Method and device for moulding a curable moulding compound

Abstract

The invention relates to a device (10) and a method for moulding a curable moulding compound (202), comprising the steps of: - receiving a curable moulding compound (202), which is in a liquid state, in a cavity (14) that is delimited by a first mould part (100) and at least a second mould part (101) of a moulding tool (12); - generating at least one first relative movement between the first and the second mould part (100, 101) such that the cavity (14) becomes smaller; - curing the moulding compound (202).

Description

[0001] Method and device for molding a curable molding compound

[0002] The invention relates to a method and a device for molding a curable molding compound. This allows a component to be produced, particularly by means of primary molding.

[0003] It is known to bring hardenable molding compounds into a desired shape using a mold and then to harden or, in other words, solidify or solidify in this form. In this way, a component with a desired shape can be produced from the initially formless molding compound. This can also be referred to as primary forming of the component. A typical primary forming process is casting. In this case, the molding compound is filled into a mold, where it solidifies and from which it can then be removed. There are various casting processes that differ, for example, in the type of mold, the molding compounds and / or the method of filling the molding compound into the mold.

[0004] A disadvantage of previous casting processes is that desired components, and in particular component sizes, cannot always be produced with the desired quality. This particularly applies to components with thin-walled regions. For the purposes of this disclosure, thin-walled regions can generally be understood as regions with a material thickness of up to 3 mm or even up to 5 mm. With such thin-walled regions, there is a risk of so-called cold runs occurring during the casting process. This can be understood as portions of the molding compound curing prematurely, for example, while the molding compound is still being poured in and before they reach an intended position within the mold.

[0005] As a result, the minimum wall thickness generally depends on the casting process and the molding compound material, but not on the component's function. The closer one approaches the process-specific minimum possible wall thickness, the greater the process-related scrap rate.

[0006] In addition, various metal alloys with inherently advantageous properties cannot be processed with thin walls. Examples include wrought aluminum alloys and steels. Plastics also encounter problems filling molds with thin-walled sections, particularly when using highly viscous molding compounds. Furthermore, not all polymers can be processed reliably (e.g., Teflon). Ceramic pressure slip casting is subject to problems such as premature dewatering and solidification, and the achievable material structure is often not very dense. Due to its low flowability, concrete as a molding compound is only suitable for thick-walled components. Furthermore, filling molds with concrete in combination with reinforcing iron is often very complex.

[0007] As a result, the possible shaping of manufactured components is currently limited, or complex additional measures must be taken, for example, to limit the risk of cold runs. These additional measures can include, for example, specially designed gating systems that retain a high proportion of liquid molding compound near the thin-walled areas. Heat-insulated and / or heated molds can also be used. Die casting processes can also be employed. However, the achievable component sizes are limited in these processes, and filling the molding compound under pressure can cause turbulence and air inclusions within the melt, thus degrading the quality of the metal structure. Cores for creating hollow structures cannot be used in die casting.

[0008] The invention therefore aims to improve the production of components from a curable molding compound, and in particular of components with thin-walled regions, particularly with regard to cost, effort, and / or quality. This object is achieved by the subject matter of the appended independent patent claims. Advantageous embodiments are specified in the dependent claims and in this description.

[0009] Accordingly, a method for forming a curable molding compound is proposed, including:

[0010] - receiving (or, in other words, arranging) a curable molding compound which is in a liquid and in particular a liquid or molten state, in a cavity which is delimited by a first mold part and at least one second mold part of a molding tool;

[0011] - generating at least a first relative movement between the first and the second mold part, so that the cavity decreases, in particular wherein the molding compound is still liquid at this stage;

[0012] - Allowing the molding compound to harden, which may in particular include allowing a defined period of time to elapse during which the molded parts are not moved and / or the cavity is not changed.

[0013] This procedure differs from known casting processes in that the size of the cavity containing the molding compound is varied, and in particular, reduced, while the molding compound is still in its uncured state. In the prior art, no such variation of the cavity occurs after filling with a liquid molding compound; instead, the process waits until the molding compound has solidified. The mold is then opened to remove the finished component, i.e., the cavity is enlarged and dissolved.

