Vehicle seat understructure

Abstract

To provide a substructure of a vehicle seat capable of preventing or inhibiting a cover from being torn starting from attaching holes even when an attached element of a cover upper part vertically moves.SOLUTION: A suspension 18 is covered by a boot 50 from outside. On an upper part 50A and a lower part 50C of the boot 50, attaching holes are formed to penetrate. The boot 50 is fixed to an immovable lower skeleton part and a liftable upper skeleton part in the suspension 18 by clips 60 which penetrate through the attaching holes. Further, in a vertical direction intermediate part of the boot 50, a bellows part 50B is formed, and the bellows part 50B is vertically extendable. Furthermore, on the upper part 50A and the lower part 50C of the boot 50, protruding embossed parts 56 are formed in parts including the outer circumferences of the heads of the clips 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In some cases, a suspension is provided under a vehicle seat, and a cover is placed on the outside of the suspension (see, for example, Patent Document 1). One such cover, for example, has a vertically intermediate portion of the cover that is a bellows portion that can expand and contract up and down, and has mounting holes formed through the top and bottom of the cover, and the cover is fixed to a stationary framework on the vehicle body floor and a movable framework on the seat main body by mounting members that pass through the mounting holes. With this configuration, the cover can hide the internal mechanisms (e.g., the suspension) even when the seat main body moves up and down. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 2-117230 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with such a configuration, when the attachment part on the top of the cover moves up and down, force is applied from the attachment member to the attachment hole of the cover, which may cause the cover to tear from the attachment hole.

[0005] Taking the above facts into consideration, the present invention aims to provide a lower structure for a vehicle seat that can prevent or suppress the cover from tearing from the mounting hole even if the attachment part of the upper part of the cover moves up and down. [Means for solving the problem]

[0006] The understructure of a vehicle seat of the present invention described in claim 1 is arranged under the vehicle seat and has a first skeleton provided on the vehicle body floor side and a second skeleton provided on the seat main body side, and is also equipped with a support mechanism in which the second skeleton is supported so that it can be raised and lowered relative to the first skeleton, a cover that covers the support mechanism from the outside and has a bellows part that is vertically expandable and contractible in the middle part in the vertical direction, and has mounting holes formed at the top and bottom and is fixed to the first skeleton and the second skeleton by mounting members that penetrate the mounting holes, and convex embossed parts formed at the top and bottom of the cover in parts that include the outer periphery of the head of the mounting member.

[0007] According to the above configuration, a support mechanism is disposed under the vehicle seat, and in this support mechanism, a second skeleton portion provided on the seat main body portion side is supported so as to be able to rise and fall relative to a first skeleton portion provided on the vehicle body floor portion side. The support mechanism is covered from the outside by a cover. Mounting holes are formed through the upper and lower portions of the cover, and the cover is fixed to the first skeleton portion and the second skeleton portion by mounting members that pass through the mounting holes. In addition, a bellows portion is formed in the vertical middle portion of the cover, and the bellows portion is able to expand and contract vertically. Therefore, even if the second skeleton portion, to which the upper portion of the cover is attached, rises and falls, the support mechanism can be covered and hidden by the cover.

[0008] Here, the upper and lower parts of the cover are formed with convex embossed portions, including the outer periphery of the head of the mounting member. Therefore, when the second skeleton moves up and down, the load is not only transferred from the mounting member to the mounting hole, but also from the head of the mounting member to the embossed portions. This distributes the load and reduces the load transferred from the mounting member to the mounting hole, thereby preventing or suppressing the cover from tearing at the mounting hole.

[0009] The lower structure of a vehicle seat of the present invention described in claim 2 is the configuration described in claim 1, wherein the embossed portion has an arc portion extending in an arc shape along the outer periphery of the head of the mounting member, and the arc portion is formed in a semicircular shape with an open bellows portion side.

[0010] With this configuration, when the second skeleton rises, the upward load from the mounting member can be stably shared by the arc portion of the embossed portion at the upper part of the cover, and the downward reaction force from the mounting member can be stably shared by the arc portion of the embossed portion at the lower part of the cover. This effectively prevents or suppresses the boot from tearing from the mounting hole when the second skeleton rises.

[0011] The vehicle seat lower structure of the present invention described in claim 3 is the configuration described in claim 2, wherein the embossed portion has extension portions that extend from both ends of the arc portion to the bellows portion.

