DE102006054588B3 - Device for introduction of at least one weakening (12) into laminar material having a gas permeable layer by laser irradiation - Google Patents

Abstract

Device for introduction of at least one weakening (12) into laminar material (2) having a gas permeable layer by laser irradiation where the device includes a hollow space (4) for reception of at least part of the laminar material, a means for guiding a gas thru a partial region of the laminar material, and an element for production and direction of the laser beam into this partial region. An independent claim is included for a method of introducing a weakening into a laminar material as described above.

Description

Field of the invention

The The invention relates to a device for introducing at least one weakening in a plane Material by means of one or more laser beams and a method for introducing at least one weakening into a flat material by means of one or more laser beams.

State of the art

The Introducing partial weakenings in areal Materials, especially for Composite materials, such as those used in the decorative area in motor vehicles find, is sufficient known. Such weakenings are mainly introduced there in decorative materials, where, for example in the case of triggering an airbag or in a crash of a motor vehicle, the decor to tear along pre-defined lines, so injury to avoid the vehicle occupant or the free and hindered To ensure deployment of the airbag.

When Decor materials are currently in motor vehicles and here, for example in the area of the instrument panel of door linings, center consoles or similar material composites of a substantially dimensionally stable decorative support and one about it arranged decorative material used. This customary decorative materials are, for example any kind of plastic, especially in film form and thickness, leather or leather-like Materials, wood veneers or the like. Between the decor carrier and the decor material are also for setting a particularly advantageous feel of the decor one or more layers arranged with a greater softness. Such haptic-adjusting layers become, for example made of foams, spacer fabrics, textile nonwovens or the like produced.

The Introduction of material weakenings in the flat used as decor Materials are usually made after gluing all above-mentioned layers with each other and a restraint at least the one to be debilitated Areas in one for that suitable jig. Subsequently, the weakening usually becomes in a line shape by means of a milling tool, a knife or The like introduced in the composite material.

Furthermore there were already approaches the weakenings by means of one or more laser beams in the composite material which in particular the accuracy in the process control and the possibilities in the design of the weakening geometries increased. However, there is the problem that by the energy input means Lasers in the composite material also burns off the weakening surrounding it Areas can be done, reducing the appearance of the weakening line and possibly the entire decor unfavorably affected becomes.

The DE 103 50 220 A1 describes a method for producing a predetermined breaking line of an airbag cover in a vehicle trim part made of plastic, in which the predetermined breaking line is introduced from a first side into the trim part by means of a laser beam and the trim part at the same time from the second, the first side opposite side a cooling medium flow, which is directed to the visible side of the trim part, is acted upon. This ensures, with suitable process control, that the visible side is not damaged, at least during the introduction of the weakening by means of a laser. However, a permanent avoidance of the appearance of uneven weakening of the trim part is not ensured hereby. In addition, this does not solve the problem of effectively removing combustion gases and / or burns from the attenuation range. In addition, the method according to the DE 103 50 220 A1 a precisely coordinated guidance of laser tool on the one side of the trim part and the device for acting on the trim part by means of a cooling medium flow on the other side of the trim part.

The DE 40 131 63 A1 suggests in this context the provision of a gas during the processing of the surface of a plastic with laser radiation, which gas should have a better thermal conductivity than air. Helium gas is particularly preferably provided at the location of the interaction between the laser radiation and the plastic. The problem of a safe removal of exhaust gases and / or burn-off from the weakened area and an environmentally non-polluting litigation is by the device according to the DE 40 131 63 A1 but also not solved.

The US 5,883,356 A describes a device for introducing a weakening line into a sheet material, which may have a gas-permeable layer. The sheet material is held on a receiving device with lateral fixing devices. Furthermore, the device according to the US 5,883,356 A an element for generating and aligning a laser beam on a portion of the sheet material. The receiving device is connected to a vacuum pump, by means of which the sheet material against the surface of the receiving device is pressed. This ensures a slip-proof holding of the material to be weakened as well as an exact alignment of the laser beam with respect to the material. However, the problem of the removal of exhaust gases or burn-offs from the weakened area is neither addressed nor solved here.