[0014] According to the invention, however, it was recognized that the proposed procedure enables the molded parts to be heated by the molding compound after it has been filled into the cavity or into at least one of the molded parts (see below). Only then is the cavity reduced in size and the wall thicknesses or volumes of the cavity, and thus of the still liquid molding compound contained therein, are locally reduced, in particular by forming thin-walled regions of the type disclosed herein. However, since the molded parts in this state have been heated to a certain extent by the previously added molding compound, they only extract heat from the molding compound to a limited extent. This means that portions of the molding compound located in thin-walled regions of the cavity cure correspondingly more slowly, which reduces the risk of cold runs.

[0015] Furthermore, the disclosed relative motion can be used to achieve reliable, high-quality formation of thin-walled regions, regardless of the risk of cold runs (i.e., even with molding compounds at room temperature, such as concrete). For example, in contrast to previous die-casting processes, the molding compound can be introduced into the thin-walled regions in a less turbulent, but rather laminar and / or uniform manner, thus avoiding casting defects.

[0016] Reducing the cavity size as a result of the first relative movement can comprise reducing the cavity volume. The cavity, and thus the molding compound accommodated therein, can thereby achieve a so-called target geometry. Additionally or alternatively, the first relative movement can be used to reduce a distance between at least one pair of opposing regions of the molded parts (for example, viewed along a movement axis of the first relative movement). This can also be accompanied by a reduction in the cavity size, in particular a reduction in a dimension of the cavity that corresponds to this distance.

[0017] The cavity can define the shape of the component to be produced. The mold parts can jointly define or, in other words, delimit at least 80% or at least 90% of a volume and / or surface of the cavity. Each of the mold parts can define or delimit at least 15% or at least 25% of the volume and / or surface of the cavity. Apart from the mold parts, no movable parts can be provided to delimit the cavity. Otherwise, these movable parts can only delimit a correspondingly small proportion of the surface and / or volume of the cavity. They can, for example, only be provided for a locally limited re-pressing of molding compound into the cavity otherwise defined by the first and second mold parts. Such a movement of a further part cannot be encompassed by the first and second relative movements of the mold parts disclosed here.

[0018] Collecting the molding compound in the cavity may include:

[0019] Filling the molding compound into the cavity defined by the first and second mold parts or, in other words, filling the molding compound into the mold when the first and second mold parts are already arranged such that the cavity is formed (at least in an enlarged initial state or as a pre-cavity). Alternatively, receiving the molding compound in the cavity may include:

[0020] Filling the molding compound into the mold in an open state and arranging the first mold part and the second mold part relative to form the cavity which receives the (already filled) molding compound.

[0021] In the open state, the first and second mold parts can be separated from each other, in particular such that they do not jointly define any wall region of the cavity and / or that the mold parts generally do not touch each other. Accordingly, in this case, the molding compound can be poured into only one of the mold parts, for example, into a recess present there. The mold parts can then be arranged relative to each other such that the cavity is formed and the already poured molding compound is held between them and within the cavity.

[0022] A further development provides that the first relative movement is only generated once the entire molding compound has been absorbed into the cavity. For example, a specific volume of molding compound may be required to produce a specific component. Only once this volume has been completely filled into the mold and consequently absorbed into the cavity can the cavity be reduced in size (particularly by defining thin-walled areas) by means of the first relative movement. This increases the extent to which the molded parts are heated by the absorbed molding compound.

[0023] In principle, the molding compound can be filled into the mold in such a way that (in particular, exclusively) laminar flows are created within the molding compound. For this purpose, a suitable filling speed for the molding compound can be selected, for example.

[0024] According to one variant, the molding compound is poured into the mold by gravity casting. Alternatively, the molding compound can be poured into the mold by die casting or low-pressure casting. In this context, the pressure applied during filling can be at least partially maintained or increased (e.g., by at least 10%) while generating the first relative movement. This can reduce turbulence within the molding compound.

[0025] On the other hand, during the first relative movement and / or as a result thereof (and in particular regardless of a filling method for the molding compound), the pressure acting on the molding compound may be increased by no more than 25% or even no more than 10%, or may remain essentially constant, to avoid turbulence. It can be assumed that at least atmospheric pressure or a defined negative pressure acts on the molding compound before the first relative movement is generated.

[0026] After the first relative movement has been completed, a fluid connection from the interior of the cavity to the exterior (in other words, to an area outside the cavity) can still be maintained. For example, a fluid connection to an overflow area for molding compound displaced from the cavity and / or a fluid connection from the cavity to the exterior can be maintained via a vent hole. This limits any pressure increases within the molding compound.

