WO2024120717A1

WO2024120717A1 - Mold insert for a mold

Info

Publication number: WO2024120717A1
Application number: PCT/EP2023/080933
Authority: WO
Inventors: Christian LAMBERTI; Christian ANDRE; Florian Keller
Original assignee: Abacus neo GmbH
Priority date: 2022-12-07
Filing date: 2023-11-07
Publication date: 2024-06-13
Also published as: DE102022132468A1

Abstract

The invention relates to a mold insert (1, 2) for a mold (3). The mold insert (1, 2) consists of at least two parts, a support module (4) and a separate mold module (5) for modular combination with the support module (4). The support module (4) has a base (6) and side walls (7) which at least partly surround a space (10).

Description

Mold insert for a mold tool

Description

The invention relates to a mold insert for a molding tool.

Forming tools are tools that are used in machine tools in the main groups of forming manufacturing processes, especially primary forming and forming. This includes in particular casting tools and pressing tools.

In injection molding, an injection molding tool is filled with plasticized plastic under pressure. The material then cools in the injection molding tool and hardens. After the tool is opened, the molded part can be removed. The process enables economical and efficient series production.

The injection molding tool is a permanent mold that is used to produce components with an injection molding machine. The injection molding tool is usually made of metal and has a cavity that determines the shape and surface structure of the part produced. Injection molds usually have a two-part structure, with one half of the tool being referred to as the nozzle side and the other as the ejector side. Both halves of the mold in turn consist of several plates that fulfill different functions.

The nozzle side is the side of the tool that does not move during the injection molding process. In addition to the half shells of the cavities, which are also known as mold inserts, the components of the sprue system are also attached here. Tools that are operated at high temperatures usually also have an insulating plate in front of the clamping plate to prevent too much heat being exchanged with the clamping plate. The ejector side of the tool is characterized by the fact that the ejector elements are positioned here. After cooling, hardening of the injection molding compound and opening of the tool halves, the component is initially located on the ejector side. The hardened molding is pressed out of the mold using the ejector device.

Injection molding tools for the plastics processing industry are usually made as permanent molds from steel. Depending on the number of planned injection processes, more wear-resistant materials such as hardened or tempered tool steel or hard metals can be used.

In steel mold construction, a distinction is made between standard molds, jaw molds and interchangeable molds. While standard molds in the form of mold plates are suitable for very versatile applications, interchangeable molds are predestined for prototypes and small series, since the mold structure remains on the machine, while only the mold inserts designed as interchangeable inserts in the mold plate frame on the nozzle and ejector side are exchanged.

DE 10 2011 055 961 A1 discloses an injection molding device for injection molding of plastic materials with devices for quickly clamping a mold with two mold plates.

Due to a mostly inhomogeneous material distribution in an injection molded component, inhomogeneous heating or an inhomogeneous temperature distribution also occurs during injection molding. However, to control the injection molding process and to achieve a high level of repeatability over several consecutive injection molding processes, a temperature or temperature distribution on the injection molding tool that is as homogeneous as possible is advantageous. In order to achieve this, injection molding tools are heated before and between the injection molding processes for producing an injection molded component. tempered, ie heated and/or cooled, in order to achieve a desired temperature distribution on the injection molding tool. There is usually a distribution system for heating or cooling agents on the nozzle side of the tool.

DE 10 2019 201 160 A1 discloses a reusable mold for injection molding comprising a reusable mold element and a mold cavity defined in the mold element and at least one heat sink recess defined in the mold element for accommodating a heat sink material therein for rapidly dissipating heat.

3D printed molds are particularly suitable for injection molded parts that are produced in small quantities and for which the development and production of a steel mold is not economical. 3D printed injection molding materials are created by a 3D printer according to a drawing and are usually made of particularly high-performance plastics.

These 3D-printed molds made of high-performance plastics are still expensive and uneconomical, especially for very small series. In addition, there are problems with the dimensional accuracy that can be achieved with mold inserts made entirely of high-performance plastic. In addition, these approaches do not yet have sufficiently well thought-out and implemented concepts for tempering the mold inserts in order to produce even delicate and ultra-fine injection-molded parts consistently.

