Vehicle seat suspension and vehicle seat

Abstract

To suppress dropping of a lower rotary shaft from rear ends of right and left lower rails in the event of collision of a vehicle.SOLUTION: A suspension 30 for a vehicle seat 10 comprises: right and left lower rails 34 fixed to a floor part of a vehicle body; right and left upper rails that are disposed above the right and left lower rails 34, and which a seat body part to which an occupant of a vehicle is restricted by a seat belt is connected to; right and left X links 38 that lift and lower the right and left upper rails by connecting the right and left lower rails 34 to the right and left upper rails respectively, and extending / shrinking in synchronization with each other; a lower rotary shaft 56 on both end parts in a lateral direction of the seat are rotatably supported by rear end parts of the right and left lower rails 34, and to which one link arm 40 that the right and left X links 38 have is fixed; and a center bracket 70 that is fixed to the floor part of the vehicle body, and which faces an intermediate part in the lateral direction of the seat of the lower rotary shaft 56 from above the seat.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to vehicle seats, and more particularly to suspensions for vehicle seats. [Background technology]

[0002] The suspension seat described in Patent Document 1 below includes left and right lower rails fixed to the floor of the vehicle body, left and right upper rails disposed above the left and right lower rails, and left and right X links connecting the left and right lower rails to the left and right upper rails, respectively. The left and right X links extend and retract in synchronization with each other to raise and lower the left and right upper rails. A seat body on which an occupant sits is connected to the left and right upper rails, and the occupant is restrained by a seat belt device to the seat body. One of a pair of link arms of the left and right X links is fixed to a lower rotation shaft. Both left and right ends of the seat of the lower rotation shaft are rotatably supported by the rear ends of the left and right lower rails. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-46172 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned prior art, if an excessive load from the occupant inertially moving toward the front of the seat acts on the seat body via the seat belt during a vehicle collision, the seat body will tend to rotate toward the front of the seat around the front ends of the left and right lower rails. In this case, the lower rotation shaft, to which one of the link arms of the left and right X links is fixed, tends to displace toward the upper and front of the seat. If the lower rotation shaft is significantly deformed as a result, it can become dislodged from the rear ends of the left and right lower rails.

[0005] In consideration of the above, the present invention aims to provide a vehicle seat suspension and a vehicle seat that can prevent the lower rotating shaft from falling off the rear ends of the left and right lower rails during a vehicle collision. [Means for solving the problem]

[0006] A suspension of a vehicle seat according to a first aspect includes left and right lower rails fixed to a floor of a vehicle body, left and right upper rails arranged above the left and right lower rails and connected to a seat body to which a vehicle occupant is restrained by a seat belt, left and right X links connecting the left and right lower rails to the left and right upper rails, respectively, and extending and contracting in synchronous with each other to raise and lower the left and right upper rails, a lower rotation shaft whose both ends in the left and right direction of the seat are rotatably supported on rear ends of the left and right lower rails and to which one of a pair of link arms of the left and right X links is fixed, and a center bracket fixed to the floor and facing a middle portion of the lower rotation shaft in the left and right direction of the seat from above the seat.

[0007] Note that "fixing" in the first aspect means preventing movement relative to the object. This "fixing" includes not only direct fixation to the object, but also indirect fixation via a separate member. This also applies to the "fixing" in the second, fourth, sixth, and seventh aspects.

[0008] In a vehicle seat suspension of a first aspect, left and right lower rails are fixed to the floor of the vehicle body, and a seat main body is connected to left and right upper rails arranged above the left and right lower rails. A vehicle occupant is restrained in the seat main body with a seat belt. The left and right lower rails and the left and right upper rails are connected to left and right X links, respectively. These left and right X links expand and contract in synchronous with each other, causing the upper rail to rise and fall together with the seat main body. One of a pair of link arms possessed by the left and right X links is fixed to a lower rotating shaft. Both left and right ends of the lower rotating shaft in the seat lateral direction are rotatably supported by the rear ends of the left and right lower rails.

