Vehicle seat frame and vehicle seat

Abstract

To achieve both securement of strength against input at the time of a rear-end collision of a vehicle and weight reduction.SOLUTION: A vehicle seat frame 12 includes: a front link 26 having one end portion rotatably connected to a front portion of a side frame 16 of a seat cushion frame 14; and a front riser bracket 30 having a rail fixing portion 32 fixed to a front portion of an upper rail 24 of a seat slide rail 20 and a link connecting portion 34 extending upward from an inner end in a seat width direction of the rail fixing portion 32, to which the other end of the front link 26 is rotatably connected. The rail fixing portion 32 is welded to the upper rail 24 at welding portions 46, 48. A bead portion 50 that bulges out toward the seat width direction outer side is formed at a lower portion of the link connecting portion 34 at a lower side of the other end portion of the front link 26.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat frame and a vehicle seat. [Background technology]

[0002] The vehicle seat described in Patent Document 1 below includes a front link having one end rotatably connected to a side frame of a seat cushion frame, and a front bracket (front riser bracket) fastened to an upper rail of a slide rail with bolts and nuts and having the other end rotatably connected to the front link. The front link and the front riser bracket are components of a lifter mechanism for adjusting the height of the seat cushion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-27745 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described prior art, the front riser bracket is firmly fastened to the upper rail using bolts and nuts, which makes it easy to ensure strength against inputs during a rear-end collision of the vehicle, but there is room for improvement in terms of weight reduction.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a vehicle seat frame and a vehicle seat that can ensure strength against input during a rear-end collision of the vehicle while also being lightweight. [Means for solving the problem]

[0006] The vehicle seat frame of the first embodiment comprises a front link having one end rotatably connected to the front portion of the side frame of the seat cushion frame, a rail fixing portion fixed to the front portion of the upper rail of the seat slide rail, and a front riser bracket extending upward from the inner end of the rail fixing portion in the seat width direction and having a link connecting portion to which the other end of the front link is rotatably connected, the rail fixing portion being fixed to the upper rail by welding, and a bead portion bulging outward in the seat width direction being formed at the bottom of the link connecting portion below the other end of the front link.

[0007] In a first aspect of the vehicle seat frame, one end of the front link is rotatably connected to a front portion of a side frame of the seat cushion frame, and the other end of the front link is rotatably connected to a link connection portion of a front riser bracket. The front riser bracket has a rail fixing portion fixed to a front portion of an upper rail of a seat slide rail, and the link connection portion extends upward from an inner end of the rail fixing portion in the seat width direction. The rail fixing portion of the front riser bracket is fixed to the upper rail by welding. This allows for a lighter weight than when the rail fixing portion is fixed to the upper rail using bolts and nuts. Furthermore, a bead portion bulging outward in the seat width direction is formed below the other end of the front link and at the bottom of the link connection portion of the front riser bracket. This suppresses deformation of the front riser bracket when a load is input from the front link to the link connection portion diagonally upward and rearward of the vehicle during a rear-end collision. As a result, stress concentration at the welded portion between the rail fixing portion and the upper rail is suppressed, making it easier to ensure strength.

[0008] The vehicle seat frame of the second aspect is the same as that of the first aspect, in which the bead portion has a ridge line extending in the fore-and-aft direction of the seat, and the welded portion between the rail fixing portion and the upper rail has a portion extending along the ridge line.

[0009] In the vehicle seat frame of the second aspect, a bead portion formed at a lower portion of a link connecting portion of a front riser bracket has a ridge line extending in the seat front-rear direction. Also, a welded portion between the rail fixing portion of the front riser bracket and the upper rail has a portion extending along the ridge line. This allows the bead portion to effectively suppress stress concentration at the welded portion.

[0010] The vehicle seat frame of a third aspect is the second aspect, wherein the welded portion has a U-shape or a substantially U-shape in plan view that opens to one side in the front-rear direction of the seat.

[0011] In the vehicle seat frame of the third aspect, the welded portion between the rail fixing portion of the front riser bracket and the upper rail is U-shaped or approximately U-shaped in plan view, opening to one side in the seat front-rear direction. This provides the welded portion with two portions that extend along the ridge line of the bead portion, and the bead portion can effectively suppress stress concentration in those portions.