The object of the present invention is to provide a mold insert which overcomes the aforementioned disadvantages and which is more cost-effective to manufacture than conventional molds. At the same time, the mold insert should be easy to handle. In addition, The mold insert can ensure precise temperature control of the injection molding device and the molded part.

This object is achieved according to the invention by a mold insert for a molding tool, a method and a use according to the independent main claims. Preferred variants can be found in the subclaims, the description, the exemplary embodiment and the drawings.

According to the invention, the mold insert is designed in at least two parts, with a carrier module and a separate mold module for modular combination with the carrier module, wherein the carrier module has a base and side walls which at least partially enclose a space.

The mold insert is an insert that is inserted into a mold plate as a removable insert and is preferably used for the production of small quantities.

Ideally, the mold module is designed as a thin plate that reproduces the negative contour of the molded part.

The mold module is preferably made of a metallic material and/or a high-performance plastic and/or a composite material. The mold module is preferably produced generatively. The low material usage and the fast printing time result in an economically favorable shaping body for molding tools that can be provided in a short time.

Advantageously, the carrier module is designed at least as the part of a mold insert that completes the mold module. Preferably The carrier module is made of an inexpensive, stable and pressure-resistant plastic.

The carrier module is preferably designed in the form of a housing that is open towards the side of the mold module. The outer contour of a mold insert corresponds to such a housing, with the area of the mold module being open. The housing is therefore preferably hollow and fillable.

In a favorable variant, the carrier module is designed as an open shell. The open shell, as a three-dimensional structure, for example as an open housing, at least partially surrounds a space and thus delimits a body as a form insert from its environment.

Ideally, the base and side walls of the carrier module partially enclose a space. The space takes up more than 60%, preferably more than 75%, in particular more than 90% of the volume of the mold insert.

In an advantageous variant, the form module and the carrier module completely enclose a room as a combined housing.

Ideally, the mold module rests on the side walls of the carrier module. The carrier module therefore supports the mold module.

Preferably, the mold module rests loosely on the side walls of the carrier module and does not form a connection.

The two-part design of the mold insert as a detailed mold module and a stable carrier module achieves an economically favorable design of a mold insert, which is particularly advantageous for the small series production of molded products and can be manufactured within the shortest possible production time. In a variant of the invention, different mold modules can be combined with a carrier module to form a mold insert that is designed as an interchangeable mold insert for very small quantities. Only the mold plate is adapted to a new molding and recreated using generative means.

In a particularly advantageous embodiment of the invention, the carrier module is indirectly connected to the mold module. Indirectly means that a further component is required to form a connection.

Ideally, the mold module and/or the carrier module have anchors and/or surface artifacts. The anchors are preferably arranged on the inside of the mold module and/or the carrier module.

In a particularly preferred variant, the mold module and/or the carrier module has on the inside more than 0.3 anchors/cm ² , preferably more than 0.6 anchors/cm ² , in particular more than 1 anchor/cm ² . The anchors can preferably be designed as round heads or as mushroom heads or as pyramid-like heads or as an internal, angular recess.

Advantageously, the space is at least partially filled by a mass.

The anchors are used to create a positive connection between a mass and the housing parts of the mold insert, based on the inner surface of the mold insert. The connection between the carrier module and the mold module is made indirectly using the mass. The surface artifacts are particularly advantageous, as they generate a particularly high volume of undercuts and make the positive connection particularly strong. This ensures that the mold insert is securely connected and made of one piece, particularly when the injection molding tool is in operation. Advantageously, the space is at least partially filled by a mass.

Preferably, the filled mass forms positive-locking connections with the anchors arranged on the mold module and/or on the carrier module, thereby creating a particularly stable unit of the mold insert consisting of housing and mass.

Alternatively, force-fitting or material-fitting connections between the carrier module and the mold module are also conceivable.

