JP7772607B2 - Vehicle seat frame and vehicle seat - Google Patents

Description

The present invention relates to a vehicle seat frame and a vehicle seat.

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

Japanese Patent Application Laid-Open No. 2018-27745

In the above prior art, the front riser bracket is firmly fastened to the upper rail using bolts and nuts, making it easy to ensure strength against the force of a rear-end collision, but there is room for improvement in terms of weight reduction.

In consideration of the above, the present invention aims to provide a vehicle seat frame and a vehicle seat that can ensure strength against inputs during a rear-end collision while also being lightweight.

The vehicle seat frame of the first aspect 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 is fixed to the upper rail by welding, and 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 connecting portion.

In the first embodiment of the vehicle seat frame, one end of the front link is rotatably connected to the front portion of the side frame of the seat cushion frame, and the other end of the front link is rotatably connected to the link connection portion of the front riser bracket. The front riser bracket has a rail fixing portion fixed to the front portion of the upper rail of the seat slide rail, and the link connection portion extends upward from the seat width direction inner end of the rail fixing portion. 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 reduces 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 weld between the rail fixing portion and the upper rail is reduced, making it easier to ensure strength.

The vehicle seat frame of the second aspect is the same as that of the first aspect, except that the bead portion has a ridgeline extending in the seat front-rear direction, and the welded portion between the rail fixing portion and the upper rail has a portion extending along the ridgeline.

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

The vehicle seat frame of the third aspect is the same as that of the second aspect, but the welded portion has a U-shape or a roughly U-shape in plan view that opens to one side in the front-to-rear direction of the seat.

In the vehicle seat frame of the third aspect, the weld 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 front-to-rear direction of the seat. This provides the weld with two sections that extend along the ridge of the bead portion, allowing the bead portion to effectively suppress stress concentration in those sections.

The vehicle seat frame of the fourth aspect is the same as the third aspect, except that the rail fixing portion is welded to the upper rail at multiple welds aligned in the seat fore-and-aft direction.

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

The vehicle seat of the fifth aspect has a framework formed by the vehicle seat frame of any one of the first to fourth aspects.

In the vehicle seat of the fifth aspect, the framework is formed by the vehicle seat frame of any one of the first to fourth aspects. Therefore, the same effects as any one of the first to fourth aspects can be obtained.

As described above, the vehicle seat frame and vehicle seat according to the present invention can ensure strength against inputs during a rear-end collision while also being lightweight.

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. 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. 3 is a perspective view showing a part of the configuration shown in FIG. 2 as viewed from the inside in the seat width direction and from the seat lower side. FIG. FIG. 2 is a perspective view showing a front riser bracket in the embodiment. 2 is a perspective view corresponding to a part of FIG. 1 and is a view for explaining an input direction to a front riser bracket in the event of a rear-end collision of the vehicle. FIG. FIG. 6 is a cross-sectional view showing a cut surface taken along line F6-F6 in FIG. 2. 7 is a cross-sectional view corresponding to FIG. 6 and is a view for explaining deformation of the front riser bracket of the embodiment when a load is input in the input direction shown in FIG. 5 . 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. 9 is a perspective view showing a part of the configuration shown in FIG. 8 as viewed from the inside in the seat width direction and from the seat lower side. FIG. FIG. 10 is a perspective view showing a front riser bracket in a comparative example. 9 is a cross-sectional view showing a cut surface taken along line F11-F11 in FIG. 8. 12 is a cross-sectional view corresponding to FIG. 11 and is a view for explaining deformation of the front riser bracket of the comparative example when an input is applied in the input direction shown in FIG. 5 . FIG. FIG. 10 is an analytical diagram showing the results of a computer simulation analysis of stresses generated in the welded portion between the front riser bracket and the upper rail in the comparative example based on the above inputs. 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. 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. 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. 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. 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. 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. 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. 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. FIG. 22 is a perspective view showing the front riser bracket shown in FIG. 21 . 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. 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. FIG. 25 is a perspective view showing the front riser bracket shown in FIG. 24. 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.

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. Furthermore, the arrow FR, as appropriate, shown in each figure indicates the front of the vehicle, the arrow UP indicates the top of the vehicle, the arrow LH indicates the left side of the vehicle, and the arrow RH indicates the right side of the vehicle. Hereinafter, when the front-rear, left-right, top-bottom directions are used in descriptions, 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 top and bottom in the up-down direction of the vehicle, unless otherwise specified.

(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 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.

The seat cushion frame 14 comprises a pair of left and right side frames 16 (only the left side frame 16 is shown in Figure 1) located on the left and right sides of the seat cushion and extending in the fore-and-aft direction of the seat, a cushion pan 18 spanning the upper ends of the front of the left and right side frames 16, and a rear frame (not shown) spanning 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.