[0009] In this configuration, if an excessive load from an occupant inertially moving toward the front of the seat acts on the seat body via the seat belt during a vehicle collision, the seat body will tend to rotate toward the front of the seat around the front ends of the left and right lower rails. In this case, the lower rotation shaft, to which one of a pair of link arms of the left and right X links is fixed, tends to displace toward the upper and front of the seat. A seat transversely intermediate portion of this lower rotation shaft faces a center bracket fixed to the floor of the vehicle body from below the seat. The center bracket engages with the lower rotation shaft, thereby suppressing deformation of the lower rotation shaft. As a result, the lower rotation shaft can be prevented from falling off the rear ends of the left and right lower rails.

[0010] The suspension of the vehicle seat of the second aspect is the same as that of the first aspect, and is provided with left and right reinforcing patches that are positioned above the seat relative to both left and right ends of the lower rotating shaft and are fixed to the upper surfaces of the left and right lower rails.

[0011] In the vehicle seat suspension of the second aspect, left and right reinforcing patches located above the seat relative to both left and right ends of the lower rotating shaft are fixed to the upper surfaces of the left and right lower rails, which suppresses deformation of the left and right lower rails when the lower rotating shaft attempts to displace upward and forward of the seat, thereby making it even easier to prevent the lower rotating shaft from falling off the rear ends of the left and right lower rails.

[0012] The suspension of the vehicle seat of the third aspect is the suspension of the first or second aspect, wherein the center bracket faces the lower rotation shaft with a gap therebetween.

[0013] In the vehicle seat suspension of the third aspect, the center bracket faces the lower rotating shaft with a gap between them, which allows the lower rotating shaft, to which one of the link arms is fixed, to rotate smoothly when the left and right X links extend and retract.

[0014] The suspension of a vehicle seat of a fourth aspect is any one of the first to third aspects, and includes a rear floor bracket that spans between the lower surfaces of the rear ends of the left and right lower rails and is fixed to the floor portion, and the center bracket is fixed to the upper surface of the rear floor bracket.

[0015] In the vehicle seat suspension of the fourth aspect, the center bracket is fixed to the upper surface of the rear floor bracket, which is bridged between the undersides of the rear ends of the left and right lower rails and fixed to the floor of the vehicle body, thereby eliminating the need to fix the center bracket to the floor of the vehicle body separately from the rear floor bracket.

[0016] The suspension of a vehicle seat of the fifth aspect is any one of the first to fourth aspects, in which the center bracket has a cutout portion that is open on both sides of the seat in the left-right direction and on the lower side of the seat, and the middle portion of the lower rotating shaft in the left-right direction of the seat is inserted into the cutout portion.

[0017] In the vehicle seat suspension of the fifth aspect, the seat left-right middle portion of the lower rotating shaft is inserted into the notch formed in the center bracket, which prevents the lower rotating shaft from accidentally coming off the center bracket when the lower rotating shaft attempts to move upward and forward of the seat.

[0018] A sixth aspect of the vehicle seat suspension is the fifth aspect, wherein the center bracket has left and right side wall portions facing each other in the left-right direction of the seat, an upper wall portion connecting the upper ends of the left and right side wall portions, and left and right fixed wall portions extending outward in the left-right direction of the seat from the lower ends of the left and right side wall portions and fixed to the floor portion, and the notch portion is formed in each of the left and right side wall portions.

[0019] In the vehicle seat suspension of the sixth aspect, the center bracket has the above-mentioned left and right side walls, upper wall, and left and right fixed walls, so it can be manufactured by, for example, press-forming a metal plate. This center bracket has an inverted U-shaped cross section formed by the left and right side walls and upper wall, and the seat left-right middle portion of the lower rotating shaft is inserted into notches formed in the left and right side walls. This makes it easy to ensure the strength of the center bracket against the load applied from the lower rotating shaft.