In a preferred variant, the molded module has elements that extend into the room. These elements can be designed, for example, as struts and/or webs and/or slats that stabilize the molded module.

In addition, the elements can also form a positive connection with the carrier module. For example, through recesses in the elements, which are then penetrated by the mass and thus form a positive connection.

Alternatively, the elements can also be equipped with surface artifacts or anchors, which additionally reinforce the form-fitting connections with the mass.

In a further variant of the invention, the elements are designed as sleeves for the ejector rods.

In a preferred variant, the space of the mold module combined with the carrier module is partially filled with a mass. For example, a Partial volume of the space for the flow of a heating or cooling medium is designed unfilled in the form of a channel.

In an alternative variant, the space delimited by the mold module and the support module is completely filled with a mass.

Preferably, the mass is made from a mixture of a binding agent and an aggregate. Such a mass is particularly vibration-damping and pressure-resistant, which is very advantageous for use in an injection molding tool in which enormous mechanical forces are at work.

In an advantageous variant of the invention, the mass comprises spheroidal solid material. The spheroidal particles are particularly round, which reduces or reduces tensions within the mass and thus within the mold. This improves the durability and resilience of the mold modules.

In a favorable embodiment of the invention, the mass consists of a completely bound and coherent unit. The mass is therefore not loose and/or free-flowing. The mass is preferably solid and hard.

Alternatively, the mass may also be made from a free-flowing mixture or in the form of an unbound unit.

The mass advantageously has a high compressive strength. This means that the so-called core of the mold insert absorbs the compressive forces and vibrations in injection molding production, which are transferred to the mass, for example, by the filigree mold module. Ideally, the mass has a thermal conductivity of more than 1 W/mK, preferably more than 2 W/mK and/or less than 6 W/mK, preferably less than 5 W/mK.

In a favorable variant of the invention, the mass has a density of more than 1.8 g/cm ³ , preferably more than 2.0 g/cm ³ , in particular more than

2.2 g/cm ³ and/or less than 3.0 g/cm ³ , preferably less than 2.8 g/cm ³ , in particular less than 2.6 g/cm ³ .

Preferably, the mass has a compressive strength of more than 50 MPa, preferably more than 100 MPa, in particular more than 140 MPa and/or less than 180 MPa, preferably less than 170 MPa, in particular less than 160 MPa.

In a preferred variant, the compressive strength of the mass is more than 30 N/mm ² , preferably more than 60 N/mm ² , in particular more than 90 N/mm ² .

In an alternative variant, the mass has at least the thermal conductivity of the material of the mold module. This makes it possible to control the temperature of the mold assembly using a cooling or heating medium in order to produce temperature-sensitive molded parts.

In a further variant of the invention, the thermal conductivity of the material of the mold module is less than 0.8 W/m-K, preferably less than 0.5 W/m-K, in particular less than 0.2 W/m-K.

Advantageously, the thermal conductivity of the mass is more than 0.35 W/m-K, preferably more than 0.8 W/m-K, in particular more than

1.3 W/mK. In a preferred variant of the invention, the thermal conductivity of the material of the mold module is more than 10 W/mK, preferably more than 50 W/mK, in particular more than 100 W/mK.

Ideally, the thermal conductivity of the material of the carrier module is less than 0.8 W/m-K, preferably less than 0.5 W/m-K, in particular less than 0.2 W/m-K.

In an advantageous variant of the invention, the mold module has a thermal conductivity of more than 150 W/m-K and the mass has a thermal conductivity of less than 0.7 W/m-K. In this variant, the mass is designed as an insulator. The mold module can, for example, be very hot while the molten material is injected into the corresponding mold inserts to form the molded part. With the help of very efficient cooling using at least one cooling channel, the mold module can be cooled down very quickly, which advantageously supports the insulating mass inside the housing. In this way, it is possible to produce very delicate molded parts that would otherwise decompose in non-tempered injection molding tools before natural cooling.

In a similar design, in which the molding must be stabilized at defined temperatures during the injection molding process, the arrangement of a better conductive mold module and insulating mass is also advantageous.

