Vehicle seat cushion frame

Abstract

Vehicle seat cushion frame, characterized by: Frame longitudinal parts (11, 12) which are arranged on the right and left sides of a frame of a seat cushion (1); Frame cross members (13, 14) connecting the front and back sides of the frame longitudinal members (11, 12); and a sheet (15) which is attached to both frame longitudinal parts (11, 12) in such a way that it covers from above the space between the front end sections of the two frame longitudinal parts (11, 12) in which the front frame transverse part (13) is located, wherein the front frame cross-section (13) has connecting sections at which it is connected to the frame longitudinal sections (11, 12), and a section of the front frame cross-section (13) located between the connecting sections is thinner than the connecting sections.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

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

[0002] In the event of a frontal collision, a phenomenon known as submarining can occur, meaning that the body of a seated occupant, while restrained by a seatbelt, slides forward and downward off the seat. For occupant protection, it is essential that the occupant does not experience excessive impact. Therefore, various prior art designs for components around the seat are employed. For example, Japanese patent application 2001-145538 (JP 2001-145538 A) describes an invention that allows a backrest frame to deform slightly in a frontal collision, thus preventing excessive stress on the occupant's lumbar region.Furthermore, in some vehicles, the energy generated in a frontal collision by the occupant sliding forward and downward from the seat is absorbed by the front part of the seat cushion deforming under the load exerted on the front top of the seat cushion due to the submarining phenomenon.

[0003] In some vehicles, the required degree of deformation to absorb the energy resulting from submarining cannot be guaranteed at the front of the seat. This is because a front frame member, which forms part of the seat's frame, is located beneath a sheet metal panel that also forms the front of the seat. Even if this panel deforms due to an impact, the front frame member restricts this deformation. Therefore, insufficient energy is absorbed by the deformation of the panel.

[0004] From EP 1 199 214 A1, a rectangular seat cushion frame is known, comprising two longitudinal frame members and two transverse frame members connecting the front and rear ends of the longitudinal frame members. The seat cushion frame also has a transverse member designed to prevent an occupant from sliding forward and downward. This transverse member is designed, for example, with thin walls, to regulate a maximum load exerted on the occupant's feet through a defined deformation. The transverse member extends between the free ends of two arms, each pivotally mounted on a support housing located in a rear region of the seat cushion frame on the inner side of the associated longitudinal frame member.

[0005] Furthermore, US patent 7,192,087 B2 specifies a seat cushion frame with two longitudinal frame members, a rear cross member, and a front cross member. It also includes an adjustable cushion ramp, mounted on sliding fittings so that it can be moved back and forth. The cushion ramp, like the cross member specified in EP 1,199,214 A2, represents a measure to prevent the so-called submarining phenomenon. SUMMARY OF THE INVENTION

[0006] It is an object of the invention to absorb the impact load caused by the submarining phenomenon with a seat front section by allowing a front frame cross-section to deform slightly due to a reduced strength (of the front frame cross-section).

[0007] One aspect of the invention provides for a vehicle seat cushion frame. The vehicle seat cushion frame comprises: longitudinal frame members arranged on the right and left sides of a seat cushion frame; transverse frame members connecting the front and rear sides of the longitudinal frame members; and a sheet metal section attached to the two longitudinal frame members, covering the space between the front end sections of the two longitudinal frame members, in which the front transverse frame member is located. The front transverse frame member has connecting sections where it is joined to the longitudinal frame members. The section of the front transverse frame member located between the connecting sections is thinner than the connecting sections. In the above-mentioned design, the thickness of the front transverse frame member, and consequently its strength with respect to pressure exerted on the sheet metal, is low.The front frame crossmember deforms along with the sheet metal, which is deformed by the submarining phenomenon during a vehicle collision, and can effectively absorb the energy generated in the impact. Additionally, the thickness of each joint where the front frame crossmember connects to the frame longitudinal members is not reduced, thus maintaining the strength of the connection between the longitudinal members and the frame crossmember. If the frame crossmember is joined to the frame longitudinal members, for example by welding, the large thickness of the frame crossmember ensures a high heat capacity in each weld section. This prevents excessive melting of the weld sections through adequate dispersion of the welding heat, thereby preventing a reduction in weld strength.

[0008] In the aspect mentioned above, the thickness of the frame cross member can be increased by superimposing additional parts on the connection sections where the frame cross member is joined to the frame longitudinal members. Therefore, to change the thickness between the section located between the connection sections where the frame cross member is joined to the frame longitudinal members and the connection sections themselves, only the additional parts need to be added, thus implementing the thickness change very efficiently.

