Patent Application
20120100342
The invention relates to a composite part according to the preamble of the main claim, as well as to a method for manufacturing such a composite part.
Composite parts of the known type are mainly applicable in the field of automobiles and in particular with inner trim parts, such as instrument panels, middle consoles, vehicle seats, arm rests, door inner trims or likewise.
Such composite parts are disclosed in the application PCT/EP2010/001890, which comprise a substrate, on which skins connected by a seam are positioned by way of a holding profile. The holding profile comprises two wings which simplify an adjustment of the course of the seam on the substrate. Thus a simple deposition of two skins connected by seams is possible for different substrates, i.e. fixed substrates. However, relatively firm haptics result in the region of the holding profile with such composite parts.
It is therefore the object of the invention to suggest a composite part, with which a course of a seam is positioned in a simple manner and which at the same time permits soft haptics.
This object is achieved by a composite part according to claim 1 as well as by a method according to claim 9. Advantageous further formations and designs are to be deduced from the features of the dependent claims.
The composite part according to the invention comprises a first and a second skin, a holding profile and a sub-material. The sub-material according to the invention has a compression hardness of 50 kPa at the most with a compression of 40%. This means that at the most, a pressure of 50 kPa is necessary in order to compress the sub-material by 40%. This value of the compression hardness may for example be determined by testing methods according to ISO 3386/1. A recess is introduced into the sub-material, in which recess the holding profile is arranged. The holding profile has a groove which extends in a longitudinal direction and is delimited by two side walls as well as a base, and at least one first wing and preferably a second wing, wherein the first wing connects to the first side wall, and the second wing to the second side wall at the open end, i.e. the side of the groove which lies opposite the base. The wings thereby extend outwards away from the groove in a direction which is essentially orthogonal to the longitudinal direction as well as an opening direction. Essentially, orthogonal is to be understood in that an angle between the longitudinal direction or the opening direction also indicated at the height direction and the wings is between 80 and 100°. Preferably, these wings each have a thickness (i.e. extension in the height direction) which is smaller than the depth of the groove. In a further embodiment, the wings have a thickness which is maximally 80%, 60%, 40% or 20% of the depth of the groove. The first and the second skin each project with an end section into the groove of the holding profile, wherein the two end sections of the skins are connected to one another by way of a seam arranged in the groove. Not only is a seam having a yarn to be seen as a seam, but also a connection of the two end sections of the skins by way of a bonding or a welding seam. The base of the groove in a further embodiment is designed in a mainly closed or continuously closed manner.
Soft haptics of the complete composite part result due to the use of a soft sub-material according to the invention. This, amongst other things, is advantageous with the use of the composite part for vehicle seats or arm rests. The fact that a positioning of skins on a soft sub-material by way of a holding profile possible in this manner was not to be expected by the man skilled in the art, since one was concerned that a softness of the sub-material reduces the positioning reliability of the holding profile in the recess.
The sub-material is preferably manufactured before introducing the holding profile. Thus no direct material-fit connection exists between the substrate and the holding profile. An indirect connection between the sub-material and the holding profile, for example by way of bonding the holding profile into the recess, may however be envisaged.
In further embodiments of the invention, a compression hardness with respect to a compression by 40% is 30 kPa, 20 kPa, 10 kPa or 5 kPa at the most. Particularly soft haptics result by way of this, wherein a high positioning reliability is given despite this.
In a further embodiment of the invention, a foam layer is used as a sub-material. Particularly preferably, the sub-material may consist of front foam, i.e. an injected foam, or from a cut foam. The foam layer preferably has a density of less than 500 kg/m3, particularly preferably of less than 200 kg/m3 and further preferably of less than 150 kg/m3, 100 kg/m3, 80 kg/m3 or 50 kg/m3. An advantageously low weight of the composite part results by way of the application of a sub-material with such a low density. Moreover, a reduced quantity of plastic is used for the manufacture of the foam layer, by which means the production costs are reduced. Moreover, such a low density influences the haptics of the composite part in a positive manner
In a further embodiment of the invention, adhesive, preferably in the form of an adhesive layer, is deposited between the sub-material and the skins. A particularly secure retention of the skins on the sub-material is made possible by way of this. In particular, a particularly reliable connection results with the use of a foamed sub-material, since either a surface of the foam layer available for the connection is very large, or the adhesive may even penetrate partly into the sub-material, depending on the type of foamed sub-material. It is to be noted that a plurality of adhesive points may be sufficient instead of a continuous adhesive layer.