[0012] According to the above configuration, the load transmitted from the head side of the mounting member to the arc portion of the embossed portion can be further transmitted to the bellows portion via the extension of the embossed portion. The vertical load transmitted from the embossed portion to the bellows portion is effectively absorbed by the bellows portion. This more effectively prevents or suppresses the cover from tearing from the mounting hole. [Effects of the Invention]

[0013] As described above, the vehicle seat lower structure of the present invention has the excellent effect of preventing or suppressing the cover from tearing from the mounting hole even if the mounting partner of the upper part of the cover moves up and down. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a vehicle seat configured to which a vehicle seat substructure according to an embodiment of the present invention is applied; [Figure 2] 2 is an enlarged perspective view showing a state in which a boot is not attached to the lower part of the vehicle seat of FIG. 1. FIG. [Figure 3] FIG. 3 is a side view of the suspension shown in FIG. 2. [Figure 4] FIG. 2 is a perspective view showing the boot and clip of FIG. 1 separated from each other. [Figure 5]2 is an enlarged perspective view of a lower portion of the vehicle seat of FIG. 1. FIG. [Figure 6] 6 is an enlarged perspective view showing a portion a of FIG. 5 in an enlarged manner, as viewed from a direction slightly different from that of FIG. 5. FIG. [Figure 7A] FIG. 10 is an enlarged perspective view showing a mounting portion of a boot and its surrounding area in a modified example of the embodiment. [Figure 7B] FIG. 10 is an enlarged perspective view showing a mounting portion of a boot and its surrounding area in another modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a description will be given of a vehicle seat understructure according to one embodiment of the present invention with reference to Figures 1 to 6. Note that in these figures, the arrow FR indicates the front side of the seat, the arrow UP indicates the upper side of the seat, and the arrow W indicates the seat width direction (left-right direction of the seat). In addition, in each figure, some reference numerals may be omitted to make the drawings easier to understand.

[0016] (Configuration of the embodiment) Fig. 1 shows a perspective view of a vehicle seat 10 configured to which the vehicle seat understructure according to this embodiment is applied. As shown in Fig. 1, the vehicle seat 10 according to this embodiment includes a seat main body 12 and a suspension 18. The seat main body 12 has a seat cushion 14 on which a vehicle occupant sits, and a seat back 16 that supports the back of the seated occupant. The suspension 18 is covered on the outer side in the seat width direction and on the front side of the seat by a boot 50 that serves as a resin cover, which will be described in detail later.

[0017] Fig. 2 shows an enlarged perspective view of the lower part of the vehicle seat 10 when the boot 50 (see Fig. 1) is not attached. Fig. 3 shows a side view of the suspension 18 shown in Fig. 2. The suspension 18 shown in Figs. 2 and 3 is a shock absorber that suppresses the transmission of vibrations of the vehicle body to the seat main body 12 (see Fig. 1) when the vehicle is traveling, and is disposed below the seat main body 12 (in other words, below the vehicle seat 10).

[0018] 3, the suspension 18 includes a support mechanism 20. The support mechanism 20 includes a lower skeleton 22 serving as a first skeleton provided on the vehicle body floor FL side, an upper skeleton 26 serving as a second skeleton provided on the seat main body 12 side, and an X link 30 connecting the lower skeleton 22 and the upper skeleton 26, and is configured so that the upper skeleton 26 is supported relative to the lower skeleton 22 so as to be movable up and down.

[0019] The lower framework 22 has a pair of left and right lower rails 23. The left and right lower rails 23 are formed, for example, from press-formed metal plates and have an elongated shape with the longitudinal direction extending in the front-to-rear direction. When viewed in the front-to-rear direction, each lower rail 23 has a generally U-shape with an open inner side in the seat width direction. The front ends of the lower rails 23 are connected to each other by a lower front cross member 24 (see FIG. 2 ) arranged with the longitudinal direction aligned with the seat width direction. This lower front cross member 24 constitutes a part of the lower framework 22.

[0020] A front floor bracket 36 is fixed to the lower surface of the front end of each lower rail 23 via a corresponding member using means such as bolts. Each front floor bracket 36 is made of, for example, a press-formed metal plate, and extends downward and forward from the lower surface of the front end of the left and right lower rails 23. The lower end of the front floor bracket 36 is fixed to the vehicle floor FL using means such as bolts.

