Seat structure element for a motor vehicle seat, method for its manufacture and motor vehicle seat with such seat structure element

Abstract

Seat structure element (10) for a motor vehicle seat, comprising at least two interconnected sheet metal components, wherein the at least two sheet metal components are at least partially overmolded or crimped with plastic and are connected to each other only by this plastic overmolding (190) or plastic crimping, wherein the at least two interconnected sheet metal components are arranged overlapping and in surface contact in a connection area (180) and are formed with at least one injection-molded or crimped-through point through which the plastic is injected, wherein the at least two sheet metal components have through holes (122, 132) with collar-shaped interlocking through-holes at the injection-molded or crimped point, wherein the through holes (122, 132) are injected with the plastic to form a plastic rivet (196), characterized in thatthat the collar-shaped interlocking passages are formed by the plastic injected between them during plastic overmolding, forming a plastic ring (197).

Description

[0001] The invention relates to a seat structure element for a motor vehicle seat, comprising several interconnected sheet metal components, and to a method for its manufacture. The invention further relates to a motor vehicle seat with such a seat structure element.

[0002] Conventional vehicle seats consist of a seat structure, foam padding applied to the seat structure, and a cover applied to the padding. The seat structure must be lightweight yet also very durable.

[0003] WO 2009 / 056294 A1 describes a motor vehicle seat that can also be provided cost-effectively using lightweight construction. The motor vehicle seat has a structural element consisting of several components that are at least partially welded, soldered, bonded, and / or positively and / or force-fitted. For example, a backrest frame is described, consisting of two backrest sides made of high-strength steel, an upper cross member, and a lower cross member, both made of aluminum. The upper and lower cross members are connected to the high-strength side members using CMT welding or other joining techniques such as bonding. The bonding can be combined with a clinching connection, i.e., a connection achieved through clinching.

[0004] The invention is based on the objective of providing a seat structure element for a motor vehicle seat that is lightweight, stable and easy to manufacture.

[0005] This problem is solved by the seat structure element according to the invention, comprising the features of claim 1. By a dependent claim, the invention also extends to a method according to the invention for manufacturing a seat structure element according to the invention. By a further dependent claim, the invention further extends to a motor vehicle seat according to the invention, which comprises at least one seat structure element according to the invention. Preferred embodiments and configurations of the invention are described analogously for all subject matter of the invention in the dependent claims, the following description, and the drawings.

[0006] The seat structure element according to the invention is characterized in that the sheet metal components are at least partially overmolded or overmolded with plastic and are only joined by this plastic overmolding or plastic overmolding.

[0007] On the one hand, the plastic overmolding or compression molding, made of thermoplastic or thermosetting plastic, preferably with fiber reinforcement, forms a stable hybrid composite with the sheet metal components. On the other hand, the sheet metal components are joined by the plastic or via the plastic overmolding or compression molding formed by it. The joining mechanism is based on a positive fit through the embedding of the sheet metal components in the plastic and on a material bond between the plastic and the sheet metal components. To improve the material bond and / or to achieve a micro-positive fit, the surfaces of the sheet metal components can be surface-treated, at least in the joining areas, and are, for example, sandblasted, brushed, etched, laser-treated, or coated with an adhesion promoter.

[0008] Furthermore, it can be provided that at least two interconnected sheet metal components are arranged overlapping in a connection area and are formed with at least one injection-molded or press-fitted through-hole (through which the plastic is injected). The injection-molded or press-fitted through-hole is preferably formed by overlapping slots, holes, and the like, through which the plastic is injected, pressed, or flowed, wherein the plastic injection-molded or press-fitted through-hole essentially forms a plastic rivet or stud. It is also preferred that the sheet metal components have interlocking, collar-shaped through-holes at the injection-molded or press-fitted through-hole. The through-holes preferably have a diameter of 5 mm to 15 mm and / or an axial length of 2 to 5 times the sheet metal thickness.These openings have multiple functions: on the one hand, they form a positive fit between the sheet metal components, preferably an indirect positive fit through an intervening plastic, which offers particular crash safety, and on the other hand, they can serve as alignment aids for the sheet metal components to be joined when manufacturing the seat structure element.

