Vehicle seat and seat mounting method

Abstract

The invention relates to a motor vehicle seat comprising a structural element (10), an airbag safety system (16) fixed against the structural element, a front band (38) and a rear band (40) of a force concentrator, a headrest (20), a rear trim panel (18), and a zipper (36) comprising a first (42) and a second band (46) provided with interlocking teeth (44), the first band of the zipper being attached to the headrest. The second band of the zipper is attached by a fusible seam (50) to an edge (45) of the front band (38) of the force concentrator, to an edge (24) of the rear trim panel, and to an edge (47) of the rear band of the force concentrator. Figure to be published with the abstract: Figure 2

Description

Title of the invention: Vehicle seat and method for mounting a seat. Technical field of the invention

[0001] The invention relates to a vehicle seat and more particularly to a vehicle seat equipped with airbag safety systems. The invention also relates to a method for mounting such a seat. Prior art

[0002] An increasing number of motor vehicle seats are equipped with airbag safety systems. An airbag safety system is, for example, attached to the seat structure behind a side bolster. To allow the airbag to deploy, the upholstery cover of the front part of the seat, also called the seat cover, consists of two parts joined by a fusible seam. During an impact, the fusible seam breaks under the pressure of the airbag, allowing it to deploy outside the seat. To guarantee the destruction of the fusible seam, a series of conformity tests must be carried out by an accredited body. Furthermore, various seat upholstery materials are available for purchase, such as fabric, leather, imitation leather, plastic, etc. It is therefore necessary to conduct a series of conformity tests on the fusible seams of each proposed upholstery material to verify that they meet the safety requirements for airbag deployment.

[0003] On the assembly line, the airbags are mounted in a pocket of a force concentrator from the rear of the seat, then screwed in with very limited visibility and by compressing the side foam of the seat. This operation, carried out on the assembly line, is long and tedious. Presentation of the invention

[0004] A first objective of the present invention is to reduce the number of validation tests of fusible seam of seat equipped with a safety airbag.

[0005] Advantageously, by placing a zipper between the headliner and the rear trim panel and sewing this zipper with a fusible seam on the side of the rear trim panel, only one series of tests can be performed regardless of the type of covering used for the headliner. This is because the rear trim panel is always the same regardless of the covering used for the headliner.

[0006] A second object of the present invention is to facilitate the mounting of the safety cushion to the seat structure.

[0007] Advantageously, the safety cushion can be screwed onto the structural element and wired before the assembly of the polyurethane foam and the cover.

[0008] Advantageously, the assembly of the airbag safety system is standardized. Summary of the invention

[0009] The present invention relates to a motor vehicle seat comprising a structural element, an airbag safety system fixed against the structural element, a front band and a rear band of a force concentrator, a headrest, a rear trim panel and a zipper comprising a first and a second band provided with interlocking teeth, the first band of the zipper being fixed to the headrest, characterized in that the second band of the zipper is fixed by a fusible seam to an edge of the front band of the force concentrator, to an edge of the rear trim panel and to an edge of the rear band of the force concentrator.

[0010] The features described in the following paragraphs may optionally be implemented. They may be implemented independently of each other or in combination with each other: - the edge of the front band of the force concentrator is sewn to the edge of the second band of the zipper by a first non-fusible seam, the fusible seam being closer to the teeth of the zipper than said first non-fusible seam. - the edge of the rear band of the force concentrator is sewn to an edge of the rear trim panel by a second non-fusible seam, the fusible seam being closer to the mesh teeth of the zipper than said second non-fusible seam. - the edge of the front band of the force concentrator is fixed to the contact of one face of the second band of the zipper, one face of an edge of the rear trim panel is fixed to the contact of an opposite face of the second band, the opposite face of the edge of the rear trim panel is fixed to the contact of the edge of the rear band of the force concentrator. - the rear trim panel has a semi-rigid shell. - the rear trim panel also features a flexible edge. - the semi-rigid hull is made by compressing expanded foam, non-expanded polyurethane and a layer of paint. - the flexible edge is made by compressing non-expanded polyurethane and a layer of paint.