[0021] A rear floor bracket 38 is fixed to the rear end of each lower rail 23. The rear floor bracket 38 is made of, for example, a press-formed metal plate. As shown in FIG. 1, the rear floor bracket 38 is an elongated plate with its longitudinal direction aligned with the seat width direction and its thickness direction aligned in the up-down direction. Both ends of the rear floor bracket 38 in the seat width direction are overlapped with the undersides of the rear ends of the left and right lower rails 23 (see FIG. 2) and fastened with bolts. Furthermore, both left and right ends of the rear end of the rear floor bracket 38 are convex downward and are fixed to the vehicle floor FL (see FIG. 3) by means of bolts or the like. That is, the lower rail 23 shown in FIG. 3 is configured to be fixed to the vehicle floor FL via the front floor bracket 36 and rear floor bracket 38 described above.

[0022] The upper framework 26 also has a pair of left and right upper rails 27. The left and right upper rails 27 are disposed above the left and right lower rails 23. Each upper rail 27 is formed, for example, from a press-formed metal plate and has an elongated shape with its longitudinal direction extending in the front-to-rear direction. When viewed in the front-to-rear direction, each upper rail 27 has a generally U-shape with its inner side in the seat width direction open. The front ends of the upper rails 27 are connected to each other by an upper front cross member 28 disposed with its longitudinal direction aligned with the seat width direction. The upper front cross member 28 constitutes a part of the upper framework 26. Furthermore, the left and right upper rails 27 are connected to the left and right lower rails 23 via left and right X links 30.

[0023] The X-link 30 is configured by two link arms 31, 32 combined in an X-shape. The two link arms 31, 32 are configured, for example, from press-formed metal plates and are elongated with the longitudinal direction as the length and the seat width direction as the plate thickness direction. One link arm 31 is inclined upward as it approaches the front, and the other link arm 32 is inclined downward as it approaches the front. The two link arms 31, 32 are connected at their longitudinal middle portions via a link shaft 34. The axial direction of the link shaft 34 is the seat width direction, and the two link arms 31, 32 are relatively rotatable around the axis of the link shaft 34.

[0024] One link arm 31 has a front end fixed to the upper slide shaft 42 by welding or the like, and a rear end fixed to the lower rotation shaft 44 by welding or the like. The other link arm 32 has a front end fixed to the lower slide shaft 46 by welding or the like, and a rear end fixed to the upper rotation shaft 48 by welding or the like. The upper slide shaft 42, the lower rotation shaft 44, the lower slide shaft 46, and the upper rotation shaft 48 are made of, for example, metal pipe material, and are arranged with their axes aligned in the seat width direction.

[0025] Both end portions of the upper slide shaft 42 in the seat width direction are inserted inside the front portions of the left and right upper rails 27, and are slidable in the front-rear direction relative to the left and right upper rails 27. Both end portions of the lower slide shaft 46 in the seat width direction are inserted inside the front portions of the left and right lower rails 23, and are slidable in the front-rear direction relative to the left and right lower rails 23.

[0026] Both ends of the lower rotating shaft 44 in the seat width direction are inserted inside the rear ends of the left and right lower rails 23 and are rotatably supported on the rear ends of the left and right lower rails 23 via left and right bearing members 45. Both ends of the upper rotating shaft 48 in the seat width direction are inserted inside the rear ends of the left and right upper rails 27 and are rotatably supported on the rear ends of the left and right upper rails 27 via left and right bearing members 49.

[0027] In the suspension 18 configured as described above, the left and right X links 30 synchronously extend and retract around the lower rotation shaft 44 as a fulcrum, causing the left and right upper rails 27 to move up and down relative to the left and right lower rails 23. Specifically, when the left and right upper rails 27 move up and down, the left and right X links 30 extend upward so that the inclination directions of the two link arms 31, 32 approach the vertical direction. At this time, the upper slide shaft 42 and the lower slide shaft 46 slide rearward relative to the left and right upper rails 27 and the left and right lower rails 23, and approach the upper rotation shaft 48 and the lower rotation shaft 44.

[0028] On the other hand, when the left and right upper rails 27 descend toward the left and right lower rails 23, the left and right X links 30 contract downward so that the inclination direction of the two link arms 31, 32 approaches the front-rear direction. At this time, the upper slide shaft 42 and the lower slide shaft 46 slide forward relative to the left and right upper rails 27 and the left and right lower rails 23 and move away from the upper rotation shaft 48 and the lower rotation shaft 44.

