, the gap existing in the cold state Ab is reduced to zero, ie the distributor and sprue block 6 rests in the region of its sprue outlets 2, 3 with a pressure-casting-tight connection 27 against the adjacent region of the fixed mold half 4. In this case, a pressure-casting-tight connection means a gap-free, tight connection which is sufficient for the die casting application and which prevents liquid, hot melt material from penetrating between the relevant components, in the exemplary embodiment of FIGS. 1 to 5 analogously to a press fit. This provides the required and desired sealing of the system for subsequent casting operations. At the same time, as a result of the different thermal expansion of said components during heating up to operating temperature, the deviation measure Ad of the position of the sprue outlets 2, 3 with respect to the position of the inlet regions 25, 26 is preferably also reduced to zero or close to zero, so that each sprue orifice 2, 3 in FIG Desired way, the associated inlet region 25, 26 is sufficiently aligned. Thus, it is ensured that the gate of the melt at the melt temperature of, for example, 380 ° C to 700 ° C operated distributor and sprue block 6 despite the different thermal expansion compared to the fixed and the movable mold half 4, 20, at an operating temperature of eg 120 ° C to 300 ° C, exactly at the desired location required with respect to. The form defined by the two mold halves and that this place despite the different thermal expansion tempered to eg 120 ° C to 300 ° C shape on the one hand and on for example, tempered runner channel structure 380 ° C. to 700 ° C. 5 taking into account its viscosity and the melt pressure used, for example about 300 bar and more, for example up to about 450 bar, is sufficiently dense over the liquid molten metal used.

Since the distributor and sprue block 6 is manufactured in one piece, in the hot runner gate system of FIGS. 1 to 5 there are no separating points to be sealed between a melt cross-manifold area and a melt outlet nozzle area. The melt is transferred from the gate mouth 1 as a central inlet and gate of a nozzle of an upstream casting system of the machine via the preferably obliquely outwardly and upwardly extending Gießlaufäle 5a, 5b directly into the Auslassgeometrie the oval exit region 6a.

FIGS. 6 to 8 illustrate another possible realization of the hot runner gate system according to the invention. This sprue system includes a melt distribution and sprue block assembly that may or may not be similar to the sprue system of Figs. 1-5, except as noted below for differences in configuration. This applies in particular to the inlet-side sprue orifice, the two outlet-side sprue orifices 2, 3 and the sprinkler channel structure extending branching from the sprue orifice to the sprue orifices. For ease of understanding, the same reference numerals are used in this case not only for identical, but also functionally equivalent elements. Unlike the one-piece manifold and sprue block 6 in the system of Figs. 1-5, the melt distribution and sprue block assembly of the system of Figs. 6-8 includes a multi-part design with a sprue orifice containing conventional melt distribution block 21 which is only partially in 8, and with two flow blocks parallel thereto sprue blocks or Angusseinsätzen 9, 10, of which the one outlet side, the first Angussausmündung 2 and the other outlet side, the second Angussausmündung 3.

The Angusseinsätze 9, 10 are on the fixed mold half 4 in a transverse direction parallel to the mold parting plane slidably disposed and fixed thereto, the transverse direction is here again parallel to the connecting line 8 between the two Angerausmündungen 2, 3. The two sprue inserts 9, 10, with which thus the melt distribution and sprue block construction form-closed and which are the In the example shown in plan view, in the example shown in FIG. 2, they have an elongated rectangular shape and are displaceable along a strip-shaped receiving region 7 'on the fixed mold half 4. As a result, in this embodiment, the corresponding thermal expansion can be compensated. This is represented in FIGS. 6 and 7 by the distance between the two sprue outlets 2, 3, which increases from a room temperature a when the system is heated to operating temperature to an operating temperature distance A which corresponds to the corresponding extent Aa = Aa is greater than the room temperature distance a. Upon heating the system to operating temperature, the sprue inserts 9, 10 are left in an unfixed, loosened state so that they can thermally expand, causing the sprue outlets 2, 3 to move away from one another accordingly. When the operating temperature range has been reached, the sprue inserts 9, 10 have expanded so far in the transverse direction parallel to the connecting line 8 that the sprue outlets 2, 3 have assumed their increased operating temperature distance value A from one another. Then, the sprue inserts 9, 10 are fixed to the fixed mold half 4 in their operating temperature state shown in FIG. An existing between the Angusseinsätzen 9, 10 gap 22 can be covered by an optional and therefore dashed lines in Figures 6 and 7 indicated covering or mounting plate 23, which can be fixed eg four dashed lines indicated attachment points 24 on the fixed mold half 4 , With the cover plate 23, an undesirable penetration of melt material and any other interfering particles into the gap 22 can be prevented if necessary.