In a further embodiment, the sub-material is deposited with a lower side onto a substrate. The substrate may for example consist of polypropylene (PP), glass-fibre reinforced polypropylene (PPLGF), a wood fibre composite material or another natural fibre material.
If a front foam is used as a sub-material, this may be injected onto the substrate and thus be directly connected to this with a material fit. With the use of cut foam as a sub-material, this may for example be bonded onto the substrate. A particularly reliable connection hereby results if a continuous adhesive layer is used between the sub-material and the substrate, for bonding the sub-material onto the substrate.
In a further preferred embodiment of the invention, a pin connects to the side of the base which is away from the groove. At least one anchor may particularly preferably connect to the pin. A secure positioning of the holding profile in the recess of the sub-material is achieved by way of the pin or anchor.
Different designs of recess are possible depending on the embodiment. It has been found to be particularly suitable to design the recess in the sub-material as a positioning groove with an elongate positioning groove trough. One shape of the positioning groove may thereby correspond to a shape of the holding profile. A particularly firm connection between the holding profile and the positioning groove is possible if the positioning groove trough is shaped as an undercut. What is meant here is that a width of the positioning groove trough on the base of this is larger than the width of the positioning groove at its upper edge. With such an embodiment, it is preferable for example if the pin and/or the anchor have a greater width than the positioning groove at the upper edge of this groove. If then the pin, as the case may be with the anchor, presses into the positioning groove, an rear engagement arises, which makes it difficult to pull out the holding profile in the direction of the open side of the groove. This thus arising connection may be indicated as a positive-fit connection, as a toothing, as a blocking or as a locking.
However embodiments are also possible, in which the positioning groove has a constant positioning groove width over the height. In these embodiments, the pin and/or the anchor are preferably designed in a manner such that a pressing between the anchor or pin and the positioning groove trough arises in the lateral direction. A pulling-out of the holding profile is then prevented by adhesive friction between the positioning groove trough and the anchor or pin. The thus arising connection may also be called a non-positive fit connection.
In a further embodiment of the invention, the composite part comprises a bend-over region, in which a height of the holding profile is reduced. A bending stiffness of the holding profile in the bend-over region is reduced by way of this, by which means a positioning of the holding profile with the skins which are introduced here, is simplified in the positioning groove trough.
Advantages arise by way of the design with a bend-over region, in which the height of the holding profile is reduced, in particular in combination with the soft sub-material according to the invention, since a bending stiffness which is too large would lead to a restoring force arising when pressing the holding profile into the positioning groove. This would deform a recess introduced into a soft sub-material or press the holding profile out of the recess, by which means an increased effort would be necessary, in order to prevent the holding profile from slipping out of the positioning groove when positioning.
In a further embodiment of the invention, the height of the holding profile in the bend-over region is reduced by way of either the pin in the bend-over region having a reduced length or no pin being arranged in the bend-over region. In this manner, a height of the holding profile may be reduced in a simple manner For example, firstly a holding profile with a height which is constant over the length may be manufactured, wherein the pin is shortened or separated off in the bend-over region or in the bend-over regions. One or more anchors may be removed when shortening or separating off the pin.
