DE102004027109A1 - Production of a tool having an impression used as a pressing tool, deforming tool or forging tool comprises placing pipelines into a cast mold, casting around the pipelines and integrating the pipelines as heating and/or cooling channels - Google Patents

Abstract

Production of a tool (2) having an impression (1) comprises placing one or more pipelines (3) into a cast mold and optionally fixing to the mold, casting around the pipelines and integrating the pipelines as heating and/or cooling channels into the cast piece forming the tool. An independent claim is also included for a tool produced by the above process.

Description

The The invention relates to a method for producing an engraving having, temperable (forming) tool by way of casting. - Tool here means in particular a press tool, forging tool or also tool for the Internal high-pressure forming. The tool or die may be also a tool half or a tool part, for. B. an upper tool or a lower tool act. In any case, it is a forming tool or die with engraving (eg engraving and / or engraving), d. H. with a (shape) contour forming the shape of the component to be produced. Temperierbares tool means that the tool under his Use heated or cooled can be. According to the invention in particular tools for the metal forming, z. As hot forming or cold forming, but also tools for the Plastic molding, z. For example Plastic injection molding machines, includes.

heatable Tools are in practice, for example, in processing of board blanks by way of press-hardening. The board cutouts are heated in a roller hearth furnace and then in a hydraulic press formed at about 850 ° C and thereby selectively cooled. Around an optimal cooling effect in the tool, are integrated into the tool cooling channels. Through the cooling channels should it will be made possible the surface temperature to set defined in the different areas of the tool z. B. lower temperature in vertical walls because of the lower To produce normal pressing. Basically, uniform surface temperatures with a maximum deviation +/- 5 ° K. The distance from the surface to the lowest point of the cooling channel should be 20 mm to allow a breakthrough in forming prevent. About that There are also turbulent flows in the channels for optimal removal of heat and contour near or close to the component design of the cooling channels advantageous. Production Such tools is relatively expensive. Because in order to achieve an appropriate design of the cooling channels in the course of drilling, Segmentation of the tool is required. The individual segments are provided with holes and corresponding plugs and in the dividing surfaces between the individual segments, seals are placed around a Leakage of the cooling medium to prevent.

In addition, a heated, preloaded forging die for isothermal forming of metals is known, which consists of a die body, a surrounding, annularly arranged ceramic body and a radial prestressing generating body. In the ceramic body inductive heating coils are embedded (see. CH 657 548 A5 ).

Furthermore, the production of steam press plates with integrated pipe system by way of casting is known. Starting point are two wrought-iron cover plates of 5 to 12 mm thickness with intervening tube system, the plates are riveted at the outer edge with interposed flat iron of the thickness of the tube system. After riveting, the gaps are filled with resistant metal (cast iron, brass, gunmetal or cast steel). The tube system is tinned in order to obtain a good connection between the metal and the tubes, whereby a good thermal conductivity is to be produced (cf. DE 17425 ).

Besides that is a heatable 3-way valve made of nodular cast iron, being in the valve body Steel pipe bends are poured through which a heating medium flows and like a Forced circulation heating works (see H. Gereke-Bornemann: "Narrow channels - composite casting", construct + pour 4/80, page 26).

From the DE 39 26 069 C1 It is known to pour a carbon steel sheathed steel tube into a cast piece of ductile iron. By sheathing with carbon fibers is achieved that the casing is not attacked by the casting material, since the Sphähroguss is practically carbon saturated. In this way, in the casting z. B. integrated hydraulic lines.

Furthermore, it is from the DE 39 17 487 A1 known as a riser hole in a cast casting container made of hot-work steel to provide a cast, bent tube, which is formed of three parts, namely a straight center piece and two each end welded to the center piece 90 ° -Krümmern.

In addition, known a cooling device for a capacitor, which is used for example in power converters for vehicles, especially rail vehicles. During operation of the capacitors, the heat loss produced thereby is dissipated to the cooling liquid of the cooling device used. The cooling device can either be cast or manufactured by means of machining methods such as drilling and milling. In this case, a pre-bent pipe or prefabricated pipe system used for the cooling channels and this pipe or pipe system with a good heat conducting material, eg. B. aluminum, whereby the cooling plate geschaf fen (cf. DE 41 16 960 A1 ).

Finally, a cooled stator for an electric machine with a rotating inner rotor is known, which stator has at least one electric laminated core and one or more cooling tubes arranged by means of casting. In this case, the cooling tubes are embedded in one or more castings formed by casting thermally conductive material. The cast body can be cast from aluminum or zinc or an alloy with aluminum and / or zinc (cf. DE 100 22 146 A1 ).