[0011] The invention also relates to a method for mounting a vehicle seat, in particular a motor vehicle seat, the method comprising the following successive steps: - attachment of an airbag safety system to a structural element of the seat, - sewing using fusible thread one edge of the front band of a force concentrator, a second band of a zipper, one edge of a rear trim panel and one edge of the rear band of the force concentrator, - mounting the rear trim panel against the seat structure, - sewing, with non-fusible thread, the first strip of the zipper against one edge of a head covering, and - assembling the first zipper strip to the second zipper strip. According to a particular embodiment, the process further comprises a step of first stitching the edge of the front band of the force concentrator against the second band of the zipper, with a non-fusible thread, the fusible stitch being closer to the teeth of the zipper than said first non-fusible stitch. Brief description of the figures

[0012] [Fig.1] is a schematic view of a part of a seat having a backrest sectioned along a horizontal plane;

[0013] [Fig.2] is a schematic view of part of the seat illustrated in [Fig.1],

[0014] [Fig.3] is a schematic view of part of the seat illustrated in [Fig.1], during the deployment of the airbag

[0015] [Fig.4] is a flowchart representing the steps of the assembly process according to the invention,

[0016] [Fig.5] is a schematic view of the assembly of the rear trim panel to the front and rear band of the force concentrator. Detailed description of the invention

[0017] With reference to Figures 1 and 2, the seat 2, according to one embodiment of the invention, comprises a seat 4 and a backrest 6 articulated to the seat. This seat is, for example, a motor vehicle seat.

[0018] The folder 6 comprises a central panel 8 and lateral structural elements 10 in metal or plastic, a padding 12 arranged against the central panel and lateral rolls 14 arranged against the lateral structural elements. The padding 12 and the side bolsters 14 are made of polyurethane foam. The backrest 6 also includes two safety cushion systems 16 inflatable each fixed to a side face 17 of a side structural element, a rear trim panel 18 and, at the front, a cap 20 covering each side bolster and a cap 21 covering the mattress 12.

[0019] The safety systems 16 each comprise a folded cushion and a pyrotechnic inflation system.

[0020] In the embodiment shown, the rear trim panel 18 comprises a semi-rigid shell 22 and a flexible edge 24. The semi-rigid shell 22 comprises a central wall and curved side edges extending substantially perpendicularly to the central wall. Preferably, the side edges extend forward of the seat to the side bolsters. They cover and conceal all the airbag safety systems 16.

[0021] The semi-rigid shell 22 is more rigid than leather and less rigid than plastic. In particular, the shore hardness of the semi-rigid hull is between 50 and 80 shores and preferably between 50 and 70 shores.

[0022] According to one embodiment, the semi-rigid hull 22 is made by compression of expanded foam, non-expanded polyurethane and a layer of paint.

[0023] The flexible edge 24 is formed by compressing unexpanded polyurethane and a layer of paint. The flexible edge 24 has a face 55 and an opposite face 57. Preferably, the semi-rigid shell and the flexible edge are formed in the same operation. Advantageously, the flexible edge 24 is folded inwards so as to hide the teeth of the second strip of the zipper.

[0024] Advantageously, since this shell is semi-rigid, it can be mounted directly in front of the airbag safety system without the addition of foam. Furthermore, it has an attractive design.

[0025] Alternatively, the rear trim panel consists solely of the semi-rigid shell without flexible edge 24.

[0026] Alternatively, the semi-rigid hull 22 is produced by thermoforming. Alternatively, the rear trim panel 18 is made using a fabric with an inner layer of foam.

[0027] In the embodiment shown, the cap 20 covering the lateral rim comprises two parts of coverings 26, 28 fixed to each other by a seam 30 made with a conventional thread, i.e. non-fusible.

[0028] Alternatively, the cap 20 covering the lateral rim is made from a single piece of covering. The seat also includes a connection device 32, a force concentrator 34, and a zipper 36.

[0029] In the embodiment shown and in no way limiting, the connection device 32 is fixed against a face of the structural element 10 opposite the lateral face 17.

