Method for manufacturing a foam molded part with clip elements, clip holders; foam molded part and vehicle seat

Abstract

Method for producing a foam molded part (210) in a molding tool, wherein a molding tool is provided in which a carrier element (400) with a plurality of clip holders (212, 312) is arranged before foaming and demolding the foam molded part (210), wherein a clip element (202) is pre-attached to the respective clip holder (212, 312) and subsequently a foam material is introduced into the molding tool and cured, wherein a gas generated during demolding of the foam molded part (210) is discharged via the respective clip holder (212, 312), and wherein after foaming and curing of the foam molded part (210) it is removed from the molding tool together with the clip holders (212, 312) and the clip elements (202).

Description

The invention relates to a method for manufacturing a foam molded part with clip elements, a clip holder for a clip element, a foam molded part with several integrated clip elements, and a vehicle seat with such a foam molded part with several integrated clip elements. State of the art Clip elements (also called clips for short) for attaching a seat cover to a foam part of a seat cushion are generally known from the prior art. These clip elements are embedded in the foam part of the seat cushion during its production. During this process, chemical reactions can typically cause gases to expand during the embedding or encasing of the clip elements, which can lead to the foam collapsing and the formation of voids in the finished foam part. For example, such clip elements for attaching a seat cover are known from US 2022 / 0080866 A1 and US 2015 / 0328808 A1. Task The invention is based on the objective of improving a manufacturing process of the type mentioned at the outset, as well as providing an improved clip holder for the manufacturing process, an improved foam molding part and a corresponding vehicle seat with an improved foam molding part. Solution The first-mentioned problem is solved according to the invention by a method for producing a foam molded part, wherein a molding tool is provided in which a carrier element with a plurality of clip holders is arranged, in particular positioned, and / or held before the foam molded part is encased and demolded, wherein a clip element is pre-attached to the respective clip holder and subsequently a foam material is introduced into the molding tool and cured, wherein a gas generated during demolding of the foam molded part is discharged via the respective clip holder. In other words, the clip holder is part of an automatic venting system for the molding tool. For example, nearly 100% of the generated gas is discharged by means of the clip holder. After the foam molding process and curing, the molded part is removed from the mold along with the clip holders and clip elements, which are either partially or fully foamed in. Using clip holders with integrated gas venting or ventilation, a molded foam part with an improved, particularly homogeneous, surface can be produced. The second problem is solved according to the invention by a clip holder with an integrated vent (also called gas vent or internal vent). The clip holder, for example, comprises a hollow inner channel. An outwardly open end of the clip holder can also serve as a receptacle for the clip element. Additionally, the clip holder can have one or more open-ended vent channels extending from the inner channel. For example, the inner channel extends longitudinally along the clip holder, and the vent channels extend radially outward from the inner channel to an open end. The outwardly open ends of several venting channels can preferably be arranged symmetrically distributed on one plane around the circumference of the clip holder. This allows for uniform venting, thereby reducing or preventing voids or depressions during the foaming process. Preferably, the clip holder can have a multi-part and height-adjustable design. This allows the same clip holders to be used for different foam molded parts. The third problem mentioned is solved according to the invention by a foam molded part which has a plurality of integrated, in particular partially foamed or partially overmolded clip elements which can be attached to the foam molded part by means of integrated, in particular partially foamed or partially overmolded or fully foamed or fully injected clip holders, wherein the integrated clip holders each have the integrated venting, for example in the form of an internal venting channel. Because each clip holder has an integrated internal vent, additional venting channels in the mold can be avoided. Furthermore, such a clip holder with integrated internal