[0009] Regarding the aspect mentioned above, the frame cross member can be cylindrical. Furthermore, the two opening faces of the cylindrical part can be connected to the respective frame longitudinal member in such a way that they penetrate the frame longitudinal member, and cylindrical stiffening elements can be attached to the inner or outer circumference of the cylindrical part at the connection points where it is joined to the frame longitudinal members. Additionally, the cylindrical part and the cylindrical stiffening elements can be integrally connected to each other by compression in the overlapping direction.With the above-mentioned design, it is possible to change the thickness by superimposing the cylindrical part forming the frame cross-section on the cylindrical stiffening parts and then integrally connecting these parts by pressing, thereby obtaining a highly productive integral connection of the cylindrical stiffening parts with the cylindrical part. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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 top view of an embodiment of the invention is shown: Fig. 2 is a side view of the embodiment; Fig. 3 is an expanded perspective view of the embodiment; Fig. 4 a cross-sectional view along line IV-IV in Fig. 2 is; Fig. 5 a horizontal cross-sectional view of a front frame cross-section according to the embodiment; and Fig. 6 a cross-sectional view along line VI-VI in Fig. 5 is. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0011] As in Fig. 1 to Fig. As shown in Figure 4, the frame of a vehicle seat cushion 1 is designed as follows. Frame longitudinal members 11 and 12 are arranged on the right and left sides, respectively, with respect to the direction of travel F of the vehicle. The front and rear sides of the frame longitudinal members 11 and 12 are each connected to one another by a frame transverse member 13 and 14, respectively. A sheet metal plate 15 is attached to the front end sections of the two frame longitudinal members 11 and 12 in such a way that it covers the space between the two frame longitudinal members 11 and 12, in which the front frame transverse member 13 is located, from above. Both frame longitudinal members 11 and 12 comprise a height adjustment mechanism known per se. The frame longitudinal member 11 is formed from an upper frame longitudinal member 111, a lower frame longitudinal member 112, a front connecting member 113, and a rear connecting member 114.The frame longitudinal section 12 is formed from an upper frame longitudinal section 121, a lower frame longitudinal section 122, a front connecting member 123, and a rear connecting member 124. The rear connecting member 114 is designed in a manner known per se such that it allows selective adjustment of the angle between the upper frame longitudinal section 111 and the lower frame longitudinal section 112. By adjusting the angle of the rear connecting member 114, the height between the upper frame longitudinal sections 111 and 121 and the lower frame longitudinal sections 112 and 122 can be adjusted.

[0012] The front frame cross member 13 is connected to the connecting end sections of the front connecting links 113 and 123, which connect the upper frame longitudinal sections 111 and 121 to the lower frame longitudinal sections 112 and 122. The rear frame cross member 14 is connected to the rear ends of the upper frame longitudinal sections 111 and 121. The front frame cross member 13 is thinner than the connecting sections in the section between the connecting sections where it is joined to the front connecting links 113 and 123. The front frame cross member 13 is specifically formed from a cylindrical part 131. The two open sides of the cylindrical part 131 extend through the front connections 113 and 123 and are welded to the front connecting links 113 and 123.At the connecting sections of the front frame cross member 13, where the cylindrical part 131 is connected to the front connecting members 113 and 123, a cylindrical stiffening part 132 or 133 (which function as additional parts according to the invention) is attached to the inner circumference of the cylindrical part 131. The cylindrical part 131 and the cylindrical stiffening parts 132 and 133 are integrally connected to each other by compression in the overlapping direction. Fig. 5 and Fig. Figure 6 shows the pressed sections 134 formed by the pressing process. It should be noted that the cylindrical stiffening elements 132 and 133 can also be attached to the outer circumference of the cylindrical part 131. If the cylindrical stiffening elements 132 and 133 are arranged on the outer circumference of the cylindrical part 131, the outer diameter of the central section of the frame cross-section 13 is reduced by the thickness of the missing cylindrical stiffening elements 132 and 133. This slightly increases the distance between the sheet metal 15 and the frame cross-section 13, advantageously allowing for greater deformation of the sheet metal 15. This means that more energy can be absorbed in the event of an impact caused by a submarining phenomenon. Fig. 5 and Fig. Figure 6 shows a state in which the cylindrical part 131 and the cylindrical stiffening parts 132 and 133 are pressed together. As can be seen from the drawings, each cylindrical stiffening part 132 and 133 has four pressed sections 134 formed circumferentially. The pressing of the four sections is carried out in pairs in two steps. In the first pressing step, the pressing of two sections takes place at points opposite the center of the cylindrical part 131. The four pressed sections 134 are formed by pressing the cylindrical part 131, which is clamped by means of opposing pressing tools, twice.