The DE 198 50 299 A1 as well as the DE 103 52 524 A1 teach moreover to direct a gas to the processing site, thereby counteracting the heat input by means of a laser beam into the material. However, the removal of exhaust fumes and burn-offs, as well as a process that does not pollute the environment, are not affected by the DE 198 50 299 A1 still the DE 103 52 524 A1 described or suggested.

Object of the invention

It was therefore an object of the invention, a device and a Procedure available too make, with the decor composites by laser at least in some areas weakened can and can at the same time burning off areas surrounding the weakened areas as well as in the weakening resulting exhaust gases safely out of the with at least one laser beam processed areas removed can be.

These Task is in accordance with the invention by means of a device according to claim 1 and a method according to claim 13 solved. advantageous Embodiments of the invention can be found in the respective dependent claims. Especially Advantageously, while the inventive method using the device according to the invention carried out.

In A first aspect of the invention provides a device, at the a flat Material into which the weakening is to be introduced, is received in a cavity, and a gas at least through portions of the received in the cavity flat Material is passed through. In the acted upon with the gas sheet material then the weakening means one or more laser beams introduced.

in this connection will the gas permeability subregions, in particular sublayers of the sheet material used to pass a gas through the sheet material, so that when burning and / or evaporating material due to the Influence of one or more laser beams on the sheet material Exhaust gases or combustion occur and these are safely removed from the weakening range can and moreover the thermal energy absorbed by the material when lasing rapidly and can be derived safely. As a result, a weakening area remains the no unwanted Material erosion and no unwanted Material reflow outside the pre-defined areas of weakness having. The geometries of the weakenings can thus safely and accurately be set; moreover will be a burden on the environment by an escape of when burning and / or evaporation occurring exhaust gases to a minimum.

The to be debilitated area Material is preferably designed so that it is the layer through which the gas is passed, substantially gas-tight closes. This is given, for example, if a spacer knit between a dimensionally stable carrier and a plastic decor is arranged. The object of the invention let yourself but then solve it, if there are deviating structures of the sheet material, where one or both sides of the gas permeable layer are not completely gas tight are sealed, such as when using a with Stitched Leather or leather-like Materials as decorative material.

In a preferred embodiment of the device according to the invention is the cavity for receiving the sheet material from a receiving device defines a means for supplying and discharging the Has gases in at least one of its walls. This will created a device in which the passage of the gas through the areal Material can also be realized if only one layer of the sheet material essentially gas impermeable is configured and a gas-permeable layer on the other Side of the layer through which the gas is to be passed essentially flush is arranged in the receiving device.

In a further preferred embodiment of the device according to the invention, the cavity moreover comprises a cover, which in a particularly preferred embodiment of the invention is gas-tight. As a result, the sheet material may preferably be held non-slip in the cavity. In a particularly preferred manner, this cover is also so gas-tight connected to the device that gases, if at all, only in the desired amount and possibly intended locations in the cavity and the material absorbed therein can get in or out of this. As a result, a device is provided which significantly increases the possibilities for process control with particularly simple means. In addition, this can also safely prevent the escape of emerging during the introduction of the weakenings by means of laser exhaust into the environment become.

In a further preferred embodiment of the device according to the invention has this a cover, which also for the or the laser beam (s) is transparent. As transparent to the laser beams in the sense of the invention is considered an embodiment in which at least a majority of Laser energy passes through the cover and from the to be weakened flat Material is absorbed within the cavity. Depending on the wavelength Therefore, the laser can be the appearance of the cover quite from a complete one differ in clear and colorless form. Essential here is alone, that in such an embodiment of the device the Laser beams preferentially pass through the cover without the need for passage openings in the cover and / or device for the Provide laser beams through which the weakening of the sheet material to the desired Places can be effected, pass through.