[0012] The vehicle seat frame of a fourth aspect is the third aspect, wherein the rail fixing portion is welded to the upper rail at a plurality of welds aligned in the seat front-rear direction.

[0013] In the vehicle seat frame of the fourth aspect, the rail fixing portion of the front riser bracket is welded to the upper rail at multiple welds aligned in the seat front-rear direction, which allows the weld length to be set short while still ensuring the required weld strength, compared to a configuration in which the rail fixing portion and the upper rail are welded at a single elongated weld extending in the seat front-rear direction, for example.

[0014] A vehicle seat according to a fifth aspect has a skeleton formed by the vehicle seat frame according to any one of the first to fourth aspects.

[0015] In the vehicle seat of the fifth aspect, the skeleton is formed by the vehicle seat frame of any one of the first to fourth aspects, and therefore, the same effects as any one of the first to fourth aspects can be obtained. [Effects of the Invention]

[0016] As described above, the vehicle seat frame and vehicle seat according to the present invention can ensure strength against input during a rear-end collision of the vehicle while also achieving weight reduction. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a configuration around a front riser bracket in a vehicle seat frame provided in a vehicle seat according to an embodiment. FIG. [Figure 2] FIG. 2 is a perspective view showing a front riser bracket and a front portion of an upper rail in the embodiment, as viewed from above the seat. [Figure 3] 3 is a perspective view showing a part of the configuration shown in FIG. 2 as seen from the inside in the seat width direction and from the seat lower side. [Figure 4] FIG. 2 is a perspective view showing a front riser bracket in the embodiment. [Figure 5] FIG. 2 is a perspective view corresponding to a part of FIG. 1, illustrating the input direction to the front riser bracket during a rear-end collision of the vehicle. [Figure 6] FIG. 6 is a cross-sectional view showing a cut surface taken along line F6-F6 in FIG. [Figure 7] 7 is a cross-sectional view corresponding to FIG. 6, illustrating deformation of the front riser bracket of the embodiment when a load is input in the input direction shown in FIG. 5. FIG. [Figure 8] FIG. 10 is a perspective view showing a front riser bracket and a front portion of an upper rail in a comparative example, as viewed from above the seat. [Figure 9] 9 is a perspective view showing a part of the configuration shown in FIG. 8 as seen from the inside in the seat width direction and from the seat lower side. [Figure 10] FIG. 10 is a perspective view showing a front riser bracket in a comparative example. [Figure 11] 9 is a cross-sectional view showing a cut surface taken along line F11-F11 in FIG. 8. [Figure 12] 12 is a cross-sectional view corresponding to FIG. 11, illustrating deformation of the front riser bracket of the comparative example when an input is applied in the input direction shown in FIG. 5. FIG. [Figure 13] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of stresses generated at the welded portion between the front riser bracket and the upper rail in the comparative example based on the above inputs. [Figure 14] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of stresses generated at the welded portion between the front riser bracket and the upper rail in the embodiment based on the above inputs. [Figure 15] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring in the welded portion between the front riser bracket and the upper rail in the comparative example due to the above inputs. [Figure 16] 10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring at the welded portion between the front riser bracket and the upper rail in the embodiment based on the above inputs. FIG. [Figure 17] 10 is a photograph showing a state in which the welded portion between the front riser bracket and the upper rail in the comparative example was broken by the above-mentioned input in an actual vehicle test. [Figure 18] 10 is a photograph showing a state in which, in an actual vehicle test, the welded portion between the front riser bracket and the upper rail in the embodiment avoids fracture due to the above-mentioned input. [Figure 19] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring in the welded portion between the front riser bracket and the upper rail in the comparative example due to the above inputs. [Figure 20]10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring at the welded portion between the front riser bracket and the upper rail in the embodiment based on the above inputs. FIG. [Figure 21] FIG. 10 is a plan view showing the configuration of the periphery of a front riser bracket in a first modified example of the embodiment. [Figure 22] FIG. 22 is a perspective view showing the front riser bracket shown in FIG. 21. [Figure 23] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring in the welded portion between the front riser bracket and the upper rail in the first modified example due to the above inputs. [Figure 24] FIG. 10 is a plan view showing the configuration of the periphery of a front riser bracket in a second modified example of the embodiment. [Figure 25] FIG. 25 is a perspective view showing the front riser bracket shown in FIG. 24. [Figure 26] FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of distortions occurring in the welded portion between the front riser bracket and the upper rail in the second modified example due to the above inputs. DETAILED DESCRIPTION OF THE INVENTION