On the production of temperature-controlled forming tools had all of these Developments have no influence.

Of the Invention has for its object to provide a method which a simple, inexpensive and flexible production of temperature-controlled tools, in particular Allows forming tools, the tools allow for optimal heating and / or cooling and withstand high loads.

to solution To this object, the invention teaches a method for the production an engraving or shape contour having temperable tool by way of casting, after which one or more pipes are placed in a mold and if necessary in the casting mold be fixed and after which the pipes in the course of casting with at least partially encapsulated the casting material and used as heating and / or cooling channels in the the tool forming (one-piece) casting are integrated. there it is advantageous if the casting material has a lower melting point has as the material of the pipes. As (metallic) Cast material can be used, for example, cast iron. It may be around (eg austenitic) cast iron with lamellar graphite (Gray cast iron) or around (eg austenitic) cast iron with nodular graphite (Nodular cast iron) act. Due to the dependence the thermal conductivity from the structure can by selecting the casting material with a certain microstructure, the heat conduction of the casting to be influenced. The pipes are made of metal, preferably from steel. The casting can be lost or permanent. As a result of that the casting material of the tool has a lower melting point as the (steel) material of the pipes, will melt the outer surface of the pipes Prevents pipes from getting safely.

The Invention is based on the recognition that the production of a temperable mold with engraving or contour shape considerably can be simplified if heating and / or cooling channels no longer by drilling or milling be introduced into the cast tool, but if the heating and / or cooling ducts as pipelines in the course of casting of the tool and thus integrated. there even costly cooling and / or Heizkanalsysteme, because in the course of casting can also elaborately shaped and single or multiple bent pipes are poured, so that there is a high degree of freedom of design. Because preferably several become a pipeline bundle or a pipeline system forming pipes poured. there exists within the scope of the invention, the possibility of the shape of the pipes and / or the course or the arrangement of the pipes in the casting mold to adjust the shape of the engraving of the tool to be generated. insofar be optimized cooling circuits and / or heating circuits created without any manufacturing restrictions consist. Adaptation of the pipes to the engraving means in particular that at least a portion of the pipes at least partially parallel or nearly parallel to individual engraving areas, z. B. to Gravurboden or a gravure wall, run. The adaptation the axial course of the pipes to the contour of the Form contour of the mold can already before pouring into the Casting material done. In this way, a high efficiency of heat dissipation and a high degree of uniformity Cooling over the area reach the shape contour.

The Pipelines can at least partially from a plurality of pipe sections or pipe segments in the way of joining be made. It can between the individual pipe sections welded joints and / or Traction connections and / or form-locking connections generated become. The cooling duct system or Heizkanalsystem can therefore relatively easy from a variety molded pipe segments are assembled into a complex design, which is adapted, for example, to the engraving of the tool. All of this succeeds in manufacturing technology easier and in particular cost-effective Wise. The pipe segments may be straight pipe segments, curved pipe segments, tees, elbow etc. act. in principle can adapt the piping to the (axial) course of the Shape contour but also by bending (one-piece pipes) done.

In the context of the invention it is possible to insert the pipes individually or in groups in the mold and to combine within the mold with connecting elements to form a pipe bundle or system. Preferably, the pipelines but before the one put into the mold with connecting elements to one or more pipe bundles or system summarized and this pipe bundle is then used in total or as a whole in the mold and at least partially poured or cast. Consequently, in the context of the invention, a prefabricated cooling channel system or heating channel system is provided in a particularly simple manner, which is then cast or poured as a whole thereafter.

The Fasteners essentially function as spacers or spacers and provide a substantially solid connection between the individual pipelines within a pipeline bundle. insofar For example, it may be relatively simple wire connections or the like. There is the possibility that the fasteners in the course of casting be integrated into the tool and thus cast and remain in the tool or even destroyed. It exists however also the possibility that the connecting elements arranged after casting outside the tool are and if necessary be separated. In the course of prefabrication of the cooling duct system outside the mold be the connecting elements, which show the relative position of each Pretend pipelines to each other thus positioned and fastened, that after casting outside the actual casting or the tool are arranged. For this purpose, however, within the mold outside the actual shape range receiving areas provided for such fasteners be.

there The invention is based on the knowledge that often anyway a part of the individual pipelines are poured so that they project from the tool to be produced by a predetermined amount. In the area of these protruding pipe parts can then arranged the connecting elements and possibly together with the projecting or supernatant Pipeline sections are removed. In this context it is useful if as connecting elements supporting plates or the like, with carrying receptacles, z. B. openings are used, in which at least one Part of the pipelines are inserted or clamped. In these Support plates can be as it were to holding plates or fixing plates to act with a variety of openings, in which case the individual Pipes each end used in such a support plate so that the entire pipeline construction between two (or more) such support plates is arranged. The arrangement will doing so so that the support plates after pouring outside of the tool are arranged so that they subsequently together with overhanging pipe sections can be removed.

