Wax formwork production device and method for producing a wax formwork

Abstract

The invention relates to a wax formwork production device for producing a wax formwork (150) for concrete casting, having: (a) a melting unit (10) for heating the wax to a predetermined temperature above the solidification temperature of the wax, (b) a mixing unit (20) which is configured to admix gas into the wax such that a wax-gas mixture is produced, (c) a nozzle (30) which is arranged downstream of the mixing unit (20) in the direction of flow and is configured to apply the wax-gas mixture in layers to a substrate, (d) a positioning system (50) for positioning the nozzle (30) relative to the substrate, and (e) a control unit (60) which is designed to control the positioning system (50) for positioning the nozzle (30) relative to the substrate such that the wax formwork (150) is produced. The invention also relates to a concrete casting manufacturing plant having such a wax formwork production device and a concrete feeding device for casting concrete in the wax formwork, to a method for producing a wax formwork, and to a method for producing a concrete component.

Description

[0001] Wax formwork manufacturing device and method for manufacturing a wax formwork

[0002] The invention relates to a wax formwork manufacturing device for producing a wax formwork for concrete casting. According to a second aspect, the invention relates to a method for producing a wax formwork for concrete casting. Furthermore, the invention relates to a concrete casting production plant and a method for producing a concrete component.

[0003] Waxes include both natural and industrially produced waxes. These include, in particular, animal waxes, vegetable waxes, mineral waxes, petroleum waxes, and synthetic waxes. Waxes are usually malleable at 20°C, solid to brittle, coarse to fine crystalline, translucent to opaque, but not glassy, ​​melt above 40°C without decomposition, have a relatively low viscosity even slightly above the melting point, are highly temperature-dependent in consistency and solubility, and can be polished under light pressure.

[0004] Formwork is a surface-sealing component that serves as a support for the concrete until it hardens, usually a temporary component. This component enables the production of concrete elements in the desired shape within the selected manufacturing tolerances. The production of precise, free-formed concrete components usually requires special formwork. These are usually made of wood, acrylonitrile butadiene styrene copolymers (ABS), polylactide (PLA), polyvinyl alcohol (PVAL or PVOH), polyurethane (PU), or polystyrene (PS). In most cases, the formwork material cannot be recycled due to the required coating. Furthermore, the tolerance deviations of most special formwork are unsatisfactory for the production of precision precast components.

[0005] The object of the present invention is to avoid disadvantages in the prior art.

[0006] The invention solves this problem by a wax formwork manufacturing device for producing a unit for heating the wax to a predeterminable temperature above a solidification temperature of the wax, (b) a mixing unit which is designed to mix gas into the wax so that a wax-gas mixture is formed, (c) a nozzle which is arranged downstream of the mixing unit in the flow direction and is designed to apply the wax-gas mixture to a substrate in layers, (d) a positioning system for positioning the nozzle relative to the substrate and (e) a control unit which is designed to control the positioning system for positioning the nozzle relative to the substrate so that the wax formwork is formed.

[0007] The invention is based on the discovery that the gas inclusions in a wax formwork made from a wax-gas mixture result in less shrinkage of the wax formwork during and after production, and thus also less warping. In other words, the dimensional stability of the wax formwork can be very high. Furthermore, the gas inclusions result in the wax formwork being heated less intensely due to the thermally insulating effect of the gas inclusions when the wax formwork is exposed to the hydration heat of the concrete during the production of a concrete component. This also promotes the strength of the wax formwork during the concrete component production. Another advantage is that the use of a wax-gas mixture reduces wax material consumption.

[0008] Another advantage is that the wax formwork is both environmentally friendly and very economical due to the reusability of the wax by melting it down. The wax formwork produced with the wax formwork manufacturing device according to the invention exhibits no cracks or cavities. Furthermore, they are very stable, making them particularly suitable for the production of concrete components made of ultra-high-performance concrete (IIHPC).

[0009] A substrate is understood to mean, in particular, a base plate, a deposited wax-gas mixture, or a base body to be printed. A gas is understood to mean a pure substance, in particular carbon dioxide, or a gas mixture, in particular air.

[0010] The glass transition temperature of the wax is preferably above 40 °C. The solidification temperature of the wax is preferably above 50 °C, particularly preferably above 60 °C. The solidification temperature can be determined according to DIN ISO 2207.

[0011] Preferably, the compressive strength of the wax at 20 °C is more than 0.25 N / mm 2 Advantageously, the compressive strength of the wax-gas mixture at 20 °C is at least half the compressive strength of the wax at 20 °C. Preferably, the elastic modulus of the wax under compressive load at 20 °C is more than 25 N / mm 2 , preferably more than 500 N / mm 2 , especially more than 1000 N / mm 2 , particularly preferably more than 2000 N / mm 2 The dropping point of the wax is preferably above 80°C, in particular above 150°C.

[0012] It may be intended that a wax made from a renewable raw material can be used. In particular, it may be intended that the wax exclusively comprises renewable raw materials. It is also conceivable that the wax consists of at least 50%, in particular 90%, and preferably 100%, of a renewable raw material. Renewable raw materials for the wax can be, for example, plant-based waxes such as soy wax, palm oil wax, coconut oil wax, and / or rapeseed oil wax. This list is not exhaustive.

