DE102023103721B3 - Welding tool for producing a bladder system and method for producing a fluid-fillable bladder system using the welding tool - Google Patents

Abstract

The invention relates to a welding tool (10) for producing a bladder system (50) by means of high-frequency welding, comprising a welding stamp (11) with an underside (12) forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field, and an outer stamp (13) surrounding the welding stamp (11), which is formed from material that does not conduct the high-frequency alternating electric field. The invention is characterized in that the outer stamp (13) has a two-part underside (14) comprising a first, radially inner part (15) surrounding the welding stamp (11) and a second, radially outer part (11) surrounding the welding stamp (11). 16), wherein the first part (15) of the underside (14) is contoured and the second part (16) of the underside (14) is flat. The invention further relates to a method for producing a bladder system using the welding tool according to the invention.

Description

The invention relates to a welding tool for producing a bladder system, in particular a fluid-fillable bladder system, using high-frequency welding and a method for producing a fluid-fillable bladder system using the welding tool.

Fluid-fillable bladders and multi-chamber bladder systems are often used in the automotive sector and usually include film bladders that can be filled with air. Such bubbles are also referred to as air bubbles or air cushions or air chambers. The flexible film bubbles are filled, for example, by means of a compressed air supply, whereby the air pressure can be variably adjusted in order, for example, to realize support contours of different hardness and intensity and/or a massage function in a seat, in particular in a vehicle seat. For this purpose, the bladders are installed in the seat, in particular the vehicle seat.

Filling or venting the bubbles is usually accomplished with the help of valves and a pneumatic pump. The amount of air filled into the bubbles influences their hardness or shape and thus the contour of the seat. This allows, for example, a lumbar support and/or a side support of a seat, in particular a vehicle seat, to be adapted to the individual seating needs of the respective user and then maintained while the seat is being used, for example while driving. To carry out a massage function, the air cushions integrated into the seat are ventilated and ventilated cyclically, so that the contour of the seat is changed selectively and dynamically.

The fluid-fillable bubbles are usually formed by two plastic films which are welded together at their edges to form a weld seam. This is for example from DE 10 2005 032 549 A1 known.

For many applications, for example to generate a larger stroke, the provision of just one bubble is not sufficient. A multi-chamber bladder system is used here, in which two or more bladders are arranged one above the other. A multi-chamber bladder system usually has a first bladder into which a compressed air supply flows. A second bladder and possibly further bladders of the multi-chamber bladder system are connected to the first bladder via a fluid channel, also called an overflow channel, either directly or indirectly via further intermediate bladders. This means that the second bubble and, if necessary, further bubbles are also supplied with compressed air. Out of US 4,965,899 , US 6,122,784 and DE 10 2011 089 749 B4 Different types of multi-chamber bubble systems are known, whereby the individual bubbles are connected to one another and two adjacent bubbles each have an overflow channel at or in the area of their joints, so that air can flow over between these adjacent bubbles.

The neighboring bladders are joined together to form a multi-chamber bladder system using high-frequency welding (HF welding). High-frequency welding is the joining of materials, such as plastics, in this application two foils lying one on top of the other, using an electromagnetic field. The high-frequency energy of the electromagnetic field heats the material; no external heat is required. Under heat and pressure, the adjacent materials begin to melt. They merge with each other. When cooling, a weld seam is formed, by means of which the two materials, in the present application the two films, are connected to one another firmly and in a fluid-tight manner.

With this HF welding, weld beads are created along the weld seams, typically also weld beads that completely surround the respective transfer channel. These can form sealing lips or sealing edges when the bubbles are in contact with opposing foils, which prevent fluid, especially air, from flowing past. Multi-chamber bubble systems, which consist of two or more air bubbles, sometimes tend to prevent the second and possibly further bubbles from opening via the overflow channel or channels when pressure builds up in the first chamber due to this effect. If a vertical force is exerted on the multi-chamber bladder system, for example by a person sitting on a vehicle seat with this multi-chamber bladder system, the opposite foil presses onto the weld bead caused by the welding, which thereby acts as a sealing lip or sealing edge and prevents the fluid from flowing in, especially the air in which subsequent air bubbles are prevented.

During the filling process, this effect means that the second and subsequent bubbles that follow the first bubble, which is the first to be filled, do not open until a limit pressure in the first bubble is exceeded. If the limit pressure is exceeded, the closed second and/or further bubbles fill suddenly and a noise is produced, for example a popping noise, which is perceived as disturbing by users of the vehicle seat, for example. This noise must therefore be avoided. In addition, the sudden change in volume creates an uncomfortable feeling for a user when using the More chamber-bladder system, for example as an adjusting element in a vehicle seat. Furthermore, the sudden opening also has negative effects on the long-term stability of the bladder.

It is therefore important to prevent the sealing effect of the welding beads when the multi-chamber bladder system is vented.