[0030] The force concentrator 34 surrounds the safety system 16. It comprises an anterior band 38 and a posterior band 40 made of a substantially non-stretchable fabric and having very high resistance to breakage.

[0031] The front strip 38 is arranged between, on the one hand, the side bead 14 and, on the other hand, the structural element 10 and the safety system 16. The rear strip 40 is arranged between the rear trim panel 18 and the safety system 16. A first edge 35 of the front strip 38 and a first edge 37 of the rear strip 40 are fixed to the connection device 32.

[0032] The zipper 36 conventionally comprises a first strip 42 of resistant fabric with interlocking teeth 44, a second strip 46 of resistant fabric with interlocking teeth 44 and a slider not shown having two grooves which meet to allow the teeth 44 to interlock and fix the first strip of fabric to the second strip of fabric.

[0033] The second band 46 of the zipper has a face 55A on the side of the meshing teeth and a face 56 opposite the face 55A.

[0034] The first strip 42 of the zipper is attached by a conventional seam 48, i.e., a non-fusible seam, to one end of the cap 20 covering the side bead. Advantageously, the seam 48 is made adjacent to the mesh teeth 44.

[0035] The second strip 46 of the zipper is attached by a fusible seam 50 to a second edge 45 of the front strip 38 of the force concentrator, to the flexible edge 24 of the rear trim panel 18, and to a second edge 47 of the rear strip 40 of the force concentrator. The second edge 45 of the front strip 38 and the second edge 47 of the rear strip are opposite the first edge 35 of the front strip 38 and, respectively, the first edge 37 of the rear strip.

[0036] Advantageously, during the deployment of the airbag, the fusible seam 50 breaks and the airbag deploys between the rear trim panel 18 and the side bolster, as illustrated in [Fig.3].

[0037] The second edge 45 of the front band 38 of the force concentrator is sewn to the edge of the second band 46 of the zipper by a first conventional non-fusible seam 52. The fusible seam 50 is closer to the mesh teeth 44 of the zipper than the first conventional seam 52.

[0038] Advantageously, this first seam 52 allows the second strip 46 of the zipper to remain attached to the front strip 38 and not to be projected into the passenger compartment when the airbag is deployed.

[0039] The second edge 47 of the rear band 40 of the force concentrator is sewn to the flexible edge 24 of the rear trim panel 18 by a second non-fusible seam 54. The fusible seam 50 is closer to the mesh teeth 44 of the zipper than the second non-fusible seam 54.

[0040] Advantageously, with this configuration the fabric of the force concentrator is not visible from outside the seat.

[0041] The invention also relates to a method of mounting a vehicle seat 2, in particular a motor vehicle seat. Referring to [Fig. 4], the assembly process begins with step 60, which involves attaching an airbag safety system 16 to a structural element 10 of the seat. This attachment is generally achieved by screwing. The safety system cables are then connected.

[0042] Then, in a step 62, the edge 35 of the front band and the edge 37 of the rear band of the force concentrator are fixed to the connecting device 32. In a step 64, a first stitch 52 is made to fix the second edge 45 of the front band 38 of the force concentrator to a face 55 of the second band 46 of the zipper, with a conventional non-fusible thread.

[0043] During a step 66, a second stitch 54 is made to fix an edge 47 of the rear band 40 of the force concentrator to a face 55 of the flexible edge 24 of the rear trim panel, with a conventional non-fusible thread.

[0044] When the rear trim panel 18 does not have a flexible edge 24, the edge 47 of the rear band 40 of the force concentrator is directly sewn against the semi-rigid shell 22.

[0045] In a step 68, the face 56 of the second strip 46 of the zipper is positioned against the face 57 of the flexible edge 24 of the rear trim panel. A fusible seam 50 is then made to fix together the edge 45 of the front strip 38 of the force concentrator, the second strip 46 of the zipper, the edge 24 of the rear trim panel 18 and the edge 47 of the rear strip 40 of the force concentrator. With reference to [Fig.5], the edge 45 of the front band 38 of the force concentrator is then fixed in contact with the face 55 of the second band 46 of the zipper, the face 57 of the edge 24 of the rear trim panel 18 is fixed in contact with the opposite face 56 of the second band 46, the opposite face 55 of the edge 24 of the rear trim panel is fixed in contact with the edge 47 of the rear band 40 of the force concentrator.