[0013] The gas and / or the wax-gas mixture preferably contain a filler, in particular a mineral and / or organic filler. Alternatively or additionally, the mixing unit is designed to admix a filler, in particular a mineral and / or organic filler, into the wax and / or the wax-gas mixture. Calcium silicate hydrate, calcium carbonate, limestone flour, talc, and / or crude cellulose, for example, can be used as fillers. The filler is selected in particular to increase the compressive strength of the wax-gas mixture and / or to improve at least one thermal and / or mechanical material property of the wax-gas mixture.

[0014] Preferably, the melting unit comprises or forms a heating element, in particular in the form of a heating cartridge, a heating band, a heat exchanger, a continuous-flow heater, a heating medium, an immersion heater or the like.

[0015] A further development of the invention provides that the melting unit is arranged in the mixing unit or upstream of the mixing unit in the direction of flow. If the melting unit is located upstream of the mixing unit in the direction of flow, the melting unit preferably has an opening for receiving wax. If the melting unit is arranged in the mixing unit, the mixing unit preferably has an opening for receiving wax.

[0016] The mixing unit preferably has a gas inlet through which gas can be supplied. The gas inlet is preferably fluidly connected to a fan and / or a gas compressor. Alternatively or additionally, a nozzle is arranged at the gas inlet or the gas inlet forms the nozzle. The nozzle is preferably controllable. The nozzle is preferably connected to a pressure vessel containing a compressed gas.

[0017] Preferably, a conveying hose is arranged between the melting unit and the mixing unit and / or between the mixing unit and the nozzle. The conveying hose is preferably heated. It is possible to arrange a conveying device on the conveying hose which is designed to assist the conveying of the wax and / or the wax-gas mixture through the conveying hose. The conveying device can be, for example, a pump, an extruder or a compressor. Alternatively or additionally, the conveying of the wax can be assisted by the pressure in the melting unit and / or in the mixing unit. It is also possible to arrange the melting unit and the mixing unit and / or the mixing unit and the nozzle in such a way that no conveying hoses are required.For this purpose, the melting unit is preferably arranged in or above the mixing unit, and the mixing unit is arranged above the nozzle, so that the conveying of the wax and / or the wax-gas mixture is assisted by gravity and no conveying device is required. Preferably, the melting unit, the mixing unit, and the nozzle have a common housing. Preferably, the positioning system is configured to accommodate the melting unit, the mixing unit, and the nozzle and to position them jointly relative to the substrate. Preferably, the control unit is configured to control the positioning system for jointly positioning the melting unit, the mixing unit, and the nozzle relative to the substrate.

[0018] The control unit is preferably configured to adjust a mass flow of the nozzle. This is particularly advantageous when the movement speed of the nozzle relative to the substrate is changed and, at the same time, the strand width of the wax-gas mixture extruded through the nozzle in strand form is to remain constant. Furthermore, the mass flow can be set to zero if the position of the nozzle relative to the substrate is to be changed without simultaneous extrusion of the wax-gas mixture. The control unit is preferably configured to control a conveying device such that the mass flow at the nozzle corresponds to a predeterminable mass flow.

[0019] A further development of the invention provides that the mixing unit comprises (a) a mixing chamber with a tempering surface, (b) a tempering device configured to temper the tempering surface to a tempering temperature such that the wax-gas mixture is tempered at the tempering surface of the mixing chamber, and (c) a scraping element for scraping the wax-gas mixture from a scraping wall of the mixing chamber and / or from the tempering surface of the mixing chamber. Preferably, the scraping wall is an outer wall of the mixing chamber. Preferably, the temperature of the wax and / or the wax-gas mixture does not fall below the solidification temperature of the wax during tempering.Alternatively, the temperature of the wax and / or the wax-gas mixture during tempering does not fall below a minimum temperature, which is preferably at most 20 °C, preferably at most 10 °C, in particular at most 5 °C, and particularly preferably at most 2 °C below the solidification temperature of the wax. The mixing chamber is preferably rotationally symmetrical, in particular cylindrical. The mixing chamber can also have an open side, which is preferably closable.

[0020] The tempering surface preferably forms a scraping wall of the mixing chamber or part of a scraping wall of the mixing chamber. The scraping wall can in particular be an outer wall, a side wall and / or an inner wall of the mixing chamber. Advantageously, the tempering surface forms an outer wall of the mixing chamber or part of an outer wall of the mixing chamber. Preferably, the mixing unit has a tempering device that is arranged on the tempering surface or forms it. Preferably, the melting unit is the tempering device. Alternatively or additionally, the tempering device can be a heating element and / or a cooling element, in particular a heating medium, a coolant, a heating band, a heat exchanger or a heating cartridge. The scraping element is preferably arranged in the mixing chamber so as to be rotatable about a rotation axis.

