DE202023100729U1 - Welding tool for making a bladder system - Google Patents

Abstract

Welding tool (10) for producing a bladder system (50) using high-frequency welding, comprising
a welding stamp (11) made of a material that conducts a high-frequency alternating electric field with an underside (12) arranged on the front in an intended welding direction (S), which forms the welding surface of the welding stamp (11), and an outer stamp (11) surrounding the welding stamp (11) 13) made of a material that does not conduct the high-frequency alternating electric field with an underside (14) arranged on the front in the intended welding direction (S),
characterized,
that the underside (14) of the outer stamp (13) is flat,
that the outer stamp (13) is mounted in a movable and spring-loaded manner relative to the welding stamp (11) by means of a suspension (17) in such a way that the underside (14) of the outer stamp (13) is under pressure against the spring force of the suspension (17) and against the intended Welding direction (S) is offset relative to the underside (12) of the welding stamp (11), and
that the underside (14) of the outer stamp (13) lies in the unloaded state of the suspension (17) in the intended welding direction (S) in front of or in a plane with the underside (12) of the welding stamp (11).

Description

The invention relates to a welding tool for producing a bladder system, in particular a bladder system that can be filled with fluid, using high-frequency welding.

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 bladders that follow the first bladder, which is filled first, do not open until a limit pressure in the first bladder is exceeded. If the limit pressure is exceeded, the closed second and/or subsequent bladders fill up abruptly and a noise is produced, such as a popping sound, which is perceived as annoying by users of the vehicle seat, for example. This noise should therefore be avoided. In addition, the sudden change in volume can cause an unpleasant feeling for a user when using the multi-chamber bladder system, for example as an actuator in a vehicle seat. In addition, the sudden opening also has negative effects on the long-term stability of the bladder.
It is therefore necessary to prevent the sealing effect of the welding beads in the vented state of the multi-chamber bladder system.

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 EN 10 2019 214 576 A1 It is known to form two or more areas of different material thickness 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 thickness in a contour zone surrounding the fluid channel, unevenness occurs 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 thus can no longer completely seal the fluid channel. This means that from the start of the filling process or at low limit pressure, the air can flow from the first bubble via the fluid channel into the second bubble. This allows the filling pressure of the air to act on the entire inner surface of the second bubble and raise it continuously. A sudden expansion of the second bubble is thus prevented.

Out of EN 10 2019 214 576 A1 A welding tool for producing a fluid-fillable multi-chamber bladder system is known, which comprises a welding stamp which is made of a material that conducts a high-frequency alternating electrical field. The welding stamp has a central recess and the welding tool further comprises an inner stamp arranged within the recess, which is made of a material that does not conduct the high-frequency alternating electrical field and is contoured on an underside. The welding stamp, which can be made of aluminum, for example, connects the film of the first bladder and the film of the second bladder by means of high-frequency welding. The two films are heated by the high-frequency alternating electrical field and the films in between are bonded together by pressing the welding stamp against an abutment surface. The displaced material entering the central recess at the inner edge of the welding stamp is formed 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-areas 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 electrical field. In this way, a welding bead that is 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 form a curve into the bubble. This curve into the bladder can form a sealing support for the opposing film of the bladder in the deflated state Surrounding the fluid channel (overflow channel), the flow of fluid, in particular air, through the fluid channel is prevented, especially in the event of an additional external force, for example from a person sitting on a seat, until a limit pressure is exceeded, which causes the problems when filling described above brings with it.

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

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

This task is solved by a welding tool with the features of claim 1. 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 made of a material that conducts a high-frequency alternating electric field with an underside arranged on the front in an intended welding direction, which forms the welding surface of the welding stamp. The welding tool further comprises an outer stamp surrounding the welding stamp made of a material that does not conduct the high-frequency alternating electric field and with an underside arranged on the front in the intended welding direction.

