DE102024205436A1 - MANUFACTURING TOOL AND METHOD FOR MANUFACTURING A CLADDING ELEMENT - Google Patents

Abstract

The invention relates to a manufacturing tool comprising a first tool part (1) and at least one second tool part (2) for manufacturing or machining a cladding element (3), wherein the first tool part and the at least one second tool part, in a closed state, form a chamber (4) for casting or pressing a cladding element, wherein the chamber, in the closed state, is gas-tightly sealed by one or more sealing elements (5), and wherein the first tool part has one or more openings (7a, 7b, 7c, 7d, 7e, 7f) on its surface (6) facing the chamber, which are connected to a gas evacuation system (9) via one or more vacuum channels (8a, 8b, 8c, 8d, 8e, 8f), and wherein each of the openings is covered by a screen (10a, 11, 12, 13) that forms part of the surface of the first tool part. The invention further relates to a manufacturing method that uses such a manufacturing tool.

Description

The invention applies in the field of mechanical engineering and manufacturing as well as the chemical treatment of parts, in particular of fairing elements for vehicles.

In many cases, fluidic or gaseous components of the material used in cladding elements, released when the material is heated or otherwise processed, pose a major problem in the manufacturing process. Gaseous components, such as water vapor, can become trapped within a cladding element beneath decorative coatings, leading to defects such as holes in the decorative surfaces.

This often happens, for example, when the material of a cladding element includes fibers, or especially natural fibers, or more generally, when the material releases moisture during a casting process.

From the patent specification EP792903A1 A mold for casting a polyimide resin is known, wherein the mold has a drain channel for expelling moisture generated during polymerization. The drain channel is provided with a porous filter.

With regard to the prior art, one object of the invention is to provide a manufacturing tool and a method for producing or machining a cladding element, with which an improved surface quality of the cladding element is provided.

The task is accomplished by a manufacturing tool and a manufacturing process for producing a cladding element according to the independent claims. The dependent claims represent possible implementations of a manufacturing tool or process.

For this reason, the invention relates to a manufacturing tool comprising a first tool part and at least one second tool part for manufacturing or machining a cladding element, wherein the first tool part and the at least one second tool part, in a closed state, form a chamber for casting or pressing a cladding element, wherein the chamber, in the closed state, is gas-tightly sealed by one or more sealing elements, and wherein the first tool part has one or more openings on its surface facing the chamber, which are connected to a gas evacuation system via one or more vacuum channels, and wherein each of the openings is covered by a screen that forms part of the surface of the first tool part.

The first tool part, together with one or more second tool parts, forms a chamber into which one or more materials of a cladding element are introduced. Within the chamber, the material(s) can be cast and/or pressed. The chamber can provide a negative mold that is filled with the material(s) to form a cladding element. The material(s) can also comprise more than one layer of other materials or of the same material, with a top layer intended to form a decorative finish on the cladding element. Openings are provided at least in the first part of the manufacturing tool, in some cases exclusively in the first part, and in some cases in the first part as well as in one of the second parts of the manufacturing tool. These openings are connected to a gas evacuation system via one or more channels. If more than one opening is provided, the openings can be evenly distributed across the surface of the first tool part, which forms a wall of the chamber.

Through the openings and the channel(s), a gas or vapor can be released or extracted from the chamber via the gas evacuation system. Such a gas or vapor may be generated or released during the manufacturing process by a material of a cladding element or a material used in the manufacturing process of a cladding element.

It is essential to prevent the material forming the cladding element from entering the openings of the first part of the manufacturing tool. For this reason, one or more screens are provided that allow gas and/or moisture to pass through while retaining the liquid or solid material of the cladding element. The screens can also function as filters. Because the screens or filters form part of the surface of the first tool part, the cladding element material, after solidification, has a flat surface that is a negative copy of the surfaces of the first and second tool parts of the manufacturing tool. The screens or filters fit into the surface of the first or second tool part of the manufacturing tool, continuing or extending the contour of the surface of the first or second tool part. The holes in the screen(s) or filters are so small that the cladding element material cannot enter them. Thus, the openings nungen with inserted sieves continue the enveloping shape of the surface of the first and in some cases of one or more second tool parts of the manufacturing tool.

It may be provided that one or more of the sieves include at least one porous body. The pores may be so small that material from the cladding part cannot pass through them. For example, the diameter or width of the pores may be less than 0.3 mm or less than 0.1 mm.