[0020] The seventh aspect of the vehicle seat suspension is the second aspect, in which two bolts for fixing the lower rail to the floor portion pass through the reinforcing patch, and the portion of the reinforcing patch between the two bolts is positioned above the seat on the lower rotating shaft.

[0021] According to a seventh aspect of the vehicle seat suspension, two bolts for securing the lower rails to the vehicle body floor pass through left and right reinforcing patches that are located above the seat relative to both left and right ends of the lower rotating shaft and are fixed to the upper surfaces of the left and right lower rails. The portion of the reinforcing patches between the two bolts is located above the seat on the lower rotating shaft. This enlarges the bearing surface for the two bolts with one reinforcing patch, thereby improving the strength of the lower rails against loads from the lower rotating shaft with a small number of parts.

[0022] The vehicle seat of the eighth aspect comprises a seat main body having a seat cushion on which a vehicle occupant sits and a seat back that supports the back of the occupant, a seat belt device that restrains the occupant to the seat main body, and a vehicle seat suspension of any one of the first to seventh aspects in which the seat main body is connected to the left and right upper rails.

[0023] In the vehicle seat of the eighth aspect, a vehicle occupant sits on a seat cushion provided in the seat main body, and the occupant's back is supported by a seat back provided in the seat main body. The occupant is restrained on this seat main body by a seat belt device. This seat main body is connected to left and right upper rails provided in the suspension. Since this suspension is any one of the first to seventh aspects, the above-mentioned functions and effects can be obtained. [Effects of the Invention]

[0024] As described above, the vehicle seat suspension and vehicle seat according to the present invention can prevent the lower rotation shaft from falling off the rear ends of the left and right lower rails in the event of a vehicle collision. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a side view showing a vehicle seat according to an embodiment; [Figure 2] 1 is a side view showing a suspension provided in a vehicle seat according to an embodiment. [Figure 3] 1 is a first perspective view showing the configuration around a lower rotation shaft of a suspension according to an embodiment. FIG. [Figure 4] FIG. 2 is a second perspective view showing the configuration around the lower rotation shaft of the suspension according to the embodiment. [Figure 5] FIG. 4 is an enlarged perspective view of a portion of the configuration shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0026] A vehicle seat 10 according to one embodiment of the present invention will be described below with reference to Figures 1 to 5. Note that in each figure, some reference numerals may be omitted to make the drawings easier to understand. Arrows FR, LH, RH, and UP, which are appropriately depicted in each figure, respectively indicate the front, left, right, and top of the vehicle seat 10. Hereinafter, when the front-rear, left-right, top-bottom directions are used in the description, they will indicate directions relative to the vehicle seat 10.

[0027] 1, a vehicle seat 10 according to an embodiment of the present invention includes a seat body 12 and a suspension 30. The vehicle seat 10 is, for example, a driver's seat in a right-hand drive vehicle. The seat body 12 includes a seat cushion 14 on which a vehicle occupant sits, a seat back 16 that supports the back of the occupant, and a three-point seat belt device 18 that restrains the occupant to the seat body 12.

[0028] The seat belt device 18 includes a retractor (not shown) provided inside the seat back 16. One longitudinal end of a seat belt (webbing) 20 is fastened to a winding shaft of the retractor. The other longitudinal end of the seat belt 20 is fastened to an anchor member (not shown) provided on one of the left and right sides (here, the right side) of the seat cushion 14. A longitudinal intermediate portion of the seat belt 20 is wound around a belt anchor bracket (not shown) provided at the shoulder on one of the left and right sides (here, the right side) of the seat back 16. A tongue plate (not shown) is attached to the longitudinal intermediate portion of the seat belt 20 between the anchor member and the belt anchor bracket. This tongue plate is connectable to a buckle 22 provided on the other left and right side (here, the left side) of the seat cushion 14.