venting allows for easy venting around the clip element. This prevents foam indentations and voids in the area of ​​the clip elements during the foaming process of the molded part. The mold is, in particular, a foam mold. Advantageously, the foam mold comprises a mold with at least one cavity, which is filled with a material of the foam part to be produced, so that the foam part is formed from the material, in particular from a foam, with embedded clip holders with integrated venting and with partially embedded clip elements. After the foam molding process and curing of the foam part, it is removed from the foam mold along with the embedded clip holders and clip elements. This prevents the partially embedded clip elements from coming loose from the foam mold during removal. The solution according to the invention reduces the manufacturing time of the foam mold because the clip elements can be positioned more easily and quickly in the foam mold. Furthermore, the amount of waste and the reject rate during the production of the foam mold are significantly reduced due to the simple, integrated venting in the clip holders. In addition, other, considerably more complex venting systems are avoided. The fourth problem mentioned above is also solved according to the invention by a vehicle seat which comprises the previously described foam molding part. The foam molding part is, for example, a seat part or a backrest part. In summary, the invention provides a foam molded part with improved, foamed-in clip elements. The idea behind this invention is to integrate the venting into the clip holder. The clip holder is part of the automatic venting system. Air or gas that needs to be vented during the foaming process is thus reliably routed from the mold to the venting point. By integrating the venting into the clip holder, the venting occurs below the clip element itself. The clip holder is attached to a support or finger. The clip element is inserted into the receptacle of the clip holder. This allows for venting all around the clip element. Figures and embodiments of the invention The invention is explained in more detail below with reference to advantageous embodiments illustrated in the figures. However, the invention is not limited to these embodiments. The figures show: Fig. 1: a side view of a vehicle seat, Fig. 2: a schematic top view of a manufactured foam molding part according to the prior art, Fig. 3: a schematic top view of a foam molding part manufactured according to the invention, Fig. 4: an enlarged view of Fig. 3 in the area of ​​two embedded clip elements, Fig. 5: a top view of a first embodiment for a clip holder, Fig. 6: a side view of the clip holder according to Fig. 5, Fig. 7: a bottom view of the clip holder according to Fig. 5, Fig. 8: a section along line VIII-VIII in Fig. 6, Fig. 9: an enlarged view of Fig. 8 in the area of ​​a receptacle for the clip element, Fig. 10: a side view of a second embodiment for a clip holder, Fig.Fig. 11: a top view of a support element before foaming, Fig. 12: a partial perspective view of the unfoamed support element in the area of ​​a clip holder with a pre-attached clip element, Fig. 13: a partial perspective view of the unfoamed support element in the area of ​​a clip holder without a pre-attached clip element, Fig. 14: a top view of a support element before foaming and with clip holders partially inserted, Fig. 15: a perspective view of the support element according to Fig. 14 with clip elements attached to the clip holders, and Fig. 16: a perspective view of the support element according to Fig. 15 with clip holders fully inserted into the support element and clip elements attached. Corresponding parts are marked with the same reference symbols in all figures. A vehicle seat 100, schematically depicted in Fig. 1 as a prior art design, is described below using three mutually perpendicular spatial directions. A longitudinal direction x of a vehicle seat 100 installed in a vehicle runs largely horizontally and preferably parallel to a longitudinal direction of the vehicle, corresponding to the vehicle's usual direction of travel. A transverse direction y, perpendicular to the longitudinal direction x, is also horizontally oriented in the vehicle and runs parallel to a transverse direction of the vehicle. A vertical direction z runs perpendicular to the longitudinal direction x and perpendicular to the transverse direction y. In a vehicle seat 100 installed in a vehicle, the vertical direction z preferably runs parallel to a vertical axis of the vehicle. The position and direction designations used, such as front, rear, top, and bottom, refer to the viewing direction of an occupant seated in vehicle seat 100 in a normal seating