This is over DE 10 2012 218 440 B4 and US 9,630,532 B2 known, by means of a special shape of a welded connection surrounding the longitudinal axis of the overflow area (overflow channel), to prevent contact between foils lying one on top of the other in the vented state, which extends completely around the overflow area and would otherwise initially block the overflow area. For this purpose, the welded connection has a course that has at least two different distances from the longitudinal axis. This shape and thus this course of the welded connection prevents the foils from being in contact with one another in such a way that pneumatic communication through the overflow area is prevented. The course of the welded connection can, for example, be cross-shaped or star-shaped.

An alternative solution is out DE 10 2019 214 576 A1 known to form two or more areas of different material thicknesses of the film forming the bubbles in a contour zone surrounding the fluid channel (overflow channel) between the first and second bubble. By forming areas of different material thicknesses in a contour zone surrounding the fluid channel, unevenness is present there and, for example, the upper film of the second bubble can no longer lie flat on the film area of the second bubble surrounding the fluid channel and can therefore no longer completely seal the fluid channel. This means that the air can flow from the first bubble via the fluid channel into the second bubble right from the start of the filling process or when the limit pressure is low. This means that the filling pressure of the air can act on the entire inner surface of the second bubble and continuously raise it. A sudden expansion of the second bubble is thus prevented.

Out of DE 10 2019 214 576 A1 a welding tool for producing a fluid-fillable multi-chamber bladder system is known, which includes a welding stamp which is formed from a material that conducts a high-frequency alternating electric field. The welding stamp has a central recess and the welding tool further comprises an inner stamp arranged within the recess, which is formed from material that does not conduct the high-frequency alternating electric field and is contoured on an underside. The welding stamp, which can be made of aluminum, for example, creates the connection between the film of the first bubble and the film of the second bubble using high-frequency welding. The two foils are heated by the high-frequency alternating electric field and by pressing the welding stamp against an abutment surface, the foils in between are connected in a material-locking manner. The displaced material entering the central recess on the inner edge of the welding stamp is shaped by the inner stamp, which can be made of a plastic, for example, and its contours. In this way, the overall shape of the bead can be controlled and contours can be formed as sub-regions of different material heights. This allows the desired overflow behavior to be achieved when filling the multi-chamber bladder system.

The welding stamp can be arranged in a surrounding outer stamp, which has a material that does not conduct the high-frequency alternating electric field. A weld bead created on the outer circumference of the welding stamp can also be shaped and contoured in order to advantageously influence the overflow behavior of the air or the filling gas from the first bubble into the second bubble.

DE 10 2019 214 576 A1 further describes that a fluid-fillable multi-chamber bladder system can be produced using this welding tool by first providing two foils arranged one above the other, the first foil being at least partially intended to form a first bubble and the second foil being at least partially intended to form a second bubble . The two foils are then welded and a weld seam is formed by pressing on the welding tool and applying a high-frequency alternating field. After the welding process, the fluid channel can be punched out of the middle of the two films. Alternatively, each of the foils can have the recess that corresponds to the fluid channel before welding and the foils can be placed one on top of the other so that they are congruent with respect to the fluid channel.

This is disadvantageous DE 10 2019 214 576 A1 The known solution is that the film sections adjacent to the outside of the weld bead formed by the outer stamp do not extend in the same plane as the welded film sections, but rather extend obliquely away from the weld bead into the bubble due to the forces and deformations during welding compared to the weld seam and thus creates a curve into the bubble the. This rounding into the bladder can form a sealing support for the opposite film of the bladder in the deflated state, which surrounds the fluid channel (overflow channel) and thus prevents fluid, in particular air, from flowing through the fluid channel, particularly in the event of an additional external force for example, by a person sitting on a seat until a limit pressure is exceeded, which causes the filling problems described above.

Another disadvantage is that the material displaced during welding can also spread outside the welding tool and is therefore not available for forming intended contours in the area of the welding tool. This can lead to the intended contours of the welding tool not being filled or at least not completely filled with the displaced material during welding and thus the intended weld beads not being formed or not being completely formed.

For further prior art, reference is made to DE 10 2007 002 002 A1 , US 2021/ 0 354 401 A1 , DE 1 063 956 A and DE 886 646 b.

The invention is based on the object of specifying a welding tool for producing a fluid-fillable bladder system and a method for producing a fluid-fillable bladder system using the welding tool, in which the disadvantages described above are at least largely overcome. In particular, a welding tool and a method are to be specified with which a bladder system with improved inflation behavior can be produced.

This task is solved with regard to the welding tool by a welding tool with the features of claim 1 and with regard to the method by a method with the features of claim 11. Advantageous refinements and further developments are specified in the dependent claims.