[0027] The first relative movement can set the molding compound in motion under essentially laminar flow conditions and, in particular, push it into the thin-walled regions in a laminar manner. For this purpose, a force and / or a speed of movement of the first relative movement can be suitably selected. In particular, the first relative movement can occur essentially force-free. This can be understood to mean that a force for generating this relative movement is limited in such a way that the movement can be achieved (e.g. by overcoming inertial or frictional forces), but no significantly exceeding force acts on the molding compound, which would be necessary, for example, for a significant (e.g., more than 20 percent) and / or permanent increase in pressure of the molding compound.

[0028] In general, no pressure casting can take place before, during, or after the first relative movement. The molding compound can be exposed to pressures of more than 0.2 MPa or even more than 1 MPa in at least one of the aforementioned states, and preferably in none of them.

[0029] One embodiment provides the following following the first relative movement and optionally after the curing of the molding compound:

[0030] - applying a feed force to at least one of the first and second mold parts, wherein the feed force urges the mold parts against each other.

[0031] A defined period of time can elapse between the first relative movement and the application of the feed force, e.g. at least 2 seconds, but preferably no more than 60 seconds or generally not until the molding compound begins to solidify. Within this period of time, the cavity can be left in its reduced state, which is achieved as a result of the first relative movement. This can be done by applying appropriate holding forces or without any force. The feed force can correspond to a subsequent increase (in particular a renewed increase) in a force that is applied to at least one of the mold components. By means of this additional feed force, the molding compound can be brought into a final shape with improved precision. In addition, it has been shown that this can improve the material structure, for example by achieving preferred grain sizes in metallic molding compounds.

[0032] Optionally, the feed force can be used to generate a further relative movement between the first and second molded parts, by means of which the cavity is reduced in size, in particular further reduced in size starting from the state after the first relative movement. This reduction can be less than during the first relative movement. For example, it can be less than 50% or even less than 10% of the reduction during the first relative movement. This takes into account the fact that the molding compound may no longer be liquid to the same extent as during the first relative movement, but may, for example, have already solidified at least partially. After the further relative movement, the cavity and thus the molding compound contained therein may have reached its final target geometry.

[0033] Additionally or alternatively, the feed force can only be generated when the molding compound is no longer liquid, at least in some areas. This may mean that the molding compound has already cured, at least partially and / or in some areas. The molding compound may also have completely hardened.

[0034] By means of the feed force, the at least partially cured molding compound can thus be formed, in particular finally formed to produce a final component shape and / or a final material structure.

[0035] According to a further aspect, the feed force is at least 10% higher than a force applied to generate the first relative movement. This enables particularly reliable and precise molding of the molding compound using the feed force. The feed force and the force applied to generate the first relative movement can be generated using the same movement device, which simplifies the method and the device used for this purpose.

[0036] The mold can form a lost mold (i.e. a mold destroyed as a result of the casting process) or a permanent mold. Particularly in the case of a lost mold, relative movements of molded parts have so far been unusual, so that thin-walled regions have not yet been able to be produced with the reliability achievable according to the invention. According to one variant, one of the molded parts is a lost molded part and the correspondingly other of the molded parts is a permanent molded part. This can be provided in particular in any variant disclosed herein in which a further relative movement occurs while generating a feed force. By means of the lost molded part, the degrees of freedom of the molding are increased, since the component can be removed without destroying this molded part. In particular, degrees of freedom with regard to the arrangement of overflow regions or collecting cavities are increased.These can, for example, be arranged outside a parting line of the molded parts and, in particular, entirely within the expendable molded part. By providing the additional molded part as a permanent molded part, however, the effort can be limited, since only one of the molded parts (namely the expendable part) needs to be remanufactured before each casting process.

[0037] Further development of the procedure also provides:

[0038] - Discharge of a portion of the molding compound from the cavity during the first relative movement (and / or during any further relative movement, for example as a result of application of the above-mentioned feed force), i.e. discharge of that portion of the molding compound which is forced out of the shrinking cavity.

[0039] This enables significant travel distances within the scope of relative movements and significant reductions in cavity size. The cavity can initially be defined with a correspondingly large volume to accommodate a large volume of molding compound for effective heating of the molded part.