[0009] Preferably, the sheet metal components are prefabricated. They are preferably single-layer sheet metal forming and / or stamping parts. At least one sheet metal component may also be manufactured from a tailored blank (a custom-made blank made from different sheet metal materials, grades, and / or thicknesses). At least one sheet metal component may also be composed of several conventionally prefabricated sheet metal pieces.

[0010] Plastic overmolding or compression molding enables the permanent joining of sheet metal components, regardless of the sheet material, grade, or thickness, and even if the sheet metal components have coatings. The sheet metal components to be joined or joined together can therefore be made of different sheet metal materials, preferably aluminum, magnesium, and / or steel (including high-strength steel), and / or have different grades, particularly different strengths. Furthermore, wire components, profile components (e.g., pipes and extruded profiles), and / or non-metallic components (e.g., fiber-reinforced composite components), and the like, can also be incorporated into the plastic overmolding or compression molding process.

[0011] The sheet metal components can be arranged in a frame-like fashion and partially or completely enclose a free space. Preferably, at least one such free space between the sheet metal components is filled with the plastic, i.e., the plastic overmolding or injection molding also includes at least one filled area. The plastic overmolding or injection molding can further incorporate integrally molded functional elements, such as support structures, ribs, hinge elements, brackets, and the like.

[0012] The inventive method for manufacturing a seat structure element according to the invention may comprise the following steps: – Providing the prefabricated sheet metal components; – Arranging the sheet metal components in the cavity of an open forming tool and, if necessary, also arranging other components (e.g. wire parts, profile components, FRP components and the like), for which the cavity may have suitable holding devices or the like; – Closing the mold and at least partially overmolding or overpressing the sheet metal components and, if necessary, also the other components with plastic, whereby the sheet metal components and, if necessary, also the other components are only joined or connected by the plastic (process-integrated joining); – Solidification or hardening of the plastic through cooling and / or cross-linking; – Opening the mold and demolding the essentially ready-to-install seat structure element.

[0013] The mold is, in particular, an injection mold, where the plastic is injected into the cavity as molten plastic after the mold is closed. The mold can also be a compression mold (hot compression or flow compression mold), where the plastic can be introduced into the cavity before the mold is closed.

[0014] Both thermosetting and thermosetting plastics can be used. Preferably, the plastic is reinforced with fibers, in particular glass fibers or recycled fibers. When using a thermosetting plastic containing reinforcing fibers, the seat structure element according to the invention can be manufactured, for example, in a press tool with SMC or BMC fiber matrix semi-finished products or the like.

[0015] As previously explained, at least two sheet metal components can be formed in a connection area with collar-shaped or collar-like recesses or projections. When arranging these sheet metal components in the cavity of the mold (injection mold or press tool), the recesses allow for precise positioning and alignment of the components relative to each other by interlocking them. During the subsequent injection molding or hot pressing / extrusion process, the recesses are then filled with plastic, creating a plastic indentation or a plastic rivet.

[0016] A motor vehicle seat according to the invention is characterized in that its seat or backrest comprises at least one seat structure element according to the invention and / or a seat structure element produced using the method according to the invention. It can be either a front or rear vehicle seat, providing space for one or more persons. Preferably, it is a rear bench seat with a one-piece or multi-piece backrest, wherein the backrest, or at least one part of the backrest, in particular the central part, is formed with at least one seat structure element according to the invention.

[0017] The invention is explained in more detail below by way of example and in a non-limiting manner with reference to the drawing. The features shown in the drawing and / or explained below can be general features and further develop the invention, even independently of specific combinations of features.

[0018] Fig. Figure 1 shows sheet metal components arranged in a perspective front view around a frame before overmolding with plastic.