The welding tool according to the invention for producing a bladder system by means of high-frequency welding comprises a welding stamp with an underside forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field, and an outer stamp surrounding the welding stamp, which is made of material that does not conduct the high-frequency alternating electric field is formed. The outer stamp has a two-part underside comprising a first, radially inner part surrounding the welding stamp and a second, radially outer part surrounding the welding stamp, the first part of the underside being contoured and the second part of the underside being flat.

This design has the advantage that the flat second part of the underside of the outer stamp is pressed during welding against the foils to be welded to form the bubble system, which means that foil material displaced during welding is spread into the area in front of the second part of the underside of the outer die and thus also prevented from reaching areas outside the outer stamp. The displaced material is therefore at least essentially completely available for forming intended contours in the area of the welding tool. This makes it possible to ensure, by appropriately matching the volumes of the contours to the volume of the film material displaced during the intended welding, that the intended contours of the welding tool are completely filled with the displaced material during welding and thus the intended weld beads are completely formed.

When welding foils, the first part of the underside of the outer stamp forms an outer region of a contour zone created during welding, the second part of the underside of the outer stamp delimits this contour zone.

Furthermore, the inventive design of the welding tool ensures that the flat second part of the underside of the outer stamp rests against the film during welding and thus acts as a hold-down device for the film, so that the film remains in the desired shape. This ensures during the welding process, including cooling, that the film in the area of the second part of the underside of the outer stamp lies in a plane with the extent of the adjacent contour zone and that the film therefore does not protrude at an angle on the outside of the contour zone after welding.

The underside of the welding stamp can be flat. However, with regard to the formation of a contour zone, it is expedient if the underside of the welding stamp is also contoured.

The welding stamp, which can be made of aluminum, for example, produces the welded connection of the film of the first bubble and the film of the second bubble using high-frequency welding. The two foils are heated by the high-frequency alternating electric field and pressed against them by pressing the welding stamp The foils in between are connected materially to an abutment surface, with softened foil material being displaced due to the pressing. Displaced film material penetrates into the area in front of the first part of the underside of the outer stamp and is formed by its contours into one or more weld beads. Further penetration of the displaced film material into the area in front of the second part of the underside of the outer stamp is prevented due to its flat design and its contact with the film. The displaced film material is therefore available to fill the contours of the welding tool. In this way, the shape of the bead or beads can be controlled and contours of different shapes and heights can be formed. Here, by preventing the penetration of displaced film material into the area in front of the second part of the underside of the outer stamp and beyond, at least substantially complete filling of the contours formed on the welding tool is ensured, in particular if the welding process, for example the pressure exerted, and so on the associated displaced material volume is matched to the volume of the contours. This allows the desired overflow behavior to be achieved when filling the bladder system.

The outer stamp can be made of a plastic, for example.

The welding stamp can be circular in cross section on an outer circumferential side. In this case, the cross section of the outer stamp is also circular on its inner circumference. The outer edge of the underside of the welding stamp and the inner edge of the underside of the outer stamp are also circular in this case.

The boundary line between the first part and the second part of the underside of the outer stamp can also be circular.

In a first variant, the outer stamp is connected to the welding stamp rigidly, that is to say in a fixed position, with the underside of the outer stamp being arranged set back from the underside of the welding stamp. The setback ensures that the underside of the welding stamp can be pressed into the softening material of the film during welding and can thus displace the material and form the contour zone. Without this setback, the underside of the outer stamp resting on the film could hinder or prevent this movement.

In a second variant, the outer stamp is movable and sprung relative to the welding stamp by means of a suspension in such a way that the underside of the outer stamp is set back relative to the underside of the welding stamp when pressure is applied against the spring force of the suspension. In particular, it can be provided that the underside of the outer stamp lies in a plane with the underside of the welding stamp or protrudes beyond the underside of the welding stamp in the unloaded state of the suspension.

In contrast to the rigid connection between the welding stamp and the outer stamp according to the first variant, this design according to the second variant makes it possible for the underside of the outer stamp to already be in contact with the film at the start of welding and thus for the second part of the underside of the outer stamp to already be in contact with the start of welding can act as a hold-down device for the film, so that the film remains in the desired shape right from the start. With the rigid connection, on the other hand, at the start of welding, the distance between the second part of the underside of the outer stamp and the film that remains due to the setback initially allows for a curvature of the film in this area, albeit limited, and the film is only separated from the second part in the further welding process the underside of the outer stamp is pressed back into the plane. However, the welding tool provided with the suspension is more complex to produce than the welding tool designed with a rigid connection between the welding stamp and the outer stamp.

The storage of the outer stamp by means of suspension ensures that when the underside of the welding stamp is pressed against the film during the welding process, the underside of the outer stamp does not hinder the pressure and movement of the welding stamp into the film material, since the underside of the outer stamp is set back relative to the underside of the welding stamp can be made and still always rests against the film.