The invention provides that the underside of the outer stamp is flat. Furthermore, the outer stamp is mounted by means of a spring mechanism so that it can move and is spring-loaded relative to the welding stamp that the underside of the outer stamp is displaced relative to the underside of the welding stamp when pressure is applied against the spring force of the spring mechanism and against the intended welding direction. When the spring mechanism is not loaded, the underside of the outer stamp is in front of or in the intended welding direction with the underside of the welding stamp.

This design has the advantage that the outer stamp with its flat underside is pressed against the foils to be welded to form the bubble system before and/or at the start of welding, which means that foil material displaced during welding is spread out into the area in front of the underside of the outer stamp and thus also into areas outside the outer stamp is prevented. 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 two foils, the flat underside of the outer stamp limits the contour zone formed by the rest of the welding tool.

Furthermore, the design of the welding tool according to the invention ensures that the flat underside of the outer punch is already in contact with the film before and/or at the start of welding and the outer punch, in particular its flat underside, thus acts as a hold-down device at the start of welding and during welding the film works so that the film remains in the desired shape right from the start. This ensures during the welding process, including cooling, that the film in the area 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 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.

One embodiment of the invention provides that the suspension is arranged on a rear side of the outer stamp opposite the underside of the outer stamp.

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 contoured.

The outer stamp can rest directly on the welding stamp. As an alternative to this, a further development provides that an intermediate stamp surrounding the welding stamp is arranged between the welding stamp and the outer stamp and is made of a material that does not conduct the high-frequency alternating electric field and has an underside arranged on the front in the intended welding direction. The underside of the intermediate stamp is contoured and lies behind it in the intended welding direction the underside of the welding stamp, so that material displaced during welding can penetrate into the area in front of the underside of the intermediate stamp. In other words: The underside of the intermediate stamp is set back from the underside of the welding stamp.

It can be provided that the intermediate punch is arranged to be adjustable relative to the welding punch in and/or against the intended welding direction, with a set position for the welding process being fixable, so that the intermediate punch is connected to the welding punch in a fixed position during a welding process. This allows the volume of the contouring provided on the underside of the intermediate stamp and thus the volume of displaced film material to be absorbed by this contouring to be adjusted.

According to one embodiment, a rear side of the intermediate stamp opposite the underside of the intermediate stamp is mounted on a projection of the welding stamp via at least one replaceable intermediate ring, the position of the intermediate stamp relative to the welding stamp being adjustable by replacing the intermediate ring or rings. For this purpose, intermediate rings of different heights can be provided and the position of the intermediate punch relative to the welding punch in the intended welding direction can be adjusted by selecting and using one or more intermediate rings of the desired height.

The position of the intermediate stamp relative to the welding stamp can be set in such a way that the volume of material displaced during the intended welding corresponds at least essentially to the volume of all contours of the welding tool intended to accommodate this displaced material.

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 by pressing the welding stamp against an abutment surface, the foils in between are materially connected, with softened foil material being displaced due to the pressing. If the outer stamp lies directly against the welding stamp, the outer stamp prevents the displaced film material on the outer edge of the welding stamp from penetrating into the area in front of the underside of the outer stamp by resting its flat underside against the film. The displaced material is therefore available to fill the contours. If an intermediate stamp is provided, the displaced film material penetrates, among other things, on the outer edge of the welding stamp into the area in front of the underside and is thereby shaped by the contoured underside of the intermediate stamp, that is, by the contours of the underside of the intermediate stamp. Further penetration of the displaced film material into the area in front of the underside of the outer stamp is prevented due to the flat underside of the outer stamp lying against the film. The displaced film material is therefore available, among other things, for filling the contours of the underside of the intermediate stamp and the contours of the underside of the welding stamp. In this way, the shape of the weld bead or beads formed 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 underside of the outer stamp and beyond, at least essentially complete filling of the contours formed on the welding tool is ensured, in particular if the welding process, for example the pressure exerted, and the associated displaced material volume is tailored 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 punch may be circular in its cross-section on an outer peripheral side. In this case, the outer punch and/or the intermediate punch is also circular in its cross-section on its inner peripheral side. The outer edge of the bottom of the welding punch and the inner edge of the bottom of the outer punch and/or the bottom of the intermediate punch are also circular in their cross-section on their inner peripheral side. In this case, the cross-section of the intermediate punch is circular. The cross-section of the intermediate punch on an outer peripheral side and, correspondingly, the outer edge of the underside of the intermediate punch can also be circular.