[0021] Furthermore, it can be provided that the device has two-stage cooling. In other words, the device can have a second temperature control device in addition to the melting unit or the temperature control device. It can be provided that the temperature control device is also arranged in the mixing unit. In this case, it can be provided that the wax-gas mixture is first cooled down in the mixing unit by the temperature control device. In particular, it can be provided that the temperature control device in the mixing unit cools the wax to a temperature above a crystallization point. The crystallization point can be understood as the point at which a change from the amorphous-liquid state of the mixture to the crystalline state occurs. In other words, the temperature of the mixture at the crystallization point is above the solidification point temperature and below the dropping point temperature.This has the advantage of allowing improved transport from the tempering device in the mixing unit to the nozzle and providing sufficient stability to allow the wax to be deposited in layers on top of one another. The second tempering device, which can be located in the nozzle, can be used to cool the wax-gas mixture to its crystallization point.

[0022] For example, it can be provided that the wax is melted in the mixing unit and mixed with gas to form a wax-gas mixture and cooled by means of the tempering device to a temperature above the crystallization point. The wax-gas mixture is then transported, among other things, to the nozzle, wherein the wax-gas mixture is further cooled in the nozzle. Preferably, the wax-gas mixture in the nozzle is cooled to the crystallization point by the second tempering device. Optionally, the tempering device can also have a heating element so that the wax-gas mixture can be heated to the crystallization point. In particular, the temperature of the wax-gas mixture at the nozzle is set to the crystallization point by means of the second tempering device.

[0023] The scraping element is preferably designed as a mixing element configured to mix gas into the wax. Alternatively or additionally, a separate mixing element can be arranged in the mixing chamber. It is also possible to design the mixing unit without a mixing element.

[0024] The mixing of a predefined gas proportion into the wax so that a wax-gas mixture is created can then be achieved, for example, by sufficient gas pressure in the mixing chamber.

[0025] The scraping element can, for example, be a stirring arm, which is preferably designed to correspond to the rotationally symmetrical and / or cylindrical mixing chamber. The outer diameter of the stirring arm preferably corresponds approximately to the inner diameter of the rotationally symmetrical and / or cylindrical mixing chamber.

[0026] Scraping is understood to mean scraping or removing from the surface. In this case, some of the wax-gas mixture can also remain as residue on the surface. Preferably, a minimum distance between the scraping wall of the mixing chamber and the scraping element when the scraping element rotates about the axis of rotation is at most 1 mm, preferably at most 0.1 mm, particularly preferably at most 0.01 mm. Preferably, a maximum distance between the scraping wall of the mixing chamber and the scraping element when the scraping element rotates about the axis of rotation is at most 1 mm, preferably at most 0.1 mm, particularly preferably at most 0.01 mm. By keeping the distance between the scraping wall of the mixing chamber and the scraping element as small as possible when the scraping element rotates about the axis of rotation, it is ensured that as little wax-gas mixture as possible remains as residue on the scraping wall of the mixing chamber.

[0027] The positioning system is preferably a robot, a gantry system, or a combination of the robot and the gantry system. The robot and / or the gantry system preferably has at least three axes, preferably at least four, in particular at least five, particularly preferably six axes, particularly preferably at least seven axes. The positioning system preferably has a fastening device or a gripper configured to receive a nozzle and / or a tool for machining. The positioning system is preferably configured to automatically pick up and / or automatically deposit the nozzle and / or the tool for machining.

[0028] A further development of the invention provides that the wax formwork production device comprises (a) a cooler arranged to cool the already deposited wax-gas mixture, and / or (b) a heating device arranged to heat the already deposited wax-gas mixture. For example, a fan, a hose with an outlet opening through which air flows, a heat radiator, and / or an infrared radiator can be provided as the cooler and / or heating device.

[0029] Preferably, the cooler and / or the warming device can be aligned to a predeterminable angular position. The control unit is preferably designed to send a control signal to the cooler and / or the warming device, so that the cooling of the cooler and / or the warming device is changed such that the path of the cooler / or the warming device is located at a position in which the nozzle will be located after a specific period of time has elapsed after the transmission of the control signal. Alternatively or additionally, the cooler and / or the warming device is arranged on a separate positioning system that is designed to move the cooler and / or the warming device into a position in which, in the effective direction of the cooler / or warming device, a position in which the nozzle will be located after a specific period of time has elapsed.With a cooler, the deposited wax-gas mixture can be cooled down so that it has sufficient strength so that new wax-gas mixture can be applied to the deposited wax-gas mixture.

[0030] A heating device, preferably present, can be used to heat the deposited wax-gas mixture, ensuring sufficient adhesion of the newly applied wax-gas mixture to the previously deposited wax-gas mixture. Preferably, the previously deposited wax-gas mixture is not heated above the solidification temperature of the wax.

[0031] Preferably, the mixing unit is configured to add a predeterminable gas proportion to the wax. Particularly preferably, the control unit is configured to automatically carry out a method comprising the steps of: (a) detecting a target gas proportion, (b) controlling the mixing unit such that, when gas is mixed into the wax, a wax-gas mixture is formed with a gas proportion that corresponds to the target gas proportion. For this purpose, the control unit preferably detects the position of the nozzle relative to the substrate and detects the target gas proportion at this position. Alternatively or additionally, the control unit can read the large target gas proportion from a CAM file or a CAM program.