The bend-over region may be arranged in an edge region of the profile, i.e. at one end of the profile seen in the longitudinal direction of the profile, depending on the design of the composite part. It is just as well possible for the bend-over region to be arranged in a middle region of the profile. Moreover, it is possible for several bend-over regions to be provided. The length of the bend-over region or bend-over regions may for example in each case lie between 10 mm and 40 mm, between 15 mm and 30 mm or between 20 mm and 25 mm. A residual height of the holding profile in the bend-over region may for example lie between 1.5 mm and 3 mm, between 1.8 mm and 2.7 mm or between 2.1 mm and 2.4 mm
It is preferable if the holding profile consists of a preferably extruded plastic and has a Shore hardness (preferably Shore A hardness) between 25 and 100, preferably between 40 and 70. A holding profile manufactured of a corresponding plastic has the necessary softness for creating complicated curved seam courses. Moreover, it is possible to manufacture infinitely long holding profiles by way of the extrusion method, wherein the longitudinal direction of the holding profile or of the groove corresponds essentially to the extrusion direction.
In a further embodiment of a composite part, the holding profile extends over the whole length of the seam connecting the skins. By way of this, a seam course may be reliably positioned over the whole length. A later deposition of the skins onto a substrate is simplified by way of this, since a course of the seam is completely defined by the profile extending over the whole length. In some embodiments, the holding profile has the same length as the seam connecting the skins. In further embodiments, the holding profile is longer than the skin connecting the skins. Independently of whether the holding profile is longer or equally long as the seam, preferably at least a 10 mm to 40 mm, 15 mm to 30 mm or 20 mm to 25 mm long coherent section of the seam connecting the skins is arranged in the bend-over region of the holding profile.
In a further embodiment of the invention, the holding profile is bent over in at least one bend-over by at least 30°, preferably at least 45° or at least 60° or at least 80° . In a further embodiment, the holding profile, in the bend-over region or in each of the bend-over regions, is bent over by about 180° at the most. In a further embodiment, a bending radius of the holding profile measured at the lower side of the base of the holding profile, in at least one bend-over region, is less than 20 mm, 10 mm or 5 mm.
Additionally or alternatively to the bending of the holding profile in the height direction, the holding profile, at least in regions, may be arranged tilted with respect to the opening direction of the recess. What is meant with this is that the holding profile, with respect to an installed position, in which the side walls of the groove (i.e. the opening direction of the groove) run parallel to the opening direction of the recess (also called mould removal direction), is tilted about an axis running in the longitudinal direction. A maximal tilting angle may for example be smaller than 30° and preferably be between 1° and 12°.
Particularly preferably, the recess at an end lying in the bend-over region may run out in a notch of the sub-material and/or substrate, wherein the base of the holding profile in the bend-over region projects into the notch region. This notch may for example also be arranged partly in the sub-material and be led further into the substrate.
In a further embodiment of the invention, the holding profile runs around the composite part. For example, the composite part may be designed as an arm rest, wherein this comprises a peripheral seam arranged in the holding profile. For example, in this embodiment, the holding profile comprises several bend-over regions which are offset to one another in the longitudinal direction of the holding profile. The holding profile between the bend-over regions preferably has the whole height, i.e. a pin is not shortened between the bend-over regions.
Moreover, the invention includes a method for manufacturing a composite part. Before the method, a sub-material with a recess is produced, whereby a compression hardness of the sub-material which at the most is 50 kPa with respect to a compression by 40%. Moreover, a holding profile with a groove which is delimited by side walls and a base and extends in a longitudinal direction is created. Moreover, the first skin and the second skin are produced. These may for example consist of leather or of an artificial leather and/or a slush skin. The exact sequence of the manufacture of these components in this context is insignificant. With the method, an end-section of the first skin is connected to an end section of the second skin by way of a seam. The seam may thereby be designed as a seam having a yarn. Likewise however, a bonding connection between the end sections is possible.
The end section of the first skin and the end section of the second skin are moreover introduced into the groove of the holding profile. This may be effected either before the connection of the end sections to one another or thereafter. If the introduction of the end sections into the groove is effected before the end sections are connected to one another, the end sections may be connected by a seam which goes through the side walls of the holding profile and simultaneously also connects the holding profile to the end sections. This seam may be produced by way of sewing through the side walls. Likewise, it is also possible to design the seam as a weld seam. For this, a heated gas (air for example) may be led to the connection location of the end sections, so that these melt with one another. The holding profile is introduced into the recess of the sub-material after the end sections are connected to one another and introduced into the groove.