[0040] In this context, it may be provided that the derivation comprises at least one of the following:

[0041] - Draining the molding compound portion into at least one collecting cavity defined by at least one of the molded parts. The collecting cavity may, for example, be at least partially unfilled beforehand and / or not define a retained component of the component to be manufactured (i.e., molding compound that solidifies there can subsequently be removed from the component). The collecting cavity may also be referred to as an overflow bean. Alternatively or additionally, general overflow areas may be provided within the mold.

[0042] Discharging the molding compound portion via a filling channel used for filling the molding compound. This may, for example, include pushing the molding compound portion back into a molding compound reservoir connected to the filling channel and / or into a melt generator connected to the filling channel and / or into a gating system connected to the filling channel.

[0043] - Discharge of the molding compound via a (fluid) channel that is formed or opened with destruction of a defined region of the mold. For example, at least one of the mold parts or the mold in general can comprise at least one predetermined breaking point that breaks in a defined manner as a result of the application of pressure by the molding compound. This predetermined breaking point can form the defined region of the mold that is broken through and thereby destroyed. This defined region and / or the predetermined breaking point can be, for example, a wall region of a lost mold with locally reduced material thickness. This wall region can separate the cavity from a discharge channel and can be broken through by the molding compound, creating a fluidic connection between the cavity and the discharge channel.The pressure applied by the molding compound may be increased beyond a threshold value as a result of the first or any subsequent relative movement of the molded parts, whereupon the predetermined breaking point breaks.

[0044] In a further development, at least one core is arranged in the cavity and is embedded in the molding compound. At least one of the molded parts, in particular one that is actively moved during the first or any further relative movement, can be movable relative to the core. The core can generally be stationary. For example, the core can be positioned within the cavity via rods or webs, with at least one (in particular actively moved) molded part being movable relative to the core. In this context, the molded part can also be penetrated by the rods or webs. For example, they can protrude into the cavity through recesses within the molded part.

[0045] The invention also relates to a device for molding a curable molding compound, including:

[0046] - a molding tool comprising a first mold part and at least one second mold part, which together define a cavity in which a curable molding compound can be received;

[0047] - a movement device arranged to generate a relative movement between the first and the second mold part;

[0048] - a control device which is designed to control the movement device to generate at least one first relative movement between the first and the second molded part which reduces the cavity when the cavity is at least partially filled with the curable molding compound.

[0049] The device can be configured to carry out a method according to any variant disclosed herein. For this purpose, the control device can, in particular, be configured to initiate any necessary measures and / or perform any necessary controls.

[0050] Further optional features and specific embodiments of general features of the method and device disclosed herein are explained below. These features and embodiments can be provided in any number and combination.

[0051] For example, according to a general aspect, the molding tool and / or the molded parts may comprise at least one of the following materials: plastic, wood, ceramic, glass, glass ceramic, concrete, cement, gypsum, composites and / or composite materials, sand / binder mixtures, molding sand, metal, steel, in particular hot-work steel.

[0052] The mold and / or its components can be unheated or heatable (i.e., temperature-controlled). The latter can be achieved using at least one of the following methods: hot air preheating, radiant heating, convective heating, heat conduction, electrical heating via resistance heating, electrical heating via induction, electrical heating via current heating, conformal heating / cooling via heating / cooling loops, temperature control with water, temperature control with oil, temperature control with liquid metals, or heating by chemical reactions.

[0053] The number of mold parts is not limited to two, meaning the mold is not necessarily limited to two mold halves formed by the mold parts. Instead, a higher number of mold parts can be provided. Generally, the mold parts can include draft angles and / or curves.

[0054] The molding tool can comprise at least one of the following as at least one of the mold parts or as an additional tool component: a punch, a die, a hold-down device, a slide, an undercut mold part and / or an undercut tool component, a mandrel, a core.

[0055] The molding tool can comprise at least one of the following features, in any number, wherein these features can also be referred to as auxiliary parts of the tool: a pouring channel, a venting channel, an overflow area, an ejector pin, a guide or guide structure, a temperature sensor, a pressure sensor, a material detector, a hot runner, a seal, a valve for controlling the flow of the molding compound, a predetermined breaking point and / or a membrane, an overflow or return flow resistance (e.g. comprising a geometric flow resistance, a cross-sectional transition, a porous structure; a deliberately induced cold run; an extended flow path; a roughening).

[0056] The working direction of the molded parts can be linear and / or comprise only one direction of movement. Alternatively, multiple working directions and / or complex movements in several consecutive working directions can occur.