A further development of the second variant provides that the suspension is arranged on a rear side of the outer stamp opposite the underside of the outer stamp.

One embodiment of the invention provides that the welding stamp has a central recess and an inner stamp is arranged within the recess, which is formed from material that does not conduct the high-frequency alternating electric field and is contoured on an underside.

The displaced film material entering the central recess on the inner edge of the welding stamp is thus removed from the inner stamp, which is made of a plastic, for example can be effective and its contours shaped. In this way, the shape of the bead can be controlled and contours of different shapes and heights can be formed. This allows the desired overflow behavior to be achieved when filling the bladder system.

The cross section of the welding stamp can be circular on an inner circumferential side. In this case, the cross section of the inner stamp is also circular on its outer circumference. The inner edge of the underside of the welding stamp and the outer edge of the underside of the outer stamp are also circular in this case

The contoured underside of the inner stamp thus forms an inner region of the contour zone created during welding, which adjoins a recess in the foils, which forms the fluid channel between the bubbles to be produced, and surrounds this recess.

The underside of the inner stamp can have a central recess which is surrounded radially by the contoured underside of the inner stamp.

A first centering pin, which protrudes beyond the underside of the inner stamp, can be inserted into the central recess. This first centering pin is preferably rigidly inserted into the recess.

The first centering pin is used for the exact positioning of the foils to be welded before welding, which already have a punched out recess for the fluid channel to be formed. Furthermore, this first centering pin is intended for the interaction of the described welding tool, which forms a first welding tool, with a further, second welding tool, which is arranged opposite the first welding tool in such a way that the respective undersides face each other. The second welding tool is designed like the first welding tool except for the inserted first centering pin. After arranging the foils to be welded between the first and second welding tools, the first centering pin of the first welding tool engages in the central recess of the second welding tool and thus, in addition to the foils, also positions the first and second welding tools for welding relative to one another, so that further movement the welding tools are guided towards each other. The first and second welding tools form a welding tool system.

Alternatively, a second centering pin can also be inserted into the central recess, which is movable relative to the inner stamp along a vertical extent of the central recess and is sprung in the central recess by means of a spring, the second centering pin protruding over the underside of the inner stamp when the spring is unloaded . An underside of the second centering pin can be contoured.

The second centering pin also initially serves to precisely position the foils to be welded before welding, which already have a punched out recess for the fluid channel to be formed. Furthermore, this first centering pin is intended for the interaction of the described welding tool, which forms a first welding tool, with a further, second welding tool, which is arranged opposite the first welding tool in such a way that the respective undersides face each other. The second welding tool is designed like the first welding tool except for the inserted second centering pin and its suspension. Instead of the spring-loaded centering pin, the second welding tool has a counter bearing pin which is inserted into the central recess and whose underside lies at least essentially in a plane with the underside of the inner stamp. This underside of the counter bearing pin can be contoured, with preferably - if present - the contours of the underside of the second centering pin and the underside of the counter bearing pin corresponding to one another. After arranging the foils to be welded between the first and second welding tools, the spring-mounted second centering pin presses with its underside against the underside of the counter-bearing pin and, as the first and second welding tools move further together, is pressed against the spring force into the central recess until its underside is at least substantially lies in one plane with the underside of the inner stamp. In this way, by contouring the underside of the second centering pin and/or the underside of the counter bearing pin, cavities can also be provided in the area of the second centering pin, into which the softened material of the film displaced by the pressure on the welding tool can penetrate during welding. This means that the material volume displaced during welding does not have to be exactly matched to the cavity volume that the contouring of the undersides of the inner stamp, welding stamp and outer stamp provides; rather, further material can penetrate into the contouring in the area of the second centering pin and the counter bearing pin and, if necessary, be removed afterwards become. The first and second welding tools also form a welding tool system in this embodiment variant.

• Bereitstellen von zwei übereinander angeordneten Folien, wobei die erste Folie zumindest teilweise zur Bildung einer ersten Blase und die zweite Folie zumindest teilweise zur Bildung einer zweiten Blase vorgesehen ist,
• Verschweißen der beiden Folien und Ausbilden einer Schweißnaht durch Aufdrücken des Schweißwerkzeugs und Beaufschlagen des Schweißwerkzeugs mit einem Hochfrequenz-Wechselfeld, und
• Formen mindestens einen sich durch das Verschweißen bildenden Schweißwulstes aus Folienmaterial zur Ausbildung einer Konturenzone der beiden verschweißten Folien.

The method according to the invention for producing a bladder system using the welding tool according to the invention described above comprises the steps:

• Providing two films arranged one above the other, the first film being at least partially intended to form a first bubble and the second film being at least partially intended to form a second bubble,
• Welding the two foils and forming a weld seam by pressing on the welding tool and applying a high-frequency alternating field to the welding tool, and
• Forming at least one weld bead formed by welding from foil material to form a contour zone of the two welded foils.

