Vehicle seat

Abstract

To provide a vehicular seat capable of suppressing the deformation amount of a front part of a slide rail and reducing a rearward inclination displacement amount of a seat back frame when a load to a seat rear side is inputted on a seat back while a seat position is at a seat fore-and-aft direction center position.SOLUTION: A vehicular seat is equipped with a seat back frame 14F, a seat cushion frame 12F, a lifter mechanism 20, a riser 30, and slide rail 34 (an upper rail 36 and a lower rail 38). In the lower rail 38, a first fixed portion 38F on a front end portion side and a second fixed portion 38R on a rear end portion side are fixed to a vehicle body floor 40. A reinforcement fixing portion 50 is provided on a front portion side of the lower rail 38 and a seat rear side of the first fixed portion 38F. The reinforcement fixing portion 50 is set at a position corresponding to a seat fore-and-aft direction position of a front side supporting portion 30F of the riser 30 while the upper rail 36 is at a slide center position.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In a vehicle seat, a slide rail having an upper rail and a lower rail is provided on the underside of the seat body to allow the seat body to slide in the fore-and-aft direction of the seat, and a riser, which is a frame mounting member, is fixed to the upper surface of the upper rail, and a seat cushion frame is attached to the front and rear of the riser via members. A technology is known (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-94990 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned prior art, when the pair of left and right upper rails are in the center position in the front-rear direction of the seat within the range in which they can slide, in other words, when the seat position is in the center position in the front-rear direction of the seat between the front most (frontmost position) and the rear most (rearmost position), Roa The position where the front side of the rail is fixed to the vehicle floor is set at a position offset forward in the front-to-rear direction of the seat from the front of the riser.

[0005] However, in this configuration, when a load is input to the seat back toward the rear of the seat due to a rear-end collision (hereinafter referred to as a "rear impact") or the like while the seat position is in the center of the seat in the front-rear direction, the path (load path) through which the load is transmitted is bent into a substantially L-shape at a portion from the front of the riser toward the front fixing position of the lower rail to the vehicle floor. In such a case, when a load is input to the seat back toward the rear of the seat, a moment load that tries to bend the front of the slide rail into an inverted V-shape is generated due to the substantially L-shape bending of the path. If the front of the slide rail is bent into an inverted V-shape, the amount of rearward tilt displacement of the seat back frame is increased.

[0006] Taking into consideration the above-mentioned facts, the present invention aims to provide a vehicle seat that can suppress the amount of deformation of the front part of the slide rail and reduce the amount of rearward displacement of the seat back frame when a load is input to the seat back toward the rear of the seat when the seat position is in the center position in the fore-and-aft direction of the seat. [Means for solving the problem]

[0007] The vehicle seat of the present invention described in claim 1 includes a seat back frame constituting a skeleton of a seat back, a seat cushion frame constituting a skeleton of a seat cushion and having a rear end connected to the seat back frame, a pair of left and right risers arranged on both sides of a seat lower side of the seat cushion frame in a seat width direction and attached to the seat cushion frame directly or via a member, the pair of risers including a front support portion supporting a front part of the seat cushion frame and a rear support portion supporting a rear part of the seat cushion frame, a pair of left and right upper rails to which lower parts of the pair of left and right risers are fixed and which extend along a seat front-rear direction, a pair of left and right upper rails constituting a pair of left and right slide rails together with the pair of left and right upper rails, which extend along the seat front-rear direction and support the pair of left and right upper rails slidably in the seat front-rear direction, and which have a first fixed portion provided on a front end side and a second fixed portion provided on a rear end side fixed to a vehicle body floor, and The pair of left and right upper rails are disposed and a load transmission portion that is set at a position corresponding to the seat fore-and-aft position of the front support portion in this state, and that transmits a load to the vehicle floor when a load is input to the rear of the seat through the upper rail to the front portion of the lower rail.

[0008] According to the above configuration, the seat cushion frame connected to the seat back frame is supported by the riser directly or via a member. Here, the front part of the seat cushion frame is supported by the front support part of the riser, and the rear part of the seat cushion frame is supported by the rear support part of the riser. The riser is supported by the lower rail via the upper rail, and the lower rail is supported by the vehicle floor with a first fixed part provided on the front end side and a second fixed part provided on the rear end side being fixed to the vehicle floor. Therefore, when a load is input to the seat back of the vehicle seat toward the rear side of the seat during a rear collision or the like, the load is transmitted from the seat back frame to the vehicle floor via the seat cushion frame, the riser, the upper rail, and the lower rail. At this time, a part of the load is transmitted from a load transmitting part provided on the front side of the lower rail to the vehicle floor.