[0029] In the seat belt device 18 configured as described above, an occupant seated on the seat cushion 14 of the seat main body 12 fastens the seat belt 20 by connecting the tongue plate to the buckle 22. In this fastened state, the portion of the seat belt 20 from the belt anchor bracket to the tongue plate functions as a shoulder belt that restrains the upper body of the occupant, and the portion of the seat belt 20 from the tongue plate to the anchor member functions as a lap belt that restrains the waist of the occupant.

[0030] The suspension 30 is a shock absorber that suppresses transmission of vehicle body vibrations to the seat main body 12 while the vehicle is in motion, and is disposed below the seat main body 12. The suspension 30 is covered by a resin cover 32 shown in Fig. 1. As shown in Fig. 2, the suspension 30 includes a lower rail 34, an upper rail 36, and an X-link 38. The lower rail 34, the upper rail 36, and the X-link 38 are provided on both the left and right sides of the suspension 30, respectively.

[0031] The left and right lower rails 34 are made of, for example, press-formed metal plate material and have an elongated shape extending in the front-to-rear direction. Each lower rail 34 is generally U-shaped with an open inner side in the left-to-right direction when viewed in the front-to-rear direction. A front floor bracket 44 (see FIGS. 1 and 2) is fixed to the front end of each lower rail 34. Each front floor bracket 44 is made of, for example, press-formed metal plate material and is fixed to the front end of the corresponding lower rail 34 by means of bolts or the like.

[0032] As shown in FIGS. 3 and 4 , the rear end of each lower rail 34 is fixed to a rear floor bracket 46. The rear floor bracket 46 is formed, for example, from a press-formed metal plate and has a long plate shape with its length in the left-right direction and its thickness in the up-down direction. Both left and right ends of the rear floor bracket 46 are superimposed on the undersides of the rear ends of the left and right lower rails 34. Each lower rail 34 is fixed to the rear floor bracket 46 using a pair of front and rear bolts 48. The front and rear bolts 48 pass through the lower rail 34 and the rear floor bracket 46 from above and are threadedly engaged with a pair of front and rear nuts (not shown) located on the underside of the rear floor bracket 46. As a result, the rear end of the left and right lower rails 34 are fastened and fixed to the rear floor bracket 46, and the rear floor bracket 46 spans between the undersides of the rear ends of the left and right lower rails 34.

[0033] The left and right front floor brackets 44 extend downward and forward from the front ends of the left and right lower rails 34, and their lower ends are fixed to the floor of the vehicle body by means of bolts or the like. Bolt holes 50 (see FIGS. 3 and 4) are formed in both left and right ends of the rear floor bracket 46, and the rear floor bracket 46 is fixed to the floor of the vehicle body using bolts (not shown) that are inserted into these bolt holes 50. In this way, the left and right lower rails 34 are fixed to the floor of the vehicle body via the left and right front floor brackets 44 and rear floor brackets 46.

[0034] The left and right upper rails 36 are disposed above the left and right lower rails 34, respectively. The left and right upper rails 36 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 upper rail 36 has a generally U-shape with an open inner side in the left-to-right direction. These upper rails 36 are connected to the left and right lower rails 34 via left and right X links 38.

[0035] The left and right X links 38 are configured by two link arms 40, 42 combined in an X shape. The two link arms 40, 42 are configured, for example, from press-formed metal plates and are elongated with the longitudinal direction as the length and the transverse direction as the plate thickness direction. One link arm 40 is inclined upward as it approaches the front, while the other link arm 42 is inclined downward as it approaches the front. The two link arms 40, 42 are connected at their longitudinal middle portions via a link shaft 52. The link shaft 52 has an axial direction in the transverse direction, and the two link arms 40, 42 are rotatable relative to each other about the axis of the link shaft 52.