[0018] A vehicle seat 10 and a vehicle seat frame 12 according to one embodiment of the present invention will be described below with reference to Figures 1 to 26. Note that in each figure, some reference numerals may be omitted to make the drawings easier to understand. Also, an arrow FR shown as appropriate in each figure indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, an arrow LH indicates the left side of the vehicle, and an arrow RH indicates the right side of the vehicle. Hereinafter, when the front-rear, left-right, up-down directions are used in the description, they refer to front and rear in the front-rear direction of the vehicle, left and right in the left-right direction of the vehicle (vehicle width direction), and up and down in the up-down direction of the vehicle, unless otherwise specified.

[0019] (composition) As shown in FIG. 1, a vehicle seat 10 according to this embodiment includes a vehicle seat frame 12 that forms the framework of the vehicle seat. The vehicle seat frame 12 includes a seat cushion frame 14 that forms the framework of a seat cushion on which a vehicle occupant sits, a seat slide rail 20 that is a component of a seat slide mechanism, and a front link 26 and a front riser bracket 30 that are components of a lifter mechanism. Although not shown, the rear end of the seat cushion frame 14 is connected to the lower end of a seat back frame that forms the framework of the seat back. Pad materials (neither of which are shown) covered with upholstery are attached to the seat cushion frame 14 and the seat back frame. The front-rear direction, left-right direction (width direction), and up-down direction of the vehicle seat 10 coincide with the front-rear, left-right, up-down directions of the vehicle.

[0020] The seat cushion frame 14 includes a pair of left and right side frames 16 (only the left side frame 16 is shown in FIG. 1 ) disposed on the left and right sides of the seat cushion and extending in the front-to-rear direction of the seat, a cushion pan 18 spanning between the upper ends of the front portions of the left and right side frames 16, and a rear frame (not shown) spanning between the rear ends of the left and right side frames 16. A seat cushion spring (not shown) spans between the cushion pan 18 and the rear frame. This seat cushion spring elastically supports the padding of the seat cushion from below the seat.

[0021] The left and right side frames 16 are formed into an elongated shape, for example, by press-molding sheet metal, and are arranged with their longitudinal direction along the front-to-rear direction of the seat and their thickness direction along the left-to-right direction of the seat. The cushion pan 18 is formed, for example, from sheet metal into a generally rectangular shape, and is arranged with its thickness direction along the up-down direction of the seat, and both left-to-right ends of the seat are fixed to the front portions of the left and right side frames 16 by means of welding or the like. The rear frame is formed, for example, from a metal pipe, and is arranged with its axis direction along the left-to-right direction of the seat, and both left-to-right ends of the seat are rotatably connected to the rear ends of the left and right side frames 16 by means of caulking or the like. The lower ends of the seatback frames are connected to the rear ends of the left and right side frames 16 via a well-known reclining mechanism so that the seat can be reclined.

[0022] The left and right side frames 16 of the seat cushion frame 14 are connected to the vehicle floor via a seat slide mechanism and a lifter mechanism, and the seat cushion frame 14 is adjustable in its longitudinal and vertical positions relative to the vehicle floor. The seat slide mechanism includes a pair of left and right seat slide rails 20 (only the left seat slide rail 20 is shown in FIG. 1 ) disposed below the left and right side frames 16. The seat slide rail 20 includes a lower rail 22 fixed to the vehicle floor by means of, for example, bolt fastening, an upper rail 24 supported so as to be slidable in the longitudinal direction relative to the lower rail 22, and a locking mechanism (not shown) that restricts sliding of the upper rail 24 relative to the lower rail 22. The lower rail 22 and the upper rail 24 are disposed with their longitudinal directions extending in the longitudinal direction.