[0009] Here, the load transmitting portion is provided rearward of the first fixed portion and is located at a center position in the front-rear direction of the seat within a range in which the pair of left and right upper rails can slide. A pair of upper rails are arranged on the left and right The slide rail is set at a position corresponding to the seat front-rear position of the front support part of the riser in the seat back position. Therefore, when the seat position is in the center position in the seat front-rear direction and a load is input to the seat back toward the rear of the seat, the load transfer path from the front support part of the riser to the vehicle floor is closer to the shortest straight path that hangs down perpendicularly from the front support part of the riser to the vehicle floor, compared to a comparative structure without a load transfer part. As a result, in the above-mentioned case, a tensile load toward the rear of the seat mainly acts on the front part of the slide rail, and the generation of a moment load that tries to bend the front part of the slide rail into an inverted V shape is suppressed. As a result, the amount of deformation of the front part of the slide rail is suppressed, and the amount of rearward tilt displacement of the seatback frame is reduced.

[0010] The vehicle seat of the present invention described in claim 2 is the configuration described in claim 1, wherein the pair of left and right risers are attached to the seat cushion frame via a height adjustment mechanism, the height adjustment mechanism includes a front link member connecting a front portion of the seat cushion frame and the front support portion of the riser, and a rear link member connecting a rear portion of the seat cushion frame and the rear support portion of the riser, and the load transmission portion is located at a center position in the front-rear direction of the seat within a range in which the pair of left and right upper rails can slide. The pair of left and right upper rails are disposed The front support portion is set at a position corresponding to a position in the front-rear direction of the seat at a connection portion between the front support portion and the front link member in this state.

[0011] According to the above-mentioned configuration, the height of the seat cushion frame relative to the slide rails can be adjusted by the height adjustment mechanism including the front link member and the rear link member. Also, the load transmission portion is located at the center of the range in which the pair of left and right upper rails can slide in the front-rear direction of the seat. A pair of upper rails are arranged on the left and right The front support portion of the riser is set at a position corresponding to the position in the front-rear direction of the seat at the connection portion between the front support portion of the riser and the front link member when the seat is in the center position in the front-rear direction. Therefore, when a load is input to the seat back toward the rear of the seat with the seat position at the center position in the front-rear direction of the seat, the load transfer path from the connection portion between the front support portion of the riser and the front link member to the vehicle floor is made closer to the shortest straight path that hangs down perpendicularly from the connection portion between the front support portion of the riser and the front link member to the vehicle floor, compared to a comparison structure without a load transfer portion. Therefore, the generation of a moment load that tries to bend the front portion of the slide rail into an inverted V shape is effectively suppressed.

[0012] The vehicle seat of the present invention described in claim 3 is the configuration described in claim 1 or claim 2, wherein the load transmission portion is located at a center position in a front-rear direction of the seat within a range in which the pair of left and right upper rails can slide. The pair of left and right upper rails are disposed The lower part of the front support portion is set at a position corresponding to the seat front-rear direction position of the fixed portion between the upper rail and the lower part of the front support portion in this state.

[0013] According to the above configuration, when a load is input to the seat back toward the rear side of the seat with the seat position at the center in the seat front-rear direction, the load transfer path from the fixing part of the lower part of the front support part of the riser to the upper rail to the vehicle floor is closer to the shortest straight path that hangs down perpendicularly from the fixing part of the lower part of the front support part of the riser to the upper rail to the vehicle floor, compared to a comparison structure without a load transfer part. Therefore, the generation of a moment load that tries to bend the front part of the slide rail into an inverted V shape is extremely effectively suppressed. Effect of the Invention

[0014] As described above, the vehicle seat of the present invention has the excellent effect of suppressing the amount of deformation of the front part of the slide rail and reducing the amount of rearward displacement of the seatback frame when a load toward the rear of the seat is input to the seatback with the seat position in the center position in the fore-aft direction of the seat. [Brief description of the drawings]

[0015] [Figure 1] 1 is a side view showing a vehicle seat according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged side view showing a part of the skeleton structure and a seat slide mechanism of the vehicle seat shown in FIG. 1. [Diagram 3] 3 is an enlarged cross-sectional view showing a state cut along line 3-3 in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A vehicle seat according to one embodiment of the present invention will be described with reference to Figures 1 to 3. In these figures, an arrow FR indicates the front side of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow W indicates the vehicle width direction.