[0057] The molding compound may comprise at least one of the following materials: thermoplastic, thermoset, fiber-reinforced composites, a ceramic casting compound, gypsum, concrete, in particular ultra-high-performance concrete (UHPC), polymer concrete, metal, e.g. magnesium, aluminum, copper, zinc, tin, iron, nickel, lead, titanium and their alloys, wrought aluminum alloy, cast iron, steel.

[0058] The material supply or, in other words, the filling of the molding compound can be carried out according to one of the following variants: the molded parts can be completely immersed in the liquid molding compound and closed there; gravity casting can take place into the open mold; one of the molded parts can comprise a filling channel, in particular a molded part designed as a punch, which is moved into a molded part designed as a die; a lateral hot runner can be provided; the molding compound can be fed vertically from below through one of the molded parts and in particular through a molded part designed as a die using the low-pressure principle; the molding compound can be taken up into the cavity and only there heated and in particular melted.

[0059] Additionally or alternatively, any of the following additives may be used, alone or in any combination: lubricants or glidants, release agents, coatings for chemical protection, coatings for adjusting heat transfer, coatings for modifying the surface layer composition / grain morphology.

[0060] Embodiments of the invention are explained below with reference to the accompanying schematic figures. Similar or equivalent features may be provided with the same reference numerals throughout the figures.

[0061] Figure 1 shows operating states a) - d) of a device according to a first embodiment, which executes a method according to a first embodiment. Figure 2 shows operating states a) - b) of a device according to a second embodiment, which executes a method according to a second embodiment.

[0062] Figure 3 shows operating states a) - b) of a device according to a third embodiment, which carries out a method according to a third embodiment.

[0063] Figure 4 shows operating states a) - b) of a device according to a fourth embodiment, which carries out a method according to a fourth embodiment.

[0064] Figure 5 shows operating states a) - d) of a device according to a fifth embodiment, which carries out a method according to a fifth embodiment.

[0065] Figure 6 shows operating states a) - b) of a device according to a sixth embodiment, which carries out a method according to a sixth embodiment.

[0066] Figure 1 shows a device 10 comprising a mold 12. The mold 12 has two mold parts 100, 101. One mold part 100 is designed as a punch, and another mold part 101 is designed as a die. The mold 12 can be designed as a lost mold, for example, made of sand, or as a permanent mold.

[0067] The molded part 101 is stationary. The molded part 100 is movable. For this purpose, it is mechanically coupled to a schematically illustrated direction of movement 18, in particular to an actuator of the movement device 18, for example, a hydraulic cylinder.

[0068] The device 10 also includes a control device 16, for example, a computer and / or comprising at least one processor. The control device 16 is configured to control the direction of movement 18 via a wired or wireless data connection (shown in dashed lines), so that the molded part 100 is moved in a desired manner.

[0069] The control device 16 and the direction of movement 18 are only shown in state a) but are also present in the other states b) - d). In the devices 10 according to the other Figures 2-6, the control device 16 and the direction of movement 18 are also not shown, but are nevertheless present. The molded part 101 has a recess 20 into which the molded part 100 can be moved. The space between this recess 20 and an opposite surface of the component 100 that can be moved into it forms a cavity 14 for receiving a molding compound (not shown).

[0070] Figure 1 shows the temporally successive operating states a)-d), which each correspond to process steps of the process carried out by the device 10.

[0071] In state a), the mold 12 is shown in an open state. The molded part 100 has clearly moved out of the recess 20 of the molded part 101, and the cavity 14 is not completely enclosed by the molded parts 100, 101 or, in other words, not completely defined by them. In this state, the cavity 14 can be described as open, dissolved, or not yet fully formed.

[0072] For example, by gravity casting, a molding compound (not shown) is poured into the recess 20 in a liquid and, in particular, molten state. The molding compound is heated to a temperature above room temperature, for example, to over 100°C. The molding compound may comprise any material example disclosed herein and, in particular, may be a molten metal.

[0073] In state b), the molded part 100 has been partially lowered into the recess 20 of the molded part 101 by means of the direction of movement 18. As a result, the cavity 14 is formed and / or is completely enclosed by the molded parts 100, 101 and completely defined between them. This can be referred to as the formation of an enlarged pre-cavity. The molding compound (not shown) completely fills the cavity 14 and thus heats the molded parts 100, 101. Not shown are features known to those skilled in the art, such as vent holes, which enable the molding compound to be enclosed by the molded parts 100, 101.