In a further embodiment of the invention, the sub-material is connected to a substrate preferably before the holding profile is introduced into the recess of the sub-material. The connection of the sub-material and the substrate may either be effected on producing the sub-material, for example by way of foaming or integrally forming the sub-material onto the substrate, or after the production of the sub-material, for example by way of bonding the sub-material onto the substrate. If a connection of the sub-material and the substrate is effected by way of foaming-on the sub-material, prior to this, the substrate is inserted into a foam mould, wherein the foam mould is subsequently closed, so that a foaming cavity arises. Then a plastic material which is suitable for foaming, for example a two-component foam, is introduced into this. A foaming procedure is preferably initiated before heating the foaming mould. Preferably, the foaming mould may contain a projection which corresponds to the shape of a recess to be produced in the sub-material.
Further details of the holding profile and of the composite part, in particular with respect to the first skin, the second skin, the wings (including a possible formation with teeth or with slots), the side walls, the base, the groove, the substrate groove (wherein this, in the framework of this invention, is arranged in the sub-material instead of in the substrate and is indicated as a positioning groove), the pin, the design and arrangement of the anchor(s), of the seam/seams, of the end sections, of the connection of the holding profile to the recess, of the materials from which the holding profile and the first and second skin as well as the substrate consist, may be deduced from the already mentioned document with the international application number PCT/EP 2010/001890, which in this context is declared as an integral part of the disclosure of the present application. Likewise, further details of the method for manufacturing a composite part, in particular with regard to the connection of the first and second skin or their end sections to one another or to the holding profile or to the wings of the holding profile, may be likewise deduced from this document. The mentioned document is to be part of the contents of disclosure of the present application, also in the framework of these mentioned features.
The at least one wing of the holding profile amongst other things serves for the connection between a part section of the first or second skin which connects to the end section, to a first or second of the at least one wing of the holding profile, by way of a first and second seam respectively. With this, the first and second seam comprises at least one yarn. This means in particular that the connection between the end section of the first or second skin and the first or second wing is such that at least one yarn engages at least in sections behind the first or second wing, seen from a viewed side of the first or second skin. With regard to the first and second skin, it is preferably the case of deco-seams or decorative seams.
The presence of two wings, amongst other things is necessary if a first or second seam is to be introduced on both sides of the connection location of the first and second skin.
Since the end sections of the first and second skin are in each case guided or held in the groove, only one layer of the first and second skin needs to be sewn to the first and second wing respectively. This reduces the quantity of the material of the first and second skin which is to be used. Moreover, the force to be applied for introducing the seam is reduced, since it is only one layer of the first or second skin which needs to be pierced.
No prior gluing (bonding) between the holding profile and the first or second skin is needed. The co-sewing of a seam strip, as is necessary in previous methods, may also be done away with. On account of the depth and the width of the groove, the first or second skin may for example be held in the groove in a slightly clamped or loose manner. By way of this, it is possible to influence the shape or the optics of the connection location between the first and second skin, which is visible from the viewed side of the first and second skin.
The wings permit an exact positioning of the holding profile in a recess of a substrate and serve as spacers or position holders. An exact dimension of the depth and width of the recess is no longer necessary due to the wings, since the wings are supported on an oppositely lying flange which is attached on a side wall of the groove, in an equalising manner on the surface of the substrate which is located next to the recess and delimits this.
Since the wings have a material thickness or wing thickness which is less than the depth of the groove and lies in the region of less than 1.5 mm, preferably less than 1 mm, the slight projection of the holding profile out of the surface of the substrate which is caused by the wings, is not significant. Thus an exact positioning of the course of the seam or groove which is simple to obtain and in not evident in its appearance, may be achieved with the help of the wings. The wing or wings are essentially not recognisable as a projection, in particular if a first and a second skin are arranged in the holding profile and cover the wing on the viewed side. Thus an essentially plane ending is effected between a viewed-side substrate surface and the holding profile arranged in a recess of the substrate, without extensive adjustment.