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 shaped by the inner stamp, which can be made of a plastic, for example, and its contours. 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 centering pin can be inserted into the central recess, which protrudes beyond the underside of the inner stamp. This centering pin is preferably rigidly inserted into the recess. This 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 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 centering pin used. After arranging the foils to be welded between the first and second welding tools, the 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 the further movement of the Welding tools are guided towards each other. The first and second welding tools form a welding tool system.

Alternatively, a 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 centering pin protruding over the underside of the inner stamp when the spring is unloaded. An underside of the centering pin can be contoured.

This 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 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 centering pin used 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 the contours of the underside of the centering pin and the underside of the counter bearing pin preferably corresponding to one another - if available. After arranging the foils to be welded between the first and second welding tools, the spring-mounted 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 essentially in lies on a level with the underside of the inner stamp. In this way, by contouring the underside of the centering pin and/or the underside of the counter-bearing pin, cavities can also be provided in the area of the centering pin, into which cavities can be created during welding due to the pressure on the weld The softened material displaced by the tool can penetrate the film. This means that the volume of material 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 centering pin and the counter bearing pin and, if necessary, be removed afterwards . 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

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

• 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, welding the two foils and forming a weld seam by pressing on the welding tool and applying a welding tool to the welding tool High-frequency alternating field, 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 provides that the flat underside of the outer stamp lies against one of the two films before and/or at the start of welding and during welding.

This prevents film material displaced by the welding stamp during welding from penetrating into the area in front 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 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 underside of the outer stamp and/or pressed against the other 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.

A further development of the method provides for the use of a welding tool according to the invention with the described intermediate punch. The position of the intermediate stamp is adjusted relative to the welding stamp in such a way that the volume of material displaced during the intended welding corresponds at least essentially to the volume of all contours of the welding tool intended to accommodate this displaced material.

The welding tool according to the invention and the method described 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 intermediate 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 thickness, 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 in einer perspektivischen Darstellung ein zweites Ausführungsbeispiel eines erfindungsgemäßen Schweißwerkzeugs, hier ein mit dem ersten Schweißwerkzeug korrespondierendes zweites Schweißwerkzeug,
• 4 einen ersten Verfahrensschritt bei der Herstellung eines Blasensystems unter Verwendung des ersten Schneidwerkzeugs nach 1 und des zweiten Schneidwerkzeugs nach 3,
• 5 einen auf den ersten Verfahrensschritt nach 4 folgenden zweiten Verfahrensschritt,
• 6 schematisch ein Blasensystem,
• 7 eine Draufsicht auf Schweißnaht und Konturenzone eines mit einem erfindungsgemäßen Schweißwerkzeug hergestellten Blasensystems,
• 8 eine perspektivische Ansicht der in 7 gezeigten Schweißnaht und Konturenzone,
• 9 eine seitliche Schnittdarstellung von Schweißnaht und Konturenzone gemäß 7 und 8, und
• 10 eine vergrößerte Ausschnittdarstellung von Schweißnaht und Konturenzone aus 9.

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 in a perspective view a second embodiment of a welding tool according to the invention, here a second welding tool corresponding to the first welding tool,
• 4 a first process step in the production of a bladder system using the first cutting tool 1 and the second cutting tool 3 ,
• 5 one to the first step of the process 4 following second process step,
• 6 schematically a bubble system,
• 7 a top view of the weld seam and contour zone of a bladder system produced with a welding tool according to the invention,
• 8th a perspective view of the in 7 shown weld seam and contour zone,
• 9 a side sectional view of the weld seam and contour zone 7 and 8th , and
• 10 an enlarged detail view of the weld seam and contour zone 9 .