One potential implementation of a manufacturing tool may involve one or more of the sieves comprising a sheet with holes.

In this case, the metal sieves are inserted into the surface of the parts of the manufacturing tool, and the sieves continue the enveloping shape of the surface of the first and possibly the second part.

The holes in the sieve(s) can have a diameter smaller than 100 micrometers or even smaller than 10 micrometers.

It may also be provided that one or more of the sieves comprise a large number of particles enclosed in a cage.

In this case, the particles can be made of metal and can have a diameter of less than 500 micrometers. The particles can be spherical or polygonal in shape. A large number of particles can be loosely enclosed in a container, which may have openings so small that the particles cannot pass through them.

Another implementation may involve one or more of the sieves comprising a multitude of particles firmly connected to each other to form a sponge-like element.

A large number of particles, each with a diameter of, for example, less than 1 millimeter or less than 100 micrometers, can be joined by soldering or a sintering process to form a sponge-like structure. Alternatively, this sponge-like structure can also be formed using loose fibers or fibrous fabrics, such as metal fibers.

It may also be provided that the diameter of one or more of the sieves in the openings is larger than the diameter of the vacuum channel that connects the respective opening covered by the sieve to the evacuation system.

This function allows the sieves to cover a large part of the surface of the first tool part, further facilitating the evacuation and removal of steam and gas.

It may also be provided that one or more of the sieves are combined with a fitting element that holds the sieve.

Another implementation can provide that the fitting element or elements fit tightly into an opening of the first or a second tool part.

The fitting elements can have a cylindrical shape or a conical shape that widens towards the surface of the first tool part in order to provide a maximized surface area on the surface of the first tool part.

Another possible implementation could involve the fitting element(s) being detachably fitted into an opening of the first or a second tool part.

One or more sieves can be held in or contained within a fitting element. A fitting element can comprise a hollow cylinder, and the hollow cylinder can include a flange extending around its outer circumference. The fitting element can be detachably fitted into a cylindrical bore that forms an opening in the surface of a part of the manufacturing tool. In this way, a sieve can be inserted into an opening by means of a fitting element and can also be removed from the opening for replacement with a new sieve. A fitting element can be made of a metal or a plastic material.

Furthermore, it may be provided that at least the first tool part includes fitting bores at its openings which are connected to a gas evacuation system, wherein the fitting bores are arranged to tightly accommodate fitting elements of sieves, and wherein the fitting bores have longitudinal axes of symmetry which are arranged vertically with respect to the surface of the first tool part which faces the chamber.

Each bore can form an opening or be part of an opening in the surface of one of the tool components of the manufacturing tool. The bores can have a cylindrical shape and can have a bottom. The fitting features a vacuum channel terminating at the bottom or shoulder of the bore. This allows a fitting element with a sieve or filter to fit into the bore and rest on its bottom or shoulder. Gas or vapor can then be released through the sieve and the vacuum channel.

By aligning the axes of symmetry of the locating bores vertically with respect to the surface of the first or second part of the tooling, the fitting elements, which may be cylindrical, and the screens can easily fit into the surface contour of the first and second parts of the tooling. If the surface of a part of the tooling is curved, the axis of a locating bore can be aligned vertically with the surface section of the part of the tooling that immediately surrounds the locating bore.

For this reason, it may be intended that the axes of symmetry of different fitting bores can be tilted relative to each other, meaning that they are not parallel. In this way, curved surfaces of the first tool part can be easily adjusted by inserting the screens in the appropriate orientation.

In another implementation, the evacuation system may be connected to the vacuum channels by means of a vacuum connection channel with a longitudinal axis that runs parallel to the surface of the first tool part or that forms an angle with the surface of the first tool part that is less than 10 degrees.

In this way, it is easy to connect more or fewer openings in the surface of the first tool parts to the vacuum connection channel and further to the evacuation system as needed, simply by adding holes that are vertically aligned with respect to the surface of the first tool part.

The invention further relates to a manufacturing method for producing a cladding element by casting or pressing a first material in a gas-tight chamber formed by a first tool part and at least a second tool part, wherein the first material is introduced into the chamber, the chamber is closed and sealed gas-tight, and then the first material is heated and gas is evacuated from the chamber by suction through one or more openings in the first tool part, each of which is covered by a screen forming part of the surface of the first tool part.