[0017] (Configuration of the embodiment) Fig. 1 shows a left side view of a vehicle seat 10 according to this embodiment, and Fig. 2 shows an enlarged left side view of a part of the skeletal structure of the vehicle seat 10. Note that since the vehicle seat 10 is basically configured symmetrically, the vehicle seat 10 and its skeletal structure are not shown as viewed from the right side.

[0018] 1, the vehicle seat 10 has a seat body 10H. The seat body 10H includes a seat cushion 12 that constitutes a seating portion and supports the buttocks PC and thighs PD of a seated occupant P, a seat back 14 that supports the back PB of the seated occupant P, and a headrest 16 that supports the head PA of the seated occupant P.

[0019] The seat cushion 12 has a seat cushion frame 12F (see FIG. 2) that constitutes the skeleton of the seat cushion 12 covered with a cushion pad 12P. The seat back 14 has a seat back frame 14F (see FIG. 2) that constitutes the skeleton of the seat cushion 12 covered with a seat back pad 14P. The headrest 16 is connected to the upper end of the seat back 14 by a pair of left and right headrest stays 15. The seat back frame 14F and the seat cushion frame 12F shown in FIG. 2 constitute a vehicle seat frame 10F, and are both configured symmetrically with respect to a center line in the seat width direction of the vehicle seat 10.

[0020] As shown in FIG. 2, the seatback frame 14F includes a side frame 14S and an upper frame 14U. The side frames 14S extend in the up-down direction of the seatback on both sides of the seatback frame 14F, and are provided in a pair on the left and right. The upper frame 14U is in an inverted U-shape when viewed from the front of the seatback, and connects the upper ends of the left and right side frames 14S to each other. The pair of left and right headrest stays 15 described above are attached to the middle part of the upper edge part of the upper frame 14U in the seat width direction. The lower parts of the pair of left and right side frames 14S are connected to each other in the seat width direction by a lower panel 14A provided on the rear side. The lower panel 14A constitutes a part of the seatback frame 14F.

[0021] In addition, a plurality of seat back springs (not shown) are suspended in the seat width direction between the pair of left and right side frames 14S. These seat back springs are arranged in a line in the seat up-down direction and elastically support the seat back pad 14P (see FIG. 1) from the rear side of the seat.

[0022] The seat cushion frame 12F includes a pair of left and right side frames 12S provided on both sides of the seat cushion 12 (see FIG. 1) in the seat width direction and extending in the seat front-rear direction. The front ends of the pair of left and right side frames 12S are connected to each other in the seat width direction by a front frame 12A. The front ends of the pair of left and right side frames 12S are connected to each other in the seat width direction by a front shaft 12B. The front shaft 12B is disposed on the rear side of the seat from the front frame 12A and is attached to the pair of left and right side frames 12S so as to be rotatable about an axis along the seat width direction. The rear ends of the pair of left and right side frames 12S are connected to each other in the seat width direction by a rear shaft 12C. The rear shaft 12C is attached to the pair of left and right side frames 12S so as to be rotatable about an axis along the seat width direction. The front frame 12A, the front shaft 12B, and the rear shaft 12C each constitute a part of the seat cushion frame 12F.

[0023] In addition, a plurality of cushion springs (not shown) are suspended in the front-rear direction between the front shaft 12B and the rear shaft 12C of the seat cushion frame 12F. These cushion springs are arranged in a line in the seat width direction and elastically support the cushion pad 12P (see FIG. 1) from the lower side of the seat.

[0024] The lower part of the base bracket 12R is fastened to the upper part of the rear end side of the pair of left and right side frames 12S by fastening members 12X. A recliner (details not shown) of a reclining mechanism 13 (illustrated simply in the drawing) and the like are attached to the base bracket 12R, and the pair of left and right base brackets 12R are connected to each other in the seat width direction by a reclining rod 13A via the recliner and the like. The reclining rod 13A constitutes a part of the reclining mechanism 13 and connects the lower ends of the left and right side frames 14S of the seatback frame 14F to each other in the seat width direction, and serves as the reclining center of the seatback 14. The reclining mechanism 13 connects the seatback frame 14F to the rear end of the seat cushion frame 12F so that the seatback frame 14F can be tilted. The reclining mechanism is a well-known technique, so a detailed description will be omitted.

[0025] A pair of left and right risers 30 are disposed on both sides in the seat width direction below the seat of the seat cushion frame 12F. The pair of left and right risers 30 are attached to a pair of left and right side frames 12S of the seat cushion frame 12F via a front link member 22 and a rear link member 24.