In a preferred embodiment the device according to the invention is the areal Material a decor that in a particularly preferred embodiment the invention is used in a motor vehicle. This decor exists in excess preferably from a wood decor or plastic decor, which on a decor carrier is applied. Between the decor carrier and the wood, leather or Plastic decor is also a spacer knitted fabric and / or a textile fleece arranged. As well are embodiments with more than one layer of a spacer knit and / or a textile web or combinations thereof of the inventive idea includes.

When Plastic decor are especially planed PVC materials, PU, TPO or TPO foam preferred. As decor carrier materials are ABS or ABS misery, PP GF or LFI carrier considered particularly advantageous. In any case, between the individual layers of decor carrier, decor and the feel improving intermediate layers in each case a layer of adhesive and / or a bonding agent be provided to a durable, dimensionally stable and also shear forces to create a resisting decorative material composite.

The Introducing the weakenings by laser does not necessarily take place through each layer of the Decor composite through. Likewise, arrangements of weakening lines includes the idea of the invention, for example, offset from each other only pass through a partial thickness of the decorative composite. moreover will also introduce laser weakening in both the visible side of the decor composite as well as the visible side facing away Side of the decor composite preferred. This can be special preferred manner be such that opposing lines of weakness in nearly one plane perpendicular to the main extension plane of the composite material , resulting in a secure tearing of the composite materials along by the weakening achieve predetermined geometries.

In an alternative and also particularly preferred embodiment of the invention the weakenings arranged in a first side of the decor composite offset to those be in the opposite Side of the decorative composite are introduced. In addition, it can be beneficial be when the depth and / or width of the weakenings on the first page of the material of those of the weakenings on the opposite side Differentiate page. The same applies to the introduced by means of the laser Form of weakening itself, where it may be advantageous on a first page of the Material composite weakenings with sharp edges, for example with a tapering angle, and at the same time on the other side weakening to introduce with significantly different cross-sectional geometries.

Finally is the invention is not limited to weakening, the linearly are formed with a main extension direction; The invention also includes nearly point-like weakenings introduced into the decorative composite, which may be arranged aligned with each other or almost free spread over a defined portion of the sheet metal are arranged.

In the sense of the invention, a gas is passed through at least one gas-permeable layer of the sheet material. The gas in this case acts in a preferred manner inhibiting the combustion of materials of the decorative composite and consists in a very particularly preferred embodiment of the invention of an inert gas, for example CO ₂ , N ₂ or any mixture thereof.

In A preferred embodiment of the invention is the temperature the gas introduced and, if appropriate, its volumetric flow, that the areal Material inside the device a temperature increase or Temperature drop experiences. In the cooled or heated sheet material then becomes the weakening introduced by means of one or more laser beams.

The knowledge is used that the heat generated during the laser process can be dissipated better via a cooled molding, resulting in less material erosion and thus less visible on the visible side of the weakened sheet material. In an alternative way, by heating the sheet material "softened" so that it can be weakened with a lower laser power than with application of the laser energy in a sheet material at room temperature, and thus with reduced heat input.

In both cases above So it's going to be a change the temperature of the to be debilitated flat Material the material property in a relatively large area compared with a small area in which the weakening introduced becomes, beneficial to changed the subsequent processing step.

In a further preferred embodiment of the device according to the invention will the warming or cooling off of the plane Material by an element comprised by the device for raising or Lowering the temperature of the sheet material received in the cavity at least supported. For this purpose, the cavity may preferably be heated or refrigerated Cradle be defined in a very special way preferred embodiment of the invention at least one channel for passing a heating or cooling medium having. In excess Preferably, a plurality of channels for the passage of a Heat or cooling medium in at least one of the side walls arranged this receiving device, wherein through the flow of heat or cooling medium the receiving device itself is heated or cooled and that changed Temperature within the defined by the cradle Cavity either by direct contact or via an intermediate medium indirectly on the plane Material is transferred within the cavity.

Especially advantageous here is of course the direct contact of the plane Material with one or more walls of the receiving device, so a particularly good heat transfer to ensure.