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

1 and 2 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 is arranged on the front in an intended welding direction S, indicated schematically by an arrow. 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 an underside 14 arranged on the front in the intended welding direction S, which is flat. The outer stamp 13 is mounted movably and sprung relative to the welding stamp 11 by means of a suspension 17, which is arranged on a back side 18 of the outer stamp 13 opposite the underside 14 of the outer stamp 13, in such a way that the underside 14 of the outer stamp 13 is under pressure against the spring force of the Suspension 17 and is offset against the intended welding direction S relative to the underside 12 of the welding stamp 11. The underside 14 of the outer stamp 13 lies in the unloaded state of the suspension 17 in the intended welding direction S or in a plane with the underside 12 of the welding stamp 11.

Between the welding stamp 11 and the outer stamp 13 there is an intermediate stamp 15 surrounding the welding stamp 11 made of a material that does not conduct the high-frequency alternating electric field and with an underside 16 arranged on the front in the intended welding direction S. The underside 16 of the intermediate stamp 15 is contoured, that is to say it has a contour 16a. The underside 16 of the intermediate stamp 15 lies in the intended welding direction S behind the underside 12 of the welding stamp 11, so that material displaced during welding can penetrate into the area in front of the underside 16 of the intermediate stamp 15.

A rear side 23 of the intermediate stamp 15 opposite the underside 16 of the intermediate stamp 15 is mounted on a projection 30 of the welding stamp 11 via a replaceable intermediate ring 29. The position of the intermediate stamp 15 relative to the welding stamp 11 can be adjusted by replacing the intermediate ring 29 with another intermediate ring with a different height. By selecting the intermediate ring 29 and installing it in the welding tool 10, the intermediate stamp 15 can be adjusted in and/or against the intended welding direction S relative to the welding stamp 11, with a position set thereby being fixed by the installed intermediate ring 29 for the welding process. The intermediate stamp 15 is therefore connected to the welding stamp 11 in a fixed position during a welding process. The position of the intermediate stamp 15 relative to the welding stamp 11 is set in particular such that the volume of material displaced during the intended welding corresponds at least essentially to the volume of all contours 12a, 16a, 21a, 26a of the welding tool intended to accommodate this displaced material.

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 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 position by means of a spring 25 recess 22 is mounted, with the centering pin 24 protruding over the underside 21 of the inner stamp 20 when the spring 25 is unloaded. 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 centering pin 24 has a contour 26a and is therefore contoured.

3 shows 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 second welding tool 10b, which is based on the above 1 and 2 shown first welding tool 10a interacts when welding the foils in the production of a bladder system, as exemplified in 4 and 5 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 flat underside 14. Between the welding stamp 11 and the outer stamp 14 there is an intermediate stamp 15 with an underside 14 which has a contour 15a and is therefore designed to be contoured.

In this second exemplary embodiment, as in the first exemplary embodiment, the outer stamp 13 is so movable and sprung relative to the welding stamp 11 by means of a suspension 17 that the flat underside 14 of the outer stamp 13 is set back relative to the underside 12 of the welding stamp 11 when pressed against the spring force of the suspension 17 becomes. In the unloaded state, the underside 14 of the outer stamp 13 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 1 of the outer stamp 13 opposite the underside 14, analogous to the design in the first exemplary embodiment.

The welding stamp 11 of the second exemplary embodiment has, as in the first exemplary embodiment, a central recess 19. However, in this second 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 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 4 and 5 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.

4 and 5 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 In the first method step shown, a first film 51 and a second film 52, which are to be welded by this method and each already have a punch-out for a fluid channel 59 to be formed (overflow channel), are inserted onto the centering pin 24 by means of these punch-outs, so that they are in are positioned as desired 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 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.

6 shows schematically a bladder system 50, as produced using the welding tools 10 according to the invention and the method described. 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 4 and 5 was explained. You can see the one from the pre-cut outs at The fluid channel 59 (overflow channel) formed by the foils 51, 52 is surrounded by a contour zone 57 in which the welding 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.