[0026] 3 shows an enlarged cross-sectional view taken along line 3-3 in FIG. 2. In FIG. 3, only a cross-section on one side in the seat width direction is shown, and a cross-section on the other side in the seat width direction is omitted, but the cross-section on the other side in the seat width direction is a cross-section that is symmetrical to the cross-section shown in FIG. 3. As shown in FIG. 3, the riser 30 is made of, for example, sheet metal, and has a substantially U-shaped cross-section as viewed from the front-rear direction of the seat. That is, the riser 30 includes a lower wall portion 30A and a pair of left and right side wall portions 30B that are bent and extended from both ends of the lower wall portion 30A in the seat width direction toward the upper side of the seat.

[0027] As shown in Figures 2 and 3, a front support portion 30F that supports a front portion of the seat cushion frame 12F is formed in a front portion of the side wall portion 30B of the riser 30. Also, as shown in Figure 2, a rear support portion 30R that supports a rear portion of the seat cushion frame 12F is formed in a rear portion of the side wall portion 30B of the riser 30. Also, the side wall portion 30B of the riser 30 has a connecting portion 30M that connects the front support portion 30F and the rear support portion 30R in the seat front-rear direction. The connecting portion 30M protrudes less toward the upper side of the seat than the front support portion 30F and the rear support portion 30R.

[0028] On the other hand, the front link member 22 and the rear link member 24 each constitute a part of the lifter mechanism 20 as a height adjustment mechanism. The front link member 22 and the rear link member 24 are formed in an elongated shape from, for example, a sheet metal material, and are arranged with their thickness direction aligned with the seat width direction.

[0029] 2 and 3, the front link member 22 connects a front portion of the side frame 12S of the seat cushion frame 12F and a front support portion 30F of the riser 30. That is, one longitudinal end of the front link member 22 is rotatably connected to the front support portion 30F of the riser 30 via a front connecting shaft 26, and the other longitudinal end of the front link member 22 is rotatably connected to the front portion of the side frame 12S via a front shaft 12B.

[0030] As shown in Fig. 3, the front connecting shaft 26 is, for example, an integrated shaft member 26A and a cylindrical member 26B, and its axis is aligned with the seat width direction, similar to the front shaft 12B. The front connecting shaft 26 is attached to the front support portion 30F of the riser 30 so as to be rotatable about an axis aligned with the seat width direction. The front link member 22 shown in Figs. 2 and 3 is rotatable about an axis aligned with the seat width direction relative to the riser 30 and the side frame 12S. In Figs. 2 and 3, the connection portion between the front support portion 30F of the riser 30 and the front link member 22 is denoted by reference symbol 30C.

[0031] The rear link member 24 shown in Fig. 2 connects a rear portion of the side frame 12S of the seat cushion frame 12F to a rear support portion 30R of the riser 30. That is, one longitudinal end of the rear link member 24 is rotatably connected to the rear support portion 30R of the riser 30 via a rear connecting shaft 28, and the other longitudinal end of the rear link member 24 is rotatably connected to the rear end of the side frame 12S via a rear shaft 12C. The axial direction of the rear connecting shaft 28 is aligned along the seat width direction, similar to the rear shaft 12C, and the rear link member 24 is rotatable about an axis aligned along the seat width direction relative to the riser 30 and the side frame 12S.

[0032] As described above, a four-joint link mechanism is formed by the front link member 22, the rear link member 24, the side frames 12S and the risers 30, and the seat cushion frame 12F is connected to the pair of right and left risers 30 so as to be vertically movable.

[0033] As an example, the lifter mechanism 20 of this embodiment is configured such that, when a lifter lever provided on a pump-type lifter device (not shown) attached to one of the side frames 12S is operated, the operating force is transmitted to the rear link member 24 on the one side. As a result, the pair of left and right rear link members 24 and the pair of left and right front link members 22 rotate, thereby adjusting the up-down position (height position) of the seat cushion frame 12F (and thus the seat cushion 12 (see FIG. 1)) relative to the pair of left and right risers 30.

[0034] Meanwhile, the lower portion of the riser 30 is fixed to an upper rail 36 extending along the front-rear direction of the seat. A pair of left and right upper rails 36 are provided corresponding to the risers 30, and the lower portions of the pair of left and right risers 30 are fixed to the pair of left and right upper rails 36 in a one-to-one correspondence. To provide a supplementary explanation of the fixing form, as shown in Fig. 3, the lower wall portion 30A of the riser 30 is fixed to the upper wall portion 36A of the upper rail 36 by crimping fastening using a rivet 32 ​​as a fastener. In Figs. 2 and 3, the fixing portion (in the narrow sense, the portion understood as the "fastening portion") at the lower portion of the front support portion 30F of the riser 30 with the upper rail 36 is denoted by the reference symbol 30D.