[0032] The target gas proportion for the production of contour surfaces is preferably lower than for the production of support structures. Contour surfaces are understood to be surfaces that come into contact with the concrete during the production of a concrete component. Support structures are understood to be structures that are located inside the component (infill) and / or do not come into contact with the concrete during the production of a concrete component. The mixing unit preferably has a sensor for detecting the gas proportion of the wax-gas mixture. The control unit is preferably configured to control the mixing unit depending on sensor data. In particular, the mixing unit can be regulated through feedback of the sensor data.

[0033] Preferably, the control unit is configured to control the melting unit to heat the wax to a predeterminable temperature above a solidification temperature of the wax.

[0034] Preferably, the predeterminable gas content in the wax-gas mixture and / or the actual gas content in the wax-gas mixture is at least 10 vol.%, preferably at least 20 vol.%. Preferably, the predeterminable gas content in the wax-gas mixture and / or the actual gas content in the wax-gas mixture for the production of support structures is at least 20 vol.%, preferably at least 40 vol.%.

[0035] Preferably, the predeterminable gas proportion in the wax-gas mixture and / or the actual gas proportion in the wax-gas mixture for the production of contour surfaces is at most 40% by volume, in particular at most 30% by volume, particularly preferably at most 20% by volume.

[0036] A further development of the invention provides that the wax formwork manufacturing device has at least one tool for machining and the control unit is configured to (i) detect a machining path for machining the wax formwork and (ii) control the tool for machining so that machining of the wax formwork takes place. Machining can be carried out by, among other things, milling, turning, drilling, grinding, cutting, eroding, honing and / or lapping. A milling cutter, a drill, a grinding wheel, a reamer or the like can be provided as a tool for machining. Preferably, the post-processing reduces a deviation of the wax formwork from a target model and / or adds and / or changes a deviating feature of the wax formwork.According to a further aspect, the invention solves the problem by a concrete casting production plant with a wax formwork production device according to the invention and a concrete feed device for pouring concrete into the wax formwork. The distance between the wax formwork production device and the concrete feed device is preferably at most 10 km, particularly preferably at most 1 km.

[0037] According to a further aspect, the invention solves the problem by a method for producing a wax formwork for concrete casting, comprising the steps of: (a) tempering the wax in a melting unit to a target temperature that is above a solidification temperature of the wax, (b) admixing gas into the wax in a mixing unit to create a wax-gas mixture, and (c) applying the wax-gas mixture layer by layer to a substrate to create the wax formwork. The layer-by-layer application of the wax-gas mixture to the substrate preferably occurs automatically. Tempering is understood to mean heating, cooling, or a combination of heating and cooling.For example, it may be advantageous to first heat the wax and / or the wax-gas mixture in a melting unit to a predeterminable temperature above a solidification temperature of the wax and then to cool the wax and / or the wax-gas mixture, wherein the temperature of the wax and / or the temperature of the wax-gas mixture does not fall below the solidification temperature of the wax.

[0038] Preferably, the method comprises the further step of mixing fillers, in particular mineral fillers, into the wax and / or into the wax-gas mixture.

[0039] A further development of the invention provides that the admixing of gas into the wax takes place simultaneously with the tempering of the wax. Simultaneous means that the admixing of gas into the wax also takes place at least at one point in time during the tempering process. Preferably, the tempering of the wax takes place at least half the times at which the admixing of gas into the wax takes place. Alternatively or additionally, the admixing of gas can also take place before and / or after the tempering of the wax. Preferably, the method comprises the additional step of scraping the wax-gas mixture from a tempering surface of the mixing unit using a scraping element. The tempering surface is a tempered surface of the mixing unit. The scraping element serves to scrape the wax-gas mixture from the tempering surface of the mixing chamber and can be designed, for example, as a stirring arm.

[0040] When applying the wax-gas mixture to the substrate, the application temperature of the wax-gas mixture is preferably a maximum of 35°C, preferably a maximum of 20°C, particularly preferably a maximum of 10°C, especially preferably a maximum of 5°C, and most preferably a maximum of 2°C below the solidification temperature of the wax. An application temperature that is below the solidification temperature of the wax ensures that the wax-gas mixture has sufficient strength. Alternatively or additionally, the application temperature of the wax-gas mixture when applying the wax-gas mixture to the substrate is a maximum of 10°C, preferably a maximum of 5°C, and particularly preferably a maximum of 2°C above the solidification temperature of the wax. An application temperature that is above the solidification temperature of the wax can be advantageous, in particular to improve the flowability and / or the adhesion properties of the wax-gas mixture during application.It is advantageous to minimize the deviation between the application temperature of the wax-gas mixture and the solidification temperature of the wax, as this minimizes shrinkage of the wax-gas mixture after application and thus also the warping of the wax formwork. The application temperature can assume different values ​​at different locations and / or times, so that the application temperature can temporarily be above the solidification temperature and temporarily below the solidification temperature, particularly during the production process.