To fix the Angusseinsätze 9, 10 two wedge plates 1 1, 12 are provided in the example shown, which are provided with wedge-shaped contact surfaces, as shown in FIG. 8, and between an underside of the respective Angusseinsatzes 9, 10 and an underlying portion of the fixed Forming half 4 can be inserted and fixed to the fixed mold half 4, in the example shown by means of a screw 13. Fixing the respective wedge plate 1 1, 12 due to a corresponding wedge plate fixing force F1 leads due to the wedge-shaped contact surfaces of the wedge plates 1 1, 12 to a perpendicular to the direction of displacement of the Angusseinsätze 9, 10 directed parallel to the mold parting plane tensioning force F2 on the adjacent Angussein- set 9, 10. In this way, the Angusseinsätze 9, 10 are secure, gap-free and sealed by mating material fixed to the fixed mold half 4.

Preferably, although not necessarily, in the exemplary embodiment of FIGS. 6 to 8, the extent to which the outlet-side block region of the melt distribution and sprue block construction with the sprue inserts 9, 10 is shortened in a transverse direction parallel to the mold parting plane is smaller than a predetermined operating extension is manufactured, as a thermal transverse expansion of this exit-side block area on heating from room temperature range to the predetermined operating temperature range experimentally by means of experiments and / or mathematically predicted by means of computer simulation. The prediction can for example be realized in such a way that the Angusseinsätze 9, 10 with their opposite outer sides against an adjacent portion of a mold frame 4a of the fixed mold half 4 create, as shown in Fig. 7. Incidentally, the advantageous effects and effects mentioned above for the exemplary embodiment of FIGS. 1 to 5 apply equally to the embodiment of FIGS. 6 to 8, to which reference may be made. This applies in particular also with regard to achieving a pressure-cast-tight connection between the melt distribution and sprue block structure 9, 10, 21 on the one hand and the surrounding area of the solid mold half 4 on the other hand, which is achieved here by the tight fixing of the sprue inserts 9, 10 on the fixed mold half 4 is reached at operating temperature.

FIGS. 9 and 10 schematically show a further advantageous realization of the hot runner gate system according to the invention with its components of interest here. In this sprue system, the melt distribution and sprue block assembly includes a melt distribution block 14, which is associated with a first exit nozzle 15 and a second exit nozzle 16 on the exit side, and an intermediate plate 17 with nozzle attachment mouthpieces 18, 19 for centering the exit nozzles 15, 16 first outlet nozzle 15 is associated with the first sprue orifice 2, which continues through the nozzle attachment mouthpiece 18 and the intermediate plate 17 therethrough. Analogously, the second outlet nozzle 16 is associated with the second sprue orifice 3, which continues through the nozzle attachment mouthpiece 19 and the intermediate plate 17 therethrough. Thus, here forms the intermediate plate 17 with the mouthpieces 18, 19 an exit block portion of the melt distribution and sprue block assembly. She is with one Distance M of the nozzle attachment mouthpieces 18, 19 made of each other, which corresponds to an operating temperature distance of the outlet nozzles 15, 16 from each other, while the melt distribution block 14 is made with a distance m of the outlet nozzles 15, 16, one with respect to the operating temperature distance M corresponds to lower room temperature distance m, as illustrated in FIG. 9.

Consequently, the difference Am = Mm in turn represents the extent by which the outlet block portion of the melt distribution and sprue block assembly, here the manifold block 14 with its outlet-side outlet nozzles 15, 16, is made shorter in a transverse direction parallel to the mold parting plane compared to a predetermined operation Sollerstreckung , Also in this case, the expansion amount Am is predicted by means of experiments and / or computer simulation as a thermal transverse expansion of this block area when heated from the room temperature range to the desired operating temperature range.

Before the casting operation, first the melt distribution block 14 with its outlet nozzles 15, 16 is brought to the desired operating temperature range. It thermally expands, whereby the distance of the outlet nozzles 15, 16 from the room temperature distance value m to the operating temperature distance value M increases. Now, the intermediate plate 17 is applied with its Düsenansetz mouthpieces 18, 19 to the brought to operating melt distribution block 14, in which case the mouthpieces 18, 19 have the same distance from each other as the two outlet nozzles 15, 16, so that the outlet nozzles 15, 16 easily into the conical insertion areas of the nozzle attachment mouthpieces 18, 19 can get into it.