The first tool part and one or more secondary tool parts can be disassembled to introduce a first material into the chamber formed by the tool parts in a closed state. In some cases, more than one material can be introduced into the chamber, and in some implementations, a piece consisting of two or more different layers can be introduced. When the chamber is closed by reassembling the tool parts, sealing elements, such as sealing rings, can be provided between the tool parts to create a gas-tight seal. The first material(s) can be cast, or the layers can be pressed into the chamber. Simultaneously, the chamber can be heated, and gas or vapor can be expelled from the material and extracted by a vacuum system through screens and vacuum channels. The vacuum system can include a vacuum pump or a low-pressure tank. The manufacturing tool can include a heater to generate heat and high temperatures in the chamber, for example, temperatures above 80, 90, or 100 degrees Celsius. At these temperatures, water or moisture that may be bound in or on the fibers, for example, natural fibers in the first material, can be drained away. By releasing the gas or vapor through the sieves, a flow of liquid or solid material from the cladding element through the openings in the tool parts is prevented.

The invention also relates to a cladding element that was cast or pressed using the method described above.

One possible implementation of a procedure may further provide that, before the first material is introduced into the chamber, it is checked whether one or more of the sieves are clogged, and the clogged sieves are replaced with new sieves.

If a sieve becomes clogged, for example by steam that has passed through it carrying liquid or solid particles, further release of gas or steam through the sieve is prevented, and therefore it must be cleaned or replaced. Replacing sieves can be greatly simplified by providing sieve fittings. The fittings can be containers holding the sieve material, for example, a perforated sheet or a volume filled with particles. The fittings can be inserted into locating holes in the Tool parts are used and can be easily removed for replacement.

It may also be provided that checking the sieves includes blowing a gas through the one or more channels and through the sieves into or out of the chamber.

To find out whether the screens in a tool part are clean or clogged, gas or steam can be blown through one or more of the screens, and the resistance of the screen(s) to a gas flow can be checked or measured.

For this reason, a gas flow element, such as a motor-driven gas pump or a fan, can be used, and the motor's current can be measured to determine the gas flow resistance by measuring the load on the gas pump. Alternatively, high gas pressure applied to the screens from the vacuum system can be used to force clogged screens out of their bores.

• 1A: ein Fertigungswerkzeug in einer Querschnittsansicht,
• 1B: ein erstes Detail aus 1A in einer vergrößerten Ansicht,
• 1C: ein zweites Detail aus 1A in einer vergrößerten Ansicht,
• 2: ein Beispiel für einen Aufbau eines Siebs,
• 3: ein anderes Beispiel für einen Aufbau eines Siebs,
• 4: eine konische Form eines Siebs und eines Beschlagelements und
• 5: eine Ansicht des Fertigungswerkzeugs in einem offenen Zustand.

The invention and some of its implementations are further illustrated in the figures of a drawing and are explained below. The figures in the drawing show:

• 1A : a manufacturing tool in a cross-sectional view,
• 1B : a first detail from 1A in an enlarged view,
• 1C : a second detail from 1A in an enlarged view,
• 2 : an example of how to construct a sieve,
• 3 : another example of how to construct a sieve,
• 4 : a conical shape of a sieve and a fitting element and
• 5 : a view of the manufacturing tool in an open state.

1A shows a manufacturing tool comprising a first lower tool part 1 and a second tool part 2 that fits on top of the first tool part. 1A Figure 1 shows the two tool parts in a closed state, forming a chamber 4 between them. A cladding element 3 is positioned in chamber 4, which can, for example, be cast or pressed into chamber 4. In the 1A In the example shown, the trim element is a trim element for a car and consists of at least two layers 3a, 3b, where 3a is a decorative top layer that is later positioned on the side of the trim element facing the passengers after installation in a car. 3b is the back layer, which can be thicker than the top layer and can provide strength to the trim element. For this purpose, the back layer 3b comprises polypropylene or another thermoplastic material as a matrix filled with fibers, for example, natural fibers. Since the fibers can be hydrophilic, a certain amount of water adhering to the fibers must be expelled from the trim element material. For this reason, a heating element 19 can be provided that heats the manufacturing tool and which is 1A It is shown symbolically.

Removing water in the form of steam from the material of the cladding element prevents the formation of water or steam bubbles that could lead to holes in the decorative top layer during the manufacturing process of the cladding element.