[0041] In a further development of the invention, the method comprises the additional step of machining the wax formwork by milling, turning, drilling, grinding, cutting, eroding, honing, and / or lapping. A target model preferably contains a predetermined model of the wax formwork with all features and dimensions and, if applicable, information about the surface quality of certain surfaces. The target model of the wax formwork is preferably made available on a digital storage device. The digital storage device can be a hard disk, a USB stick, a memory card, a server, or the like. A control unit is preferably configured to read this target model and to create a movement path for machining therefrom, such that the deviation of the wax formwork from the target model is reduced and / or a deviating feature of the wax formwork is added and / or modified.Alternatively or additionally, the target model itself contains a movement path for machining. Deviating features are features that distinguish the wax formwork before machining from the target model, for example, holes, threads, fits, dimensional deviations, or specified surface finishes. Machining can also be used to smooth a surface, especially a contour surface.

[0042] The method preferably comprises the additional steps: (a) cooling the wax formwork to room temperature and (b) heat-treating at least one surface by tempering. Room temperature is understood to mean the temperature of a room in which the wax formwork cools. The room temperature is preferably more than 15°C and less than 25°C. Cooling can be carried out both actively and passively. For example, cooling can be carried out in room air, in water, in another fluid and / or assisted by fans and / or coolants. Tempering is understood to mean that the wax formwork is heated after cooling to a tempering temperature that approximately corresponds to the glass transition temperature of the wax. This increases the crystallinity of the wax formwork. The deviation of the tempering temperature from the glass transition temperature of the wax is preferably at most 10°C, preferably at most 5°C, particularly preferably at most 2°C.

[0043] A further development of the invention provides for the coating of at least one surface. The coating can, for example, improve the surface quality and / or hardness of the wax formwork. Plastic coatings with glass fiber-reinforced plastic and / or polyurethane are particularly suitable for this purpose. According to a further aspect, the invention solves the problem by a method for producing a concrete component, comprising the steps of: (a) producing a wax formwork using the method according to the invention for producing a wax formwork for concrete casting, and (b) filling the wax formwork with concrete, thereby creating a concrete component.

[0044] A further development of the invention provides for the melting out of a displacement body of the wax formwork from the concrete component. A displacement body is understood to be a partial structure of the wax formwork that is essentially enclosed within the concrete component after the concrete has been poured.

[0045] The method preferably comprises the further steps: (a) separating the wax formwork from the concrete component, and (b) refilling the wax formwork with concrete to create another concrete component. The wax formwork can therefore preferably be used to produce multiple concrete components, which preferably have consistent dimensional accuracy. Alternatively or additionally, the wax formwork can be melted down and / or the wax from the wax formwork can be used as starting material for producing a new wax formwork. This new wax formwork can have the same geometry as the previous wax formwork or a different one. It is also possible to use a wax and / or a wax mixture containing a certain proportion of recycled wax when producing a wax formwork. Recycled wax is wax that has already been used to produce a wax formwork.Separation means the non-destructive removal of the wax formwork or a part of the wax formwork from the concrete component.

[0046] The method and device described above can in particular also be used for the production of prototypes, unique items and / or small series. In particular, it can be provided that negatives are produced as wax molds for the production of prototypes, unique items and / or small series. In other words, it can be provided that a so-called negative is produced as a wax mold using the method and device. The production of the prototype, unique item and / or small series can take place based on the negative as a wax mold. The method is also suitable for the production of prototypes on a scale of 1:1 as positives. This means that the prototype is produced directly using the method or device. The method is particularly suitable for the production of prototypes on a scale of 1:1.Such prototype production can be used particularly in the aerospace, automotive, ship and boat building sectors for individual components and hull construction, and / or in the packaging industry for formwork as a negative model for papier-mâché. This list is not exhaustive.

[0047] Furthermore, the method and device described above can be used not only for the production of formwork for concrete components, but also for the production of formwork made of elastomers, clay, mycelium, aerogels, resins (epoxy resin, polyurethane resin, polyester resin), silicone rubber, gypsum, plastics, ceramics, biopolymers, bacterial biocements, and / or papier-mâché. This list is not exhaustive.

[0048] Furthermore, the method and device described above can also be used for the production of repair parts or replacement parts. The method and / or device can be used in manual operation. This means that at least the nozzle is manually controlled.

[0049] For example, the position of the nozzle is adjusted manually. It is also conceivable for the nozzle to be moved manually during the extrusion of the wax-gas mixture, and for the area to be applied to be specified manually. This has the advantage that the device and / or method can also be used to repair or touch up defects. This has the particular advantage that the surface to be repaired does not have to be trained, and a path to be traveled does not have to be specified based on the surface. In particular, defects and / or flaking of the wax formwork can be repaired this way.