[0019] Fig. Figure 2 shows, in a perspective front view and a side view, the frame made of plastic by overmolding. Fig. 1 manufactured seat structure element.

[0020] Fig. Figure 3 shows a section of the frame in a perspective view. Fig. 1.

[0021] Fig. Figure 4 shows, in three separate sectional views, the positive-locking connections of the plastic overmolding to the sheet metal components of the frame at the points in Fig. 3 marked locations.

[0022] Fig. 1. Show a frame 100 from as yet unassembled individual parts for the production of a seat structure element for the backrest of a vehicle rear seat. The frame 100 includes two side panels or stiles 110and 120 , a lower transverse part 130 , an upper transverse part 140 and a diagonal brace 150 . These frame parts 110 until 150 These are prefabricated sheet metal components that can be made from different sheet metal materials, grades, and / or thicknesses. The side panels 110 and 120 Their middle sections are shaped like U-profiles. At their lower ends, the side parts are... 110 and 120 with bearing bushings 125 fitted with components that will later serve to fold the backrest to the vehicle body. The bearing bushings 125 They are, for example, pressed in or welded in. Fig. Figure 1 also shows a lock plate 160 for locking the backrest and a wire-shaped retaining bracket 170 for locking an armrest that is swivelled and attached to the backrest.

[0023] Fig. Figure 1 shows the frame parts in their final position, without yet being connected or joined together. For this purpose, the components are... 110 until 170 The part is placed in the cavity of an injection mold in the position and orientation shown and overmolded with plastic, in particular fiber-reinforced plastic, in a so-called one-shot process, as explained above. Alternatively, overmolding with plastic or fiber-reinforced plastic can be carried out, as explained above. In this process, the part is... Fig. 2 shown seat structure elements 10 Manufactured for the middle section of the multi-part backrest of a rear bench seat.

[0024] Alone Fig. 1 shown components 110 until 170 are at least partially incorporated into the plastic overmolding process. 190 embedded and thus joined. Furthermore, injection-molded joints are provided, as explained in more detail below. Through plastic overmolding190 are also those from the sheet metal components 110 , 120 , 130 , 140 and 150 The outlined open areas are filled and formed by molded ribs. 191 Stiffened. The plastic overmolding. 190 also includes ribbed support structures 192 in the U-profile sections of the side panels 110 and 120 , which serve for stiffening. The plastic overmolding 190 It also features an integrally molded central bearing bushing. 193 on, which are aligned between the overmolded bearing bushings 125 located and partly over ribs 194 directly on the lower cross section 130 is supported. For plastic overmolding 190 It also includes two molded-in brackets. 195 for the swiveling attachment of the armrest.

[0025] Fig. 3 shows the connection area 180 between the left side panel 120 and the lower transverse part130 , still without plastic overmolding 190 In the connection area 180 are the side panel 120 and the transverse part 130 They are arranged overlapping and touching over their entire surface and are furthermore equipped with several through holes. 121 and 131 or slots formed, which are injected through by the plastic during injection molding, as from Fig. 4a is shown. The plastic injection molding essentially forms a plastic rivet. 196 .

[0026] More through holes 122 and 132 are additionally designed with collar-shaped openings that form a plastic rivet during injection molding. 196 are injection-molded from plastic, as in Fig. 4b is visible. The plastic rivet 196 has a molded-on cover cap 198 , which mark the ends of the passages 122 and 132 Covered like a hat. With the interlocking passages. 122and 132 is also due to the injected plastic in between, which forms a plastic ring. 197 forms an indirect positive fit between the two sheet metal components. 120 and 130 created. If the plastic overmolding 190 and especially the plastic ring 197 If the components are damaged in a crash or similar incident, they will be... 120 and 130 by mechanical stop between the nested passages 122 and 132 held together (catch plate function). The through holes with collar-shaped openings. 122 and 132 They are arranged in such a way that they act in the expected main directions of force flow in a crash. The collar-shaped openings 122 and 132 can also be used in the production of the seat structure element 10 They act as alignment aids, as described above. The passages 122 and 132They can have any suitable geometry and therefore, unlike what is shown, can also be oval or rectangular, for example.