[0046] During a step 70, the rear trim panel is mounted against the seat structure.

[0047] During a step 72, the polyurethane foam of the side bead 14 is fixed.

[0048] In a step 74, the first strip 42 of the zipper is sewn against an edge of the cap 20 by a conventional non-fusible seam 48. The cap is installed on the polyurethane foam of the side bolster 14.

[0049] During a step 76, the first strip 42 of the zipper is assembled to the second strip of the zipper using the slider.

Claims

Demands

1. Motor vehicle seat (2) comprising a structural element (10), an airbag safety system (16) fixed against the structural element, a front band (38) and a rear band (40) of a force concentrator, a cap (20), a rear trim panel (18) and a zipper (36) comprising a first band (42) and a second band (46) having interlocking teeth (44), the first band (42) of the zipper being fixed to the cap (20), characterized in that the second band (46) of the zipper is fixed by a fusible seam (50) to an edge (45) of the front band (38) of the force concentrator, to an edge (24) of the rear trim panel (18) and to an edge (47) of the rear band (40) of the force concentrator.

2. Seat (2) according to claim 1, wherein the edge (45) of the front band of the force concentrator is sewn to the edge of the second band (46) of the zipper by a first non-fusible seam (52), the fusible seam (50) being closer to the meshing teeth (44) of the zipper than said first non-fusible seam (52).

3. Seat (2) according to any one of claims 1 to 3, wherein the edge (47) of the rear band of the force concentrator is sewn to an edge (24) of the rear trim panel (18) by a second non-fusible seam (54), the fusible seam (50) being closer to the meshing teeth (44) of the zipper than said second non-fusible seam (54).

4. Seat (2) according to any one of claims 1 to 3, wherein the edge (45) of the front band (38) of the force concentrator is fixed in contact with a face (55) of the second band (46) of the zipper, a face (57) of an edge (24) of the rear trim panel (18) is fixed in contact with an opposite face (56) of the second band (46), the opposite face (55) of the edge (24) of the rear trim panel is fixed in contact with the edge (47) of the rear band (40) of the force concentrator.

5. Seat (2) according to any one of claims 1 to 4, wherein the rear trim panel (18) comprises a semi-rigid shell (22).

6. Seat (2) according to any one of claims 1 to 4, wherein the rear trim panel (18) further comprises a flexible edge (24).

7. Seat (2) according to any one of claims 5 and 6, wherein the semi-rigid shell (22) is made by compression of expanded foam, non-expanded polyurethane and a layer of paint.

8. Seat (2) according to any one of claims 6 and 7, wherein the flexible edge (24) is made by compression of unexpanded polyurethane and a layer of paint.

9. A method for mounting a vehicle seat, in particular a motor vehicle seat, the method being specifically designed for manufacturing the seat according to claim 1, the method comprising the following successive steps: - attaching (60) an airbag safety system against a structural element (10) of the seat, - sewing (68) using a fusible thread of an edge (45) of the front band (38) of a force concentrator, a second band (46) of a zipper, an edge (24) of a rear trim panel and an edge (47) of the rear band (40) of the force concentrator, the zipper (36) comprising a first band (42) and a second band (46) having interlocking teeth (44), - mounting (70) the rear trim panel (18) against the seat structure, - sewing (74) with a non-fusible thread, of a first strip (42) of the zipper against an edge of a cap (20),and - assembly (76) of the first strip (42) of the zipper to the second strip (46) of the zipper.

10. Assembly method according to claim 9, further comprising a first stitching step (52) of the edge (45) of the front band (38) of the force concentrator against the second band (46) of the zipper, with a non-fusible thread, the fusible stitch (50) being closer to the teeth (44) of the zipper than said first non-fusible stitch (52).

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