[0050] Furthermore, it can be provided that the device has a displacement unit. The displacement unit can introduce a displacement body into the area to be printed in a step which takes place either before the extrusion of the wax-gas mixture or during the extrusion of the wax-gas mixture. The displacement body ensures that no wax-gas mixture can be extruded into a space formed by the displacement body and / or that expansion of the extruded wax-gas mixture into the space can be prevented. In particular, it can be provided that the displacement body is removable. It is preferably provided that the displacement body can be removed by heating. It is advantageous if the displacement body can be removed without leaving any residue.For example, it can be provided that the displacement body evaporates upon heating, and the resulting gases diffuse through the concrete or the material being poured into the wax component. In particular, it is provided that the wax mold with the displacement bodies is first printed, and then the material is poured into the wax mold. It can be provided that the removal of the displacement body and / or the displacement bodies takes place after the material has been poured into the mold.

[0051] This has the advantage that material can be saved by inserting displacement bodies, as the displacement bodies form a hollow space. Furthermore, the displacement bodies can also be inserted in such a way that the space is kept free for installed components such as pipes, power cables, sockets, or similar. This list is not exhaustive.

[0052] By combining 3D printing technologies with the precast concrete industry, displacement bodies can be printed from the wax-gas mixture, which are prefabricated before the concrete 3D printing or can be printed in the 3D printing process at the same time as the concrete printing.

[0053] These displacement bodies can be installed in concrete components where, from a static point of view, no concrete is necessary in order to save concrete material.

[0054] In both cases, the wax is melted out of the concrete component if possible, creating a cavity that can then be used for built-in components.

[0055] Removal can be achieved, for example, by melting. It is also conceivable for the displacement bodies to be made of a biodegradable material. It can also be provided that the displacement bodies are etched out. It is conceivable to introduce the wax foam inside a concrete component in order to absorb vibrations. In particular, it can be provided that another body is arranged inside the displacement body in the space formed by the displacement body. The displacement body can be made of a material that can be selectively removed, so that only the displacement body but not the vibrating body in the displacement body is removed. For example, the vibrating body in the displacement body can be made of concrete and / or the wax foam is left in the concrete component as a vibrating body to absorb vibrations.The vibrating body can, for example, have the shape of a sphere, but is not limited to this.

[0056] These vibration mounts could, in particular, absorb vibrations. Such vibration mounts could conceivably be used in components used in earthquake zones.

[0057] The invention is explained in more detail below with reference to the accompanying drawings.

[0058] Figure 1 is a schematic view of a wax formwork manufacturing device according to the invention for producing a wax formwork for concrete casting,

[0059] Figure 2 is a schematic view of a positioning system of a wax formwork manufacturing device with a tool for machining,

[0060] Figure 3 is a schematic partial sectional view of an embodiment of a mixing unit in a wax formwork manufacturing device and

[0061] Figure 4 is a schematic partial sectional view of another embodiment of a mixing unit in a wax formwork manufacturing apparatus.

[0062] Figure 1 shows a schematic view of a wax mold manufacturing device according to the invention, which comprises a melting unit 10, a mixing unit 20, a nozzle 30, and a positioning system 50. The melting unit 10 has a wax inlet 11 on its top, through which wax can be supplied to the melting unit 10.

[0063] The melting unit 10 contains a heating element (not shown), for example in the form of a heating cartridge, a heating band, a heat exchanger, a flow heater, a heating medium, an immersion heater, or the like. In the melting unit 10, the wax is heated to a predeterminable temperature above a solidification temperature of the wax. It is then conveyed to the mixing unit 20 via a conveying hose 110. The mixing unit 20 has a gas inlet 26 through which a gas can be supplied to the mixing unit 20. The gas can be a gas, in particular carbon dioxide, or a gas mixture, in particular air. In the mixing unit 20, the gas is mixed into the wax to create a wax-gas mixture.

[0064] From the mixing unit 20, the wax-gas mixture is conveyed via a conveying hose 110 to a conveying device 100. The conveying device 100 can be designed as a pump, extruder, or compressor. From the conveying device 100, the wax-gas mixture is conveyed via another conveying hose 110 to a nozzle 30. The wax-gas mixture is applied layer by layer to a substrate through the nozzle, creating a wax mold.

[0065] It can also be provided that the conveying device 100 is arranged between the conveying hose 110 and the gas inlet 26. In particular, it can be provided that the conveying device 100 is part of the mixing unit 20.

[0066] The substrate can be a base plate 120, a deposited wax-gas mixture 40, or a base body to be printed. The nozzle 30 is arranged on a positioning system 50, which in the illustrated embodiment is embodied as a robot. In the illustrated embodiment, the positioning system 50 has a control unit 60 configured to control the positioning system 50 to position the nozzle 30 relative to the substrate, thereby creating a wax mold. The control unit 60 can also be embodied as a separate component and connected to the positioning system 50 via a control line or transmitter-receiver devices, which are arranged both in the control unit 60 and in the positioning system 50 and communicate with each other wirelessly.

[0067] The control unit 60 can be connected to the mixing unit 20, for example, via a control line or via transmitter-receiver devices arranged both in the control unit 60 and in the mixing unit 20 and communicating with each other wirelessly. The transmitter-receiver device of the mixing unit 20 can be connected to a sensor (not shown) in the mixing unit 20, which can, in particular, detect a gas content of the wax-gas mixture in the mixing unit 20 and transmit the sensor data from the sensor to the control unit 60.