In a further preferred embodiment of the device according to the invention, the latter has one or more passage openings for the laser beam or beams. As a result, a device is provided, is ensured by the sure that the weakening lines can be introduced only at precisely defined locations in the sheet material. In particular, when using a CO ₂ laser, particularly preferably with a power of ≦ 2000 W, as is commonly used in the processing of plastics, especially in combination with the passage openings described above, a faulty insertion of lines of weakness or areas is reliably prevented, since such lasers do not penetrate the metal materials commonly used for such receptacles.

In Another aspect of the invention is a method of introduction at least one weakening in at least one gas-permeable layer having flat surface Material provided by means of one or more laser beams, wherein in a preferred embodiment of this method, the gas the burning of the plane At least inhibits material within the gas-permeable layer.

In a further advantageous embodiment of the method according to the invention becomes the temperature of the sheet material disposed in the cavity before introducing the weakening increased by laser or lowered, which, as already mentioned above, by a preheating of the through the gas permeable Layer passed through gas can be achieved. The change the temperature of the flat Material opposite the ambient temperature, whether by heating or cooling, can however, to any skilled in the art Art done. For example, the application of a heat or cold current on the plane Material, the irradiation of the plane Material called by infrared lamps or the like. Especially However, preferred is a method in which the pre-tempering by cooling down or heating the cavity defining the receiving device is at least supported.

Preferably becomes the areal Material to a temperature in the range of -40 ° C to 0 ° C, preferably -40 ° C to -30 ° C cooled. in this connection is used that on decor composites for use in motor vehicles requirements with regard to resistance to thermal cycling regular temperatures of up to -40 ° C. For example, an airbag shot must be in a temperature window safe from -40 ° C to + 85 ° C and almost independent guaranteed by the temperature be.

In the preferred temperature of -40 ° C to 0 ° C and more preferably from -40 ° C to -30 ° C is also guaranteed in any case that the heat generated during the laser process compared to sheet materials at room temperature can be dissipated improved. In addition, less material erosion occurs in the advantageous temperature range and thus less signage of the swelling on the decor side.

In an alternative and equally preferred embodiment of the inventive method becomes the areal Material, however, to a temperature in the range of + 50 ° C to + 120 ° C, especially preferably from + 80 ° C up to + 120 ° C heated. In turn Here is an advantage that in motor vehicles as decorative materials used composites regularly withstand temperatures of up to + 120 ° C have to, wherein in climate change tests of car companies an invisible damage to the Decorations in the temperature range of -35 ° C to + 120 ° C is expected.

In However, the most preferred range of + 50 ° C to + 120 ° C and in particular from + 80 ° C to + 120 ° C is In any case, it ensures that the component has its material properties such changes that it is sufficiently "soft" for laser processing is, so the weakening at significantly reduced laser power and thus also reduced energy input can be realized. This will also be a significantly reduced local material burn in the immediate vicinity of the weakened area causes what finally to a less visible sign of the weakening the decorative side leads.

In Regarding the advantages of the method according to the invention in alignment the laser beams through one or more ports in a receiving device defining the cavity at least a portion of the sheet material or in relation on the heat transfer from the receiving device on the sheet material over the Contact of the plane Material with at least one of the walls of the receiving device will be on the discussion related to the first aspect of Referenced invention.

The same applies to the weakening of the plane Materials with laser beams passing through a transparent cover the cavity can be effected.

The Method according to the invention, in which a gas through at least one gas-permeable layer of a composite material is passed through and during this passage process by means of one or more laser beams one or more weakenings introduced into at least partial layers of the sheet material will be particularly advantageous then can be executed when the cavity for receiving at least a portion of the sheet material can be closed with a cover to the sheet material at least non-slip. In a preferred embodiment of the However, the method is the cover gas-tight with the cavity defining receiving device connectable, so no special Gas tightness requirements of one or more gas-permeable layers limiting layers are provided. In such a case can the gas readily and without the risk of escape through the cavity and thus also by the planar material arranged therein be passed through.

