Seat cushion frame for a vehicle

Abstract

Seat cushion frame for a vehicle, characterized by: Frame longitudinal parts (11, 12) which are arranged on both sides of a frame of a seat cushion (1); Frame cross members (13, 14) connecting the front and rear sections of the frame longitudinal members (11, 12); and a sheet (15) which is attached to the two frame longitudinal parts (11, 12) and covers from above the space between the front ends of the frame longitudinal parts (11, 12) in which the front frame transverse part (13) is located, wherein the sheet metal side of the front frame cross member (13) has a concave section which increases the distance to the sheet metal (15).

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to a seat cushion frame for a vehicle, in which the frame of a seat cushion is formed from longitudinal frame parts arranged on both sides, which are connected to each other at their front and rear by a frame cross part, and in which a sheet is attached to the two longitudinal frame parts in such a way that the space between the front ends of the longitudinal frame parts, in which the front frame cross part lies, is covered from above. 2. State of the art

[0002] In the event of a vehicle collision, the so-called submarining phenomenon can occur, in which the body of an occupant seated and restrained by a seatbelt slides forward on the seat surface. With regard to occupant protection, it is essential that the occupant is not subjected to excessive stress during an impact. For this reason, various external seat components have already been designed. For example, the Japanese patent application No. 2001-145538 (JP 2001-145538 A), described below, discloses an invention in which a backrest frame is partially deformable in a vehicle collision to prevent excessive stress on the occupant's lower back.In addition, some vehicles have a seat cushion that deforms at its front to counteract a load exerted from the front top of the seat cushion and to absorb energy generated when the occupant slides forward and downward from the seat due to the submarining phenomenon in a vehicle collision.

[0003] US Patent 7,192,087 B2 discloses a seat cushion frame with longitudinal frame sections and transverse frame sections, as well as a front transverse plate designed to suppress the submarining phenomenon. US Patent 7,104,601 B2 discloses a cross brace for suppressing a submarining phenomenon, which has a concave section. SUMMARY OF THE INVENTION

[0004] However, some vehicle seats cannot deform sufficiently to absorb the energy generated by the submarining phenomenon. This is because a front frame cross member, which forms part of the seat frame, is located below a sheet metal panel that forms the front of the seat. This front frame cross member hinders the deformation of the sheet metal panel, even when the panel deforms under the impact load, ultimately resulting in insufficient energy absorption. In light of this problem, the objective of the present invention is to pre-deform a front frame cross member in such a way that a space is ensured between the frame cross member and the sheet metal panel, allowing the sheet metal to deform under the impact load associated with the submarining phenomenon and enabling the impact load to be absorbed by the front of the seat.

[0005] In one aspect of the present invention, longitudinal frame members arranged on both sides of a seat cushion frame are connected to each other at their front and rear by transverse frame members. A sheet metal plate is attached to the two longitudinal frame members, covering the space between the front ends of the longitudinal frame members, in which the front transverse frame member is located, from above. The vehicle seat cushion frame has a concave section such that the sheet metal side of the front transverse frame member is further away from the sheet metal. Because the sheet metal side of the front transverse frame member has a concave section to increase the distance to the sheet metal, the sheet metal in the seat cushion frame according to the invention can be significantly deformed under the impact load associated with the submarining phenomenon, thereby enabling the front part of the seat to absorb more energy.

[0006] From the perspective described above, the front frame cross member can have a concave section such that the outer cross-sectional area of ​​a section located between connecting sections to the two frame longitudinal members is smaller than the outer cross-sectional area of ​​the connecting sections themselves. In this respect, the section of the front frame cross member located between the connecting sections joined to the two frame longitudinal members has a small outer cross-sectional area, and therefore lower strength, to increase the distance to the sheet metal. However, since the outer cross-sectional area of ​​the connecting sections is not reduced, their original strength is maintained, thus preserving the strength of the seat cushion frame.

[0007] From the perspective described above, the sheet metal has bent profile sections that adjoin the fastening sections with the two frame longitudinal members and can be designed such that the height between the fastening sections is lower than at the fastening sections themselves. The concave section of the front frame cross member can accommodate the bent sheet metal profile; furthermore, a deformation start section can be arranged below the bent profile sections of the sheet metal in such a way that a uniform distance is maintained along the longitudinal direction of the front frame cross member between the front frame cross member and the underside of the sheet metal. In this respect, a uniform distance is provided between the front frame cross member and the underside of the sheet metal along the longitudinal direction of the front frame cross member.Therefore, even if the sheet metal is deformed at any point between the frame longitudinal members during a vehicle collision, a comparable amount of energy can be absorbed, reliably ensuring safety in a collision.

