Vehicle seat

Abstract

To fix a lower connection member to side frames with sufficient strength.SOLUTION: A vehicle seat includes: a seating frame 2 which is a frame of a seating part on which an occupant is seated; and a seat back frame 1 supported by the seating frame 2. The seat back frame 1 includes: side frames SF which are disposed separating from each other in a lateral direction; and a lower connection member 30 which is disposed so as to be spanned between lower parts of the left and right side frames SF and connects the left and right side frames SF. The left and right side frames SF have: side wall parts 12A; and inner extension parts 13 which extend from rear ends of the side wall parts 12A to the inner side in the lateral direction and are positioned separating from each other. The lower connection member 30 has: a front wall part 31 disposed at the occupant side; and a rear wall part 32 connected to the rear side of the front wall part 31. The rear wall part 32 is formed with a through hole 38 into which another member enters, and the through hole 38 overlaps with the front wall part 31 in an anteroposterior direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat such as a car seat, and more particularly to a vehicle seat that provides a comfortable seating experience for an occupant in the event of a rear-end collision. [Background technology]

[0002] In the event of a rear-end collision, where a vehicle collides with the rear end of the vehicle, such as when it is rear-ended or when it is rear-ended while reversing, the head of a seated occupant may tilt backward due to inertia, and the neck may be subjected to impact.

[0003] Therefore, vehicle seats are provided with a headrest above the seat back to support the occupant's head from behind in order to protect the occupant's head and neck from the impact of a rear-end collision and to reduce the impact on the neck. In order to effectively reduce the impact of a rear-end collision, it is desirable to quickly reduce the gap between the occupant's head and the headrest during a rear-end collision.

[0004] For this reason, a seat back has been proposed that is configured to move the occupant's upper body backward during a rear-end collision, and the load caused by this movement is received by a pressure-receiving member, causing the headrest to move forward, supporting the occupant's head and reducing the impact on the neck (Patent Document 1).

[0005] Furthermore, in the seatback frame of the vehicle seat described in Patent Document 1, the left and right side frames are connected to each other at their lower parts by a plate-shaped lower frame (lower connecting member) and a shaft for supporting rotation of the reclining mechanism, which is disposed in front of the lower frame. As in Patent Document 2, the lower frame is not simply plate-shaped, but may have flanges extending forward at the upper and lower ends. In a normal seated position, these lower frames are positioned approximately vertically and slightly lean forward relative to the upper part of the backrest (the part that the upper back of the occupant rests against). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-083269 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-067723 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, since the lower connecting member receives a load from an occupant in the event of a rear collision, it is desirable that the lower connecting member be fixed to the side frame with sufficient strength.

[0008] The present invention has been made in view of the above-mentioned background, and has an object to fix a lower connecting member to a side frame with sufficient strength. [Means for solving the problem]

[0009] The vehicle seat of the present invention, which solves the above-mentioned problems, includes a seating frame, which is a frame of a seating portion on which an occupant sits, and a seatback frame supported by the seating frame. The seatback frame includes side frames spaced apart from each other on the left and right, and a lower connecting member that is disposed between the lower portions of the left and right side frames and connects the left and right side frames.

[0010] The left and right side frames each have a side wall portion and an inner extension portion that extends inward in the left-right direction from the rear end of the side wall portion and is positioned apart from each other.

[0011] The lower connecting member has a front wall portion disposed on the occupant side and a rear wall portion connected to the rear of the front wall portion. The rear wall portion has a through hole formed therein through which other members can be inserted. The through hole overlaps with the front wall portion in the front-to-rear direction.

[0012] With this configuration, the lower connecting member can be fixed to the side frame with sufficient strength.

[0013] In the vehicle seat described above, the front wall portion may extend so as to move away from the rear wall portion as it moves away from the connecting portion between the front wall portion and the rear wall portion.

[0014] In addition, in the vehicle seat described above, the seatback frame may be configured to be reclined relative to the seating frame, and a shaft connecting the left and right side frames may be arranged on the rotation axis of the seatback frame, with the shaft being positioned between the rear wall portion and the front wall portion.

[0015] In the vehicle seat described above, the shaft may be provided at a location where the distance between the front wall portion and the rear wall portion is the widest.

[0016] In the vehicle seat described above, the rear wall portion may have a front end formed with a bent portion that is inclined forward. [Effects of the Invention]

[0017] According to the present invention, the lower connecting member can be fixed to the side frame with sufficient strength. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a vehicle seat. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 10A and 10B are diagrams illustrating the angle of the front surface of the front wall portion. [Figure 5] FIG. 10 is a rear view of the seat back frame showing the welded portion between the rear wall portion and the inner extension portion. [Figure 6] FIG. 10 is a side cross-sectional view illustrating the mounting structure of the cover on the rear surface of the seat back. [Figure 7] FIG. 4 is a side cross-sectional view showing the seat back frame in a normal state. [Figure 8]FIG. 10 is a side cross-sectional view showing the seat back frame in a mild rear-end collision. [Figure 9] FIG. 10 is a side cross-sectional view showing the seat back frame during a strong rear-end collision. [Figure 10] FIG. 10 is a side cross-sectional view of a lower connecting member according to a modified example. [Figure 11] 10 is a perspective view showing a modified example of the recess portion of the lower connecting member. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1, a vehicle seat S as an example of a vehicle seat of the present invention is configured to include a seat back S1, a seating portion S2, and a headrest S3. In this specification, the front, back, left, and right directions are based on an occupant seated in the vehicle seat S in a normal state with the seat back S1 upright (not reclined and facing up).