In a preferred variant, the carrier module is positively connected to the mold module using the mass. This connection is extremely stable and can absorb enormous vibrations without affecting the connection. In an alternative variant, the mold module can also be connected to the carrier module in a force-locking manner. In this design, a screwed connection is conceivable.

In a preferred variant of the invention, the mold module has at least a partial coating. This makes it particularly easy to form the molded part and/or to control the temperature of the mold module particularly quickly. This makes the mold arrangement wear-resistant and at the same time offers good demoldability.

In a variant of the invention, the coating is made of a polyhaloolefin. The Shore hardness D of the coating is more than 40, preferably more than 50, in particular more than 60.

In an alternative variant, the coating is formed from a thin copper layer in which the mean roughness value Ra _of the copper layer is less than 0.4 pm, preferably less than 0.2 pm, in particular less than 0.1 pm.

In a further, alternative variant of the invention, the coating has a proportion of nanocolloidal surfactants, whereby the demoldability of the mold is particularly favorable.

In a particularly advantageous variant of the invention, the coating has at least one layer of carbon. Such a coating is particularly hard and at the same time smooth.

Carbon layers are layers in which carbon is the predominant component. The carbon layer can be applied using PVD (Physical Vapor Deposition), a physical vapor deposition process such as evaporation or sputtering. or a CVD (chemical vapor deposition) process.

Preferably, it is an amorphous carbon layer, in particular a tetrahedral hydrogen-free amorphous carbon layer, which is also referred to as a ta-C layer. The atomic bonds belonging to the crystal lattice of graphite (3 in total) are designated "sp2". This is sp2 hybridization.

In a diamond layer, each carbon atom forms a tetrahedral arrangement with four neighboring atoms. In this spatial arrangement, all atomic distances are equally small. There are therefore very strong bonding forces between the atoms in all spatial directions. This results in the high strength and extreme hardness of diamond. The atomic bonds belonging to the crystal lattice of diamonds, four in total, are designated "sp3". This is sp3 hybridization.

In a particularly advantageous variant of the invention, the carbon layer consists of a mixture of sp3 and sp2 hybridized carbon. This layer is characterized by an amorphous structure. Foreign atoms such as hydrogen, silicon, tungsten or fluorine can also be incorporated into this carbon network.

Ideally, the carbon coating has an extremely smooth axial surface with non-stick properties, where the mean roughness value Ra _of the carbon layer is less than 0.6 pm, preferably less than 0.3 pm, in particular less than 0.1 pm.

The ta-C coating has a very low coefficient of friction and at the same time very good chemical resistance. The hardness of the coating is very close to that of diamonds, with the hardness preferably being more than 20 GPa. preferably more than 30 GPa, in particular more than 40 GPa and less than 120 GPa, preferably less than 110 GPa, in particular less than 100 GPa.

Advantageously, the carrier module and/or the mold module are designed generatively.

The term generative training encompasses all manufacturing processes in which material is applied layer by layer to create three-dimensional housings. The layer-by-layer construction is computer-controlled from one or more liquid or solid materials according to specified dimensions and shapes. Physical or chemical hardening or melting processes take place during construction. Typical materials for 3D printing are plastics, synthetic resins, ceramics, metals, carbon and graphite materials.

In an alternative variant of the invention, cold gas spraying and/or extrusion in combination with the application of meltable plastic is also an applicable method.

In a variant of the invention, the carrier module and/or the mold module are produced using an additive manufacturing process in which a grid of points is applied to a surface made of meltable plastic or meltable composite material. By extruding using a nozzle and then hardening by cooling at the desired position, a load-bearing structure is produced, in particular in the form of a carrier module. By producing the housing with a cavity-forming structure with a particularly load-bearing structure, the carrier module has enormous strength and at the same time is very light. The carrier module is usually constructed by repeatedly moving along a work plane line by line and then the working level is stacked upwards so that the support module is created layer by layer.