The left and right side frames 16 are formed into an elongated shape, for example by press-molding sheet metal, and are positioned so that their lengthwise direction is along the front-to-rear direction of the seat and their thickness direction is along the left-to-right direction of the seat. The cushion pan 18 is formed, for example, from sheet metal into a roughly rectangular shape, and is positioned so that its thickness direction is along the up-down direction of the seat, with both left-to-right ends of the seat fixed to the front portions of the left and right side frames 16 by means such as welding. The rear frame is formed, for example, from a metal pipe, and is positioned so that its axis is along the left-to-right direction of the seat, with both left-to-right ends of the seat rotatably connected to the rear ends of the left and right side frames 16 by means such as caulking. The lower ends of the seatback frames are recliningly connected to the rear ends of the left and right side frames 16 via a well-known reclining mechanism.

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 Figure 1) located 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 upper rail 24 are arranged with their longitudinal directions extending in the longitudinal direction.

The lifter mechanism is composed of a pair of left and right front riser brackets 30 (only the left front riser bracket 30 is shown in Figure 1), a pair of left and right front links 26 (only the left front link 26 is shown in Figure 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, for example, by press-forming sheet metal. Note that 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.

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 of the upper rail 24, a link connecting portion 34 extending upward from the inner end (inner end in the left-right direction) of the rail fixing portion 32 in the seat width direction, an upper flange portion 36 extending inward in the seat width direction from the upper end of the link connecting portion 34, a front wall portion 38 connecting the front end of the rail fixing portion 32 and the front end of the link connecting 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 connecting portion 34.

The rail fixing portion 32 is a long plate with its thickness in the up-down direction and its length in the front-to-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-to-rear direction. These welds 46, 48 are laser-welded weld beads. The front weld 46 secures the front portion of the rail fixing portion 32 to the upper surface of the upper rail 24, and the rear weld 48 secures the rear portion of the rail fixing portion 32 to the upper surface of the upper rail 24.

The front welded portion 46 is composed of a pair of front-to-rear extending portions 46A, 46B that are aligned in the seat width direction and extend along the seat front-to-rear direction, and a front connection portion 46C that connects the front ends of the pair of front-to-rear extending portions 46A, 46B. In plan view, the front-to-rear welded portion 46 is roughly U-shaped and opens toward the rear of the seat. The front-to-rear extending portion 46A on the outer side of the seat width direction extends parallel to the seat front-to-rear direction, while the front-to-rear extending portion 46B on the inner side of the seat width direction is inclined relative to the seat front-to-rear direction so that it approaches inward in the seat width direction as it moves toward the rear of the seat. The front connection portion 46C forms an arc shape that convex toward the front of the seat.

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

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 smoothly connects 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 positioned 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. The 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 the 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 both formed so that their heights increase as they extend inward in the seat width direction.

A bead portion (bulge) 50 that bulges outward in the seat width direction is formed at the lower front portion of the link connection portion 34. As a result, the cross section of the front portion of the link connection portion 34, when viewed from the seat front-rear direction, is generally crank-shaped, 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 upper side of the seat, and a ridge line RL that extends in the seat front-rear direction is formed at the upper portion of the bead portion 50. This bead portion 50 reinforces the area near the connection between the link connection 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. The front and rear extension portions 46A, 46B, 48A, 48B of the front and rear weld portions 46, 48 extend along the ridge line RL.

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 positioned 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 this connecting shaft 28.

Although not shown in the figure, 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.

The left and right front links 26 and the left and right rear links are positioned with a rearward tilt. A sector gear, for example, is formed on one of the left and right rear links, and the one rear link is rotated by manually or electrically rotating a pinion (not shown) meshed with the sector gear. 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.

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

In the vehicle seat 10 configured as described above, one end of the front link 26 is rotatably connected to the 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 the link connection portion 34 of the front riser bracket 30. The front riser bracket 30 has a rail fixing portion 32 fixed to the front portion of the upper rail 24 of the seat slide rail 20, and the link connection portion 34 extends upward from the 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.

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 bottom of the link connection portion 34 of the front riser bracket 30. This makes it easier to ensure strength against inputs during a rear-end collision. Specifically, during a rear-end collision, the 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 connection portion 34 diagonally upward and rearward of the vehicle, causing the front riser bracket 30 to deform near the connection between the link connection portion 34 and the rail fixing portion 32. However, this deformation is suppressed by the bead portion 50. This suppresses stress concentration at the weld 46, thereby suppressing fracture of the welds 46, 48 originating from the weld 46, making it easier to ensure the strength of the welds 46, 48.