[0035] As shown in Fig. 2, the vehicle seat 10 has a lower rail 38 that supports the upper rail 36 so that the upper rail 36 is slidable in the front-rear direction of the seat. In Fig. 2, the front portion of the upper rail 36 in a state in which the upper rail 36 is in the forwardmost position of the range in which the upper rail 36 can slide (the range indicated by the arrow X) is indicated by a two-dot chain line and given the reference symbol 36F, and the rear portion of the upper rail 36 in a state in which the upper rail 36 is in the rearmost position of the range in which the upper rail 36 can slide is indicated by a two-dot chain line and given the reference symbol 36R.

[0036] The lower rails 38 extend along the front-rear direction of the seat, and are provided in a pair on the left and right sides to correspond to the pair of left and right upper rails 36. The pair of left and right lower rails 38, together with the pair of left and right upper rails 36, constitute a pair of left and right slide rails 34 (which are elements that may be broadly understood as a "slide mechanism").

[0037] Although not shown, the slide rail 34 is provided with a slide lock mechanism that locks the sliding movement of the upper rail 36 relative to the lower rail 38. The locking by the slide lock mechanism is released by operating a lock release lever 39 provided at the front of the slide rail 34.

[0038] A first fixed portion 38F is provided on the front end side of the bottom wall portion 38A (see FIG. 3) of the pair of left and right lower rails 38. The first fixed portion 38F is supported on the vehicle floor 40 via a ring-shaped spacer 42S arranged below the first fixed portion 38F. In addition, in FIG. 1 and FIG. 2, the cross section of the vehicle floor 40 is shown by a thick line for convenience. As shown in FIG. 2, a bolt 42A that penetrates the first fixed portion 38F, the spacer 42S, and the vehicle floor 40 from the upper side of the vehicle is screwed into a weld nut (broadly speaking, "nut") 42B that is fixed in advance to the back surface of the vehicle floor 40, so that the first fixed portion 38F is fixed to the vehicle floor 40. In addition, instead of one or both of the pair of left and right weld nuts 42B arranged corresponding to the front end sides of the pair of left and right lower rails 38, a floating nut (broadly speaking, "nut") may be provided. In other words, the type of nut arranged to screw the bolt 42A can be appropriately selected.

[0039] In addition, a second fixed portion 38R is provided on the rear end side of the bottom wall portion 38A (see FIG. 3) of the pair of left and right lower rails 38. The second fixed portion 38R is supported on the vehicle body floor 40 via a ring-shaped spacer 44S arranged below it. A bolt 44A passing through the second fixed portion 38R, the spacer 44S, and the vehicle body floor 40 from the upper side of the vehicle is screwed into a weld nut (broadly speaking, "nut") 44B fixed in advance to the rear surface of the vehicle body floor 40, thereby fixing the second fixed portion 38R to the vehicle body floor 40. Note that instead of one or both of the pair of left and right weld nuts 44B arranged corresponding to the rear end sides of the pair of left and right lower rails 38, a floating nut (broadly speaking, "nut") may be provided. That is, the type of nut arranged to screw the bolt 44A can be appropriately selected.

[0040] Furthermore, a reinforcing fixing portion 50 is provided as a load transmitting portion on the front side of the pair of left and right lower rails 38 and on the seat rear side of the first fixed portion 38F. The reinforcing fixing portion 50 is a structural portion in which a part of the bottom wall portion 38A (see FIG. 3) of the lower rail 38 is fixed to the vehicle floor 40 in a structure substantially similar to the structure in which the first fixed portion 38F and the second fixed portion 38R are fixed to the vehicle floor 40. The reinforcing fixing portion 50 will be described in detail below.

[0041] A third fixed portion 38X is provided as a fixed portion of the reinforcing fixing portion 50 on the bottom wall portion 38A (see FIG. 3) of the pair of left and right lower rails 38 on the front side of the lower rails 38 and on the seat rear side of the first fixed portion 38F. As shown in FIGS. 2 and 3, the third fixed portion 38X is supported on the vehicle body floor 40 via a ring-shaped spacer 46S arranged below it. A bolt 46A passing through the third fixed portion 38X, the spacer 46S, and the vehicle body floor 40 from the vehicle upper side is screwed into a weld nut 46B fixed in advance to the back surface of the vehicle body floor 40, whereby the third fixed portion 38X is fixed to the vehicle body floor 40.