[0023] The lifter mechanism includes a pair of left and right front riser brackets 30 (only the left front riser bracket 30 is shown in FIG. 1), a pair of left and right front links 26 (only the left front link 26 is shown in FIG. 1), a pair of left and right rear riser brackets (not shown), and a pair of left and right rear links (not shown). The left and right front riser brackets 30, the left and right front links 26, the left and right rear riser brackets, and the left and right rear links are manufactured by, for example, press-forming sheet metal. The left and right front riser brackets 30, the left and right front links 26, the left and right rear riser brackets, and the left and right rear links are basically configured the same except that they are formed symmetrically.

[0024] As shown in Figures 1 to 3, the front riser bracket 30 has a rail fixing portion 32 fixed to the upper surface of the front end portion of the upper rail 24, a link connecting portion 34 extending upward from the inner end portion in the seat width direction (inner end portion in the left-right direction) of the rail fixing portion 32, an upper flange portion 36 extending inward in the seat width direction from the upper end portion of the link connecting portion 34, a front wall portion 38 connecting the front end portion of the rail fixing portion 32 and the front end portion of the link connecting portion 34, and a rear wall portion 40 connecting the rear end portion of the rail fixing portion 32 and the rear end portion of the link connecting portion 34.

[0025] The rail fixing portion 32 is an elongated plate with its thickness in the up-down direction and its length in the front-rear direction, and is superimposed on the upper surface of the upper rail 24. As an example, this rail fixing portion 32 is welded to the upper surface of the upper rail 24 at multiple (here, two) welds 46, 48 aligned in the seat front-rear direction. These welds 46, 48 are laser-welded weld beads. The front weld 46 fixes the front portion of the rail fixing portion 32 to the upper surface of the upper rail 24, and the rear weld 48 fixes the rear portion of the rail fixing portion 32 to the upper surface of the upper rail 24.

[0026] The front welded portion 46 is composed of a pair of front-rear extending portions 46A, 46B aligned in the seat width direction and extending along the seat front-rear direction, and a front connecting portion 46C connecting the front ends of the pair of front-rear extending portions 46A, 46B. The front welded portion 46 has a generally U-shape that opens toward the rear of the seat in a plan view. The front-rear extending portion 46A on the outer side of the seat width direction extends parallel to the seat front-rear direction, while the front-rear extending portion 46B on the inner side of the seat width direction is inclined relative to the seat front-rear direction so as to move inward in the seat width direction as it extends toward the rear of the seat. The front connecting portion 46C has an arc shape that convex toward the front of the seat.

[0027] The rear welded portion 48 is composed of a pair of front-rear extending portions 48A, 48B aligned in the seat width direction and extending along the seat front-rear direction, and a rear connecting portion 48C connecting the rear ends of the pair of front-rear extending portions 48A, 48B, and has a U-shape that opens toward the front of the seat in a plan view. The pair of front-rear extending portions 48A, 48B extend parallel to the seat front-rear direction. The rear connecting portion 48C has an arc shape that convex toward the rear of the seat.

[0028] The link connection portion 34 extends upward from the inner end of the rail fixing portion 32 in the seat width direction. The lower end of the link connection portion 34 curves outward in the seat width direction as it extends downward, and is smoothly connected to the inner end of the rail fixing portion 32 in the seat width direction. The link connection portion 34 is curved in a crank-like cross section so that its front portion is located more outward in the seat width direction than its rear portion. A circular link connection hole 42 is formed in the upper part of the front portion of the link connection portion 34. An upper flange portion 36 extends inward in the seat width direction from the upper end of the rear portion of the link connection portion 34. A front wall portion 38 connecting the front end of the rail fixing portion 32 and the front end of the link connection portion 34, and a rear wall portion 40 connecting the rear end of the rail fixing portion 32 and the rear end of the link connection portion 34 are formed so that their heights increase toward the inner side in the seat width direction.

[0029] A bead portion (bulge) 50 bulging outward in the seat width direction is formed at the lower front portion of the link connecting portion 34. As a result, the front portion of the link connecting portion 34 has a generally crank-shaped cross section when viewed from the seat front-rear direction, with the lower portion where the bead portion 50 is formed bulging outward in the seat width direction more than the upper portion. The upper portion of this bead portion 50 curves inward in the seat width direction as it approaches the seat upper side, and a ridge line RL extending in the seat front-rear direction is formed at the upper portion of the bead portion 50. This bead portion 50 reinforces the area surrounding the connection between the link connecting portion 34 and the rail fixing portion 32. This bead portion 50 is located inward in the seat width direction relative to the front weld portion 46. Front-rear extension portions 46A, 46B, 48A, 48B of the front and rear weld portions 46, 48 extend along the ridge line RL.