From moreover, it is of particular importance that the inventive method not on heating channels or cooling channels with circular Cross section restricted is, but that cooling channels or heating channels with arbitrary Cross section can be generated in the appropriate piping with the desired, possibly of the circular shape deviating cross section are poured. So can in Frame of the invention Pipes with round, oval or square Cross section, z. B. rectangular cross section can be used. rectangular profiles are characterized for example by the fact that they are compared to round profiles at the same cross section a larger surface and consequently have a larger contact area, so that an improved temperature compensation, z. B. a better one heat dissipation can be done. Furthermore can By selecting a certain cross-section turbulent flows generated will continue to heat transfer to optimize.

All in all insists on simple and inexpensive Way the possibility To create temperature-controlled tools that are optimal and highly targeted Temperature control (eg cooling) in use, z. B. in the course of pressing, allow. Despite being simpler and cost-effective Production is a great constructive Freedom regarding the design and arrangement of the cooling channels or heating channels given. It can even with complex shapes of the contour uniform surface temperatures achieved or different surface temperatures (or cooling rates) be achieved in defined areas. So can by a change the distance of one or more tubes to the surface of the Form contour of the mold specifically reaches a non-uniform over the mold contour surface cooling become. This may be desirable be, if a press molding in certain areas stronger or cooled faster should be, for. B. locally different properties (eg. Hardness, tensile strength etc.) of the press molding to achieve.

In this case, the generation of turbulent flow in the channels achieves optimal heat exchange while at the same time contouring the cooling or heating channels. It is achieved a high degree of flexibility even with the most complex cooling duct systems, the production of piping or pipe segments z. B. can be done by means of a hydroforming, so that even complicated geometries can be realized. Elaborate drilling and the introduction of seals, plugs or the like are no longer required. All this is achieved at the same time high stability of the formed forming tools. The cast-in pipes disturb the stability of even complicated forming tools with engraving not, although such tools often have areas of significantly different thickness, etc., and are often subject to high tensile, compressive and / or bending stresses. Overall, the tools meet all requirements in terms of stability.

Otherwise leave with the inventive method also excellent tools for the plastic injection molding produce. Because in the context of the invention, the production succeeds of tools with particularly high surface quality, since no segmentation of the mold must be made so that the tool generated free of Edges or the like on the surface. Nevertheless - though a segmentation is omitted - an optimal design of the cooling duct system possible.

Further beats the invention that for determining the heat transfer between the heating and / or Cooling channels and the casting the heating and / or Cooling channels after the casting heated and the temperature of the tool surface (eg, with a thermal camera or infrared camera) is determined position-resolved. To this Way can after pouring the tool but before finishing a review of the heat transfer and consequently the operability the generated tool in terms of quality control. To can removed after molding gates, feeders, sprues, etc., the blank sandblasted and with connections be provided. These connections can then connected to a heating unit and heated the blank become. With an infrared camera can then be checked whether the surface evenly or in the desired Heated form, so that already before the relatively expensive Finishing a quality review can. The measurement of the temperature distribution can be done with a conventional Infrared camera done, with the spatially resolved measurement, for example the camera or even the tool can be moved. The Camera can do this for a simultaneous measurement of several measuring points (eg a whole Line) be formed in the sense of a line camera with line sensor. By choosing an optimal distance of the camera from the tool let yourself with the line length the camera cover the entire width of the tool to be examined. Altogether, a temperature field can consist of a large number of lines and columns are recorded, the measurement points then graphically (eg color) can be displayed. The measurement is therefore carried out preferably contactless. The temperature of the tool can be done via a heating unit. It but it is also possible the channels to apply a heating medium.