The method according to the invention provides that the planar second part of the underside of the outer stamp lies against one of the two films during welding. In particular, it can be provided that the planar second part of the underside of the outer stamp lies against one of the two films before and/or at the start of welding.

This prevents film material displaced by the welding stamp during welding from penetrating into the area in front of the second part of the underside of the outer stamp and thus also into areas outside the outer stamp. The displaced material is therefore at least essentially completely available for forming intended contours in the area of the welding tool. According to a further development, it is therefore provided that foil material displaced during welding does not penetrate into the area in front of the second part of the underside of the welding stamp, but is used to fill the contours of the welding tool.

Furthermore, the film is held down by the flat second part of the underside of the outer stamp and/or pressed against the further film. Thus, the two foils are pressed against each other during welding by the welding tool and its counterpart present during welding and therefore cannot tilt or deform. Even after welding, the films also extend in the area surrounding the contour zone at least essentially in a plane with the contour zone and therefore do not form any exposed, possibly sealing contact surfaces for films lying above them.

The welding tool according to the invention and the method according to the invention enable the formation of a contour zone, through which the disadvantages described above when filling a multi-chamber bladder system are at least largely avoided. In particular, the contouring of the undersides of the welding stamp and/or outer stamp and/or inner stamp can be designed in such a way that the contour zone has areas and/or beads of different shapes and/or material thicknesses, i.e. height. This results in unevenness that counteracts a sealing effect in connection with a film lying above it, since this can no longer lie flat on a uniformly high film area surrounding the fluid channel. In particular, it can be provided that the beads in the contour zone extend in a circle around the fluid channel, with interruptions in the beads for the passage of fluid, in particular air, being provided along the respective circular lines. For example, radial fluid guides can be formed in the contour zone.

The invention is explained in more detail below with regard to further features and advantages based on the description of exemplary embodiments and with reference to the accompanying schematic drawings.

• 1 in einer perspektivischen Schnittdarstellung ein erstes Ausführungsbeispiel eines erfindungsgemäßen Schweißwerkzeugs,
• 2 eine Draufsicht auf eine Unterseite des Schweißwerkzeugs nach 1,
• 3 eine Schnittdarstellung durch das Schweißwerkzeug nach 1 und 2, geschnitten entlang der Linie C-C in 2,
• 4 in einer perspektivischen Schnittdarstellung ein zweites Ausführungsbeispiel eines erfindungsgemäßen Schweißwerkzeugs, hier ein erstes Schweißwerkzeug,
• 5 eine Draufsicht auf eine Unterseite des Schweißwerkzeugs nach 4,
• 6 eine Schnittdarstellung durch das Schweißwerkzeug nach 4 und 5, geschnitten entlang der Linie A-A in 5,
• 7 in einer perspektivischen Darstellung ein drittes Ausführungsbeispiel eines erfindungsgemäßen Schweißwerkzeugs, hier ein mit dem ersten Schweißwerkzeug korrespondierendes zweites Schweißwerkzeug,
• 8 eine Schnittdarstellung durch das Schweißwerkzeug nach 7,
• 9 einen ersten Verfahrensschritt bei der Herstellung eines Blasensystems unter Verwendung des ersten Schneidwerkzeugs nach 4 und des zweiten Schneidwerkzeugs nach 7,
• 10 einen auf den ersten Verfahrensschritt nach 9 folgenden zweiten Verfahrensschritt,
• 11 schematisch ein Blasensystem,
• 12 eine Draufsicht auf Schweißnaht und Konturenzone eines erfindungsgemäß hergestellten Blasensystems,
• 13 eine perspektivische Ansicht der in 12 gezeigten Schweißnaht und Konturenzone,
• 14 eine seitliche Schnittdarstellung von Schweißnaht und Konturenzone gemäß 12 und 13, und
• 15 eine vergrößerte Ausschnittdarstellung von Schweißnaht und Konturenzone aus 14.

Show it

• 1 in a perspective sectional view a first embodiment of a welding tool according to the invention,
• 2 a top view of an underside of the welding tool 1 ,
• 3 a sectional view through the welding tool 1 and 2 , cut along the line CC in 2 ,
• 4 in a perspective sectional view a second embodiment of a welding tool according to the invention, here a first welding tool,
• 5 a top view of an underside of the welding tool 4 ,
• 6 a sectional view through the welding tool 4 and 5 , cut along line AA in 5 ,
• 7 in a perspective view a third embodiment of a welding tool according to the invention, here a second welding tool corresponding to the first welding tool,
• 8th a sectional view through the welding tool 7 ,
• 9 a first process step in the production of a bladder system using the first cutting tool 4 and the second cutting tool 7 ,
• 10 one after the first procedural step 9 following second process step,
• 11 schematically a bubble system,
• 12 a top view of the weld seam and contour zone of a bladder system produced according to the invention,
• 13 a perspective view of the in 12 shown weld seam and contour zone,
• 14 a side sectional view of the weld seam and contour zone 12 and 13 , and
• 15 an enlarged detail view of the weld seam and contour zone 14 .