[0042] Here, as shown in FIG. 2, the reinforcing fixing portion 50 is set at a position corresponding to the seat longitudinal position of the front support portion 30F of the riser 30 when the pair of left and right upper rails 36 are in the seat longitudinal center position within the sliding range (the range indicated by the arrow X) (the state indicated by the solid lines in FIG. 2, hereinafter abbreviated as "sliding central position state"), and when a load toward the rear of the seat is input to the front portion of the lower rail 38 via the upper rails 36, the load is transmitted to the vehicle floor 40.

[0043] More specifically, the reinforcing fixing portion 50 is set at a position corresponding to the seat front-rear direction position of the connecting portion 30C of the front support portion 30F of the riser 30 with the front link member 22 when the pair of left and right upper rails 36 are in the slide central position. Furthermore, in this embodiment, the reinforcing fixing portion 50 is set at a position corresponding to the seat front-rear direction position of the fixing portion 30D of the lower portion of the front support portion 30F of the riser 30 with the upper rails 36 when the pair of left and right upper rails 36 are in the slide central position.

[0044] In other words, when the pair of left and right upper rails 36 are in the slide center position, in a side view of the seat, the connection portion 30C between the front link member 22 at the front support portion 30F of the riser 30, the fixing portion 30D between the upper rails 36 at the lower part of the front support portion 30F of the riser 30, and the reinforcing fixing portion 50 are set on the same straight line, and this straight line is perpendicular to the vehicle floor 40.

[0045] (Actions and Effects of the Embodiments) Next, the operation and effects of the above embodiment will be described.

[0046] The seat cushion frame 12F to which the seat back frame 14F is connected is supported by the riser 30 via the front link member 22 and the rear link member 24. Here, the front part of the seat cushion frame 12F is supported by the front support part 30F of the riser 30, and the rear part of the seat cushion frame 12F is supported by the rear support part 30R of the riser 30. The riser 30 is supported by the lower rail 38 via the upper rail 36, and the lower rail 38 is supported by the vehicle floor 40 with a first fixed part 38F provided on the front end side and a second fixed part 38R provided on the rear end side being fixed to the vehicle floor 40.

[0047] Therefore, for example, when a load F is input to the seat back 14 of the vehicle seat 10 toward the rear of the seat due to the rearward inertial movement of a seated occupant P shown in Fig. 1 during a rear-end collision of the vehicle, the load F is transmitted from the seat back frame 14F shown in Fig. 2 through the seat cushion frame 12F, the rear link member 24, the front link member 22, the riser 30, the upper rail 36, and the lower rail 38 to the vehicle floor 40. At this time, part of the load is transmitted to the vehicle floor 40 from the reinforcing fixing portion 50 provided on the front side of the lower rail 38.

[0048] Here, the reinforcing fixing portion 50 is provided on the seat rear side of the first fixed portion 38F, and is set at a position corresponding to the seat front-rear direction position of the front support portion 30F of the riser 30 when the pair of left and right upper rails 36 are in the slide center position. Therefore, when the seat position of the vehicle seat 10 is in the seat front-rear direction center position and a load F is input to the seat back 14 toward the rear of the seat, the load transfer path from the front support portion 30F of the riser 30 to the vehicle floor 40 is made closer to the shortest straight line path that hangs down perpendicularly from the front support portion 30F of the riser 30 to the vehicle floor 40, compared to a comparative structure without the reinforcing fixing portion 50.

[0049] As a result, in the above case, a tensile load toward the rear side of the seat acts mainly on the front portion of the slide rail 34, and the generation of a moment load that tries to bend the front portion of the slide rail 34 into an inverted V shape is suppressed. As a result, the deformation amount of the front portion of the slide rail 34 is suppressed, and the rearward tilt displacement amount of the seatback frame 14F is reduced. Note that the thin band-shaped path 100 indicated by the two-dot chain line in FIG. 2 is a simplified representation of a part of the load transfer path in this embodiment.

[0050] In this embodiment, the height of the seat cushion frame 12F relative to the slide rail 34 can be adjusted by the lifter mechanism 20 including the front link member 22 and the rear link member 24. Here, the reinforcing fixing portion 50 described above is set at a position corresponding to the seat front-rear direction position of the connecting portion 30C of the front support portion 30F of the riser 30 with the front link member 22 when the pair of left and right upper rails 36 are in the slide center position. Therefore, when a load F toward the rear side of the seat is input to the seat back 14 with the seat position of the vehicle seat 10 being in the center position in the seat front-rear direction, the load transfer path from the connecting portion 30C of the front support portion 30F of the riser 30 with the front link member 22 to the vehicle floor 40 is made closer to the shortest straight path that hangs down perpendicularly to the vehicle floor 40 from the connecting portion 30C of the front support portion 30F of the riser 30 with the front link member 22 to the vehicle floor 40, compared to a comparative structure without the reinforcing fixing portion 50. Therefore, the generation of a moment load that tends to bend the front portion of the slide rail 34 into an inverted V shape is effectively suppressed.