[0008] Considering the aforementioned aspect, the sheet metal can be beveled in such a way that the height of a section located between the mounting points gradually decreases from front to rear; furthermore, the concave section of the front frame cross member can be beveled in such a way that the height of the sheet metal side decreases from front to rear, following the sheet metal profile. According to this aspect, the beveled profile of the sheet metal can prevent the body of an occupant from sliding forward and downward due to the submarining phenomenon; furthermore, deformation of the sheet metal can be ensured because the sheet metal side of the front frame cross member runs at an angle, following the sheet metal profile. This allows the energy absorption capacity to be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals are assigned to the same elements and: Fig. 1 a perspective view of an embodiment according to the present invention, Fig. 2 is an expanded perspective view of the embodiment; Fig. 3 is a top view of the embodiment; Fig. 4 is a side view of the embodiment; Fig. 5 is a view to illustrate the connection between a front frame cross-section and frame longitudinal sections of the embodiment; Fig. 6 is a view to illustrate a positional relationship between the front frame cross member and a sheet of the embodiment; Fig. 7 a cross-sectional view along line VII-VII in Fig. 3 is; Fig. 8A is a cross-sectional view of a first modified example of the frame cross-section according to the embodiment; Fig. 8B is a cross-sectional view of a second modified example of the frame cross-section according to the embodiment; and Fig. 8C is a cross-sectional view of a third modified example of the frame cross-section according to the embodiment; DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0010] As it is in Fig. As shown in Figures 1 to 4, the frame of a vehicle seat cushion 1 is designed such that longitudinal frame members 11, 12 are arranged parallel to each other on both sides with respect to the direction of travel F of a vehicle, and that the longitudinal frame members 11, 12 are each connected to each other at their front and rear ends by a transverse frame member 13, 14. A sheet 15 is attached to the front ends of the two longitudinal frame members 11, 12, covering the space between the longitudinal frame members 11, 12, in which the front transverse frame member 13 lies, from above. The front transverse frame member 13 has a flat section 131, which is obtained by flattening the center of one side of a cylindrical tube and forming it convexly to increase the distance to the sheet 15. The center of one side of a cylindrical tube, viewed in the longitudinal direction of a cylinder, lies near the center of one side of the cylinder. Fig. Figure 7 shows a cross-section of the frame cross-section 13; the length of the flat section 131, viewed longitudinally, is greater than the diameter of the cylindrical tube from which the frame cross-section 13 is formed. The front frame cross-section 13 is convexly shaped such that the section located between the connecting sections 132 with the frame longitudinal sections 11, 12 has a smaller outer contour cross-sectional area than the connecting sections 132. The outer contour cross-sectional area is an area resulting from the cross-sectional area of ​​a tube section and the area of ​​the space enclosed by the tube. If the frame cross-section 13 is formed from a solid body, the outer contour cross-sectional area corresponds to the cross-sectional area of ​​the solid body.

[0011] The sheet 15 has bending profile sections 152 that adjoin the fastening sections 153 with the two frame longitudinal members 11, 12. The sheet 15 is shaped such that the height of a flat section 151 between the fastening sections 153 is less than the height of the two fastening sections 153. The front frame cross member 13 is convexly shaped as described above so that it accommodates the bending profile of the sheet 15. Below the bending profile sections 152 of the sheet 15, further deformation start sections 133 are arranged on the front frame cross member 13 such that a uniform distance is maintained along the longitudinal direction of the frame cross member 13 between the frame cross member 13 and the underside of the sheet 15. Fig. Figure 6 illustrates this state. However, as can be seen from... Fig. As can be seen in Figure 3, the initial deformation sections 133 of the frame cross member 13 are designed parallel to the direction of travel F of a vehicle, while the bending profile sections 152 of the sheet 15 are shaped so that they run at an angle to the direction of travel F of a vehicle. Compared with the one in Fig. In the position shown in Figure 6, the width-position relationship between the bending profile sections 152 and the deformation start sections 133 therefore changes depending on the position in the longitudinal direction. Fig. 6. The initial deformation sections 133 are located closer to the two ends of the frame cross-section 13 than the bending profile sections 152. In other words, the initial deformation section 133 is located closer to the end of the frame cross-section 13 than the bending profile section 152. This positional relationship applies near the in Fig. 3 recognizable rearmost section of the frame cross-section 13; near the in Fig. In the 3 identifiable front section of the frame cross-section 13, the deformation start sections 133 are located more in the middle of the frame cross-section 13 than the bending formation sections 152. As can be seen in Fig. As shown in Figure 6, the connecting sections 132 of the front frame cross-section 13 with both frame longitudinal sections 11,12 have undeformed sections of length L which are provided to hold the frame cross-section 13 in a processing machine when the frame cross-section 13 undergoes the deformation process.