position, whereby the vehicle seat 100 is installed in the vehicle, in a suitable position for passenger transport with the backrest 104 upright, and oriented in the direction of travel as usual. However, the vehicle seat 100 can also be installed or moved in a different orientation, for example, transversely to the direction of travel. Unless otherwise described, the vehicle seat 100 is designed to be mirror-symmetrical about a plane perpendicular to the transverse direction y. The backrest 104 can be pivotally mounted on a seat section 102 of the vehicle seat 100. For this purpose, the vehicle seat 100 can optionally include a fitting 106, in particular an adjustment fitting, swivel fitting, locking fitting or wobble fitting. The position and direction specifications used, such as radial, axial, and circumferential, refer to a rotation axis 108 of the fitting 106. Radial means perpendicular to the rotation axis 108. Axial means in the direction of or parallel to the rotation axis 108. The vehicle seat 100 can optionally include a longitudinal adjustment device 110. The longitudinal adjustment device 110 comprises, for example, a rail arrangement 112 with a first rail element 114 and a second rail element 116. The first rail element 114 is adjustable in the longitudinal direction x relative to the second rail element 116. The first rail element 114 is attached to the seat part 102. The second rail element 116 is attached to a structural element of a vehicle, for example, a vehicle floor. For clarity, the first rail element 114 will be referred to as the upper rail 114 in the following description. This upper rail 114 (also called running rail or carriage) is assigned to and designed to support the vehicle seat 100. The second rail element 116 will be referred to as the lower rail 116. The lower rail 116 is fixed and, for example, connected to the floor of a vehicle. Fig. 2 schematically shows a top view of a molded foam part 200, which was manufactured according to the prior art. The molded foam part 200 can be a cushioning part for the vehicle seat 100 according to Fig. 1. The molded foam part 200 can, for example, be a cushioning part for the backrest 104, the seat part 102, or a headrest. The foam molding 200 includes integrated clip elements 202 (also called clips for short) for attaching a seat cover (not shown) to the foam molding 200 (also called upholstery element). These clip elements 202 were embedded in the foam during the manufacturing of the foam molding 200. Due to insufficient ventilation during the embedding or surrounding of the clip elements 202, cavities 204 formed in the area of ​​the clip elements 202 of the manufactured foam molding 200. The clip elements 202 each comprise, for example, a foot element 206 to be foamed into the foam molding part 200 and a receiving element 208 for attaching the seat cover (not shown). For example, a seat cover fastening element can be hooked or clipped into the receiving element 208. For this purpose, the at least one receiving element 208 is designed, for example, as a hook or double hook. In another embodiment, the at least one receiving element 208 is designed, for example, as a bridge to which at least one seat cover fastening element, designed as a so-called hogring, can be attached. Such a hogring is a substantially ring-shaped clamp or clip which has a through-opening in its circumference for the passage of the bridge, which can then be closed, for example, by squeezing the hogring together with pliers. The respective clip element 202 comprises, for example, a plate-like area as a foot element 206 for the form-fit and / or material-fit fastening of the clip element 202 in the foam molding 200 by foaming the plate-like area during the manufacture of the foam molding 200. The respective clip element 202 can thus be partially foamed over with material for forming the foam molding 200 during the manufacture of the foam molding 200, so that after the foam molding 200 has hardened, the clip element 202 is partially arranged in the foam molding 200 and is thereby form-fit and / or material-fit fast to the foam molding 200. Fig. 3 schematically shows a top view of a foam molded part 210 manufactured according to the invention. Identical clip elements 202 are foamed into the foam molded part 210 manufactured according to the invention. The clip elements 202 correspond to the clip elements 202 described above with regard to structure and function. In particular, due to an improved venting process during the manufacturing of the foam molded part 210, the clip elements 202 are integrated into the foam molded part 210 manufactured according to the invention without cavities 204 in the area of ​​the foot elements 206 (shown in Fig. 