In a preferred variant, the mold module is produced by means of selective laser melting. In selective laser melting, the housing is produced using a process in which a layer of a construction material is first applied to a base. The construction material for producing the housing is preferably metallic powder particles or composite material particles. In a variant of the invention, iron-containing and/or aluminum-containing powder particles are used for this purpose. These can contain additives such as chromium, molybdenum or nickel. The metallic construction material or the aluminum-containing construction material interspersed with plastic is applied in powder form in a thin layer to a plate. The powdered material is then completely melted locally at the desired locations using radiation and a solid layer of material forms after solidification. The base is then lowered by the amount of one layer thickness and powder is applied again. This cycle is repeated until all layers have been melted and the finished mold module has been created. According to the invention, a mold module is produced that is particularly delicate and detailed.

For example, a laser beam can be used as radiation, which generates the mold module and/or the carrier module from the individual powder layers. The data for guiding the laser beam is generated using software on the basis of a 3D CAD body. As an alternative to selective laser melting, an electron beam (EBN) can also be used.

In a favorable variant of the invention, a channel for tempering is formed generatively. Preferably, the channel is formed using the selective Laser melting is printed onto the inside of the mold module. Preferably, the filled mass is directly adjacent to the tempering channel.

Ideally, the carrier module is made of a plastic, in particular a thermoplastic and/or composite material.

Advantageously, the plastic of the carrier module has a density of more than 0.8 g/cm ³ , preferably more than 1.0 g/cm ³ , in particular more than 1.1 g/cm ³ and/or less than 1.5 g/cm ³ , preferably less than 1.4 g/cm ³ , in particular less than 1.3 g/cm ³ .

Ideally, the plastic of the carrier module has a thermal conductivity of more than 0.15 W/m-K, preferably more than 0.3 W/m-K and/or less than 0.85 W/m-K, preferably less than 0.65 W/m-K.

Preferably, the plastic of the carrier module has a compressive strength of more than 5 MPa, preferably more than 15 MPa, in particular more than 25 MPa and/or less than 80 MPa, preferably less than 60 MPa, in particular less than 40 MPa.

In an alternative variant, the carrier module is made of a metal material or a metallic alloy.

The carrier module can be made, for example, from a zinc or zinc alloy or an aluminum or an aluminum alloy or brass.

In a further variant of the invention, the carrier module is made of zinc die-casting. This makes it possible to achieve a carrier module that is manufactured with high precision and has high hardness and high strength. In a favorable variant of the invention, the carrier module is made of a polyamide. For example, the carrier module is made of a PA 6.6.

In an alternative variant of the invention, the carrier module is made of a polyetheretherketone or a polycarbonate.

In a preferred variant, the mold module is made of a metallic material. The mold module is preferably made of aluminum. The generative production of a defined and filigree mold module is possible with very precise dimensions and true to detail.

Preferably, the mold module is made of a nickel-based alloy, for example Inconel 718 or Inconel 600, which combines particularly favorable mechanical properties with excellent resistance for high-temperature applications.

Advantageously, the metallic material of the carrier module and/or the mold module has a density of more than 2.5 g/cm ³ , preferably more than 5.0 g/cm ³ , in particular more than 7 g/cm ³ and/or less than 9.5 g/cm ³ , preferably less than 9.0 g/cm ³ , in particular less than 8.5 g/cm ³ .

Ideally, the metallic material of the carrier module and/or the mold module has a thermal conductivity of more than 9 W/m-K, preferably more than 14 W/m-K and/or less than 25 W/m-K, preferably less than 20 W/m-K.

In an alternative variant, the metallic material of the carrier module and/or the mold module has a thermal conductivity of more than 90 W/mK, preferably more than 100 W/mK and/or less than 160 W/mK, preferably less than 130 W/mK.

The metallic material preferably has a tensile strength of more than 150 MPa, preferably more than 450 MPa, in particular more than 700 MPa and/or less than 2300 MPa, preferably less than 2000 MPa, in particular less than 1700 MPa.

Ideally, the mold module is made of a high-performance plastic, in particular a polyetheretherketone.