Corresponding parts and components in the figures are designated with the same reference numerals, even across different exemplary embodiments.

1 , 2 and 3 show a first exemplary embodiment of a welding tool 10 according to the invention for producing a bladder system 50 using high-frequency welding. The welding tool 10 includes a welding stamp 11 with an underside 12 forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field. The underside 12 has a contour 12a and is therefore contoured.

The welding tool 10 further comprises an outer stamp 13 surrounding the welding stamp 11, which is formed from material that does not conduct the high-frequency alternating electric field. The outer stamp 13 has a two-part underside 14 comprising a first, radially inner part 15 surrounding the welding stamp 11 and a second, radially outer part 16 surrounding the welding stamp 11. The first part 15 of the underside 14 shows a contour 15a and is therefore designed to be contoured. The second part 16 of the underside 14 is flat.

The outer stamp 13 is rigidly connected to the welding stamp 11. The underside 14 of the outer stamp 13, in particular the first part 15 of the underside 14, is arranged set back from the underside 12 of the welding stamp 11.

The welding stamp 11 has a central recess 19. An inner stamp 20 is arranged within the recess 19, which is formed from material that does not conduct the high-frequency alternating electric field and shows a contour 21a on an underside 21 and is therefore contoured.

The underside 21 of the inner stamp 20 has a central recess 22 which is surrounded radially by the contoured underside 21 of the inner stamp 20. A first centering pin 23 is inserted into the central recess 22 and protrudes beyond the underside 22 of the inner stamp 20. When producing a bladder system 50, the centering pin 23 is inserted through existing punchings to form a fluid channel of the two films to be welded and the two films are thereby positioned relative to the welding tool 10 for welding.

4 , 5 and 6 show a second embodiment of a welding tool 10 according to the invention for producing a bladder system 50 using high-frequency welding. This second exemplary embodiment is a first welding tool 10a, which is described below with reference to 7 and 8th shown second welding tool 10b interacts when welding the foils in the production of a bladder system, as exemplified in 9 and 10 shown.

In this second exemplary embodiment, the welding tool 10 also includes a welding stamp 11 with an underside 12 forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field. The underside 12 has a contour 12a and is therefore contoured.

The welding tool 10 further comprises an outer stamp 13 surrounding the welding stamp 11, which is formed from material that does not conduct the high-frequency alternating electric field. The outer stamp 13 has a two-part underside 14 comprising a first, radially inner part 15 surrounding the welding stamp 11 and a second, radially outer part 16 surrounding the welding stamp 11. The first part 15 of the underside 14 shows a contour 15a and is therefore designed to be contoured. The second part 16 of the underside 14 is flat.

In this second exemplary embodiment, unlike in the first exemplary embodiment, the outer stamp 13 is not rigidly connected to the welding stamp 11, but is mounted in such a movable and resilient manner relative to the welding stamp 11 by means of a suspension 17 that the underside 14 of the outer stamp 13, in particular also the first part 15 the underside 14, when pressure is applied against the spring force of the suspension 17 compared to the underside 12 of the welding stamp 11 is set back, as in 6 indicated. In the unloaded state, the underside 14 of the outer stamp 13, in particular also the first part 15 of the underside 14, can lie at least essentially in a plane with the underside 12 of the welding stamp 11. The suspension 17 is arranged on a rear side 18 of the outer stamp opposite the underside 14.

The welding stamp 11 of the second exemplary embodiment has, as in the first exemplary embodiment, a central recess 19. An inner stamp 20 is arranged within the recess 19, which is formed from material that does not conduct the high-frequency alternating electric field and shows a contour 21a on an underside 21 and is therefore contoured.

The underside 21 of the inner stamp 20 has a central recess 22 which is surrounded radially by the contoured underside 21 of the inner stamp 20. In this second exemplary embodiment, a second centering pin 24 is inserted into the central recess 22, which is movable relative to the inner stamp 20 along a vertical extent of the central recess 22 and is sprung in the central recess 22 by means of a spring 25, the second centering pin 24 being at unloaded spring 25 protrudes over the underside 21 of the inner stamp 20. When producing a bladder system 50, the centering pin 24 is inserted through existing punchings to form a fluid channel of the two films to be welded and the two films are thereby positioned relative to the welding tool 10 for welding.

An underside 26 of the second centering pin 24 has a contour 26a and is therefore contoured.

