FRAME FOR A MOTOR VEHICLE SEAT AND ASSOCIATED VEHICLE SEAT

Description

Technical field of the invention

[0001] The present invention relates generally to seat frames, and in particular to seat frames for motor vehicles.

[0002] It relates more particularly to a seat frame of a motor vehicle comprising a seat structure and a backrest structure, the backrest structure comprising at least one gusset designed to fix said backrest structure to the rear of the seat structure, said gusset comprising, on the side of its rear edge, a first opening.

[0003] The invention finds a particularly advantageous application for manually adjustable motor vehicle seats.

[0004] It also relates to a seat comprising such a seat frame. State of the art

[0005] Car manufacturers are currently developing and manufacturing flexible seat frames designed to withstand high-speed rear impacts without breaking or tearing (crash tests carried out at speeds of 50 km / h and 90 km / h).

[0006] US patent 10266087 discloses a seat frame in which the backrest structure includes an elongated opening on its lower rear portion. This opening allows the side uprights of the backrest structure to deform rearward during a rear-end collision. US patent 102009057880 also discloses a frame incorporating a gusset.

[0007] However, this type of seat frame is not flexible enough at low speeds (crash tests were conducted at speeds of 16 km / h and 24 km / h) to absorb the energy transmitted by the impact without transferring it to the seat occupant. A spring-like movement can then occur on the occupant's body, potentially causing various injuries, including cervical trauma (or "cervical trauma"). whiplash (according to the acronym of Anglo-Saxon origin). Presentation of the invention

[0008] The present invention proposes to improve the seat frame in order to allow absorption of the energy transmitted by a low-speed rear impact without returning it to the seat occupant.

[0009] More particularly, the invention proposes a seat frame as defined in the introduction, in which the gusset further comprises at least one second opening adjacent to the first opening, said first opening and said second opening having respectively elongated shapes along first and second directions substantially parallel.

[0010] Thus, the presence of two adjacent openings on the gusset, particularly due to their shape and arrangement, ensures the desired deformation of the seat frame during a rear-end collision. The presence of the second opening further weakens the seat frame structure during such an impact, allowing the frame to deform under the effect of the energy transmitted by the impact rather than undergoing elastic deformation (which would then transmit the energy back to the seat occupant, with the associated risk of injury).

[0011] This gusset structure according to the invention is further advantageous because it also allows for the desired deformation during other types of impacts, also avoiding the risk of injury to the seat occupant.

[0012] Other advantageous and non-limiting features of the seat frame according to the invention, taken individually or in all technically possible combinations, are as follows: the gusset being formed by a plate of which at least one side located along the rear edge is folded, said folded side forms an end edge for the first opening and for the second opening; said folded side has a flat shape along the end edge of the second opening and an angled shape along the end edge of the first opening; the angled shape formed by said folded side along the end edge of the first opening has an angle between 140 and 160 degrees; the end edge of the first opening extends over a length between 5 and 10 millimeters; the second opening has an overall triangular shape; the first opening has, at an end opposite the rear edge, a local narrowing in width; the gap between the first opening and the second opening is between 6 and 10 millimeters;and the file structure includes a second gusset having two openings, the openings of said gusset and said second gusset being arranged symmetrically with respect to a plane of symmetry of the gussets.

[0013] The invention also proposes a vehicle seat comprising a seat frame as previously introduced and a trim attached to the frame.

[0014] Of course, the different features, variants and embodiments of the invention can be combined with each other in various ways as long as they are not incompatible or mutually exclusive. Detailed description of the invention

[0015] The description that follows, with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0016] Regarding the attached drawings: [ fig.1 ] is a schematic side perspective view of a seat frame according to the invention; [ fig.2 ] is a schematic detail view of zone II of the figure 1 , on which appears a gusset included in the seat frame, in an undeformed state; fig.3 ] is another schematic detail view of the gusset included in the seat frame, in a deformed state; and [ fig.4 ] is a schematic planar front view of the openings included in a gusset of the seat frame.

[0017] On the figure 1 , we have represented a frame 1 of a seat intended to be installed in the passenger compartment of a motor vehicle (car, bus, truck...) and to be fixed to the floor of this motor vehicle.

[0018] Here we will consider that this motor vehicle is a car which has at least one driver's seat located opposite a steering wheel and one passenger seat located next to the driver's seat.

[0019] These two seats are virtually identical. We will therefore only describe the driver's seat, considering that it is located on the left side of the vehicle's passenger compartment.

[0020] The seat described here is in the form of an armchair designed to accommodate a single occupant.

[0021] In the following description, the terms "front" and "rear" will be used in relation to the motor vehicle, the front part of an element referring to the part of that element which is located on the side of the hood of the motor vehicle and the rear part referring to the part of that element which is located on the opposite side.