[0027] Such joining plastic injections can also be used in the other connection areas between the sheet metal components. 110 / 130 , 110 / 150 , 110 / 140 , 120 / 140 and 120 / 150 be provided for. Likewise, on the lock plate. 160 .

[0028] Fig. Figure 4c shows a different plastic injection molding that does not function as a joining connection between two or more sheet metal components, but as a positive locking connection in the U-profile section of the side carrier. 120 formed ribbed support structure 192 It serves as a support structure. 192 is related to plastic injection molding or riveting 196 practically against the side panel 120 riveted. The side support 120This requires appropriate through holes or slots. 123 formed. Such plastic injection moldings can also be found at other locations on the seat structure element. 10 be planned. Reference symbol list 10 Seat structure elements 100 frames 110 right side panel 120 left side panel 121 Through hole 122 Through hole with draft 123 Through hole 125 Bearing bushing 130 lower cross section 131 Through hole 132 Through hole with draft 140 upper cross section 150 diagonal brace 160 lock plate 170 retaining brackets 180 connection area 190 Plastic overmolding 191 ribs 192 Support structure 193 Bearing bushing 194 ribs 195 bracket 196 Plastic injection molding, plastic rivet 197 plastic ring 198 plastic cap QUOTES INCLUDED IN THE DESCRIPTION

[0029] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0030] WO 2009 / 056294 A1

[0003]

Claims

[1] Seat structure element ( 10 ) for a motor vehicle seat, which consists of several interconnected sheet metal components ( 110 , 120 , 130 , 140 , 150 ) shows, characterized by that the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) are at least partially overmolded or overmolded with plastic and are only covered by this plastic overmolding or overmolding ( 190 ) are joined. [2] Seat structure element ( 10 ) according to claim 1, characterized by that at least two interconnected sheet metal components ( 120 , 130 ) in a connection area ( 180 ) arranged overlapping and with at least one injection or pressing point ( 121 / 131 ; 122 / 132 are trained. [3] Seat structure element ( 10 ) according to claim 2, characterized by that the sheet metal components ( 120 , 130) interlocking collar-shaped passages at the injection or pressing point ( 122 / 132 exhibit. [4] Seat structure element ( 10 ) according to one of the preceding claims, characterized by that the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) are made from different sheet metal materials. [5] Seat structure element ( 10 ) according to one of the preceding claims, characterized by that at least one free space between the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) is filled with plastic. [6] Seat structure element ( 10 ) according to one of the preceding claims, characterized by that the plastic overmolding or compression molding ( 190 ) molded functional elements ( 191 , 192 , 193 , 194 , 195 ) exhibits. [7] Method for manufacturing a seat structure element ( 10 ), which only involves plastic overmolding or compression molding ( 190 ) connected sheet metal components ( 110 , 120 , 130 , 140 , 150 ) exhibits, encompassing: – Arranging the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) in the cavity of an open mold; – Closing the mold and overmolding or overpressing the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) with plastic, whereby the sheet metal components ( 110 , 120 , 130 , 140 , 150 ) are joined only by the plastic. [8] Method according to claim 7, characterized by that the plastic contains reinforcing fibers. [9] Method according to claim 7 or 8, characterized by that at least two sheet metal components ( 120 , 130) in a connection area ( 180 ) with collar-shaped openings ( 122 , 132 ) are designed to be used when arranging these sheet metal components ( 120 , 130 ) in the cavity, precise positioning and alignment takes place, after which the passages ( 122 , 132 ) then injected or pressed with plastic. [10] Motor vehicle seat, the backrest of which is a seat structure element ( 10 ) according to any one of the preceding claims 1 to 6.

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