[0068] The control unit 60 can control the mixing unit 20 depending on the sensor data, so that when gas is mixed into the wax, a wax-gas mixture is formed with a gas proportion that corresponds to a predeterminable target gas proportion. The control unit 60 can be connected to the melting unit 10 and configured to control the melting unit 10 to heat the wax to a predeterminable temperature above a solidification temperature of the wax.

[0069] A cooling and heating device 70 in the form of a hose with an outlet through which air flows is arranged on the nozzle. The cooling and heating device 70 serves to cool and / or heat the deposited wax-gas mixture 40. Depending on whether the deposited wax-gas mixture 40 is to be cooled or heated, the cooling and heating device 70 is supplied with cold or hot air.

[0070] Figure 2 shows a schematic view of a positioning system 50. The positioning system 50 is again designed as a robot and has a control unit 60. A wax formwork 150 is arranged on a base plate 120. A milling head 130 with a tool drive 140 and a tool for machining 90 in the form of a milling cutter is arranged on the positioning system 50. Instead of a milling cutter, a drill, a reamer, or the like can also be used as the tool for machining 90. The tool for machining 90 is driven by the tool drive 140. The tool drive 140 is connected to the control unit 60 via a control line or transmitter-receiver devices that are arranged in the control unit 60 in the tool drive 140 and are connected to each other via radio.The control unit 60 is configured to detect a machining path for a machining rework and to control the machining rework tool 90 so that a machining rework of the wax formwork 150 takes place.

[0071] To capture the machining path, the control unit 60 can read a target model of the wax formwork 150, which is also made available to a digital memory (not shown). The target model contains a predefined model of the wax formwork 150 with all features and dimensions and, if applicable, information about the surface quality of certain surfaces of the wax formwork 150. By machining the wax formwork 150, a deviation of the wax formwork 150 from a target model is reduced and / or a deviating feature of the wax formwork 150 is added and / or modified.

[0072] Figure 3 shows a schematic partial sectional view of an embodiment of a mixing unit 20 in a wax formwork manufacturing device. The mixing unit has a mixing chamber 21, which in the embodiment shown is rotationally symmetrical and consists of an upper cylindrical part and a lower conically tapered part. A tempering device 22 is arranged in the upper cylindrical part, which circumferentially encloses the mixing chamber 21 and forms a tempering surface that is part of the outer wall of the mixing chamber 21. The outer wall of the mixing chamber 21 is also the scraping wall. An inlet 24 and a gas inlet 26 are arranged on the top side of the mixing chamber 21. The inlet 24 and the gas inlet 26 can alternatively also be arranged on the side of the mixing chamber 21. Wax or already heated wax is supplied to the mixing chamber 21 via the inlet 24.

[0073] A fan 160 is fluidly connected to the gas inlet 26 and supplies gas to the mixing chamber 21 via the gas inlet 26. As an alternative to a fan 160, a gas compressor or a pressure vessel containing a compressed gas may also be provided.

[0074] Centrally located in the mixing chamber is a shaft 27, which is mounted for rotation about a rotational axis and driven by a mixing motor 28. A melting unit 10 with several heating wires is arranged on the shaft 27. The melting unit 10 heats the wax entering the mixing chamber 21 to a predeterminable temperature above the solidification temperature of the wax. A mixing element 29 is arranged on the shaft 27 below the melting unit 10. As the shaft 27 rotates about the rotational axis, the mixing element 29 mixes the gas into the wax, creating a wax-gas mixture.

[0075] A scraping element 23 is arranged on the shaft below the mixing element 29. When the shaft 27 rotates about its axis of rotation, the scraping element 23 scrapes the wax-gas mixture from the outer wall of the mixing chamber 21. This conveys the wax-gas mixture to the outlet nozzle 25. The outlet nozzle 25 is arranged downstream of the mixing unit 20 in the flow direction and is attached to the mixing unit 20. A valve 170 is arranged on the outlet nozzle 25. The valve 170 can be controllable and, in particular, can be actuated by the control unit 60.

[0076] Figure 4 shows a schematic partial sectional view of another embodiment of a mixing unit 20 in a wax mold manufacturing device. The mixing unit 20 is designed here as an extruder. The mixing unit 20 has a mixing chamber 21 with a cylindrical part and a conical part. A shaft 27 in the form of an extruder screw is arranged centrally in the mixing chamber 21. The shaft 27 is driven by a mixing motor 28, which is arranged on the shaft 27.

[0077] Arranged downstream of the mixing unit 20 in the direction of flow is an outlet nozzle 25 which is fastened to the mixing unit 20. On the side opposite the outlet nozzle 25, the mixing unit 20 has an inlet 24 on the top and a gas inlet 26 on the bottom. Alternatively, the inlet 24 can be arranged on the side or bottom and / or the gas inlet 26 can be arranged on the top or side of the mixing unit. Wax or already heated wax is supplied to the mixing chamber 21 via the inlet 24. A fan 160 is fluidly connected to the gas inlet 26 and supplies gas to the mixing chamber 21 via the gas inlet 26. As an alternative to a fan 160, a gas compressor or a pressure vessel with a compressed gas can also be provided, via which gas is supplied to the mixing chamber 21.