[0051] Further, in this embodiment, the reinforcing fixing portion 50 is set at a position corresponding to the seat front-rear direction position of the fixing portion 30D with the upper rail 36 at the lower portion of the front support portion 30F of the riser 30 when the pair of left and right upper rails 36 are in the slide center position. Therefore, when a load F toward the rear side of the seat is input to the seat back 14 with the seat position of the vehicle seat 10 at the center position in the seat front-rear direction, the load transfer path from the fixing portion 30D with the upper rail 36 at the lower portion of the front support portion 30F of the riser 30 to the vehicle floor 40 is made closer to the shortest straight path that hangs down perpendicularly from the fixing portion 30D with the upper rail 36 at the lower portion of the front support portion 30F of the riser 30 to the vehicle floor 40, compared to a comparative structure without the reinforcing fixing portion 50. Therefore, the generation of a moment load that tries to bend the front portion of the slide rail 34 into an inverted V shape is extremely effectively suppressed.

[0052] As described above, according to the vehicle seat 10 of this embodiment, when the load F toward the rear of the seat is input to the seat back 14 while the seat position is in the center position in the seat front-rear direction, the deformation amount of the front part of the slide rail 34 can be suppressed and the rearward tilt displacement amount of the seat back frame 14F can be reduced. As a result, the restraint ability of the head PA of the seated occupant P by the headrest 16 shown in Fig. 1 is improved, and the difference between the head G (acceleration of the head) and T1G (acceleration of the first thoracic vertebra) is reduced.

[0053] (Supplementary explanation of the embodiment) In the above embodiment, as shown in Figures 1 to 3, the vehicle seat 10 is equipped with a lifter mechanism 20 as a height adjustment mechanism. However, as a modification of the above embodiment, a vehicle seat provided with a reinforcing fixing part (50) as a load transmission part may not be equipped with a height adjustment mechanism (lifter mechanism 20), and a pair of left and right risers (30) arranged on the seat lower side of the seat cushion frame (12F) may be directly attached to the side frames (12S) of the seat cushion frame (12F).

[0054] In the above embodiment, as shown in FIG. 2, the connection portion 30C of the front support portion 30F of the riser 30 with the front link member 22 and the fixing portion 30D of the lower portion of the front support portion 30F of the riser 30 with the upper rail 36 are aligned in the fore-and-aft direction of the seat. Although such a configuration is preferable, it is also possible to adopt a configuration in which their positions in the fore-and-aft direction of the seat are slightly misaligned.

[0055] In addition, as a modified example of the above embodiment, a load transmission portion (hereinafter simply referred to as the "load transmission portion") that is provided on the front side of the pair of left and right lower rails (38) and is located rearward of the seat from the first fixed portion (38F) and transmits the load to the vehicle floor (40) when a load is input toward the rear of the seat to the front portion of the lower rails (38) via the upper rails (36) may be set at a position corresponding to the seat fore-and-aft direction position of the front support portion (30F) of the riser (30) when the pair of left and right upper rails (36) are in the slide center position, but may be set offset in the seat fore-and-aft direction from the setting position of the reinforcing fixing portion 50 in the above embodiment.

[0056] To further explain this point, the load transmission part may be set in the seat front-rear direction from "a position corresponding to the seat front-rear direction position of the connection part (30C) with the front link member (22) in the front support part (30F) of the riser (30) in a state where the pair of left and right upper rails (36) are in the slide center position" as long as it is set in a position corresponding to the seat front-rear direction position of the front support part (30F) of the riser (30) in the seat front-rear direction when the pair of left and right upper rails (36) are in the slide center position. Also, the load transmission part may be set in the seat front-rear direction from "a position corresponding to the seat front-rear direction position of the fixing part (30D) with the upper rail (36) in the lower part of the front support part (30F) of the riser (30) in the seat front-rear direction when the pair of left and right upper rails (36) are in the slide center position" as long as it is set in a position corresponding to the seat front-rear direction position of the front support part (30F) of the riser (30) in the seat front-rear direction when the pair of left and right upper rails (36) are in the slide center position.