[0074] Subsequently, the molded part 100 is lowered further to reach state c). It should be noted that, starting from state a), the lowering of the molded part 100 can occur within the framework of a continuous first relative movement. This first continuous relative movement can include state b) as an intermediate stage and end with state d), in which a target geometry is reached. In this case, state c) represents an intermediate stage, which can also be referred to as the achievement of a preliminary geometry. However, a first relative movement of the type disclosed herein (in particular a continuous relative movement) can also only occur starting from state b). For example, after reaching state b), a defined period of time can be waited for the molded parts 100, 101 to heat up.

[0075] In state c), the cavity 14 is significantly reduced in size compared to state b), i.e., the volume of the cavity 14 has decreased. This reduction also occurs with the formation of thin-walled regions, since the distances between opposing regions and surfaces of the molded parts 100, 101 are reduced.

[0076] These thin-walled areas can have material thicknesses of no more than 5 mm or no more than 3 mm. In other words, such thin-walled material thicknesses can be formed or specified by the cavity.

[0077] In stage c), the still-liquid molding compound penetrates into the thin-walled areas without forming cold runs and completely fills them. This occurs under laminar flow conditions, which significantly improves the quality of the cast product compared to, for example, turbulent die casting.

[0078] During the transition from state b) to state c), excess molding compound flows back into a filling channel (not shown). As mentioned, the reduction of cavity 14 can be continued while the molding compound is still liquid until state d) (i.e., until the target geometry is reached) before the molding compound solidifies.

[0079] In summary, within the framework of a continuous relative movement starting from state b) (pre-cavity) and passing through state c) (pre-geometry), state d) (target geometry) can be reached and only then can the molding compound cure.

[0080] Alternatively, state d) can be reached starting from state c) only after a defined period of time has elapsed. Within this period, the molding compound begins to harden at least partially and / or in certain regions and is therefore no longer completely liquid. Subsequently, a feed force is generated by means of the direction of movement 18, which pushes the molded part 100 further into the recess 20 of the molded part 101 to reach state d). The already partially or completely solidified molding compound is thereby formed into a final component geometry. In such a case, the molding tool 12 is advantageously designed as a permanent mold in order to withstand the feed force.

[0081] Finally, the mold 12 can be switched to state a) or to an even more open state (not shown) in order to remove the component formed from the cured molding compound to the mold 12.

[0082] Figure 2 shows a modification of the first embodiment, wherein a filling channel 201 for carrying out a gravity casting process is formed in the first mold part 101. State a) of Figure 2 largely corresponds to state b) of Figure 1 (pre-cavity) and shows the initial filling of a molten molding compound 200 through the filling channel 201. As a result, the mold parts 100, 101 are heated by the molding compound 200.

[0083] State b) of Figure 2 corresponds to a target geometry according to state d) of Figure 1 and is achieved by a relative movement of the molded part 100 into the molded part 101 (see movement arrow in state b)). The cavity 14 defined between these molded parts 100, 101 shrinks, forming thin-walled regions. The still-liquid molding compound penetrates into these regions without casting defects and under laminar flow conditions along the heated adjacent surfaces of the molded parts 101, 100.

[0084] Figure 3 shows a process comparable to Figure 2, but for low-pressure casting. In this case, the molding compound 200 is filled vertically from below through a filling channel 300 into the cavity 14 between the mold parts 100, 101 according to known low-pressure casting processes. In other words, the molding compound 200 rises into the cavity 14 under pressure, see flow direction 301. The mold parts 100, 101 can form a permanent mold and be made, for example, of hot-work steel.

[0085] In state a) (pre-cavity), the molding compound then at least partially and in particular completely fills the cavity 14 to heat the molded parts 100, 101. Subsequently, the molded part 100 is lowered relative to the molded part 101 (see movement arrow in state b), which corresponds to a target geometry). The cavity 14 then shrinks, forming and filling thin-walled regions with the still-liquid molding compound 200. Excess molding compound 200 is forced back from the cavity 14 into the filling channel 300, see flow direction 302.

[0086] Optionally, analogous to state d) in Figure 1, after the molding compound has cured, the solidified component can be further formed by applying an additional feed force, further reducing the size of the cavity 14. In this case, the filling channel 300 can be closed, for example, by means of a valve (not shown) before the feed force is applied. Figure 4 shows a process analogous to Figure 3, but for a die-casting process with lateral feeding of the molding compound 200. More precisely, the molding compound 200 is filled in a laminar manner into the cavity 14 between the molded parts 100, 101 by means of a slide 400 in state a) (enlarged pre-cavity), and heats the molded parts 100, 101.