Note that Figure 6 is a cross-sectional view taken along line F6-F6 in Figure 2, and Figure 7 is a cross-sectional view corresponding to Figure 6 when the above-mentioned load F is applied. As shown in Figure 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 of the front/rear extending portion 46B).

The above effects will be further explained using comparative examples shown in Figures 8 to 12. Note that Figure 11 is a cross-sectional view taken along line F11-F11 in Figure 8, and Figure 12 is a cross-sectional view corresponding to Figure 11 when the above load F is applied. In this comparative example, the bead portion 50 is not formed at the bottom of the link connection portion 34 of the front riser bracket 30', and the rigidity near the connection between the link connection 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 above load F is applied to the link connection portion 34, the front riser bracket 30' deforms near the connection between the link connection portion 34 and the rail fixing portion 32 (see Figure 12). As a result, stress concentrates at the weld 46 between the rail fixing portion 32 and the upper rail 24 (particularly near the front end of the front/rear extension 46B), causing the welds 46, 48 to fracture.

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 lift up along with the upper rail 24 due to the load F described above. This suppresses stress concentration at the welded portion 46, which in turn suppresses 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.

In addition, in this embodiment, the bead portion 50 formed at the bottom of the link connection portion 34 of the front riser bracket 30 has a ridge line RL that extends in the seat fore-and-aft direction. Furthermore, the welded portions 46, 48 between the rail fixing portion 32 of the front riser bracket 30 and the upper rail 24 have front-to-rear extending portions 46A, 46B, 48A, 48B that extend along the ridge line RL. This allows the bead portion 50 to effectively suppress stress concentration on the front-to-rear extending portions 46A, 46B, 48A, 48B.

In addition, 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's fore-and-aft direction. As a result, each weld 46, 48 has two front-to-rear extending portions 46A, 46B, 48A, 48B that extend along the ridge line RL of the bead portion 50, which effectively prevents stress concentration in these areas.

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 aligned in the seat fore-and-aft direction. This allows the weld length to be set short while still maintaining the required weld strength, compared to a configuration in which the rail fixing portion 32 and the upper rail 24 are welded at a single elongated weld extending in the seat fore-and-aft direction, for example.

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

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

Next, with reference to Figures 19 to 26, we will explain the results of a computer simulation analysis of the plastic strain that varies depending on the welding pattern. Figure 19 shows, in percentage, the plastic strain that occurs in the weld 46 when a load F is applied in this embodiment. Figure 20 shows, in percentage, the plastic strain that occurs in the weld 46 when a load F is applied in a comparative example.

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 fore-and-aft 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, 62 aligned in the seat fore-and-aft direction. Figure 26 shows, in percentage terms, the plastic strain that occurs in the welded portion 56 of the second modified example when a load F is applied. In Figures 19, 20, 23, and 26, the load F is set to the same value. From Figures 19, 20, 23, and 26, it was confirmed that plastic strain is particularly small when the welded portion 46 is approximately U-shaped, as in this embodiment.

In the above embodiment, the rail fixing portion 32 and the upper rail 24 are welded at two (or multiple) welds 46, 48 aligned in the seat front-to-rear direction, but this 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-to-rear direction.

In addition, in the above embodiment, the welded portions 46, 48 are configured to be U-shaped or approximately U-shaped in plan view, but this is not limited to this. For example, the welded portions may be configured to be oval in plan view with the longitudinal direction of the seat.

The present invention can be modified and implemented in various ways without departing from its spirit. It goes without saying that the scope of the present invention is not limited to the above-described embodiment.

REFERENCE SIGNS LIST 10 Vehicle seat 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 portion 34 Link connecting portion 46 Welded portion 46A, 46B Front and rear extending portion 48 Welded portion 48A, 48B Front and rear extending portion 50 Bead portion 52, 54, 56, 58, 60, 62 Welded portion RL Ridge line

Claims (6)

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 . 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. The vehicle seat frame according to claim 2, wherein the welded portion has a U-shape or a substantially U-shape in plan view, opening to one side in the front-to-rear direction of the seat. The vehicle seat frame of claim 3, wherein the rail fixing portion is welded to the upper rail at multiple welds aligned in the seat fore-and-aft direction. The vehicle seat frame according to any one of claims 1 to 4, wherein the front portion of the link connection portion has a generally crank-shaped cross section when viewed from the seat front-rear direction, and the lower portion where the bead portion is formed bulges outward in the seat width direction more than the upper portion. A vehicle seat having a skeleton formed by the vehicle seat frame according to any one of claims 1 to 5.