[0030] One end (upper end) of the front link 26 overlaps the front end of the side frame 16 from the inside in the seat width direction, and is rotatably connected to the front end of the side frame 16 using a connecting shaft whose axis is the seat width direction. The other end (lower end) of the front link 26 overlaps the upper part of the link connecting portion 34 from the outside in the seat width direction, and is disposed above the bead portion 50 of the front riser bracket 30. A connecting shaft 28 whose axis is the seat width direction is inserted into a link connecting hole 42 formed in the upper part of the link connecting portion 34, and the other end of the front link 26 is rotatably connected to the link connecting portion 34 using the connecting shaft 28.

[0031] Although not shown, the rear riser bracket is fixed to the upper surface of the rear part of the upper rail. One end of the rear link is fixed to the rear frame of the seat cushion frame 14 and is connected to the seat cushion frame 14 so as to be rotatable about an axis along the seat width direction. The other end of the rear link is connected to the rear riser bracket so as to be rotatable about an axis along the seat width direction.

[0032] The left and right front links 26 and the left and right rear links are disposed in a position tilted rearward. One of the left and right rear links is formed with, for example, a sector gear, and a pinion (not shown) meshed with the sector gear is rotated manually or electrically to rotate the one rear link. This rotates the left and right rear links and the left and right front links 26, changing the vertical position of the seat cushion frame 14.

[0033] (Action and effect) Next, the operation and effects of this embodiment will be described.

[0034] In the vehicle seat 10 configured as described above, one end of the front link 26 is rotatably connected to a front portion of the side frame 16 of the seat cushion frame 14, and the other end of the front link 26 is rotatably connected to a link connecting portion 34 of the front riser bracket 30. The front riser bracket 30 has a rail fixing portion 32 fixed to a front portion of the upper rail 24 of the seat slide rail 20, and the link connecting portion 34 extends upward from an inner end of the rail fixing portion 32 in the seat width direction. The rail fixing portion 32 of the front riser bracket 30 is fixed to the upper rail 24 by welding. This allows for a lighter weight than when the rail fixing portion 32 is fixed to the upper rail 24 using bolts and nuts.

[0035] Furthermore, a bead portion 50 that bulges outward in the seat width direction is formed below the other end of the front link 26 at the lower portion of the link connecting portion 34 of the front riser bracket 30. This makes it easier to ensure strength against inputs during a rear-end collision of the vehicle. That is, during a rear-end collision of the vehicle, a load from the occupant, who tends to inertially move toward the rear of the vehicle, is applied to the seat cushion frame 14 via the seatback frame. As a result, a load F (see FIG. 5 ) is input from the front link 26 to the link connecting portion 34 diagonally upward and rearward of the vehicle, and the front riser bracket 30 tends to deform near the connection portion between the link connecting portion 34 and the rail fixing portion 32. However, this deformation is suppressed by the bead portion 50. This suppresses stress concentration at the welded portion 46, thereby suppressing fracture of the welded portions 46, 48 originating from the welded portion 46, and makes it easier to ensure the strength of the welded portions 46, 48.

[0036] 6 is a cross-sectional view showing a cut surface taken along line F6-F6 in Fig. 2, and Fig. 7 is a cross-sectional view corresponding to Fig. 6 when the above-mentioned load F is input. As shown in Fig. 7, in this embodiment, deformation of the front riser bracket 30 near the connection between the link connecting portion 34 and the rail fixing portion 32 is suppressed, thereby suppressing stress concentration at the welded portion 46 (particularly near the front end portion of the front / rear extending portion 46B).