In a further particularly preferred embodiment of the method according to the invention is the cover moreover transparent for The laser light is designed so that the weakenings also in one state in the area Material can be introduced in which the cover seals the cavity.

In Another preferred embodiment of the invention the areal Material before introducing the weakening in a suitable device clamped. This can be particularly advantageous by inserting the flat Materials in the for provided cavity of the device according to the invention and possibly the Placing a cover on the cavity can be achieved. Likewise is However, a device of the inventive concept comprises, in the such a jig outside the cavity and spaced is arranged to the laser.

Brief description of the drawings

The invention is explained below on the basis of exemplary embodiments, as shown in the attached 1 and 2 are shown. However, the exemplary illustrations of the figures are in no way intended to limit the scope of the invention as defined in the appended claims.

In the figures shows:

1 a schematic cross-sectional view of a recorded in a cavity sheet material, and

2 a schematic cross-sectional view of another embodiment of a sheet material.

Ways to execute the invention

In 1 a cross-sectional view of a part of a device according to the invention is shown, which consists essentially of a receiving device 7 that have a cavity 4 defined, as well as a cover 6 that exists on the cradle 7 rests. Inside the cavity 4 is a flat material 2 so included that with it the side walls 7a . 7b and the bottom wall 7c the cradle 7 in contact. Moreover, the sheet material lies 2 also at the bottom of the cover 6 completely on. The cover 6 is made of a transparent clear plastic so that laser beams of almost any wavelength can pass substantially unhindered without losing a substantial part of their energy already in the cover.

Between the cradle 7 and the cover 6 is also a circumferential seal 14 arranged through which a gas-tight cavity 4 is trained. In the bottom wall 7c the cradle 7 are a gas inlet 8a and a gas outlet 8b arranged, via which an inert gas, here nitrogen, at least during the introduction of the (not shown) weakenings in the sheet material 2 is passed through. The cradle 7 consists essentially of a full metal body through which, however, a plurality of channels 13 pass through which a fluid can flow as a heating medium. By passing the heating medium through the channels 13 becomes the cradle 7 completely and evenly heated, taking the heat of the receiving device 7 about the contact with the sheet material 2 on the inner walls of the receiving device 7 completely passed on. A similar structure is of course also for the passage of a cooling medium through the channels 13 suitable and in both alternative embodiments presented above, by the passage of a preheated gas, the temperature change of the sheet material 2 get supported.

In 2 is another embodiment of a sheet material according to the invention 2 represented here in the form of a decorative composite 2 present, as it is used to cover the instrument panel in a motor vehicle use. The decor composite 2 consists here of a decor carrier 2 B , a spacer knitted above 2c and one the decor composite 2 towards the visible side final plastic decoration 2a ' , This plastic decor 2a ' is completely gas tight and does not allow passage of any in the spacer fabric 2c present or passing gas. In the decor carrier 2 B are also a gas inlet 8s and a gas outlet 8b arranged, via which a gas through the decorative composite within the Abstandgewirks 2c can be passed through. During the combustion of at least parts of the decorative composite by absorbing the energy of a laser beam (not shown) for introducing weakenings (not shown) into the decorative composite 2 This could result in the resulting exhaust gases and / or burns quickly through the gas outlet 8b be discharged to the outside.

Claims (24)