7 and 8th show a third embodiment of a welding tool 10 according to the invention for producing a bladder system 50 using high-frequency welding. This third exemplary embodiment is a second welding tool 10b, which is based on the above 4 , 5 and 6 shown first welding tool 10a interacts when welding the foils in the production of a bladder system, as exemplified in 9 and 10 shown.

In this third exemplary embodiment, the welding tool 10 also includes a welding stamp 11 with an underside 12 forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field. The underside 12 has a contour 12a and is therefore contoured.

The welding tool 10 further comprises an outer stamp 13 surrounding the welding stamp 11, which is formed from material that does not conduct the high-frequency alternating electric field. The outer stamp 13 has a two-part underside 14 comprising a first, radially inner part 15 surrounding the welding stamp 11 and a second, radially outer part 16 surrounding the welding stamp 11. The first part 15 of the underside 14 shows a contour 15a and is therefore designed to be contoured. The second part 16 of the underside 14 is flat.

In this third exemplary embodiment, as in the second exemplary embodiment, the outer stamp 13 is mounted in such a way that it is movable and sprung relative to the welding stamp 11 by means of a suspension 17, so that the underside 14 of the outer stamp 13, in particular also the first part 15 of the underside 14, when pressed against the spring force of the Suspension 17 is set back relative to the underside 12 of the welding stamp 11. In the unloaded state, the underside 14 of the outer stamp 13, in particular also the first part 15 of the underside 14, can lie at least essentially in a plane with the underside 12 of the welding stamp 11. The suspension 17 is arranged on a rear side 18 of the outer stamp opposite the underside 14, analogous to the design in the second exemplary embodiment.

The welding stamp 11 of the third exemplary embodiment has a central recess 19, as in the first exemplary embodiment. However, in this third exemplary embodiment, a counter bearing pin 27 is arranged within the recess 19, which is formed from material that does not conduct the high-frequency alternating electric field and shows a contour 28a on an underside 28 and is therefore contoured. The contouring 28a is designed to correspond to the contouring 26a of the underside 26 of the second centering pin 24, so that when the first welding tool 10a and second welding tool 10b are placed next to each other during the production of the film bubble, as in 9 and 10 shown, through the contours 26a and 28a common cavities are formed for the formation of weld beads 56 when the softened film material is displaced during welding. During welding, the underside 28 of the counter bearing pin 27 forms a counter bearing for the resiliently mounted second centering pin 24.

9 and 10 show two process steps in the production of a bladder system 50 using the first welding tool 10a described above and the second welding tool 10b described above. Im in 9 The first method step shown is a first film 51 and a second film 52, which are to be welded by this method and each already has a punched out for a fluid channel 59 (overflow channel) to be formed, inserted onto the second centering pin 24 by means of these punched outs, so that they are positioned in the desired manner relative to the first welding tool 10a. Im in 10 In the second method step shown, the first welding tool 10a and the second welding tool 10b are moved together and the welding is carried out by applying a high-frequency alternating field and under pressure to one or both welding stamps 11. The resiliently mounted second centering pin 24 is pressed into the recess 19 of the welding stamp 11 of the first welding tool 10a by the counter bearing pin 27.

11 shows schematically a bladder system 50, as produced using the welding tools 10 according to the invention and the method according to the invention. This is a multi-chamber bladder system, which in the present case includes a first bladder 53 and a second bladder 54. These bubbles 53, 54 are typically formed from two foils placed one on top of the other and welded at the edges, which is not shown in the figures. The first film 51 and the second film 52 can be seen, the welding of which is shown above as an example 9 and 10 was explained. You can see the fluid channel 59 (overflow channel) formed from the pre-punched cut-outs of the two films 51, 52, which is surrounded by a contour zone 57 in which the weld beads formed by the contours of the undersides of the welding tools are arranged. The first bladder 53 has a compressed air supply 58. Compressed air supplied here to the first bladder 53 reaches the second bladder 54 via the fluid channel 59.

12 , 13 , 14 and 15 show the two foils 51, 52 welded together. The welding can be carried out both with a welding tool 10 according to the first exemplary embodiment and with the welding tools 10a, 10b according to the second and third exemplary embodiments. What can be seen is a weld seam 55 formed by welding and a contour zone 57 in which the weld beads 56 formed by the contours of the undersides of the welding tools 10 are arranged. Any accumulation of foil material displaced during welding is referred to as a weld bead 56, regardless of its specific shape.

Can be seen in particular in 14 and 15 that the two films 51, 52 extend parallel to each other away from the outermost weld bead 56 after welding on the outside of the contour zone 57 and lie in a plane with the extent of the contour zone 57. The second part 16 of the underside 14 of the outer stamp 13 of the welding tools 10, 10a, 10b according to the invention thus acts as a hold-down device for the foils 51, 52 during welding and ensures that they do not protrude obliquely on the outside of the contour zone 57.