In an advantageous variant of the invention, the mold module is made of a composite material. The composite material is preferably made of Alumide®.

Preferably, the modulus of elasticity of the composite material according to DIN EN ISO 527 is more than 3000 N/mm ² , preferably more than 3400 N/mm ² , in particular more than 3800 N/mm ² . A mold module made of this composite material is extremely stable and dimensionally stable, which is particularly advantageous for use as a mold insert in injection molding.

The mass is advantageously made from a mixture of a binding agent and an aggregate. The mass can preferably be designed as an anchor mortar and/or as an anchor and injection glue and/or as a high-strength grouting and/or as a basalt grouting and/or mixtures thereof.

In a favorable variant of the invention, the mass is in the form of a high-performance concrete, which has particularly vibration-damping properties and is therefore ideally suited for use in a mold, in particular in an injection mold. The high-performance concrete with its damping properties significantly compensates for the lower damping of the form module.

Preferably, the mass may contain a proportion of a colored substance, preferably organic dyes. This advantageously gives the entire mass a colored shimmer and/or a colored appearance.

In an advantageous variant of the invention, the mass contains a proportion of fibers or metallic particles. The metallic particles increase the thermal conductivity of the mass, which makes it possible to set a specific temperature or temperature distribution within the mold insert. This also makes it possible to produce very delicate molded parts that cannot be formed stably without a specific temperature setting.

Alternatively, fibers from a composite material can be incorporated into the mass, which can increase the strength of the mass.

In an advantageous variant, the mold module has a channel for tempering. A heating or cooling medium can flow through this channel.

Ideally, the channel for tempering the mold insert is arranged directly and immediately on the mold module.

Ideally, the mold insert has particularly thin walls, which can favorably support the heat transfer.

Advantageously, the mold module has a channel for tempering which more than 80%, preferably more than 90%, in particular more than 95% of the Area under the cavity is covered. This creates a heating or

Cooling performance that has not yet been achieved with conventional molding tools.

In a variant of the invention, the channel for tempering comprises more than six, preferably more than ten, in particular more than fourteen turns. The deflection of the medium for cooling or heating leads to a favorable turbulence, which favors the heat transfer to an advantageous extent.

Preferably, the ratio of the area of the channel to the area of the wall thickness of the channel is more than four, preferably more than six, in particular more than eight. This makes it possible to achieve impressive cooling or heating performance.

In a favorable variant of the invention, the channel for tempering is rectangular or square or almost rectangular with small radii.

In a cheaper variant, the channel is printed onto the mold module using the same material as the mold module. Alternatively, another suitable material that adheres to the mold module can be used.

In an alternative variant of the invention, only the walls of a preferably rectangular and/or square channel are printed onto the mold module. The missing base is created by means of cast mass.

In a further variant of the invention, a preformed channel is arranged on the inside of the mold module and fixed by filling the space with the mass. According to the invention, the mold module and the carrier module are manufactured using a method in which the mold module and the carrier module are produced generatively. The mold module is then connected to the carrier module.

Preferably, the mold module is positively connected to the carrier module by filling the space enclosed by the mold module and the carrier module with a mass. Preferably, a mass is poured that hardens and forms a solid bond.

In a preferred variant of the invention, the molding module is at least partially provided with a coating. This makes it particularly easy to form the molded part and/or to control the temperature of the molding module particularly quickly.

According to the invention, a mold insert made of a combined mold module and carrier module is used in a mold tool for the production of small series. The mold insert according to the invention made of a mold module and carrier module is inexpensive to manufacture and can be produced particularly quickly. In addition, the mold insert is advantageously designed for targeted temperature control.

Advantageously, the mold insert with a channel for tempering is used in a mold arrangement to shorten cycle times and thus increase production capacity. The precise tempering ensures faster cooling of the injection molded part.

Ideally, the mold insert with a channel for tempering is used in a mold arrangement for the production of injection molded parts that have temperature-sensitive areas. Particularly thin and delicate components can be produced flawlessly. In addition to injection molding tools, the molding tool category also includes pressing tools, drawing tools and deep-drawing tools, for which the design in the form of a filled housing can also be produced quickly, inexpensively and with great value for money.