2) and thus with the foot elements 206 (shown in Fig. 2) completely foamed in. In other words, the foot elements 206 are completely covered by the material, in particular by the foam material. The receiving element 208 protrudes from the foam molded part 210 manufactured according to the invention. Fig. 4 shows an enlarged view of Fig. 3 in the area of ​​two clip elements 202 foamed into the foam molded part 210 manufactured according to the invention. The respective receiving element 208 is designed as a double hook and protrudes from the foam molded part 210 manufactured according to the invention. Fig. 5 shows a top view of a first embodiment of a clip holder 212. Fig. 6 shows a side view of the clip holder 212 according to Fig. 5. Fig. 7 shows a bottom view of the clip holder 212 according to Fig. 5. Fig. 8 shows a section along line VIII-VIII in Fig. 6. The clip holder 212 serves to pre-attach the clip element 202 (shown in Fig. 2, Fig. 3 to Fig. 4) before foaming or overmolding the clip element 202. The respective clip holder 212 is designed to vent any gas generated during the demolding of the foam molded part 210. In other words, the clip holder 212 is part of an automatic venting system for a mold tool (not shown in detail). For example, the clip holder 212 allows almost 100% of the gas produced to be discharged. The clip holder 212, for instance, has an integrated vent 214 (also called internal venting). An integrated vent 214 refers in particular to an internal venting system, especially an internal channel system, incorporated into the clip holder 212. The clip holder 212 includes, for example, an inner channel 216 (shown in Fig. 8). An outwardly open end 218 (shown in Fig. 5 and Fig. 9) of the clip holder 212 can additionally be designed, for example, as a receptacle 220 (shown in Fig. 8 and Fig. 9) for the clip element 202. Additionally, the clip holder 212 can have one or more end-open vent channels 222 extending from the inner channel 216 (shown in Fig. 6). For example, the inner channel 216 (shown in Fig. 8) extends longitudinally along the clip holder 212, and the vent channels 222 extend radially outward from the inner channel 216 to an open channel end 224 (shown in Fig. 6). The channel ends 224 are arranged symmetrically around the circumference of the clip holder 212 on a plane. The clip holder 212 has a closed end 226 (shown in Fig. 6) opposite the open end 218. Fig. 9 shows an enlarged view of Fig. 8 in the area of ​​the receptacle 220 for the clip element 202. Fig. 10 shows a side view of a second embodiment for a clip holder 312. The alternative clip holder 312 differs from the clip holder 212 in that the clip holder 312 is adjustable in its dimensions. For example, the length of the clip holder 312 can be changed. Additionally or alternatively, an outer circumference, in particular a diameter, of the clip holder 312 is adjustable. The clip holder 312 has an internal integrated vent 314, analogous to the clip holder 212. The clip holder 312 comprises a height-adjustable receptacle 320, an internal channel 316 adjustable in length 330, and several venting channels 322, the channel ends 324 of which are arranged one above the other along the longitudinal extent of the clip holder 312. The internal integrated venting 314 can be varied and controlled during the foaming process in the mold by means of the length-adjustable clip holder 312. For example, the number of open channel ends 324 of the venting channels 322 can be varied. For this purpose, the clip holder 312 is designed in multiple parts. The clip holder 312 comprises, for example, several interlocking and mutually adjustable elements 332. These elements 332 have different and corresponding external dimensions to allow for telescopic movement relative to one another. This allows both a first external dimension 334, in particular an external diameter, of the receptacle 320 and a second external dimension 336 of the closed end 326 of the clip holder 312 to vary. For adjustment, in particular longitudinal adjustment, of the elements 332, these can be provided with mutually corresponding adjustment mechanisms 338, in particular with threads, for example mutually corresponding internal threads and external threads. Fig. 11 shows a top view of a support element 400 before the foaming and molding of the foam molded part 210 produced according to the invention. The support element 400 is, for example, a support plate or a support shell for the seat part 102 or the backrest 104 (shown in Fig. 1). The support element 400 can, for example, be made of a metal alloy or a metal or a hybrid material, in particular a fiber-reinforced plastic material. The support element 400 comprises a plurality of openings 