[0029] The suspension 18 configured as described above includes springs (not shown) that urge the left and right upper rails 27 upward relative to the left and right lower rails 23, and dampers (not shown) that absorb vibrations of the springs. The springs are, for example, air springs that are supplied with compressed air via air tubes from an air compressor that constitutes an air brake device of the vehicle. The dampers are, for example, hydraulic cylinder type dampers.

[0030] The seat body 12 shown in Fig. 1 is connected to the left and right upper rails 27 via, for example, a well-known seat slide mechanism. The weight of an occupant seated on this seat body 12 is elastically supported by the air spring, and vibrations of the seat body 12 are absorbed by the damper. The air spring expands upward when air is supplied, thereby lifting the left and right upper skeletons 26 (see Fig. 3) and the seat body 12. The air spring contracts downward when air is exhausted, thereby lowering the left and right upper skeletons 26 (see Fig. 3) and the seat body 12.

[0031] 4 shows a boot 50 that covers the outside of the support mechanism 20 (see FIG. 3) and a clip 60 that serves as an attachment member for attaching the boot 50, in a separated state. As shown in FIG. 4, the boot 50, as an example, has a substantially U-shape that is open on the rear side when viewed in the up-down direction, and is formed to be generally symmetrical on the left and right.

[0032] A vertically expandable bellows portion 50B is formed in the vertically intermediate portion of the boot 50. The upper and lower portions 50A and 50C of the boot 50 are formed along the vertical direction, and the general portion is formed flat. A circular hole 52 shown in Fig. 4 is formed through the rear portion of the upper portion 50A of the boot 50 so that the bolt heads 25 arranged on the outer surface in the seat width direction at the rear portion of the upper rail 27 shown in Fig. 3 do not interfere with the inner surface.

[0033] A plurality of mounting holes 54 are formed at horizontal intervals through each of the upper portion 50A and the lower portion 50C of the boot 50. The boot 50 is fixed to the lower skeleton 22 and the upper skeleton 26 (see FIG. 3, etc.) by clips 60 that pass through the mounting holes 54.

[0034] The clip 60 is a component made of, for example, a resin material, and known components can be used. The clip 60 includes an insertion portion 60A that is inserted into the mounting hole 54 of the boot 50, and a head portion 60B that is provided on one axial end of the insertion portion 60A. The insertion portion 60A is generally axially shaped and includes a portion that is elastically deformable in its radial direction. The head portion 60B includes an umbrella-shaped portion that extends radially outward from the clip 60.

[0035] 3, through holes 23H, 27H are formed in the lower rails 23 and the upper rails 27 at positions corresponding to the mounting holes 54 (see FIG. 4) for attaching the boots 50 (see FIG. 4). Although not shown, through holes are also formed in the lower front cross member 24 and the upper front cross member 28 at positions corresponding to the mounting holes 54 (see FIG. 4) for attaching the boots 50 (see FIG. 4).

[0036] The insertion portion 60A of the clip 60 shown in Fig. 4 is inserted from the outside into the mounting hole 54 of the boot 50, and is also inserted into the through-holes 23H, 27H of the lower skeleton 22 and the upper skeleton 26 shown in Fig. 3 (the through-holes of the lower front cross member 24 and the upper front cross member 28 are not shown). In this way, the boot 50 shown in Fig. 4 is attached to the lower skeleton 22 and the upper skeleton 26 shown in Fig. 3. Note that while Fig. 2 illustrates a state in which the boot 50 (see Fig. 4) is not attached, for convenience's sake, the clip 60 is shown inserted into the through-holes 23H, 27H (see Fig. 3) of the lower rails 23 and the upper rails 27 and the through-hole (not shown) of the lower front cross member 24.

[0037] 5 shows an enlarged perspective view of the lower part of the vehicle seat 10. A convex embossed portion 56 is formed on the outer surface of the upper part 50A and the lower part 50C of the boot 50 in a portion including the outer periphery of the head part 60B of the clip 60. In other words, the embossed portion 56 is formed on the outer surface of the boot 50 in a portion including one circumference outside the mounting hole 54 (see FIG. 4). The embossed portion 56 has an arcuate portion 56A that extends in an arc shape along the outer periphery of the head part 60B of the clip 60. The arcuate portion 56A is formed in a semicircular shape that is open on the bellows part 50B side.