Reference symbol list

10

Welding tool

10a

first welding tool

10b

second welding tool

11

Welding stamp

12

Bottom of the welding stamp 11

12a

Contouring the bottom 12

13

Outside stamp

14

Underside of the outer stamp 13

15

first part of the bottom 14

15a

Contouring of the first part 15 of the underside 14

16

second part of the bottom 14

17

suspension

18

Back of the outer stamp 13

19

Recess of the welding stamp 11

20

Inside stamp

21

Bottom of the inner stamp 20

21a

Contouring the bottom 21

22

central recess in the underside 21 of the inner stamp 20

23

first centering pin

24

second centering pin

25

Feather

26

Underside of the second centering pin 24

26a

Contouring the bottom 26

27

counter bearing pin

28

Underside of the counter bearing pin 27

28a

Contouring of the underside 28 of the counter bearing pin 27

50

Bladder system

51

first slide

52

second slide

53

first bubble

54

second bubble

55

Weld

56

weld bead

57

Contour zone

58

Compressed air supply

59

Fluid channel (overflow channel)

Claims (13)

Welding tool (10) for producing a bladder system (50) by means of high-frequency welding, comprising a welding stamp (11) with an underside (12) forming the welding surface, which is made of a material that conducts a high-frequency alternating electric field, and a welding stamp ( 11) surrounding outer stamp (13), which is formed from material that is non-conductive to the high-frequency alternating electric field, characterized in that the outer stamp (13) has a two-part underside (14) comprising a first, radially inner part (15) surrounding the welding stamp (11). ) and a second, radially outer part (16) surrounding the welding stamp (11), the first part (15) of the underside (14) being contoured and the second part (16) of the underside (14) being flat. Welding tool (10). Claim 1 , characterized in that the outer stamp (13) is rigidly connected to the welding stamp (11), the underside (14) of the outer stamp (13) being arranged set back from the underside (12) of the welding stamp (11). Welding tool (10). Claim 1 , characterized in that the outer stamp (13) is mounted so that it is movable and sprung relative to the welding stamp (11) by means of a suspension (17) that the underside (14) of the outer stamp (13) when pressed against the spring force of the suspension (17) is set back relative to the underside (12) of the welding stamp (12). Welding tool (10). Claim 3 , characterized in that the underside (14) of the outer stamp (13) in the unloaded state of the suspension (17) lies in a plane with the underside (12) of the welding stamp (11) or above the underside (12) of the welding stamp (11) protrudes. Welding tool (10). Claim 3 or 4 , characterized in that the suspension (17) is arranged on a rear side (18) of the outer stamp (13) opposite the underside (14) of the outer stamp (13). Welding tool (10) according to one of the preceding claims, characterized in that the welding stamp (11) has a central recess (19) and an inner stamp (20) is arranged within the recess (19), which is made of material that does not conduct the high-frequency alternating electric field formed and contoured (21a) on an underside (21). Welding tool (10). Claim 6 , characterized in that the underside (21) of the inner stamp (20) has a central recess (22) which is surrounded radially by the contoured underside (21) of the inner stamp (20). Welding tool (10). Claim 7 , characterized in that a first centering pin (23) is inserted into the central recess (22), which protrudes beyond the underside (22) of the inner stamp (20). Welding tool (10). Claim 7 , characterized in that a second centering pin (24) is inserted into the central recess (22), which is movable relative to the inner stamp (20) along a vertical extent of the central recess (22) and sprung in the central one by means of a spring (25). Recess (22) is mounted, with the second centering pin (24) protruding beyond the underside (21) of the inner stamp (20) when the spring (25) is unloaded. Welding tool (10). Claim 9 , characterized in that an underside (26) of the second centering pin (24) is contoured (26a). Method for producing a bubble system (50) by means of the welding tool (10) according to one of the preceding claims, comprising the steps: providing two foils (51, 52) arranged one above the other, the first foil (51) being at least partially used to form a first bubble (53) and the second film (52) is at least partially intended to form a second bubble (54), welding the two films (51, 52) and forming a weld seam (55) by pressing on the welding tool (10) and applying pressure to the welding tool (10) with a high-frequency alternating field, and forming at least one weld bead (56) formed by the welding made of film material to form a contour zone (57) of the two welded films (51, 52), characterized in that the planar second part (16) the underside (14) of the outer stamp (13) during ver welding rests on one of the two foils (51, 52). Procedure according to Claim 11 , characterized in that the flat second part (16) of the underside (14) of the outer stamp (13) already rests on one of the two foils (51, 52) before and/or at the start of welding. Procedure according to Claim 11 or 12 , characterized in that film material displaced during welding does not penetrate into the area in front of the second part (16) of the underside (14) of the welding stamp (13), but rather to fill contours (12a, 16a, 21a, 26a) of the welding tool (10 ) is used.

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