[0037] The above-described effects will be further explained using a comparative example shown in FIGS. 8 to 12. FIG. 11 is a cross-sectional view taken along line F11-F11 in FIG. 8, and FIG. 12 is a cross-sectional view corresponding to FIG. 11 when the load F is applied. In this comparative example, the bead portion 50 is not formed at the bottom of the link connecting portion 34 of the front riser bracket 30′, and the rigidity near the connection between the link connecting portion 34 and the rail fixing portion 32 is lower than in this embodiment. However, the other configurations are the same as in this embodiment. In this comparative example, when the load F is applied to the link connecting portion 34, the front riser bracket 30′ deforms near the connection between the link connecting portion 34 and the rail fixing portion 32 (see FIG. 12). As a result, stress concentrates at the welded portion 46 between the rail fixing portion 32 and the upper rail 24 (particularly near the front end of the front-rear extending portion 46B), which can cause the welded portions 46, 48 to break.

[0038] In contrast, in this embodiment, the bead portion 50 improves the rigidity near the connection between the link connecting portion 34 and the rail fixing portion 32, thereby suppressing deformation of the front riser bracket 30 and causing the front riser bracket 50 to tend to rise together with the upper rail 24 due to the load F described above. This suppresses stress concentration at the welded portion 46, thereby suppressing fracture of the welded portions 46, 48 originating from the welded portion 46, making it easier to ensure the strength of the welded portions 46, 48. As a result, for example, the front riser bracket 30 can be made thinner, enabling further weight reduction.

[0039] In this embodiment, the bead portion 50 formed at the lower portion of the link connecting portion 34 of the front riser bracket 30 has a ridge line RL extending in the seat front-rear direction. The welded portions 46, 48 between the rail fixing portion 32 of the front riser bracket 30 and the upper rail 24 have front-rear extending portions 46A, 46B, 48A, 48B extending along the ridge line RL. This allows the bead portion 50 to effectively suppress stress concentration on the front-rear extending portions 46A, 46B, 48A, 48B.

[0040] In this embodiment, the welds 46, 48 between the rail fixing portion 32 of the front riser bracket 30 and the upper rail 24 are U-shaped or approximately U-shaped in plan view, opening to one side in the seat front-rear direction. As a result, each weld 46, 48 is provided with two front-rear extending portions 46A, 46B, 48A, 48B that extend along the ridge line RL of the bead portion 50, and the bead portion 50 can effectively suppress stress concentration in those portions.

[0041] In addition, in this embodiment, the rail fixing portion 32 of the front riser bracket 30 is welded to the upper rail 24 at multiple welds 46, 48 that are aligned in the seat front-rear direction. This makes it possible to ensure the required weld strength while shortening the weld length, compared to a configuration in which the rail fixing portion 32 and the upper rail 24 are welded at a single elongated weld that extends longitudinally in the seat front-rear direction.

[0042] Next, the results of a computer simulation of the stress and plastic strain generated in the welded portion 46 due to the input of the load F in this embodiment and the comparative example will be described with reference to FIGS. 13 to 16. In this computer simulation, the load F was set to the same value in this embodiment and the comparative example. FIG. 13 shows the stress generated in the welded portion 46 due to the input of the load F in the comparative example, in units of MPa. FIG. 14 shows the stress generated in the welded portion 46 due to the input of the load F in this embodiment, in units of MPa. From FIGS. 13 and 14, it can be seen that the stress distribution in the welded portion 46 has changed and stress concentration has been alleviated in this embodiment. Furthermore, FIG. 15 shows the plastic strain generated in the welded portion 46 due to the input of the load F in the comparative example, expressed as a percentage. From FIG. 16, it can be seen that the plastic strain generated in the welded portion 46 due to the input of the load F in this embodiment, expressed as a percentage. From FIGS. 15 and 16, it can be seen that the plastic strain generated in the welded portion 46 is also reduced in this embodiment.

[0043] The above-described effects of this embodiment were also confirmed in an actual vehicle test simulating a rear-end collision of a vehicle. As shown in Fig. 17, in the comparative example, the front riser bracket 30' fractured starting from the front-rear extension 46B of the weld 46. On the other hand, as shown in Fig. 18, in the countermeasure product in which a separate part simulating the bead portion 50 was welded to the lower part of the link connecting portion 34, fracture of the front riser bracket 30 was avoided in the above-described actual vehicle test.