[0038] Fig. 6 shows an enlarged perspective view of portion a in Fig. 5, viewed from a slightly different direction than in Fig. 5. As shown in Fig. 6, a slight gap is provided between the head 60B of the clip 60 and the arcuate portion 56A of the embossed portion 56 to avoid assembly failure due to interference between the head 60B of the clip 60 and the arcuate portion 56A of the embossed portion 56. Also, as shown in Figs. 5 and 6, the embossed portion 56 has extension portions 56B that extend from both ends of the arcuate portion 56A to the bellows portion 50B. The extension portions 56B extend linearly in the up-down direction of the sheet.

[0039] 5, in addition to the embossed portion 56, an inverted U-shaped portion 58 that is convex and extends in an inverted U shape is formed on the outer surface of the upper portion 50A of the boot 50. Both ends of the inverted U-shaped portion 58 extend to the bellows portion 50B. As an example, a recess 59 is formed on the upper inside portion of the inverted U-shaped portion 58.

[0040] (Actions and Effects of the Embodiments) Next, the operation and effects of the above embodiment will be described.

[0041] In the above embodiment, the suspension 18 is disposed below the vehicle seat 10 shown in FIG. 1 , and in the support mechanism 20 of the suspension 18 shown in FIG. 3 , the upper skeleton 26 is supported relative to the lower skeleton 22 so as to be able to move up and down. The support mechanism 20 is covered from the outside by a boot 50 shown in FIG. 4 . Mounting holes 54 are formed through the upper portion 50A and the lower portion 50C of the boot 50, and the boot 50 is fixed to the lower skeleton 22 and the upper skeleton 26 shown in FIG. 3 by clips 60 passing through the mounting holes 54. In addition, as shown in FIG. 5 , a bellows portion 50B is formed in the vertical middle portion of the boot 50, and the bellows portion 50B is vertically expandable and contractible. Therefore, even if the upper skeleton 26 shown in FIG. 3 , to which the upper portion 50A of the boot 50 is attached, moves up and down, the boot 50 (see FIG. 5 ) can cover and conceal the support mechanism 20.

[0042] 5, the upper part 50A and the lower part 50C of the boot 50 have convex embossed portions 56 formed in portions including the outer periphery of the head 60B of the clip 60. Therefore, when the upper skeleton 26 shown in FIG. 3 moves up and down, a load is transmitted from the clip 60 shown in FIG. 5 to the mounting hole 54 (see FIG. 4), and also from the head 60B of the clip 60 to the embossed portion 56. This distributes the load and reduces the load transmitted from the clip 60 to the mounting hole 54 (see FIG. 4), thereby preventing or suppressing the boot 50 from tearing at the mounting hole 54 (see FIG. 4).

[0043] In the present embodiment, the embossed portion 56 includes an arc portion 56A extending in an arc shape along the outer periphery of the head 60B of the clip 60, and the arc portion 56A is formed in a semicircular shape that is open on the bellows portion 50B side. As a result, when the upper skeleton 26 shown in FIG. 3 rises, the arc portion 56A of the embossed portion 56 can stably share the upward load from the clip 60 in the upper portion 50A of the boot 50 shown in FIG. 5, and the arc portion 56A of the embossed portion 56 can stably share the downward reaction force from the clip 60 in the lower portion 50C of the boot 50. Therefore, when the upper skeleton 26 shown in FIG. 3 rises, the boot 50 shown in FIG. 5 can be effectively prevented or suppressed from tearing at the mounting hole 54 (see FIG. 4).

[0044] 6, in this embodiment, a slight gap is provided between the head 60B of the clip 60 and the arc portion 56A of the embossed portion 56 to avoid assembly failure. Therefore, when the upper skeleton portion 26 (see FIG. 3) is raised, the head 60B of the clip 60 deforms a portion of the boot 50 that is inside the arc portion 56A (a thin arc-shaped flat portion between the head 60B of the clip 60 and the arc portion 56A), and then comes into indirect or direct contact with the arc portion 56A of the embossed portion 56 to transmit the load.