[0012] The sheet 15 is further shaped such that the flat section 151 between the fastening sections 153 runs at an angle, decreasing in height from front to back. In addition, the flat section 131 is shaped at an angle such that its height decreases from front to back, following the profile of the sheet 15 (see Fig. 2, Fig. 4 and Fig. 7) The drawings do not show those sections which are not directly related to the present invention.

[0013] According to the foregoing embodiment, the sheet metal 15 can deform considerably when subjected to an impact load associated with the submarining phenomenon, since the side of the front frame cross-section 13 facing the sheet metal 15 is convexly shaped to increase the distance to the sheet metal, thereby increasing the amount of energy absorption at the front of the seat. Furthermore, the section of the front frame cross-section 13 located between the connecting sections 132 of the front frame cross-section 13 and the two frame longitudinal sections 11, 12 has a small outer contour cross-sectional area and low strength to increase the distance to the sheet metal 15; however, since the outer contour cross-sectional areas of the two connecting sections 132 are maintained and not reduced, the original strength of the seat cushion 1 is also preserved.Furthermore, a uniform distance is provided between the frame cross member 13 and the underside of the sheet 15 in the longitudinal direction of the front frame cross member 13. Therefore, comparable energy absorption can be maintained even if the sheet 15 is deformed at any point between the frame longitudinal members 11, 12 during a vehicle collision, thus reliably ensuring safety in a collision. Moreover, the inclined surface profile of the sheet 15 protects the body of an occupant from sliding forward and downward due to the submarining phenomenon; furthermore, deformation of the sheet 15 and thus energy absorption capacity can be maintained because the flat section (the sheet-side surface) 131 of the front frame cross member 13 runs at an angle along the profile of the sheet 15.

[0014] As it is in Fig. As shown in Figure 3 with the dashed line, a stiffening plate 18 is welded to the underside of the flat section 151 of the sheet 15. As mentioned above, the strength of the sheet 15 is adjusted by attaching the stiffening plate 18 to the sheet 15; furthermore, the amount of energy absorbed by the deformation of the sheet 15 in a vehicle collision is adjusted accordingly. Forward / reverse sliding mechanisms 16, 17 are mechanisms for moving the seat cushion forward and backward; an operating lever 19 is a lever for operating the forward / reverse sliding mechanisms 16, 17. As shown in Fig. 1 and Fig. As shown in Figure 2, the operating lever 19 is U-shaped and convex in the direction of travel F of a vehicle and is designed such that it pivots about a central bearing in the longitudinal direction of the operating lever when it is pulled upwards at its front in a known manner for operation in order to unlock the forward / reverse sliding mechanisms 16, 17 at the rear ends. Fig. Figure 4 shows a position of the operating lever 19 indicated by a solid line, a position in which the operating lever 19 is unactuated, while an operating lever position 19a indicated by a two-dot dashed line shows a position in which the operating lever 19 has been pulled up to engage the forward / reverse sliding mechanisms 16, 17, and an operating lever position 19b indicated by a two-dot dashed line shows a position in which the operating lever 19 has been actuated to an upper limit position beyond a position in which the forward / reverse sliding mechanisms 16, 17 are unlocked. As described above, the operating lever 19 is located below the frame cross member 13 and is designed so that it does not collide with the frame cross member 13 even when pulled up to its upper limit position.If the frame cross member 13 were convexly shaped downwards in its entirety to create the concave section, there would be insufficient space between the frame cross member 13 and the operating lever 19. However, if, as in the preceding embodiment, only the side of the frame cross member 13 facing the sheet metal 15 is deformed to create the concave section, this has no effect on the space between the frame cross member 13 and the operating lever 19.