[0036] The front end of one link arm 40 of each of the left and right X links 38 is fixed to the upper slide shaft 54 ​​and the rear end is fixed to the lower rotation shaft 56. The front end of the other link arm 42 of each of the left and right X links 38 is fixed to the lower slide shaft 58 and the rear end is fixed to the upper rotation shaft 60. The upper slide shaft 54, the lower rotation shaft 56, the lower slide shaft 58, and the upper rotation shaft 60 are made of, for example, metal pipe material, and are arranged with their axes extending in the left-right direction. The link arms 40, 42 are fixed to the upper slide shaft 54, the lower rotation shaft 56, the lower slide shaft 58, and the upper rotation shaft 60 by means of welding or the like.

[0037] The upper slide shaft 54 ​​is inserted inside the front portions of the left and right upper rails 36 and is slidable in the front-to-rear direction relative to the left and right upper rails 36. Both left and right ends of the lower slide shaft 58 are inserted inside the front portions of the left and right lower rails 34 and are slidable in the front-to-rear direction relative to the left and right lower rails 34.

[0038] Both left and right ends of the lower rotating shaft 56 are inserted inside the rear ends of the left and right lower rails 34. As shown in FIGS. 3 and 4 , bearing members 62 are fitted inside the rear ends of the left and right lower rails 34, respectively. The left and right bearing members 62 are manufactured, for example, by injection molding of resin and have a long block shape with the longitudinal direction as the length. Two front and rear bolts 48 that secure each lower rail 34 to the rear floor bracket 46 pass through each bearing member 62. Between these two bolts 48, a bearing hole 64 is formed in the bearing member 62, with its axis extending in the left and right direction and opening inward in the left and right direction. Both left and right ends of the lower rotating shaft 56 are rotatably fitted into the bearing holes 64 of the left and right bearing members 62. As a result, the lower rotating shaft 56 is rotatably supported on the rear ends of the left and right lower rails 34 via the left and right bearing members 62.

[0039] Both left and right ends of the upper rotating shaft 60 are inserted inside the rear ends of the left and right upper rails 36. Although not shown, bearing members having basically the same configuration as the above-mentioned bearing member 62 are fitted inside the rear ends of the left and right upper rails 36. The upper rotating shaft 60 is rotatably supported on the rear ends of the left and right upper rails 36 via these bearing members.

[0040] In the suspension 30 configured as described above, the left and right X links 38 synchronously expand and contract with the lower rotation shaft 56 as a fulcrum, causing the left and right upper rails 36 to rise and fall in the vertical direction relative to the left and right lower rails 34. Specifically, when the left and right upper rails 36 rise, the left and right X links 38 extend upward so that the inclination direction of the two link arms 40, 42 approaches the vertical direction. At this time, the upper slide shaft 54 ​​and the lower slide shaft 58 slide linearly rearward relative to the left and right upper rails 36 and the left and right lower rails 34, and approach the upper rotation shaft 60 and the lower rotation shaft 56.

[0041] On the other hand, when the left and right upper rails 36 descend toward the left and right lower rails 34, the left and right X links 38 contract downward so that the inclination direction of the two link arms 40, 42 approaches the front-to-rear direction. At this time, the upper slide shaft 54 ​​and the lower slide shaft 58 slide linearly forward relative to the left and right upper rails 36 and the left and right lower rails 34, and move away from the upper rotation shaft 60 and the lower rotation shaft 56.

[0042] The suspension 30 configured as described above includes springs (not shown) that urge the left and right upper rails 36 upward relative to the left and right lower rails 34, and dampers (not shown) that absorb vibrations of the springs. The springs are, for example, air springs that receive compressed air from an air compressor constituting the vehicle's air brake system via an air tube, and the dampers are, for example, hydraulic cylinder-type dampers. The seat body 12 is connected to the left and right upper rails 36 via, for example, a well-known seat slide mechanism. The weight of an occupant seated on the seat body 12 is elastically supported by the air springs, and vibrations of the seat body 12 are absorbed by the dampers. The air springs expand upward when air is supplied, thereby raising the height of the left and right upper rails 36 and the seat body 12. The air springs contract downward when air is exhausted, thereby lowering the height of the left and right upper rails 36 and the seat body 12.