[0022] The terms "lower" and "upper" shall be used in the same way, the lower part of an element referring to the part of that element which is located on the floor side of the motor vehicle and the upper part referring to the part of that element which is located on the roof side of the motor vehicle.

[0023] The terms "right" and "left" are defined with reference to the ordinary orientation of a seat in a motor vehicle.

[0024] The adjective "longitudinal" applies to an object, direction, or axis oriented from the front to the rear of the motor vehicle, parallel to the direction of travel of the motor vehicle when the steering wheel is in the neutral position. On the figure 1 The arrow referenced X illustrates a longitudinal direction.

[0025] The seat frame 1 primarily comprises a load-bearing structure, a seat structure 5, and a backrest structure 8. Typically, the seat therefore consists of a seat and a backrest, each comprising the seat structure 5 and the backrest structure 8 respectively, and upholstery (not shown) attached to the seat frame 1. This upholstery might be, for example, a piece of expanded padding shaped to the desired form and covered with a cap. The seat frame 1 is made of metal.

[0026] Here, the supporting structure is designed to be fixed to two cross members of the vehicle floor, represented here as four brackets 2 arranged at the four corners of a square.

[0027] As shown by figure 1The supporting structure comprises two slides 30 aligned along the longitudinal direction X and equipped with means for fixing (here by screwing) to the vehicle floor. The seating structure 5 further comprises rails 34, 35 engaged in these slides 30 to allow longitudinal sliding of the seat relative to the vehicle floor along the longitudinal direction X.

[0028] The seat structure 5 is mounted on the supporting structure, here using four connecting rods. Alternatively, the seat structure could be mounted directly onto the slides (without the connecting rods). In this case, no vertical lifting movement would be permitted.

[0029] The seating structure 5 is designed to be fixed in a generally horizontal manner to the floor of the motor vehicle. It therefore extends between a front end 10 and a rear end 12.

[0030] More specifically, as depicted on the figure 1 , the seating structure 5 includes in particular two lateral flanges 20, 21, fixed together by means of a rear tube element 26 and a front cross member 27.

[0031] Each flange 20, 21 is a stamped metal plate extending lengthwise along the longitudinal direction X and widthwise along a vertical direction Z. In practice, each flange 20, 21 includes a plurality of openings 40, 42 designed to accommodate fastening means. These fastening means allow, for example, the backrest structure 8 to be attached to the seat structure 5.

[0032] As shown by figure 1, the backrest structure 8 extends globally along the vertical direction Z, between a lower end 16 and an upper end 18. It includes two lateral stampings, called left flange 19A and a right flange 19B, connected together at their two ends by lower cross member 19C and upper cross member 19D.

[0033] In practice, this backrest structure 8 is articulated, at its lower end 16, to the rear end 12 of the seat structure 5 in order to allow it to have a variable inclination with respect to the vertical direction Z. This inclination is for example adjusted by means of a mechanical and manually operated mechanism (not described here).

[0034] We will focus more particularly here on the backrest structure 8, and more specifically on the element that links the backrest structure 8 to the seat structure 5.

[0035] Indeed, as the figures 1 to 3 The backrest structure 8 here includes at least one gusset 50, 60 designed to fix the backrest structure 8 to the rear of the seat structure 5. It has two here, including a left gusset 50 and a right gusset 60 allowing the left end and right end of the backrest structure 8 to be fixed respectively to the seat structure 5.

[0036] Each 50, 60 gusset comes in the form of an embossed metal plate.

[0037] Each gusset 50, 60 is an integral part of the backrest structure 8 by being mechanically welded to a joint 17 of the backrest structure 8, which is mounted to pivotally mobile relative to the right and left flanges 19A, 19B so as to be able to give the backrest its tilting mobility.

[0038] The connection to the seat structure 5 is made at the lower part of the gusset 50, 60, for example by screwing through the holes 40, 42 of the flange 20, 21 of the seat structure 5. Here, two screws are used to fix each gusset 50, 60 on the corresponding flange 20, 21 of the seat structure 5.

[0039] As shown by figure 1 , the seat frame 1 includes here two gussets 50, 60, a left gusset 50 and a right gusset 60 allowing the left end and right end of the backrest structure 8 to be fixed respectively to the seat structure 5.

[0040] The two gussets 50, 60 are, in shape and arrangement, symmetrical with respect to a plane of symmetry P ( figure 1) passing through the center of the cross members. Thus, in the following, the characteristics of a single gusset 50, 60 will be described without distinction of one or the other of the gussets 50, 60 in particular (their specific arrangement can be deduced by symmetry with respect to the plane of symmetry P).