[0087] In state b) (target geometry), the cavity 14 shrinks due to the movement of the molded part 100 into the molded part 101 (see movement arrow). Excess molding compound is forced out of the cavity 14 by pushing back the slide 401.

[0088] Figure 5 shows a device 10 in which the stationary mold part 101 comprises at least one collecting cavity 500 (for example, designed as a circumferential ring). The collecting cavity 500 can also be referred to as an overflow bean.

[0089] In state a) (pre-cavity), the molding compound is filled via a filling channel 504 using a low-pressure process analogous to Figure 4 and rises into the cavity 14 (see flow direction indicated by the arrow). It then heats the molded parts 100, 101. In state b) (pre-geometry), the molded part 100 is lowered into the molded part 101, whereby excess molding compound is forced out of the cavity 14 (see flow direction indicated by the lower arrow). As indicated by a different hatching or filling, the molding compound 501 then begins to solidify and becomes viscous and / or hardens. After a corresponding curing period has elapsed, a feed force is applied to achieve state d) (target geometry), whereby the molded part 100 is further lowered and the cavity 14 is further reduced in size. The molding compound 501 then enters the collecting cavity 500 and forms excess component areas 502 there, which can then be removed.

[0090] In the state of Figure d), the filling channel 504 can be closed by means of a valve not shown and / or the filling channel 504 can be closed by solidified molding compound.

[0091] Figure 6 shows a variant with an additional core 600 for defining a hollow structure in the manufactured component. The molded part 100 has recesses into which rods 601 are inserted. The rods 601 serve as a holding and positioning device for positioning the core 600 in the cavity 14.

[0092] In state a), molding compound 200 is again filled into the cavity 14 via a filling channel 300 using a low-pressure process (see flow direction 301). The molding compound 200 embeds the core 600 or, in other words, envelops it. The core 600 initially has a defined clearance 610 relative to the molded part 100, particularly along a movement axis of the molded part 100. This clearance can be used to adjust the extent of movement of the core 600 relative to the molded parts 100, 101. To reach state b), the molded part 100 is lowered into the molded part 101 (see movement arrows), relative to the initially stationary rods 601. Only after the play 610 has been bridged is a movement force transferred from the molded part 101 to the core 600, so that the core can be lowered together with the molded part 100.

[0093] Upon reaching state b), the target geometry is achieved, in which the cavity 14 is reduced in size and has thin-walled regions. As indicated by flow arrow 302, excess molding compound can be forced out of the cavity 14 via the filling channel 300.

[0094] The following table shows the states of a molding compound for exemplary embodiments of processes according to the invention as a function of the positions of the molded parts 100, 101. The "open" state corresponds to the state shown in Figure 1 a). The "precavity" state corresponds to a state with an initially enlarged cavity, such as in Figure 1 b).

[0095] The "pre-geometry" state corresponds to a cavity that is already reduced in size compared to the "pre-cavity" but not yet completely reduced, as in the case of Figure 1 c). The "target geometry" state corresponds to a maximally reduced volume of the cavity, see for example Figure 1 d).

[0096] The following states of the molding compound can be achieved, for example, by selecting suitable time periods between the individual movement states of the mold and / or by selecting the molding compound and / or by selecting its filling temperature.

[0097] When casting into a sand mold (optionally with a moving core package as in Figure 6), the following sequence results according to one embodiment, where "X" marks the state of the molding compound at the respective molding tool state:

[0098] Another example process, which corresponds to a type of thixoforming process due to the molding of a slurry mass, results in the following sequence. For example, the molding compound is only filled once the pre-cavity is present, using a low-pressure process, for example:

[0099] In another exemplary process, in which the molding compound solidifies when the pre-geometry is already present and is only subsequently formed into the target geometry by applying a further feed force, the following process results.