402. One of the previously described clip holders 212 or 312 can be inserted into the openings 402, in particular by plugging them in. The clip holder 212 is fixed with respect to its longitudinal dimension. The clip holder 312 is variably adjustable with respect to its longitudinal and / or transverse dimension. The clip holders 212 or 312 can first be pre-positioned and pre-fixed in one of the respective openings 402, or fully inserted and fixed. The clip holders 212 or 312 are inserted into the corresponding opening 402 and fixed with their closed end 226 or 326, respectively. The clip holder 212 or 312 is arranged and held in the opening 402 such that the open end 218 or 318 and the receptacle 220 or 320 formed at the open end 218 or 318, respectively, are freely accessible for positioning and fixing the corresponding clip element 202. Figure 11 shows four openings 402, in all of which the clip holders 212 or 312 are arranged and fixed. In particular, the receptacle 220 or 320 is arranged flush with the surface of the support element 400. Only one of the clip elements 202 is inserted, in particular plugged in and fixed, into one of the receptacles 220 or 320. Fig. 12 shows a perspective partial view of the unfoamed support element 400 in the area of ​​the clip holder 212 or 312 with a pre-attached clip element 202. The clip element 202 is inserted with its receiving element 208 (shown in Fig. 2, Fig. 3 to Fig. 4) into the opening 402, in particular into the receptacle 220 or 320 of the clip holder 212 or 312 inserted into the opening 402. The base element 206 has larger dimensions than the dimensions of the opening 402 and thus extends radially beyond the dimensions of the opening 402 of the support element 400. Fig. 13 shows a perspective partial view of the unfoamed support element 400 in the area of ​​the clip holder 212 or 312 without pre-attached clip element 202 (shown in Fig. 11 or Fig. 12) and with the receptacle 220 or 320 for the clip element 202. Fig. 14 shows a top view of the support element 400 before foaming and with clip holders 212 or 312 partially inserted. Fig. 15 shows a perspective view of the support element 400 according to Fig. 14 with clip elements 202 attached to the clip holders 212 or 312. Fig. 16 shows a perspective view of the support element 400 according to Fig. 15 with clip holders 212 or 312 fully inserted into the support element 400 and clip elements 202 attached. For the production of the foam molded part 210 manufactured according to the invention (shown in Fig. 3 and Fig. 4) a molding tool not shown in detail is provided in which the support element 400 can be arranged, positioned and / or fixed. The support element 400 has the openings 402 (shown in Fig. 11 and Fig. 12). The openings 402 have been previously introduced into the support element 400, for example by drilling. The length of the bore for the opening 402 is selected, for example, such that a predetermined height of the clip element 202 is achieved in the mold. In each of these openings 402, a clip holder 212 or 312 (shown in Fig. 11, Fig. 12 to Fig. 13) can be arranged, in particular positioned and / or fixed. The clip holder 212, 312 is, for example, secured against rotation in the opening 402 and fixed. The respective clip holder 212, 312 can be inserted and fixed in the corresponding opening 402 in the appropriate orientation. Different types of clip holders 212, 312, for example with different facets, and different types of clip elements 202, for example with different heights, can be pre-positioned in the support element 400. The clip holder 212, 312 includes the previously described internal or integrated vent 214, 314. The clip element 202 is then pre-attached to the respective clip holder 212 or 312. Thus, the clip holder 212, 312 with the integrated internal vent 214, 314 is positioned below the clip element 202. The respective clip element 202 can be directly vented via such a clip holder 212, 312 with integrated internal vent 214, 314. Subsequently, a foam material is introduced into the mold (not shown) and cured. The clip holder 212 or 312 is designed such that any gas generated during the demolding of the foam part 210, particularly in the area of ​​the clip element 202, can be vented, for example, directly via the clip holder 212 or 312. For this purpose, the respective clip holder 212 or 312 is part of an automatic venting system for the mold. Nearly 100% of the generated gas is vented via the clip holder 212 or 312. For example, the clip holder 212 or 312 has the previously described integrated vent 214 or 314 (shown in Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig. 10) with the inner channel 216 or 316 and the vent channels 222 or 322. Because the