Steam is removed from the material of the cladding element 3 by heating it, and simultaneously or after heating, chamber 4 is evacuated by drawing gas and steam through openings 7a-7f and channels 8a-8f using vacuum pumps 9 and 9a. A condenser can be provided at the vacuum pump to separate water from the steam.

To prevent the material of the cladding element, which can soften when exposed to high temperatures, from being transported into the openings 7a-7f by the low pressure, each opening is covered by a sieve 10a, 11, 12, 13. The sieves are located in the 1B , 1C , 2 and 3 shown in more detail.

A sealing ring 5 is provided between the two tool parts 1, 2 to allow a vacuum to build up in the chamber 4.

In 1A Two circles indicate parts of the figure that appear enlarged in the 1B and 1C shown.

It shows 1B An example of a sieve 10a, which has a fitting element 16 in the form of a hollow metal or plastic cylinder. The fitting element is filled with particles that can be sintered together to form a sponge-like or porous body with channels between the particles. The particles can be made of a metal, such as steel. The channels between the particles are wide enough to allow gas and vapor to pass through, but narrow sufficient to prevent solid or liquid material from entering the cladding element. The diameter of each sieve in the example shown is larger than the diameter of the evacuation channels 8a-8f, which connect the openings 7a-7f in the surface 6 of the first tool part to the evacuation system 9. With this feature, the inlet area of the sieve on the surface 6 of the first tool part is larger than the cross-sectional area of the evacuation channels, and gas or vapor can be collected from an enlarged area. In the example shown 1A In the example shown, the evacuation channels 8a-8f are connected to the evacuation system 9 by a horizontal vacuum connection channel 20. By providing this horizontal vacuum connection channel, which runs parallel to the surface 6 below the surface, additional openings 7a-7f can be easily connected to the evacuation system simply by providing additional evacuation channels in the form of bores that intersect the horizontal vacuum connection channel.

The surface of each sponge-like or porous body formed by the particles is flat or flush with the surface 6 of the first tool part 1 and continues the contour of the surface of the first tool part. For this purpose, the fitting elements 16 are inserted into locating bores 17 of the first tool part. The axes of symmetry 18 of the fitting elements are then aligned with the axes of symmetry of the locating bores, which are vertically aligned on the surface 6 of the section of the first tool part adjacent to the respective locating bore.

1C Figure 11 shows in detail the fitting element 11 with its axis of symmetry 18, which is inclined with respect to the axis of symmetry of the fitting element 10a, since the surface 6 of the first tool part 1 is curved and the section next to the opening 7f is inclined relative to the section of the surface 6 next to the opening 7a. In this way, the sieves 10a, 11, which are distributed over the surface 6, form parts of the surface 6 and continue the curved surface in a smooth manner.

2 Figure 1 shows in detail a sieve containing particles that are contained in a fitting element 16. In this case, the particles are not necessarily bound together and can be held loosely in the fitting element by a cover 13a with holes. Instead of particles, loose metal fibers or metal fiber fabric or a metal fiber sponge can also be used and filled into a fitting element.

3 shows another sieve with a fitting element 16, wherein the sieve without particles is formed only by the cover 13a, which has small holes 13b, 13c.

4 Figure 1 shows a sieve in a conical shape, wherein the fitting element 16 has a conical outer shape and forms a conical container for the porous body or volume of particles. The fitting element 16 fits tightly into a conical opening 17 in the first tool part. This feature enlarges the inlet area of the sieve on the surface 6 of the first tool part, allowing gas or vapor to be collected from this larger area. Furthermore, the surface of the sieve fits perfectly into the surface contour of the surface 6 of the first tool part 1.

5 Figure 1 shows a manufacturing tool in an open state, where the first tool part 1 is not yet completely covered by the second tool part 2 and the chamber 4 is not yet tightly closed. In this state, a prepared cladding element or raw material for forming a cladding element 3 can be placed into the chamber 4 before the chamber is closed.

Before the prepared cladding element or raw material for forming a cladding element 3 is placed on the first tool part 1 or into chamber 4, the screens in openings 7a-7f can be checked to determine if one or more of them are clogged and should be replaced or cleaned. For this purpose, a pressure pump 9b can be connected to the vacuum system instead of the vacuum pump 9a. This will create overpressure, allowing gas to be blown through the screens and out of openings 7a-7f into chamber 4. If one of the screens is clogged, this can be detected by a pressure increase or an increase in the pump load, or the clogged screen itself can be forced out of its opening. The clogged screen can then be easily cleaned or replaced.