A time-saving of between 20% and 80% with respect to conventional methods for manufacturing a composite part according to the state of the art may be achieved with the help of the profile according to the invention and the composite part according to the invention.
An independent part of the invention relates to composite parts, with which a welding connection or welding seam of the skins is envisaged instead of a connection of the skins by way of a seam arranged in the groove. A design with a welding connection instead of a seam having a yarn may be considered as being advantageous with all composite parts disclosed in this application. Likewise, the independent part of the invention relates to any composite parts disclosed by PCT/EP 2010/001890, wherein a welding connection is each provided instead of the seam arranged in the groove.
This independent part of the invention therefore relates to a composite part with the first skin, a second skin and a holding profile, wherein the holding profile comprises a groove extending in a first direction. The first and second skin is hereby connected by way of a welding seam. An end section of the first skin, an end section of the second skin and the welding seam are thereby arranged in the groove. The holding profile furthermore comprises at least one, preferably two wings.
In a method according to the independent part of the invention, the composite part is manufactured as is defined in one of the claims 4 to 11 of PCT/EP 2010/001890, wherein the seam arranged in the groove is designed as a welding seam. Preferably, the welding seam may be manufactured by way of a hot-air welding process. For this, the end sections of the first and second skin may be arranged in the groove of the holding profile and subsequently heated by way of hot air, so that a bonding (frictional) connection is produced by way of bonding the end sections to one another. A sewing guide for positioning the skins in the groove is not necessary on account of this.
Embodiment examples of the invention are hereinafter explained in more detail by way of the figures. There are shown in:
a a sectioned view through the composite part of
b a sectioned view through a bend-over region of the composite part according to an alternative preferred embodiment,
a and 4b a representation of steps of a method for manufacture of the composite part of
The holding profile 2 which is arranged in the recess 18 comprises a groove 3 which extends in the longitudinal direction (the direction orthogonal to the picture plane) of the holding profile 2 and which is delimited by a first side-wall 4, a base 5 and a second side-wall 6. A pin 7 connects to the lower side of the base 5. The pin 7 is equipped with one or more anchors 8 which produce a particularly firm retention of the holding profile 2 in the recess 18.
End-sections 13, 14 of the two skins 11, 12 are arranged in the groove 3. The end-sections 13, 14 there are connected by way of a first seam 15 which for example comprises a yarn. A glued connection or welding connection would also be possible instead of a seam 15. A welding connection may for example be manufactured in a manner such that firstly the end-sections 13, 14 of the skins 11, 12 are arranged in the groove 3 and subsequently heated by way of hot air and welded to one another.
Additionally to the connection of the skins 11, 12 to one another by way of the seam 15, the first skin 11 is connected to the first wing 9 by way of a second seam 16, and the second skin 12 to a second wing 10 by way of a third seam 17. The seams 16, 17 may thereby preferably be designed as decorative seams (also called deco-seams) and the seam 15 may be designed as a functional seam. With this, the wings 9, 10 are a constituent of the holding profile 2 and connect to the upper edges of the side walls 4, 6 in a manner running outwards away from the groove. A positioning of a course of the seam 15 is simplified by way of the wings 9, 10. Rest regions 20 which are arranged set back with respect to a surrounding surface of the sub-material 19, are provided, in order to permit a flush termination of the wings 9, 10 with the upper edge of the sub-material 19. Moreover, a positioning of the course of the seam 15 is further simplified by the rest regions 20, since when pressing the holding profile 2 in the groove 3, and automatic centring of the holding profile in the groove 3 is achieved by way of this.
A sectioned view of a second advantageous embodiment of a composite part is represented in
A section along the line 25 through the bend-over region 27 according to an alternative embodiment of an arm rest is represented in
Method steps for manufacturing an arm rest 24 of
Even if composite parts according to the invention have been described previously be way of the example of an arm rest, the invention also relates to other analogously designed vehicle inner trim parts such as dashboards, door inner trims or seats.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 045 729.9 | Sep 2010 | DE | national |