By corresponding conical oblique surface design of the front of the outlet nozzles 15, 16 on the one hand and the inlet-side surfaces of the mouthpieces 18, 19 on the other hand, the outlet nozzles 15, 16 are safe and tight and forming a flat or at least line-shaped sealing effect gap-free sealing in the nozzle attachment mouthpieces 18, 19th the intermediate plate 17 added. The intermediate plate 17 is now fixed to the fixed mold half and forms during subsequent casting in the corresponding area a contact surface to an opposite, movable mold half 20. Fig. 10 shows the arrangement in this brought to operating temperature and ready mounted state. As the illustrated and illustrated embodiments illustrate, the invention provides a very advantageous hot runner gate system with characteristic expansion compensation. It goes without saying that the invention encompasses numerous further realization possibilities, for example sprue systems with more than two, for example three or four, outlet-side sprue outlets and / or a differently branching sprue-channel structure. The hot runner gate system according to the invention is particularly well suited for casting a large number of non-ferrous alloys in corresponding temperature ranges of typically between 300 ° C. and 700 ° C., eg for casting magnesium, zinc, aluminum, tin, lead and brass, but also of Salt melts eg at temperatures above 700 ° C. Length expansions of the system when heating up are compensated, in particular in a controlled manner by predetermining a corresponding extent of expansion and taking account of the same as shortening during production. The heated system parts can be structurally inserted into the mold in such a way that they reliably absorb the forces of mold locking and melt pressure. The tightness is achieved at the contact A / binding points preferably by suitable material pairings with respect to steel, to which the different thermal expansion coefficient can contribute. For this purpose, suitable bias voltages can be calculated depending on the temperature. In addition, conical sealing surfaces can be used in the temperature range of the tool. In appropriate applications, steel-steel material pairings of different steel alloys can be used.

Preferably, sensors are used for temperature control at suitable locations of the tool, so that the heaters used can be controlled or regulated accordingly, as is known in the art per se. In particular, it is possible if necessary to set and maintain a predeterminable temperature profile along the melt flow path of the runner channel structure. Such a temperature profile can include, for example, a comparatively hot inlet-side region in the melt distributor section and a non-heated or less heated exit-side region, which can function as a transient region from the melt distribution region heated to, for example, above 600 ° C. to the contouring part of the mold, eg at about 80 ° ° to about 380 ° C, preferably at 100 ° C to 300 ° C, is located. The lower temperature in the transient region reduces the reactivity in strongly oxidizing melts and, for example, in magnesium also the fire danger, so that in the casting cycle the melt in the mold does not necessarily have to be subjected to protective gas.

Claims

claims

1 . Hot runner gate system for a die, with

a melt distribution and sprue block assembly having an entry-side gate mouth (1), at least first and second exit-side gate openings (2, 3) opening into a mold parting plane between a fixed and a movable mold half (4, 20) of the die; a runner channel structure (5) extending in a branching manner from the sprue mouth opening to the sprue outlets;

d a d u r c h e s e n c i n e s, d a s s

- The melt distribution and sprue block construction at least in one of the two Spritzausmündungen (2, 3) containing exit side block area in a transverse direction parallel to the mold parting plane compared to a predetermined operating Sollerstreckung by a Ausmaßungsungsmaß (Ab, Aa, Am) is made shortened, referred to as thermal transverse expansion this block area is predicted when heated from a room temperature range to an elevated, predetermined operating temperature range.

The hot runner runner system of claim 1, further characterized in that the melt distribution and runner block assembly includes a one-piece manifold and sprue block (6) including the runner channel structure from the runner mouth to the sprue outlets, comprising the exit side block portion.

3. hot runner-Angusssystem according to claim 2, further characterized in that the outlet-side block portion forms an elongated oval (6a), wherein the two sprue outlets are located at opposite end portions of the oval.

4. hot runner-Angusssystem according to claim 2 or 3, further characterized in that the outlet-side block portion in a receptacle (7) of the fixed mold half of the die is insertable, wherein the receptacle has a Sollerstreckung the outlet side block portion corresponding transverse extent.

5. Hot runner runner system according to claim 1, further characterized in that the melt distribution and sprue block assembly comprises a melt distribution block (21) containing the runner orifice and thereafter a first runner insert (9) containing the first runner orifice and a second runner orifice containing the second runner orifice Angusseinsatz (10) includes, wherein the Angusseinsätze on the fixed mold half in a transverse direction parallel to the mold parting plane slidably disposed and fixed thereto.

6. hot runner-Angusssystem according to claim 5, further characterized in that the Angusseinsätzen each a wedge plate (1 1, 12) is assigned to the wedged clamping the Angusseinsätze on the fixed mold half.

7. Hot runner-Angusssystem according to claim 6, further characterized in that the Angusseinsätze along a connecting line (8) of the first and the second sprue orifice are displaceable and in a transverse direction perpendicular thereto by the wedge plates are clamped.

The hot runner runner system of claim 1, further characterized in that the melt distribution and runner block assembly includes a melt distribution block (14) having a first exit nozzle (15) associated with the first runner orifice and a second exit nozzle (16) associated with the second runoff orifice (16) and an intermediate plate (16). 17) having nozzle attachment mouthpieces (18, 19) for centering the discharge nozzles, the intermediate plate being machined with a distance (M) from the nozzle attachment mouthpieces corresponding to an operating temperature separation of the exit nozzles, and the melt distribution manifold at a distance the outlet nozzle is made, which corresponds to a relation to the operating temperature distance lower space temperature distance (m).