The invention provides an effective manufacturing tool and method for producing cladding elements with a high surface quality and without trapped steam or water bubbles.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 792903A1 [0004]

Claims (15)

Manufacturing tool comprising a first tool part (1) and at least one second tool part (2) for manufacturing or machining a cladding element (3), wherein the first tool part and the at least one second tool part form a chamber (4) for casting or pressing a cladding element in the closed state, wherein the chamber is gas-tightly sealed by one or more sealing elements (5) in the closed state, and wherein the first tool part has one or more openings (7a, 7b, 7c, 7d, 7e, 7f) on its surface (6) facing the chamber, which are connected to a gas evacuation system (9) via one or more vacuum channels (8a, 8b, 8c, 8d, 8e, 8f), characterized in that each of the openings is covered by a sieve (10a, 11, 12, 13) which forms part of the surface of the first tool part. Manufacturing tool according to Claim 1 , characterized in that one or more of the sieves (10a, 11, 12, 13) have at least one porous body. Manufacturing tool according to Claim 1 or 2 , characterized in that one or more of the sieves (13) have a sheet (13a) with holes (13b, 13c). Manufacturing tool according to Claim 1 , 2 or 3 , characterized in that one or more of the sieves (12) comprise a plurality of particles (14, 15) enclosed in a cage. Manufacturing tool according to Claim 1 , 2 , 3 or 4 , characterized in that one or more of the sieves (10a, 11) comprise a plurality of particles which are firmly connected to one another and form a sponge-like element. Manufacturing tool according to one of the Claims 1 until 5 , characterized in that the diameter of one or more of the sieves (10a, 11, 12, 13) in the openings (7a, 7b, 7c, 7d, 7e, 7f) is larger than the diameter of the vacuum channel that connects the respective opening covered by the sieve to the evacuation system (9). Manufacturing tool according to one of the Claims 1 until 6 , characterized in that one or more of the sieves (10a, 11, 12, 13) are combined with a fitting element (16) holding the sieve. Manufacturing tool according to Claim 7 , wherein the fitting element or elements fit snugly into an opening (7a, 7b, 7c, 7d, 7e, 7f) of the first or a second tool part (1, 2). Manufacturing tool according to Claim 8 , characterized in that the fitting element or each fitting element (16) fits detachably into an opening (7a, 7b, 7c, 7d, 7e, 7f) of the first or a second tool part (1, 2). Manufacturing tool according to Claim 8 or 9 , characterized in that at least the first tool part (1) has fitting bores (17) at its openings (7a, 7b, 7c, 7d, 7e, 7f) which are connected to an evacuation system (9), wherein the fitting bores are arranged for the tight reception of fitting elements (16) of sieves and wherein the fitting bores have longitudinal axes of symmetry (18) which are arranged perpendicular to the chamber-side surface of the first tool part. Manufacturing tool according to Claim 10 , characterized in that the axes of symmetry (18) of different fitting bores (17) can be tilted relative to each other. Manufacturing tool according to one of the Claims 1 until 11 , characterized in that the evacuation system (9) is connected to the vacuum channels (8a, 8b, 8c, 8d, 8e, 8f) by a vacuum connection channel (20) with a longitudinal axis that runs parallel to the surface (6) of the first tool part or that forms an angle with the surface of the first tool part which is less than 10 degrees. Manufacturing method for producing a cladding element (3) by casting or pressing a first material in a gas-tight sealed chamber (4) formed with a first tool part (1) and at least one second tool part (2), characterized in that the first material is introduced into the chamber, the chamber is closed and gas-tightly sealed, and then the first material is heated and gas is evacuated from the chamber by suction through one or more openings (7a, 7b, 7c, 7d, 7e, 7f) in the first tool part, each of which is covered by a sieve (10a, 11, 12, 13) forming part of the surface (6) of the first tool part. Manufacturing process according to Claim 13 , in which, before the first material is introduced into the chamber, it is checked whether one or more of the sieves (10a, 11, 12, 13) are blocked, and the blocked sieves are replaced by new sieves. Manufacturing process according to Claim 14 , where checking the sieves (10a, 11, 12, 13) the Bubbles of gas through one or more channels (8a, 8b, 8c, 8d, 8e, 8f) and through the sieves into the chamber (4) comprise.