[0043] 3 to 5, the suspension 30 includes a center bracket 70 fixed to the upper surface of the rear floor bracket 46, and left and right reinforcing patches 84 fixed to the upper surfaces of the rear ends of the left and right lower rails 34. As shown in FIGS. 3 and 4, the center bracket 70 is made of, for example, a press-formed metal plate, and is disposed above the center portion of the rear floor bracket 46 in the left-right direction. The center bracket 70 includes left and right side wall portions 72 opposing each other in the left-right direction, an upper wall portion 74 connecting the upper ends of the left and right side wall portions 72 in the left-right direction, and left and right fixed wall portions 76 extending outward in the left-right direction from the lower ends of the rear portions of the left and right side wall portions 72.

[0044] The left and right fixed wall portions 76 are overlapped on the upper surface of the rear floor bracket 46, and two bolts 81 that pass through the left and right fixed wall portions 76 and the rear floor bracket 46 from above are threaded into two nuts (not shown) on the underside of the rear floor bracket 46. As a result, the left and right fixed wall portions 76 are fastened and fixed to the rear floor bracket 46, and are fixed to the floor of the vehicle body via the rear floor bracket 46. One of the fixed wall portions 76 (here, the left fixed wall portion 76) has a positioning portion 78 that extends rearward. The tip of this positioning portion 78 is bent downward and inserted into a positioning hole 82 formed in the rear floor bracket 46. When the left and right fixed wall portions 76 are fastened and fixed to the rear floor bracket 46, the center bracket 70 is positioned on the rear floor bracket 46 by this insertion.

[0045] The left and right side wall portions 72 and the upper wall portion 74 of the center bracket 70 extend forward beyond the rear floor bracket 46 and face the left-right intermediate portion of the lower rotating shaft 56 from above. Specifically, a notch 80 is formed in each of the left and right side wall portions 72 forward of the left and right fixed wall portions 76. These notches 80 are open on both left-right sides and on the lower side, and the seat left-right intermediate portion of the lower rotating shaft 56 is inserted into these notches 80. Each notch 80 has a semicircular shape that is concentric with the outer peripheral surface of the lower rotating shaft 56. A roughly C-shaped gap (reference number omitted) is formed between the edge of each notch 80 and the outer peripheral surface of the lower rotating shaft 56, and the center bracket 70 faces the lower rotating shaft 56 with the above-mentioned gap in between.

[0046] The left and right reinforcement patches 84 are disposed above both left and right ends of the lower rotating shaft 56 and are fixed to the upper surfaces of the left and right lower rails 34. The left and right reinforcement patches 84 are formed, for example, in a generally plate-like shape using a press-formed metal plate and are superimposed on the upper surfaces of the rear ends of the left and right lower rails 34. When viewed in the vertical direction, the left and right reinforcement patches 84 have an oval shape with the longitudinal direction as the length. Two front and rear bolts 48 that secure the rear end of the lower rail 34 to the rear floor bracket 46 pass through the front and rear ends of each reinforcement patch 84. The front and rear ends of each reinforcement patch 84 serve as bearing surfaces for the heads of the two bolts 48.

[0047] The portion of each reinforcement patch 84 between the two bolts 48 is positioned above the lower rotation shaft 56. A bent portion 86 (reference numeral omitted except in Figure 5) bent downward is formed at the edge portion on the inner side in the left-right direction of each reinforcement patch 84. This bent portion 86 extends in the front-to-rear direction above the lower rotation shaft 56. This bent portion 86 improves the bending strength of each reinforcement patch 84. Furthermore, a substantially circular through-hole 88 is formed in the middle portion of each reinforcement patch 84 in the front-to-rear direction, thereby reducing the weight of each reinforcement patch 84.

[0048] (Action and effect) Next, the operation and effects of this embodiment will be described.