[0044] Next, the results of a computer simulation analysis of the plastic strain that varies depending on the welding pattern will be described with reference to Figures 19 to 26. Figure 19 shows, in this embodiment, the plastic strain that occurs in the welded portion 46 when a load F is applied, expressed as a percentage. Figure 20 shows, in a comparative example, the plastic strain that occurs in the welded portion 46 when a load F is applied, expressed as a percentage.

[0045] FIG. 21 shows a plan view of the configuration around the front riser bracket 30 in a first modified example of this embodiment, and FIG. 22 shows a perspective view of the front riser bracket 30 shown in FIG. 21. In this first modified example, the front riser bracket 30 and the upper rail are welded at two arc-shaped welds 52, 54 aligned in the seat front-rear direction. FIG. 23 shows, in percentage, the plastic strain that occurs in the weld 52 of the first modified example when a load F is applied. FIG. 24 shows a plan view of the configuration around the front riser bracket 30 in a second modified example of this embodiment, and FIG. 25 shows a perspective view of the front riser bracket 30 shown in FIG. 24. In this second modified example, the front riser bracket 30 and the upper rail are welded at four circular welds 56, 58, 60, and 62 aligned in the seat front-rear direction. FIG. 26 shows, in percentage, the plastic strain that occurs in the weld 56 of the second modified example when a load F is applied. 19, 20, 23, and 26, the load F is set to the same value. It is confirmed from Fig. 19, 20, 23, and 26 that the plastic strain is particularly small when the welded portion 46 is substantially U-shaped as in this embodiment.

[0046] In the above embodiment, the rail fixing portion 32 and the upper rail 24 are welded at two (plurality) welds 46, 48 aligned in the seat front-rear direction, but the present invention is not limited to this. For example, the rail fixing portion and the upper rail may be welded at a long weld whose longitudinal direction is the seat front-rear direction.

[0047] In the above embodiment, the welded portions 46, 48 are U-shaped or approximately U-shaped in plan view, but this is not limiting. For example, the welded portions may be oval-shaped in plan view, with the longitudinal direction of the seat extending in the fore-and-aft direction.

[0048] In addition, the present invention can be implemented with various modifications within the scope of the gist thereof. Furthermore, it goes without saying that the scope of the rights of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0049] 10 Vehicle seats 12. Vehicle seat frame 14 Seat cushion frame 16 Side frame 20 Seat slide rail 24 Upper Rail 26 Front link 30 Front riser bracket 32 Rail fixing part 34 Link connection part 46 Welded section 46A, 46B Front and rear extensions 48 Welds 48A, 48B Front and rear extensions 50 Bead section 52, 54, 56, 58, 60, 62 Welds RL Ridgeline

Claims

1. a front link having one end rotatably connected to a front portion of the side frame of the seat cushion frame; a front riser bracket including a rail fixing portion fixed to a front portion of an upper rail of a seat slide rail, and a link connecting portion extending upward from an inner end portion of the rail fixing portion in the seat width direction, and to which the other end of the front link is rotatably connected; Equipped with the rail fixing portion is fixed to the upper rail by welding, a bead portion that bulges outward in the seat width direction is formed below the other end of the front link and at a lower portion of the link connecting portion, The other end of the front link is connected to the link connecting portion using a connecting shaft, The bead portion is disposed below the connecting shaft.

2. the bead portion has a ridgeline extending in the seat front-rear direction, The vehicle seat frame according to claim 1 , wherein the welded portion between the rail fixing portion and the upper rail has a portion extending along the ridge line.

3. The vehicle seat frame according to claim 2, wherein the welded portion has a U-shape or a substantially U-shape that opens to one side in the front-rear direction of the seat in a plan view.

4. 4. The vehicle seat frame according to claim 3, wherein the rail fixing portion is welded to the upper rail at a plurality of welds aligned in the seat front-rear direction.

5. A vehicle seat frame as described in any one of claims 1 to 4, wherein the front part of the link connection part has a roughly crank-shaped cross section when viewed from the fore-and-aft direction of the seat, and the lower part in which the bead part is formed bulges outward in the seat width direction more than the upper part.

6. A vehicle seat whose skeleton is formed by a vehicle seat frame described in any one of claims 1 to 5.

Images