[0057] In addition, in the above embodiment, as shown in Figures 2 and 3, a reinforcing fixing portion 50 is provided as a load transmission portion. However, as a modified example of the above embodiment, instead of the reinforcing fixing portion 50, a locking structure may be provided as the load transmission portion, for example, a hook that is fixed to the lower rail (38) at the same seat fore-and-aft position as the reinforcing fixing portion (50) and opens toward the rear of the vehicle so that it can be hooked onto a locking hole in the vehicle floor (40).

[0058] In addition, in the above embodiment, in the reinforcing fixing portion 50 serving as a load transmission portion, the third fixed portion 38X, which is part of the bottom wall portion 38A of the pair of left and right lower rails 38, is the fixed portion to the vehicle floor 40. However, as a modified example of the above embodiment, the reinforcing fixing portion serving as a load transmission portion may not use the third fixed portion (38X) as the fixed portion, but may be, for example, a reinforcing fixing portion in which flange portions protruding from the pair of left and right lower rails (38) to both sides in the seat width direction at the same seat fore-and-aft position as the third fixed portion (38X) are the fixed portions to the vehicle floor (40).

[0059] As a modification of the above embodiment, the lower portion of the front support portion (30F) of the riser (30) may be fixed to the upper rail (36) by bolting or welding. In other words, the fixed portion of the lower portion of the front support portion (30F) of the riser (30) to the upper rail (36) may be a portion fixed by bolting or welding.

[0060] In addition, in the above embodiment, the front support portion 30F and the rear support portion 30R of the riser 30 are connected by the connecting portion 30M, but as a modification of the above embodiment, the front support portion (30F) and the rear support portion (30R) of the riser may be separate bodies.

[0061] The above-described embodiment and the multiple modified examples can be implemented in appropriate combinations.

[0062] While one example of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0063] 10 Vehicle seats 12 Seat cushion 12F Seat cushion frame 14 Seat back 14F Seat back frame 20 Lift mechanism (height adjustment mechanism) 22 Front link member 24 Rear link member 30 Riser 30F Riser front support 30C Connection portion of front support portion of riser with front link member 30D The part where the front support part of the riser is fixed to the upper rail at the bottom 30R riser rear support 34 Slide rail 36 Upper Rail 38 Lower rail 38F First fixed part 38R Second fixed part 40 Body floor 50 Reinforcement fixing part (load transfer part)

Claims

1. A seat back frame that constitutes the framework of the seat back; a seat cushion frame that constitutes a framework of the seat cushion and has a rear end to which the seat back frame is connected; a pair of right and left risers arranged on both sides in the seat width direction on the seat lower side of the seat cushion frame and attached to the seat cushion frame directly or via a member, the risers including a front support portion supporting a front portion of the seat cushion frame and a rear support portion supporting a rear portion of the seat cushion frame; A pair of left and right upper rails to which lower portions of the pair of left and right risers are fixed and which extend along the front-rear direction of the seat; a pair of left and right lower rails which together with the pair of left and right upper rails constitute a pair of left and right slide rails, extend along a front-rear direction of the seat, support the pair of left and right upper rails so as to be slidable in the front-rear direction of the seat, and have a first fixed portion provided on a front end side and a second fixed portion provided on a rear end side fixed to a vehicle body floor; a load transfer section that is provided on the front side of the pair of left and right lower rails and on the seat rear side of the first fixed portion, the load transfer section being set at a position corresponding to a seat front-rear direction position of the front support section in a state in which the pair of left and right upper rails are disposed at a center position in the seat front-rear direction within a range in which the pair of left and right upper rails can slide, and that transfers a load to the vehicle body floor when a load is input toward the rear of the seat to the front part of the lower rails via the upper rails; A vehicle seat having:

2. The pair of left and right risers are attached to the seat cushion frame via height adjustment mechanisms, the height adjustment mechanism includes a front link member that connects a front portion of the seat cushion frame and the front support portion of the riser, and a rear link member that connects a rear portion of the seat cushion frame and the rear support portion of the riser, 2. The vehicle seat according to claim 1, wherein the load transfer portion is set at a position corresponding to a seat front-rear direction position of a connection portion between the front support portion and the front link member when the pair of left and right upper rails are disposed at a seat front-rear direction central position within a range in which the pair of left and right upper rails can slide.

3. 3. The vehicle seat according to claim 1, wherein the load transfer portion is set at a position corresponding to a seat front-rear direction position of a fixed portion between the upper rails and a lower portion of the front support portion when the pair of left and right upper rails are positioned at a center position in the seat front-rear direction within a range in which the pair of left and right upper rails can slide.

Images