respective clip holder 212 or 312 has the integrated vent 214 or 314, additional venting systems can be avoided. Furthermore, such a clip holder 212 or 312 with integrated vent 214 or 314 allows for simple venting around the clip element 202. This prevents the foam indentations and cavities 204 in the area of ​​the clip elements 202 known from the prior art when foaming the molded foam part 210 manufactured according to the invention. The mold is, in particular, a foam mold. Advantageously, the foam mold comprises, in a manner not shown in detail, a mold with at least one cavity, which is filled with a material of the foam molded part 210 to be produced, so that the foam molded part 210 is formed from the material, in particular from a foam, with embedded clip holders 212, 312 with integrated venting 214, 314 and with partially embedded clip elements 202. After the foam molding and curing of the foam molding part 210, it is then removed from the foam mold together with the largely completely foamed-in clip holders 212, 312 and the partially foamed-in clip elements 202. Dislodging of the partially foamed-in clip elements 202 from the foam molding part 210 during removal of the foam molding part 210 from the foam mold is avoided. The features disclosed in the foregoing description, the claims and the figures may be important for the realization of the invention in its various embodiments, both individually and in combination, insofar as they remain within the scope of protection of the claims. Reference symbol list 100 Vehicle seat 102 Seat section 104 Backrest 106 Fitting 108 Pivot axis 110 Longitudinal adjustment device 112 Rail arrangement 114 First rail element / Upper rail 116 Second rail element / Lower rail 200 Foam molding according to the prior art 202 Clip element 204 Cavity 206 Foot element 208 Receptacle element 210 Foam molding manufactured according to the invention 212 Clip holder 214 Integrated vent 216 Inner channel 218 Open end 220 Receptacle 222 Vent channel 224 Channel end 226 Closed end 312 Clip holder 314 Integrated vent 316 Inner channel 318 Open end 320 Receptacle 322 Vent channel 324 Channel end 326 Closed end 328 Height 330 Length 332 Element 334 First outer dimension 336 second external dimension 338 adjustment mechanism 400 support element 402 opening x longitudinal direction y transverse direction z vertical direction

Claims

Method for producing a foam molded part (210) in a molding tool, wherein a molding tool is provided in which a carrier element (400) with a plurality of clip holders (212, 312) is arranged before foaming and demolding the foam molded part (210), wherein a clip element (202) is pre-attached to the respective clip holder (212, 312) and subsequently a foam material is introduced into the molding tool and cured, wherein a gas generated during demolding of the foam molded part (210) is discharged via the respective clip holder (212, 312), and wherein after foaming and curing of the foam molded part (210) it is removed from the molding tool together with the clip holders (212, 312) and the clip elements (202). Clip holder (212, 312) for a clip element (202), wherein the clip holder (212, 312) has an integrated vent (214, 314) for discharging a gas which is generated in a method for producing a foam part (210) with injected clip holders (212, 312) according to claim 1. Clip holder (212, 312) according to claim 2, wherein the integrated vent (214, 314) has a hollow inner channel (216, 316) which has an outwardly open end (218, 318). Clip holder (212, 312) according to claim 3, wherein a number of vent channels (222, 322) extend to the outside from the hollow inner channel (216, 316). Clip holder (212, 312) according to claim 3 or 4, wherein the hollow inner channel (216, 316) extends in the longitudinal extent of the clip holder (212, 312) and the at least one vent channel (222, 322) extends radially outwards from the inner channel (216, 316). Clip holder (212, 312) according to claim 4 or 5, wherein outwardly open channel ends (224, 324) of several venting channels (222, 322) are arranged symmetrically distributed on a plane around the circumference of the clip holder (212, 312). Clip holder (312) according to one of claims 2 to 6, characterized by a multi-part and height-adjustable structure. Foam molded part (210) with a plurality of integrated clip elements (202) which can be attached to the foam molded part (210) by means of integrated clip holders (212, 312), wherein the integrated clip holders (212, 312) each have an integrated vent (214, 314). Vehicle seat (100) with a seat part (102) and / or a backrest (104), comprising at least one foam molded part (210) according to claim 8.

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