7 , 8th , 9 and 10 show the two foils 51, 52 welded together. The welding can be carried out using the welding tools 10a, 10b according to the first and second 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 9 and 10 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 flat 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

Intermediate stamp

16

Bottom of the intermediate stamp 15

16a

Contouring the bottom 16

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 underside 21

22

central recess in the underside 21 of the inner stamp 20

23

Back of the intermediate stamp

24

Centering

25

Feather

26

Underside of the 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

29

Intermediate ring

30

Projection of the welding stamp 11

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)

S

intended welding direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005032549 A1 [0004]
• US 4965899 [0005]
• US 6122784 [0005]
• DE 102011089749 B4 [0005]
• DE 102012218440 B4 [0009]
• US 9630532 B2 [0009]
• DE 102019214576 A1 [0010, 0011, 0013, 0014]

Claims (11)

Welding tool (10) for producing a bladder system (50) by means of high-frequency welding, comprising a welding stamp (11) made of a material that conducts an alternating high-frequency electrical field and has a lower side (12) arranged at the front in a designated welding direction (S), which forms the welding surface of the welding stamp (11), and an outer stamp (13) surrounding the welding stamp (11) made of a material that does not conduct the alternating high-frequency electrical field and has a lower side (14) arranged at the front in the designated welding direction (S), characterized in that the lower side (14) of the outer stamp (13) is flat, that the outer stamp (13) is mounted by means of a spring (17) in such a way that it can move and is spring-loaded relative to the welding stamp (11) that the lower side (14) of the outer stamp (13) is offset relative to the lower side (12) of the welding stamp (11) when pressure is applied against the spring force of the spring (17) and against the designated welding direction (S). and that the underside (14) of the outer punch (13) in the unloaded state of the spring (17) lies in front of or in a plane with the underside (12) of the welding punch (11) in the intended welding direction (S). Welding tool (10). Claim 1 , 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). Claim 1 or 2 , characterized in that the underside (12) of the welding stamp (11) is contoured (12a). Welding tool (10) according to one of the preceding claims, characterized in that between the welding stamp (11) and the outer stamp (13) there is an intermediate stamp (15) surrounding the welding stamp (11) made of a material that does not conduct the high-frequency alternating electric field and with a welding direction in the intended welding direction (S) arranged on the front underside (16), the underside (16) of the intermediate punch (15) being contoured (16a), and the underside (16) of the intermediate punch (15) in the intended welding direction (S) behind the The underside (12) of the welding stamp (11) lies so that material displaced during welding can penetrate into the area in front of the underside (16) of the intermediate stamp (15). Welding tool (10). Claim 4 , characterized in that the intermediate punch (15) is arranged to be adjustable in and/or against the intended welding direction (S) relative to the welding punch (11), a set position for the welding process being fixable, so that the intermediate punch (15) during a Welding process is connected to the welding stamp (11) in a fixed position. Welding tool (10). Claim 4 or 5 , characterized in that a rear side (23) of the intermediate punch (15) opposite the underside (16) of the intermediate punch (15) is mounted on a projection (30) of the welding punch (11) via at least one replaceable intermediate ring (29), the Position of the intermediate stamp (15) relative to the welding stamp (11) can be adjusted by replacing the intermediate ring or rings (29). Welding tool (10) according to one of the Claims 4 until 6 , characterized in that the position of the intermediate stamp (15) relative to the welding stamp (11) is adjusted such that the volume of material displaced during the intended welding is at least essentially the volume of all contours (12a, 16a, 21a) intended to accommodate this displaced material. 26a) of the welding tool corresponds. 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 8 , 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) to Claim 9 , characterized in that a centering pin (24) is inserted into the central recess (22), which is movable relative to the inner punch (20) along a vertical extension of the central recess (22) and is spring-loaded in the central recess (22) by means of a spring (25), wherein the centering pin (24) protrudes beyond the underside (21) of the inner punch (20) when the spring (25) is not loaded. Welding tool (10). Claim 10 , characterized in that an underside (26) of the centering pin (24) is contoured (26a).

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