Further advantages and features of the invention will become apparent from the description of an embodiment with reference to drawings and from the drawings themselves.

This shows

Fig. 1 is an exploded view of a mold,

Fig. 2 a perspective view of two corresponding mold inserts,

Fig. 3 another perspective view of two corresponding mold modules,

Fig. 4 is a perspective view of a cooling channel on a mold insert,

Fig. 5 is a perspective view of another embodiment of a cooling channel in a mold module,

Fig. 6 some embodiments of anchors.

Fig. 1 shows an exploded view of a mold 3. A clamping plate 21 is arranged between two insulating plates 20. The nozzle-side mold plate 23 is arranged directly on the nozzle side 22, into which the Sprue bushing 24 engages. On the ejector side 25, the mold plate 26 is arranged on an intermediate plate 27, with an ejector package 28 with ejector plates 29 and strips 30 positioned between the intermediate plate 27 and the clamping plate 21. The nozzle-side mold insert 2 is integrated into the nozzle-side mold plate 23 and the ejector-side mold insert 1 is inserted into the ejector-side mold plate 26. The mold inserts 1 and 2 as well as the mold plates 23 and 26 form a mold arrangement.

Fig. 2 shows a perspective view of two corresponding mold inserts 1 and 2. In this embodiment, the mold insert 2 is designed in two parts with a mold module 5 and a carrier module 4. The mold module 5 forms a housing with the modularly combined carrier module 4, which encloses a space 10. In this embodiment, the mold insert 1 is designed as a one-piece housing that encloses a space 10.

The support module 4 is formed from side walls 7 and a base 6. The mold module 5 has elements 8 in the form of webs that extend into the space 10 and have cylindrical recesses 17. The webs stabilize the thin mold module 5 made of aluminum, which is produced generatively by means of selective laser melting.

The two housings of the mold inserts 1 and 2 are hollow on the inside and are filled or cast with a mass. The mass clings to the elements 8 and fills the cylindrical recesses 17, so that a secure, positive connection is created between the carrier module 4, the mold module 5 and the mass. In this design variant, the mass is designed as a high-strength cast, which has a compressive strength of more than 120 N/mm ² after 28 d. The side walls 7 and the base 6 are made of a polyamide and are produced generatively. The thermal conductivity of the carrier module 4 is 0.23 W/m*K, the thermal conductivity of the mold module 5 is 250 W/m*K and the thermal conductivity of the mass is 1 W/m*K. The surface of the mold module 5 has a coating 11 made of amorphous carbon. As a result, the coating 11 has a hardness of more than 40 GPa.

The housing of the mold insert 1 is generatively formed from Alumide® and has guides 15 for the ejector pins. Both mold inserts 5 and 6 have holes 16 for fastening to the mold plates 23 and 26.

Fig. 3 shows a variant in which both mold inserts 1, 2 are designed in two parts with a mold module 5 and a carrier module 4, whereby the carrier module 4 of the mold insert 1 is not shown. The carrier module 4 of Fig. 3 corresponds to the description of the mold insert 2 from Fig. 2.

The mold modules 5 are made of a nickel-based alloy, in this version Inconel 718. The thermal conductivity of the mold modules 5 is 11 W/m*K, the Vickers hardness is 470 HV and the tensile strength is 1530 MPa.

Fig. 4 shows a perspective view of a channel 12 for tempering on a section of a mold module 5. In this embodiment, walls 13 made of aluminum are applied to the inside of the mold module 5 by means of generative manufacturing. The open cooling channel 12 is filled with a waxy substance before the mold insert 1, 2 is filled with the mass. After the mass in the mold insert 1, 2 has hardened and solidified, the waxy substance is thermally removed, resulting in a finished channel 12 for tempering with walls 13 made of aluminum and a base made of the solid mass. The channel 12 has connections 14 for connecting to an external heating or cooling circuit. The channel for tempering 12 has particularly thin walls 13, whereby the channel for tempering 12 covers more than 90% of the surface area of the cavity of the mold module 5. The medium that flows through the channel 12 is deflected particularly frequently by the more than six turns. This creates favorable turbulence. In the embodiment shown, the channel 12 has a rectangular cross-section.