[0015] In Fig. 7 a suspension body 2 is stretched between the sheet metal 15 and the rear frame cross member 14; the suspension body 2 is coated with resin as a shock-absorbing material around a suspension material. Fig. Figure 5 shows a connection state between the two frame longitudinal parts 11, 12 and the front frame transverse part 13; as shown from Fig. As can be seen from Figure 5, the sides of the frame longitudinal members 11, 12 are each pierced by a through hole 111, 121 in line with the two connecting sections 132 of the frame transverse member 13. The edge sections of the frame longitudinal members 11, 12, which form the through holes 111, 121, were welded to the connecting sections 132 of the frame transverse member 13 in a state in which the two connecting sections 132 of the frame transverse member 13 were inserted into the through holes 111, 121. Fig. Figure 8 shows modified examples of the front frame cross-section 13, with each of the frame cross-sections 13a, 13b and 13c in Fig. 8A to Fig. 8C analogous to the one in Fig. 7 in cross-section frame cross-section 13 is shown in cross-section. Fig. 8A is a first modified example that has an ellipse whose major axis lies on a line parallel to the flat section 151 of the sheet 15. Fig. 8B is a second modified example in which a recess 134 is formed in the longitudinal direction of the frame cross-section 13 opposite the flat section 151 of the sheet 15. Fig. 8C is a third modified example, which has a rectangular shape whose longer side lies on a line parallel to the flat section 151 of the sheet 15. Each of the frame cross-sections 13a, 13b, 13c ensures the distance to the sheet 15 and also guarantees the strength by maintaining the cross-section as much as necessary. In the case of Fig. 8C is like the flat section 131 of the frame cross-section 13 in the previous embodiment (see Fig.7) The side facing the sheet metal 15 is flat. Accordingly, the frame cross member 13c receives the sheet metal 15 with its flat side when the latter is deformed in a vehicle collision and impacts the frame cross member 13c, and can thus partially prevent an increase in the reaction force experienced by the occupant via the sheet metal 15. The frame cross members 13a, 13b, and 13c of these modified examples can each be designed as a hollow tube or a solid bar.

[0016] The present invention is not limited to the design or configuration of the embodiment described above; rather, various modified examples, additions, and omissions are possible within the scope of the present invention. For example, firstly, the frame cross member is not limited to a cylindrical shape but can also be formed as a square tube or a plate. Secondly, the frame cross member can be concave not only on the sheet-faced surface but also overall, including the surface opposite the sheet-faced surface.

Claims

[1] Seat cushion frame for a vehicle, characterized by : Frame longitudinal parts (11, 12) which are arranged on both sides of a frame of a seat cushion (1); Frame cross members (13, 14) connecting the front and rear sections of the frame longitudinal members (11, 12); and a sheet (15) which is attached to the two frame longitudinal parts (11, 12) and covers from above the space between the front ends of the frame longitudinal parts (11, 12) in which the front frame transverse part (13) is located, wherein the sheet metal side of the front frame cross member (13) has a concave section which increases the distance to the sheet metal (15). [2] Seat cushion frame for a vehicle according to claim 1, wherein the concave section in the front frame cross-section (13) is designed such that a section of the front frame cross-section (13) which lies between the connecting sections (132) connected to the two frame longitudinal sections (11, 12) has a smaller outer contour cross-sectional area than the connecting sections (132). [3] Seat cushion frame for a vehicle according to claim 1, wherein a section of the front frame cross-section (13) located between the connecting sections (132) has a lower strength than the connecting sections (132) connected to the two frame longitudinal sections (11, 12). [4] Seat cushion frame for a vehicle according to claim 1, wherein the sheet (15) has bending profile sections (152) in the vicinity of fastening sections (153) attached to the two frame longitudinal parts (11, 12) and is designed such that the height of a section of the sheet (15) lying between the fastening sections (153) is less than the height of each of the fastening sections (153), the concave section of the front frame cross-section (13) accommodates the bending profile sections (152) of the sheet (15), and deformation start sections (133) are arranged below the bending profile sections (152) of the sheet (15) such that the distance between the front frame cross-section (13) and the underside of the sheet (15) is uniform throughout in the longitudinal direction of the front frame cross-section (13). [5] Seat cushion frame for a vehicle according to claim 4, wherein the deformation start sections (133) are located at the ends of the frame cross section (13) in comparison to the bending profile sections (152). [6] Seat cushion frame for a vehicle according to one of claims 1 to 5, wherein the sheet metal (15) is beveled in such a way that the height of a section located between the fastening sections (153) decreases from front to rear, and the concave section of the front frame cross-section (13) is beveled in such a way that the sheet metal side decreases from front to rear following the sheet metal profile.

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