[0078] On the outside of the cylinder, the mixing unit 20 has two temperature control devices 22 in the form of heating bands. The temperature control device 22 can also simultaneously form the melting unit 10, thus eliminating the need for a separate melting unit. The thread pitches of the shaft 27, designed as an extruder screw, are the scraping elements 23. When the shaft 27 is rotated by the mixing motor 28, the scraping elements 23 scrape the wax-gas mixture from the outer wall of the mixing chamber 21 and convey it toward the outlet nozzle 25. The outer wall of the mixing chamber 21 is therefore the scraping wall.

[0079] List of reference symbols

[0080] 10 melting units

[0081] 11 Wax inlet

[0082] 20 mixing unit

[0083] 21 Mixing chamber

[0084] 22 Tempering device

[0085] 23 Scraping element

[0086] 24 Admission

[0087] 25 Outlet nozzle

[0088] 26 Gas inlet

[0089] 27 Wave

[0090] 28 mixing motor

[0091] 29 Mixing element

[0092] 30 nozzle

[0093] 40 deposited wax-gas mixture

[0094] 50 Positioning system

[0095] 60 control unit

[0096] 70 Cooling and warming device

[0097] 90 tool for machining

[0098] 100 conveyor device

[0099] 110 conveyor hose

[0100] 120 base plate

[0101] 130 milling head

[0102] 140 tool drive

[0103] 150 wax formwork

[0104] 160 fan

[0105] 170 valve

Claims

Patent claims 1 . Wax formwork manufacturing device for producing a wax formwork (150) for concrete casting with (a) a melting unit (10) for heating the wax to a predeterminable temperature above a solidification temperature of the wax, (b) a mixing unit (20) designed to mix gas into the wax to form a wax-gas mixture, (c) a nozzle (30) arranged downstream of the mixing unit (20) in the flow direction and designed to apply the wax-gas mixture in layers to a substrate, (d) a positioning system (50) for positioning the nozzle (30) relative to the substrate and (e) a control unit (60) configured to control the positioning system (50) for positioning the nozzle (30) relative to the substrate so that the wax mold (150) is formed.

2. Wax formwork manufacturing device according to claim 1, characterized in that (a) the melting unit (10) is arranged in the mixing unit (20) or upstream of the mixing unit (20) in the flow direction and (b) the control unit (60) is arranged to adjust a mass flow of the nozzle (30).

3. Wax formwork manufacturing device according to one of the preceding claims, characterized in that the mixing unit (20) (a) a mixing chamber (21) with a tempering surface, (b) a tempering device (22) which is arranged to temper the tempering surface to a tempering temperature so that the wax-gas mixture is tempered at the tempering surface of the mixing chamber (21), and (c) a scraping element (23) for scraping the wax-gas mixture from a scraping wall of the mixing chamber (21) and / or from the tempering surface of the mixing chamber (21). Wax formwork manufacturing device according to one of the preceding claims, characterized by (a) a cooler arranged to cool the already deposited wax-gas mixture (40), and / or (b) a heating device arranged to heat the already deposited wax-gas mixture (40), (c) wherein the mixing unit (20) is configured to add a predeterminable gas content to the wax. Wax formwork manufacturing device according to claim 4, characterized in that the control unit (60) is configured to automatically carry out a method comprising the steps: (a) Determining a target gas proportion, (b) controlling the mixing unit (20) so that, when gas is mixed into the wax, a wax-gas mixture is formed with a gas proportion that corresponds to the desired gas proportion. Wax formwork manufacturing device according to one of the preceding claims, characterized by (a) at least one tool for machining (90), (b) wherein the control unit (60) is arranged to (i) to record a machining path for a machining rework of the wax formwork (150) and (ii) to control the tool for machining (90) so that machining of the wax formwork (150) takes place. Concrete casting production plant with (a) a wax formwork manufacturing device according to any one of the preceding claims, and (b) a concrete feed device for pouring concrete into the wax formwork (150). A method for producing a wax formwork (150) for concrete casting, comprising the steps of: (a) tempering the wax in a melting unit (10) to a target temperature which is above a solidification temperature of the wax, (b) mixing gas into the wax in a mixing unit (20) to form a wax-gas mixture, and (c) applying the wax-gas mixture layer by layer onto a substrate to form the wax formwork (150). A method according to claim 8, characterized in that (a) an application temperature of the wax-gas mixture when applying the wax-gas mixture to the substrate is a maximum of 35 °C, preferably a maximum of 20 °C, particularly preferably a maximum of 10 °C, particularly preferably a maximum of 5 °C, most preferably a maximum of 2 °C below the solidification temperature of the wax and / or a maximum of 10 °C, preferably a maximum of 5 °C, particularly preferably a maximum of 2 °C above the solidification temperature of the wax. A method for producing a concrete component comprising the steps: (a) producing a wax formwork (150) using a method according to one of claims 8 or 9, and (b) Filling the wax formwork (150) with concrete to form a concrete component.

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