[0041] As depicted on the figures 1 to 3 , the metal plate of each gusset 50, 60 includes a generally flat central part 51A, which notably includes openings complementary to the openings 40, 42 of the flange 20, 21 allowing the fixing of the backrest structure 8 onto the seat structure 5. The central part 51A also includes a central opening 52 intended to accommodate the tilting mechanism (not described here) of the backrest structure 8.

[0042] As shown in particular by figures 2 and 3The metal plate forming the gusset 50, 60 has, on its rear edge 51C, a folded side 51D towards the inside of the seat frame 1. It also has, on its front edge 51B, another folded side towards the inside of the seat frame 1 (not explicitly visible in the figures). Each gusset 50, 60 thus has an overall U-shape, with the central part 51A corresponding to the base of the U and the folded sides of the front and rear edges corresponding to the arms of the U.

[0043] Each gusset 50, 60 includes here, on the side of its rear edge 51C, a first opening 53. This first opening 53 has an elongated shape along a first direction A1, here substantially parallel to the longitudinal direction X ( figures 2 And 4). In this description, two directions are considered to be substantially parallel when the associated axes defining them are inclined at a small angle, for example less than 20 degrees, preferably less than 10 degrees.

[0044] In the event of a rear impact on the motor vehicle at low speed (for example less than 30 km / h), this first opening 53 acts as an element weakening the seat frame 1 during a low-speed rear impact, forcing the seat frame 1 to deform in order to dissipate the energy received by the impact (rather than transmitting it to the seat occupant).

[0045] However, during such an impact, the main risk lies in the fact that the seat frame, equipped with gussets having only the first opening, absorbs the energy transmitted by the impact without plastically deforming or breaking, and that it returns to its original position once the impact has passed, thus returning the stored energy to the seat occupant (thereby potentially causing various injuries).

[0046] To limit this elastic deformation of the seat frame 1 and the transmission of energy from the rear impact to the seat occupant, advantageously, each gusset 50, 60 further comprises at least one second opening 54, adjacent to the first opening 53 ( Figures 1 , 2 And 4 ).

[0047] The first opening 53 and the second opening 54 are described as adjacent in that they are located edge to edge, the distance between the opposite edges of the first opening 53 and the second opening 54 being small compared to a characteristic dimension of the gusset (for example, the length of the rear edge 51C). The first opening 53 and the second opening 54 are therefore located in the immediate vicinity of each other.

[0048] In practice, the spacing e between the first opening 53 and the second opening 54 is here between 6 and 10 millimeters (mm). This spacing e is defined as the spacing between the adjacent edges (i.e., the facing edges) of the first opening 53 and the second opening 54 ( figure 2 ).

[0049] As depicted on the figures 2 And 4, this second opening 54 also has an elongated shape, here along a second direction A2, also substantially parallel to the longitudinal direction X. This second direction A2 is substantially parallel to the first direction A1 defining the elongated shape of the first opening 53.

[0050] The first opening 53 and the second opening 54 are understood here to be between 10 and 15 mm in length.

[0051] The first opening 53 and the second opening 54 lead to the folded side 51D of the rear edge 51C of the gusset 50, 60. In other words, these first and second openings 53, 54 are delimited, on the side of their rear ends, by the folded side 51D of the rear edge 51C of the gusset 50, 60. This folded side 51D therefore forms an end edge for the first opening 53 and the second opening 54.

[0052] The part of the folded side 51D which forms the rear end edge of the second opening 54 has a flat shape.

[0053] In contrast, the part of the folded side 51D that forms the rear end edge of the first opening 53 has an angled shape. As shown in the figure 4 This elbow has two arms which together form an angle α, for example between 140 and 160 degrees (in the undeformed state). The angle α therefore corresponds to a deformation, here forward, of the folded side portion 51D of the first opening 53. The end edge of the first opening 53 extends over a length (i.e., in a direction substantially parallel to the vertical direction Z) here between 5 and 10 mm.

[0054] In practice, the part of the folded side 51D that forms the rear end edge of the first opening 53 takes the form of a folded tab. The width of this folded tab is, for example, between 3 and 5 mm here.

[0055] Advantageously, this angled shape will allow the deformation of the first opening 53 to be directed during a rear impact on the motor vehicle at low speed.

[0056] The second opening 54 here has an overall isosceles triangular shape. The portion of the folded side 51D that forms the rear end edge of the second opening 54 forms the base of this isosceles triangle. This portion extends over a length here between 5 and 10 mm.

[0057] In practice, the part of the folded side 51D that forms the rear end edge of the second opening 54 takes the form of a flat tab. The width of this flat tab is, for example, between 3 and 6 mm here.