[0049] In the suspension 30 provided in the vehicle seat 10 configured as described above, left and right lower rails 34 are fixed to the floor of the vehicle body, and the seat main body 12 is connected to left and right upper rails 36 disposed above the left and right lower rails 34. A vehicle occupant is restrained on the seat main body 12 by a seat belt 20. The left and right lower rails 34 and the left and right upper rails 36 are connected to left and right X links 38, respectively. These left and right X links 38 extend and retract in synchronous with each other, causing the upper rails 36 to rise and fall together with the seat main body 12. One link arm 40 of each of the left and right X links 38 is fixed to a lower rotation shaft 56. Both left and right ends of the lower rotation shaft 56 in the seat left-right direction are rotatably supported by the rear ends of the left and right lower rails 34.

[0050] In this embodiment, if an excessive load from an occupant inertially moving forward acts on the seat main body 12 via the seat belt 20 during a vehicle collision, the seat main body 12 will tend to rotate forward about the left and right front floor brackets 44 provided at the front ends of the left and right lower rails 34. At this time, the lower rotation shaft 56, to which one link arm 40 is fixed, will tend to displace upward and forward. A lateral intermediate portion of the lower rotation shaft 56 faces from below a center bracket 70 fixed to the floor of the vehicle body. The center bracket 70 engages with the lower rotation shaft 56, thereby suppressing deformation of the lower rotation shaft 56. As a result, the lower rotation shaft 56 can be prevented from falling off the rear ends of the left and right lower rails 34.

[0051] In addition, in this embodiment, left and right reinforcing patches 84 are disposed above both left and right ends of the lower rotating shaft 56 and are fixed to the upper surfaces of the left and right lower rails 34. This suppresses deformation of the left and right lower rails 34 when the lower rotating shaft 56 attempts to displace upward and forward, making it even easier to prevent the lower rotating shaft 56 from falling off the rear ends of the left and right lower rails 34.

[0052] In this embodiment, the center bracket 70 faces the lower rotation shaft 56 with a gap therebetween. This allows the lower rotation shaft 56, to which one link arm 40 is fixed, to rotate smoothly when the left and right X links 38 extend or contract.

[0053] In this embodiment, the center bracket 70 is fixed to the upper surface of the rear floor bracket 46, which is bridged between the undersides of the rear ends of the left and right lower rails 34 and fixed to the floor of the vehicle body. This eliminates the need to fix the center bracket 70 to the floor of the vehicle body separately from the rear floor bracket 46.

[0054] Furthermore, according to this embodiment, a cutout 80 that is open on both left and right sides and on the lower side is formed in the center bracket 70, and the left-right intermediate portion of the lower rotating shaft 56 is inserted into this cutout 80. This prevents the lower rotating shaft 56 from accidentally coming off the center bracket 70 when the lower rotating shaft 56 attempts to displace upward and forward.

[0055] Furthermore, in this embodiment, the center bracket 70 has left and right side wall portions 72, an upper wall portion 74, and left and right fixed wall portions 76, so the center bracket 70 can be manufactured by, for example, press forming a metal plate. The center bracket 70 has an inverted U-shaped cross section formed by the left and right side wall portions 72 and the upper wall portion 74, and the left and right intermediate portion of the lower rotating shaft 56 is inserted into notches 80 formed in the left and right side wall portions 72, respectively. This makes it easy to ensure the strength of the center bracket 70 against the load applied from the lower rotating shaft 56.

[0056] Furthermore, according to this embodiment, two bolts 48 for fixing the lower rails 34 to the vehicle body floor pass through left and right reinforcing patches 84 that are disposed above both left and right ends of the lower rotation shaft 56 and fixed to the upper surfaces of the left and right lower rails 34. The portion between the two bolts 48 in each reinforcing patch 84 is disposed above the lower rotation shaft 56. This increases the bearing surface for the two bolts 48 with one reinforcing patch 84, thereby improving the strength of the lower rails 34 against the load from the lower rotation shaft 56 with a reduced number of parts.