Contraption ( 1 ) for introducing at least one weakening ( 12 ) in at least one gas-permeable layer ( 2c . 2c ' . 2c '' ) having flat material ( 2 ) by means of one or more laser beams, comprising a cavity ( 4 ) for receiving at least part of the sheet material ( 2 ), a means ( 8th ) for passing a gas through at least portions of the sheet material ( 2 ), as well as an element ( 10 ) for generating and aligning one or more laser beams on at least a portion of the sheet material ( 2 ). Contraption ( 1 ) according to claim 1, characterized in that the means ( 8th ) for supplying and discharging a gas in at least one of the walls ( 7a . 7b . 7c ) one of the cavity ( 4 ) receiving device ( 7 ) is arranged. Contraption ( 1 ) according to one of the preceding claims, characterized in that the cavity ( 4 ) a cover ( 6 ), preferably a gas-tight cover ( 6 ). Contraption ( 1 ) according to one of the preceding claims, characterized in that the gas is combustion-inhibiting. Contraption ( 1 ) according to claim 4, characterized in that the gas is an inert gas, preferably CO ₂ , N ₂ or a mixture thereof. Contraption ( 1 ) according to one of the preceding claims, characterized in that the sheet material ( 2 ) a decor ( 2a ), in particular for use in a motor vehicle, for example a wood decor ( 2a ' ) or a plastic decor ( 2a ' ), and a decor carrier ( 2 B ) and optionally a spacer knitted fabric ( 2c ) and / or a foam layer ( 2c ' ) and / or a fleece ( 2c '' ). Contraption ( 1 ) according to one of the preceding claims, characterized in that the cover ( 6 ) transparent to the laser beam (s). Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ) an element for raising or lowering the temperature of the in the cavity ( 4 ) recorded sheet material ( 2 ). Contraption ( 1 ) according to one of the preceding claims, characterized in that the cavity ( 4 ) of a heatable or coolable receiving device ( 7 ) is defined. Contraption ( 1 ) according to claim 9, characterized in that the receiving device ( 7 ) at least one channel ( 13 ) for the passage of a heating or cooling medium. Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ) one or more passage openings (s) ( 9 ) for the laser beam (s). Contraption ( 1 ) according to one of the preceding claims, characterized in that the element ( 10 ) for generating and aligning one or more laser beams, a CO ₂ laser, preferably with a power of ≤ 2000 watts. Method for introducing at least one weakening into at least one gas-permeable layer ( 2c . 2c ' . 2c '' ) having flat material ( 2 ) by means of one or more laser beams, comprising the steps of - depositing at least a portion of the sheet material ( 2 ) in a cavity ( 4 ), - the passage of a gas through the at least one gas-permeable layer ( 2c . 2c ' . 2c '' ) of the sheet material ( 2 ), and - introducing at least one weakening into the sheet material ( 2 ) by means of one or more laser beam (s). A method according to claim 13, characterized in that the gas, the combustion of the sheet material ( 2 ) is at least inhibited by the gas. Method according to one of claims 13 or 14, characterized in that the temperature of the cavity in the cavity ( 4 ) arranged sheet material ( 2 ) is increased or decreased. Method according to claim 15, characterized in that the sheet material ( 2 ) is cooled to a temperature in the range of -60 ° C to 0 ° C, preferably -40 ° C to -10 ° C. Method according to claim 15, characterized in that the sheet material ( 2 ) is heated to a temperature in the range of + 50 ° C to + 120 ° C, preferably + 50 ° C to + 90 ° C. Method according to one of claims 15 to 17, characterized in that the raising or lowering of the temperature of the sheet material ( 2 ) is at least supported by the gas. Method according to one of claims 13 to 18, characterized in that the laser beam or beams pass through one or more passage openings (s) ( 9 ) in a cavity ( 4 ) receiving device ( 7 ) on at least a portion of the sheet material ( 2 ). according to claim 19, characterized in that the receiving device ( 9 ) can be heated or cooled and the heat input into or the heat removal from the sheet material ( 2 ) for raising or lowering the temperature of the sheet material ( 2 ) about the contact of the sheet material ( 2 ) with at least one of the walls of the receiving device ( 7 ) is effected. Method according to one of claims 13 to 20, characterized in that the method further comprises closing the cavity ( 4 ) with a cover which is preferably transparent to the laser beam (s) ( 6 ) before introducing at least one weakening into the heated or cooled sheet material ( 2 ). A method according to claim 21, characterized in that the laser beam or rays through the transparent cover ( 6 ) through the sheet material ( 2 ) partially weaken. Method according to one of claims 13 to 22, characterized in that the sheet material ( 2 ) is clamped in a suitable device prior to the introduction of the weakening. Method according to one of claims 13 to 23, characterized in that it is in a device ( 1 ) is carried out according to one of claims 1 to 12.