[0058] As can be seen on the figure 2 The first opening 53 exhibits, on a portion opposite its rear end edge, a local narrowing in width. More precisely, the front end 53A of the first opening 53 has a width H. Following the longitudinal direction X, the width of the first opening 53 decreases locally from this width H until it reaches a minimum width h. The width of the first opening 53 then increases again until it reaches its rear end edge.

[0059] Advantageously, this local narrowing of width gives the first opening 53, at the front end 53A, a buttonhole shape. This buttonhole shape increases the gusset's fragility in the event of a low-speed rear impact, causing the seat frame 1 to deform and dissipate the energy stored in the seat frame following the impact.

[0060] When the motor vehicle is subjected to a low-speed rear-end collision (for example, at speeds of around 16 and 24 km / h), the impact energy is transmitted to the seat frame 1. This energy will cause deformation at the first opening 53, the upper edge of which will then bend outwards from the seat frame 1 due to the energy transmitted by the impact ( figure 3 ). The deformation of the first opening 53 is oriented thanks to the presence of the bent tab on the end edge 51D of the first opening 53.

[0061] Since the energy transmitted by the low-speed rear impact is insufficient to directly cause the collapse of the second opening 54, it is the fragility created by the presence of the first opening 53 that allows the gusset to collapse, thus destabilizing the seat frame 1 (and consequently causing its deformation by dissipating the energy transmitted by the low-speed rear impact without direct impact on the seat occupant). Furthermore, since the two gussets 50 and 60 of the seat frame 1 are symmetrical with respect to the plane of symmetry P, the deformation occurs simultaneously and is substantially identical on both sides of the seat frame 1, thus limiting the twisting of the seat frame 1.

[0062] When a motor vehicle is subjected to a high-speed rear-end collision (for example, at speeds of around 50 and 90 km / h), the impact energy is transmitted to the seat frame 1. As shown in the figure 3 By folding, the two openings 53 and 54 cause the gusset to deform through complete collapse. The presence of the second opening 54 allows for the simultaneous collapse of the left and right gussets in order to limit the twisting of the seat frame 1.

[0063] Since the two gussets 50 and 60 of the seat reinforcement 1 are symmetrical with respect to the plane of symmetry P, the deformation occurs simultaneously and substantially identically on both sides of the seat reinforcement 1. Therefore, there is no asymmetry in collapse between the two sides of the seat reinforcement 1.

[0064] The applicant observed that the solution proposed by the invention in the case of a low-speed rear-end collision did not impair the performance of the motor vehicle in other situations encountered (for example, in the case of higher-speed collisions).

Claims

1. Motor vehicle seat frame (1) comprising a seat pan structure (5) and a backrest structure (8), the backrest structure (8) comprising at least one gusset (50, 60) designed to fasten said backrest structure (8) to the rear of the seat pan structure (5), said gusset (50, 60) comprising, on the side of its rear edge (51C), a first opening (53), characterized in that said gusset (50, 60) further comprises at least one second opening (54) adjacent to the first opening (53), said first opening (53) and said second opening (54) respectively having elongate shapes in a first direction (A1) and a second direction (A2) that are substantially parallel, the gusset (50, 60) being formed by a plate of which at least one side (51D) situated along the rear edge (51C) is folded, said folded side (51D) forms an end edge for the first opening (53) and for the second opening (54), and characterized in that said folded side (51D) has a flat shape along the end edge of the second opening (54) and a bent shape along the end edge of the first opening (53).

2. Seat frame (1) according to Claim 1, wherein the bend formed by said folded side (51D) along the end edge of the first opening (53) has an angle (α) of between 140 and 160 degrees.

3. Seat frame (1) according to either of Claims 1 and 2, wherein the end edge of the first opening (53) extends over a length of between 5 and 10 millimetres.

4. Seat frame (1) according to any one of Claims 1 to 3, wherein the second opening (54) has a generally triangular shape.

5. Seat frame (1) according to any one of Claims 1 to 4, wherein the first opening (53) has, at an end opposite the rear edge, a local narrowing of width.

6. Seat frame (1) according to any one of Claims 1 to 5, wherein the spacing (e) between the first opening (53) and the second opening (54) is between 6 and 10 millimetres.

7. Seat frame (1) according to any one of Claims 1 to 6, wherein the backrest structure (8) comprises a second gusset (60) having two openings, the openings of said gusset (50) and of said second gusset (60) being disposed symmetrically with respect to a plane of symmetry (P) of the gussets (50, 60).

8. Motor vehicle seat comprising a seat frame (1) according to any one of Claims 1 to 7 and a trim attached to the seat frame (1).