[0057] In the above embodiment, the two bolts 48 for fixing the lower rail 34 to the floor of the vehicle body are configured to pass through one reinforcement patch 84, but this is not limiting. For example, two bolts may be configured to pass through two reinforcement patches, respectively.

[0058] Furthermore, in the above embodiment, the center bracket 70 has left and right side wall portions 72, an upper wall portion 74, and left and right fixed wall portions 76, and notches 80 are formed in the left and right side wall portions 72, respectively, but this is not limited to this, and the configuration of the center bracket can be changed as appropriate.

[0059] In addition, in the above embodiment, the center bracket 70 is fixed to the floor of the vehicle body via the rear floor bracket 46, but this is not limited to this, and the center bracket may be fixed directly to the floor of the vehicle body.

[0060] In the above embodiment, the center bracket 70 faces the lower rotating shaft 56 with a gap therebetween, but the present invention is not limited to this. For example, a resin member may be interposed between the center bracket and the lower rotating shaft.

[0061] In addition, the present invention can be implemented with various modifications within the scope of the gist thereof. Furthermore, it goes without saying that the scope of the rights of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0062] 10 Vehicle seats 12 Seat body 14 seat cushion 16 Seat back 20 Seatbelt 30 Suspension 34 Lower rail 36 Upper Rail 38 X-Link 40 One link arm 46 Rear floor bracket 48 volts 56 Lower rotating shaft 70 Center bracket 72 Side wall 74 Upper wall 76 Fixed wall section 80 Cutout 84 Reinforcement Patch

Claims

1. Left and right lower rails fixed to the floor of the vehicle body, left and right upper rails disposed above the left and right lower rails, to which a seat main body portion to which a vehicle occupant is restrained by a seat belt is connected; left and right X links that connect the left and right lower rails to the left and right upper rails, respectively, and that extend and contract in synchronization with each other to raise and lower the left and right upper rails; a lower rotation shaft, the left and right ends of which are rotatably supported by rear ends of the left and right lower rails, and to which one of a pair of link arms of the left and right X links is fixed; a center bracket fixed to the floor portion and facing a middle portion of the lower rotation shaft in the seat left-right direction with a gap therebetween from above the seat; A vehicle seat suspension comprising:

2. 2. A vehicle seat suspension according to claim 1, further comprising left and right reinforcing patches disposed above the seat relative to both left and right ends of the lower rotating shaft and fixed to upper surfaces of the left and right lower rails.

3. a rear floor bracket that is bridged between lower surfaces of the rear ends of the left and right lower rails and fixed to the floor; 3. A suspension for a vehicle seat according to claim 1, wherein the center bracket is fixed to an upper surface of the rear floor bracket.

4. A suspension for a vehicle seat as described in any one of claims 1 to 3, wherein a cutout portion is formed in the center bracket that is open on both sides of the seat in the left-right direction and on the lower side of the seat, and a middle portion of the lower rotating shaft in the left-right direction of the seat is inserted into the cutout portion.

5. the center bracket has left and right side wall portions facing each other in the seat left-right direction, an upper wall portion connecting upper ends of the left and right side wall portions, and left and right fixed wall portions extending outward in the seat left-right direction from lower ends of the left and right side wall portions and fixed to the floor portion, 5. The vehicle seat suspension according to claim 4, wherein the notches are formed in the left and right side wall portions, respectively.

6. A vehicle seat suspension as described in claim 2, wherein two bolts for fixing the lower rail to the floor portion pass through the reinforcement patch, and the portion of the reinforcement patch between the two bolts is positioned above the seat of the lower rotation shaft.

7. A seat body having a seat cushion on which a vehicle occupant sits and a seat back that supports the back of the occupant; a seat belt device that restrains the occupant in the seat main body; a suspension for a vehicle seat according to any one of claims 1 to 6, in which the seat main body portion is connected to the left and right upper rails; A vehicle seat comprising:

Images