Fig. 5 shows a perspective view of a sectioned part of a mold module 5. In this embodiment, attention was paid to a particularly large heat transfer surface and high cooling capacity. The channel 12 for tempering has a triangular cross-section with rounded corners. The webs 8, which in this embodiment are designed as a T-shaped support and have cylindrical recesses 17, are directly adjacent to the channel 12 for tempering. The T-shape and the recesses 17 promote a particularly stable formation of the form-fitting connection with a mass filling the mold set.

In Fig. 6, some embodiments of the surface artifacts are shown which take on the function of anchors 9 of the mold module 5 and the carrier module 4 in the mass. This creates a positive connection between the carrier module 4 forming the mold insert 1, 2 and the mold module 5 and the mass, whereby the mass and the carrier module 4 as well as the mold module 5 form a unit of a mold insert 1, 2. The surface-related design of the positive connection is particularly advantageous, with 1 anchor/cm ² being arranged on the inside of the carrier module 4 and the mold module 5. The anchors 9 can preferably be designed as round heads or as mushroom heads or as T-shaped pillars or as pyramid-like heads or as an internal, angular depression. Ideally, the anchors 9 have a high undercut volume, which promotes the reliable formation of the positive connection with the mass. The Anchors 7 may partially have grooves 18 which intensify or secure the positive connection with the mass.

In a further variant, the anchors 9 have a web-like shape, which in the embodiment shown are T-shaped and have openings, for example in the form of cylindrical recesses 15. When the mass is poured, the cylindrical recesses 15 are filled and form a positive connection between the mold module 5 and the mass.

Claims

Mold insert for a molding tool Patent claims

1. Mold insert (1, 2) for a molding tool (3), characterized in that the mold insert (1, 2) is designed in at least two parts with a carrier module (4) and a separate mold module (5) for modular combination with the carrier module (4), wherein the carrier module (4) has a base (6) and side walls (7) which at least partially enclose a space (10).

2. Mould insert according to claim 1, characterized in that the

The carrier module (4) is indirectly connected to the mold module (5).

3. Mold insert according to claim 1 or 2, characterized in that the mold module (5) rests on the side walls (7).

4. Mold insert according to one of claims 1 to 3, characterized in that the mold module (5) has elements (8) which extend into the space (10).

5. Mold insert according to one of claims 1 to 4, characterized in that the mold module (5) and/or the carrier module (4) has anchors (9).

6. Mold insert according to one of claims 1 to 5, characterized in that the space (10) is at least partially filled with a mass.

7. Mold insert according to claim 6, characterized in that the carrier module (4) is connected to the mold module (5) with the mass indirectly, in a form-fitting manner.

8. Mold insert according to one of claims 1 to 7, characterized in that the mold module (5) at least partially has a coating (11).

9. Mold insert according to one of claims 1 to 8, characterized in that the carrier module (4) and/or the mold module (5) is formed generatively.

10. Mold insert according to one of claims 1 to 9, characterized in that the carrier module (4) is made of a plastic and/or a metal.

11. Mold insert according to one of claims 1 to 10, characterized in that the mold module (5) is made of a plastic or a composite material or of a metallic material.

12. Mold insert according to one of claims 6 to 11, characterized in that the mass is formed from a mixture of a binder and a spheroidal solid.

13. Mold insert according to one of claims 1 to 12, characterized in that the mold module (5) has a channel (12) for tempering.

14. Method for producing a mold insert (1,2) with the following steps:

Generative manufacturing of the mold module (5) and the carrier module (4), combining the mold module (5) with the modular carrier module (4)

15. Use of a two-part mold insert (1, 2) with a carrier module (4) and a mold module (5) according to one of claims 1 to 13 in a mold (3) for the production of small series.