[0100] This can also be called cast forging:

[0101]

[0102] 10 Device

[0103] 12 mold tool

[0104] 14 Cavity

[0105] 16 Control device

[0106] 18 Movement device

[0107] 20 Deepening

[0108] 100 molded parts

[0109] 101 molded part

[0110] 201 filling channel

[0111] 202 molding compound

[0112] 300 filling channel

[0113] 301-302 Flow direction

[0114] 500 collecting cavities

[0115] 501 hardened molding compound

[0116] 502 excess component area

[0117] 504 filling channel

[0118] 600 core

[0119] 601 bar

[0120] 610 game

Claims

Patent claims 1. Method for forming a hardenable molding compound (202), comprising: - Receiving a curable molding compound (202) in a liquid state into a cavity (14) which is bounded by a first molding part (100) and at least one second molding part (101) of a molding tool (12); - after a defined period of time for the molded parts (100, 101) to be heated by the molding compound (202): generating at least a first relative movement between the first and the second molded part (100, 101), so that the cavity (14) shrinks while forming thin-walled areas, the thin-walled areas having a material thickness of no more than 5 mm or no more than 3 mm; - Allowing the molding compound to harden (202).

2. Method according to claim 1, wherein the first relative movement is carried out such that the molding compound enters the thin-walled areas in a substantially laminar manner.

3. Method according to claim 1 or 2, wherein the first relative movement takes place in a still liquid state of the molding compound (202).

4. Method according to any of the preceding claims, wherein the receiving of the molding compound (202) comprises: Pouring the molding compound (202) into the cavity (14) bounded by the first and second mold parts (100, 101); or Pouring the molding compound (202) into the molding tool (12) in an open state and arranging the first molding part (100) and second molding part (101) relative to form the cavity (14) which receives the molding compound (202).

5. Method according to any of the preceding claims, the first relative movement is only generated when the entire molding mass (202) has been received in the cavity (14).

6. Method according to one of the preceding claims, wherein the molding compound (202) is filled into the molding tool (12) by means of pressure casting or low-pressure casting, wherein the pressure applied for filling is at least partially maintained or increased when generating the first relative movement.

7. Method according to any one of claims 1 to 5, wherein, when generating the first relative movement, a pressure acting on the molding compound (202) is increased by no more than 25% or no more than 10%.

8. Method according to one of the preceding claims, wherein the time period for heating the molded parts (100, 101) is at least 2 seconds.

9. Method according to one of the preceding claims, further comprising, following the first relative movement: - Applying a pressure force to at least one of the first and second molded parts (100, 101) which pushes the molded parts (100, 101) against each other.

10. Method according to claim 9, wherein a further relative movement between the first and the second mold part (100, 101) is generated by means of the feed force, by means of which the cavity (14) is reduced in size.

11. Method according to claim 9 or 10, wherein the delivery force is only generated when the molding compound (202) is no longer liquid, at least in some areas.

12. Method according to any one of claims 9 to 11, wherein the delivery force is at least 10% higher than a force applied to generate the first relative movement.

13. Method according to any of the preceding claims, wherein the forming tool (12) forms a lost mold or a permanent mold.

14. Method according to any one of claims 1 to 11, wherein one of the molded parts (100, 101) is a lost molded part and the other of the molded parts (100, 101) is a permanent molded part.

15. Method according to any of the preceding claims, further comprising: - Deriving a proportion of the molding compound (202) from the cavity (14) during the first relative movement.

16. The method of claim 15, wherein the derivation comprises at least one of the following: - Diverting the molding compound portion into at least one collecting cavity (500) which is bounded by at least one of the mold parts (100, 101); - Diverting the molding compound portion via a filling channel used for filling the molding compound (300, 504); - Diverting the molding compound portion via a channel that is formed or opened by destroying a defined area of ​​the molding tool.

17. Method according to one of the preceding claims, wherein at least one core (600) is arranged in the cavity (14) which is embedded in the molding compound (202).

18. Device (10) for forming a hardenable molding compound (202), comprising: - a molding tool (12) comprising a first molding part (100) and at least a second molding part (101) which together define a cavity (14) in which a curable molding compound (202) can be received; - a motion device (18) which is designed to generate a relative motion between the first and the second molded part (100, 101); - a control device (16) configured to control the motion device (18) to generate at least one first relative motion reducing the cavity (14) between the first and the second mold part (100, 101) when the cavity (14) is at least partially filled with the curable molding compound (202) and after a defined period of time for the mold parts (100, 101) to be heated by the molding compound (202); wherein the control device (16) is further configured to control the first movement device (18) in such a way that the cavity (14) is reduced in size by the first relative movement, forming thin-walled areas, wherein the thin-walled areas have a material thickness of no more than 5 mm or no more than 3 mm.

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