[0045] 5, the embossed portion 56 has extensions 56B that extend from both ends of the arcuate portion 56A to the bellows portion 50B. This allows the load transmitted from the head 60B of the clip 60 to the arcuate portion 56A of the embossed portion 56 to be further transmitted to the bellows portion 50B via the extensions 56B of the embossed portion 56. The vertical load transmitted from the embossed portion 56 to the bellows portion 50B is effectively absorbed by the bellows portion 50B. This more effectively prevents or suppresses the boot 50 from tearing from the mounting hole 54 (see FIG. 4).

[0046] As described above, according to this embodiment, even if the upper skeleton 26 (see Figure 3), to which the upper part 50A of the boot 50 is attached, moves up and down, the boot 50 can be prevented or suppressed from tearing from the attachment hole 54 (see Figure 4).

[0047] (Modification of the embodiment) As a modification of the above embodiment, as shown in Fig. 7A, the embossed portion 70 may include an arc portion 70A similar to the arc portion 56A (see Fig. 6) of the above embodiment, and may also include linear portions 70B extending from both ends of the arc portion 70A toward the bellows portion (not shown, see the bellows portion 50B in Fig. 4), but not extending to the bellows portion. As another modification, as shown in Fig. 7B, the embossed portion 72 may be formed solely of an arc portion 72A similar to the arc portion 56A (see Fig. 6) of the above embodiment. In Figs. 7A and 7B, the boot 50 as a cover and the clip 60 as an attachment member are denoted by the same reference numerals as in the above embodiment for convenience.

[0048] As a modification of the above embodiment, the convex embossed portion formed on the outer periphery of the head 60B of the clip 60 serving as the attachment member in the upper and lower portions 50A and 50C of the boot 50 serving as the cover may be, for example, a circular embossed portion formed along the outer periphery of the head 60B of the clip 60, or an embossed portion formed intermittently along the outer periphery of the head 60B of the clip 60. As another modification, the embossed portion may extend in an arc shape along the outer periphery of the head 60B of the clip 60, but may not be semicircular.

[0049] In addition, in the above embodiment, the boot 50 as a cover shown in Figure 1 etc. covers the suspension 18 having the support mechanism 20 (see Figure 3) from the outside in the seat width direction and the front side of the seat, but the cover may, for example, cover the support mechanism (20) so as to surround it from the front, back, left and right, or it may cover only the left and right portions of the support mechanism (20) from the outside in the seat width direction.

[0050] In addition, in the above embodiment, the support mechanism 20 shown in FIG. 3 is configured to include an X-link 30, but the support mechanism may also be a support mechanism including a four-bar link mechanism or the like that is applied to a lifter device, etc.

[0051] Furthermore, in the above embodiment, the clip 60 shown in FIG. 5 and the like is used as the mounting member, but the mounting member may be another mounting member having a head, such as a bolt.

[0052] The above-described embodiment and the above-described modifications can be implemented in appropriate combinations.

[0053] Although 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 within the scope of the gist of the present invention. [Explanation of symbols]

[0054] 10 Vehicle seats 12 Seat body 20 Support mechanism 22 Lower skeleton (first skeleton) 26 Upper skeletal part (second skeletal part) 50 Boots (covers) 50A Upper part of boot (upper part of cover) 50B Bellows 50C Bottom of boot (bottom of cover) 54 Mounting hole 56 Embossed section 56A Arc section 56B Extension 60 Clip (mounting part) 60B head 70 Embossed section 70A arc section 72 Embossed section 72A Arc section FL Body floor

Claims

1. a support mechanism disposed under the vehicle seat, the support mechanism having a first skeleton provided on the vehicle body floor side and a second skeleton provided on the seat main body side, the second skeleton supported on the first skeleton so as to be movable up and down; a cover that covers the support mechanism from the outside, has a bellows portion that is expandable and contractible in the vertical direction intermediate portion, has attachment holes formed at the top and bottom portions thereof, and is fixed to the first skeleton portion and the second skeleton portion by attachment members that penetrate the attachment holes; a convex embossed portion formed on the upper and lower portions of the cover in a portion including the outer circumferential side of the head of the mounting member; A vehicle seat understructure comprising:

2. 2. The vehicle seat understructure according to claim 1, wherein the embossed portion includes an arc portion extending in an arc shape along an outer periphery of the head portion of the mounting member, and the arc portion is formed in a semicircular shape that is open on the bellows portion side.

3. The vehicle seat underbody structure according to claim 2 , wherein the embossed portion has extensions extending from both ends of the arc portion to the bellows portion.

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