[0013] In the embodiment described above, the front frame cross member 13, due to its small thickness, has low resistance to pressure exerted from above through the sheet metal 15. Therefore, if the sheet metal 15 deforms as a result of the submarining phenomenon in the event of a frontal collision, the front frame cross member 13 will also deform, and the energy generated in the collision can be effectively absorbed. Furthermore, the thickness of each of the connection sections where the front frame cross member 13 is connected to the frame longitudinal members 11 and 12 is not reduced, thus preserving the strength of the connection between the frame longitudinal members 11 and 12 and the frame cross member 13.The frame cross-section 13 is welded to the front connecting members 113 and 123 of the frame longitudinal sections 11 and 12. Thanks to the large thickness of the frame cross-section 13, a high heat capacity is ensured in the welded sections. This prevents excessive melting of the welded sections and counteracts a reduction in weld strength through sufficient dispersion of the welding heat. Furthermore, to change the thickness between the connecting sections where the frame cross-section 13 is joined to the frame longitudinal sections 11 and 12, and the section between these connecting sections, only the cylindrical stiffening elements 132 and 133 need to be added. These serve as additional components, thus achieving high efficiency in changing the thickness.Furthermore, it is possible to change the thickness by superimposing the cylindrical part 131, which forms the frame cross-section 13, on the cylindrical stiffening parts 132 and 133, and then to integrally connect these parts by pressing, thereby achieving high productivity in the integral formation of the cylindrical stiffening parts 132 and 133 with the cylindrical part 131.

[0014] It should be noted that a support plate 18 is welded to the underside of the rear central section of the sheet 15, as shown by the dashed line in Fig. Figure 1 shows that the addition of the support plate 18 adjusts the rigidity of the plate 15. This appropriately controls the amount of energy absorbed by the deformation of the plate 15 in a vehicle collision. Furthermore, the longitudinal displacement mechanisms 16 and 17 allow the seat cushion to deform longitudinally.

[0015] The invention is not limited to the design and configuration of the embodiment described above. Various modifications, additions, and omissions are possible, as long as the scope of protection of the invention is not altered. For example, the frame cross member is not limited to a cylindrical shape, but can equally be square tubular or plate-shaped. A seat cushion frame without a vertical adjustment mechanism can also be used.

Claims

[1] Vehicle seat cushion frame, characterized by : Frame longitudinal parts (11, 12) which are arranged on the right and left sides of a frame of a seat cushion (1); Frame cross members (13, 14) connecting the front and back sides of the frame longitudinal members (11, 12); and a sheet (15) which is attached to both frame longitudinal parts (11, 12) in such a way that it covers from above the space between the front end sections of the two frame longitudinal parts (11, 12) in which the front frame transverse part (13) is located, wherein the front frame cross-section (13) has connecting sections at which it is connected to the frame longitudinal sections (11, 12), and a section of the front frame cross-section (13) located between the connecting sections is thinner than the connecting sections. [2] Vehicle seat cushion frame according to claim 1, wherein the frame cross-section (13, 14) has a greater thickness by superimposing the connecting sections where the frame cross-section (13, 14) is connected to the frame longitudinal sections (11, 12) with additional parts (132, 133). [3] Vehicle seat cushion frame according to claim 1 or 2, wherein the frame cross-section (13, 14) is a cylindrical part (131). [4] Vehicle seat cushion frame according to claim 3, wherein the two open sides of the cylindrical part (131) are connected to the frame longitudinal parts (11, 12) in such a way that they penetrate the frame longitudinal parts (11, 12), and cylindrical stiffening parts (132, 133) are attached to the inner or outer circumferential side of the cylindrical part (131) at the connecting sections where the cylindrical part (131) is connected to the frame longitudinal parts (11, 12). [5] Vehicle seat cushion frame according to claim 4, wherein the cylindrical part (131) and the cylindrical stiffening parts (132, 133) are integrally connected to each other by compression in the superposition direction. [6] Vehicle seat cushion frame according to claim 4, wherein the cylindrical stiffening parts (132, 133) are each attached to the inner circumferential side of the cylindrical part (131) at the connecting sections where the cylindrical part (131) is connected to the frame longitudinal parts (11, 12). [7] Vehicle seat cushion frame according to claim 4, wherein the cylindrical stiffening parts (132, 133) are each attached to the outer circumferential side of the cylindrical part (131) at the connecting sections where the cylindrical part (131) is connected to the frame longitudinal parts (11, 12).

Images