Besides that is The invention also relates to a (mold) tool with integrated Pipelines, which produced by the described method is. It is therefore an internally cooled or internally heated mold with cooling channels or heating ducts, which as a casting material existing (one-piece) casting is trained. The cooling channels are z. B. formed by a plurality of spaced-apart tubes, the are cast around the casting material. The (axial) course of the pipes is adapted to the contour of the contour. At the tool is it z. B. to a press die or forging die or also a hydroforming tool. The mold can for the press hardening be formed of metallic moldings. It also exists the possibility, that the mold for the injection molding is formed of plastic parts.

in the The invention will be described below with reference to a purely exemplary embodiment drawing closer explained. Show it

1 a forming tool produced by the method according to the invention and

2 a modified embodiment of a forming tool according to the invention.

In the figures, one is an engraving 1 having temperable tool 2 represented, which was manufactured by way of casting. It is a forming tool, for. B. a press or forging die with a the engraving 1 forming indentation or recess. It can be seen that in the internally cooled tool 2 one of a plurality of pipelines 3 existing piping system or pipe bundle is integrated. In the course of the production were the pipelines 3 placed in a mold and then the pipes were cast in the course of casting with the casting material and so in the tool-forming one-piece casting 2 integrated. In this respect, it is as it were a forming die with cast heat exchanger. Because the cast-in pipes form here cooling channels for flow with a coolant.

In particular in 1 it can be seen that the individual pipelines 3 of the pipe bundle in each case from a plurality of pipe sections or pipe segments 4a . 4b consisting of straight pipe segments 4a and bent pipe segments 4b each relatively costly shaped pipes 3 be formed. In the embodiment, it is piping with a round cross-section.

In 2 it is recognizable that the tool 2 in the areas next to the engraving 1 two curved pipes extending essentially in the tool longitudinal direction 4c having, wherein these pipelines 4c through a variety of connecting pipes 4d each paired together. In this context, it can be seen that these each have five connecting pipes 4d of which only a few are indicated, are formed as curved tubes, which are the contour 1 intervene as it were. In this embodiment, the connecting pipes form 4d as it were connecting elements for the longitudinally extending pipes 4c , The pipelines 4d thus connect the flow cross sections of the pipes 4c , so that the entire cooling channel system of the mold can be acted upon by only one supply line and a drain with coolant.

Claims (18)

Method for producing an engraving, tempered tool by way of casting, after which one or several pipes inserted into a mold and possibly in the mold be fixed and after which the pipes in the course of casting with the Casting material at least partially cast around and as heating and / or Cooling channels in the the tool forming casting to get integrated. The method of claim 1, wherein the casting material has a lower melting point than the material of the pipelines. Method according to claim 1 or 2, according to which the casting material Cast iron is used. Method according to one of claims 1 to 3, according to which pipes made of steel. Method according to one of claims 1 to 4, wherein several a pipeline bundle or a pipeline system forming pipes are poured. Method according to one of claims 1 to 5, according to which the pipelines at least partially from several pipe sections in the way of joining be made, for. B. by welded joints and / or frictional connections and / or Positive connections. Method according to one of claims 1 to 6, according to which the form the piping and / or the course or the arrangement of the pipes in the mold at least partially to the shape of the engraving of the generated Tool is adjusted. Method according to one of claims 1 to 7, according to which the pipes individually or in groups inserted into the mold and within the mold with Connecting elements to a pipe bundle or piping system be summarized. Method according to one of claims 1 to 7, according to which the pipes before inserting into the mold with connecting elements to one or more pipe bundles or Piping systems are summarized and the pipe bundle in the mold is inserted and poured. A method according to claim 8 or 9, wherein the connecting elements in the course of casting be integrated into the tool. The method of claim 10, wherein the connecting elements themselves are designed as pipelines. A method according to claim 8 or 9, wherein the connecting elements after the pouring outside of the tool produced are arranged and possibly separated. The method of claim 12, wherein as connecting elements Support plates or the like, with support receptacles, z. B. breakthroughs for the pipelines be used, in which at least part of the piping is inserted or clamped. Method according to one of claims 1 to 13, according to which the determination the heat transfer between the heating and / or cooling channels and the casting the heating and / or cooling channels after the casting heated and the temperature of the tool surface, z. With an infrared camera, position resolved is determined. Method according to one of claims 1 to 14, according to which pipes with a round, oval or angular cross-section, z. B. rectangular Cross section, to be used. Temperable tool with integrated piping, prepared according to a method of claims 1 to 15. Tool according to claim 16, which serves as a mold for the Metal forming, z. For example Press hardening of metallic molded parts, is formed. Tool according to claim 16, which serves as a mold for the injection molding of plastic Share is formed.