[0020] A seat frame F as shown in FIG. 2 is provided within a vehicle seat S. The seat frame F is composed of a seat back frame 1, which is the frame of the seat back S1, and a seat frame 2, which is the frame of the seating portion S2. The seat frame 2 and the seat back frame 1 are connected via a reclining mechanism 3 (detailed structure is not shown). A cushion and a covering are provided on the outside of the seat back frame 1 and the seat frame 2, and a cover 5 (see FIG. 6), which is an example of a mounting member, is attached to the back surface with clips 51, which are an example of a fixing member, thereby forming the seat back S1 and the seating portion S2.

[0021] The seatback frame 1 is configured in a frame shape by side plates 10 arranged spaced apart on the left and right and extending in the vertical direction, an upper frame 21 connecting the upper ends of the side plates 10, and a lower connecting member 30 connecting the lower ends of the left and right side plates 10. The upper frame 21 is made by bending a metal pipe into a U-shape and has upper connecting portions 21A extending left and right and connecting portions 21B extending downward from the left and right ends of the upper connecting portion 21A. The connecting portions 21B are connected to the upper ends of the side plates 10 by welding.

[0022] The side plate 10 is composed of a lower member 12 made of sheet metal provided at the lower end, and an upper member 11 that is integrated by welding to the upper part of the lower member 12. The lower member 12 is equipped with a side wall portion 12A and an inner extension portion 13 that extends inward from the rear end of the side wall portion 12A.

[0023] 5, the inner extending portion 13 has an inclined edge portion 13A that is inclined at an angle γ with respect to the vertical direction so that the inner end portion goes from the inside to the outside as it goes from top to bottom. This inclined edge portion 13A is the portion where the lower connecting member 30 and the inner extending portion 13 are welded, as will be described later. The inner extending portion 13 also has clip holes 13B as an example of mounting holes, into which clips 51 are inserted for attaching the cover 5 to the rear surface of the seat back S1.

[0024] Returning to FIG. 2 , the side frames SF of the seatback frame 1 are composed of side plates 10 and connection portions 21B of the upper frame 21. A pressure-receiving member 40 made of a plate-shaped resin is disposed between the left and right side frames SF. The pressure-receiving member 40 is connected to the left and right side frames SF at two locations, top and bottom, via connecting wires (connecting members) 41 made of bent wires with spring properties. Specifically, the upper connecting wire 41 has an end engaged with a bracket 43 welded to the connection portion 21B, and the lower end of the lower connecting wire 41 is connected to a pivoting member 45 that can swing back and forth. The pivoting member 45 is fixed to the side plates 10 (upper member 11). As disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 2010-179748, the lower end of the arm is normally positioned forward. However, when a large rearward force is applied from the connecting wire 41, the lower end swings rearward, allowing the pressure-receiving member 40 to move significantly rearward.

[0025] A pillar support portion 23 is provided on the upper frame 21, and a headrest frame (not shown) is provided on the pillar support portion 23. A cushion member is provided on the outside of the headrest frame to form the headrest S3.

[0026] Next, details of the lower connecting member 30 will be described. The lower connecting member 30 is arranged so as to span between the lower parts of the left and right side frames SF. This prevents the seat frame F from collapsing in the left-right direction even when a load is applied from the side, and allows the load from the side to be transmitted to the center of the vehicle.

[0027] The lower connecting member 30 is made of sheet metal, and as shown in Figure 3, it has a front wall portion 31, a rear wall portion 32, an upper wall portion 33 extending rearward from the upper end of the front wall portion 31 to connect the front wall portion 31 and the rear wall portion 32, a lower flange 34, and a folded flange 35.

[0028] The front wall 31 is located in front of the shaft 3S of the reclining mechanism 3. The shaft 3S is disposed on a rotation axis between the seat frame 2 and the seatback frame 1, and is provided to connect the left and right side frames SF to each other to support the rotation caused by the reclining mechanism 3. By positioning the front wall 31 of the lower connecting member 30 in front of the shaft 3S, the load applied from the occupant's buttocks and the like via the seatback cushion is not applied directly to the shaft 3S but to the front wall 31, thereby mitigating the impact that the occupant feels from the shaft 3S on their buttocks and the like.

[0029] As shown in FIG. 4(a), the front wall portion 31 has a front surface 31A that is parallel to the extension direction (straight line L1) of the connection portion 21B in a side view or angled upward relative to the extension direction. In the example shown in FIG. 4(a), the front surface 31A is angled upward relative to the straight line L1 at an angle α. The front wall portion 31 also is angled upward relative to the rear wall portion 32 at an angle β. This allows the front and rear wall portions 31 and 32 to be connected at their upper ends and have a downwardly open shape, ensuring a sufficient stroke for the front wall portion 31 to deform rearward in the event of a rear-end collision. Note that the connection portion 21B, which is a pipe that constitutes the side frame SF, is not straight in a side view. Instead, as shown in FIG. 4(b), the upper portion may be curved upward or downward. In such cases, the angle of the front surface 31A relative to the pipe (connection portion 21B) refers to the angle with respect to the direction in which the pipe is most upright.

[0030] The lower end of the front wall portion 31 extends below the lower end of the rear wall portion 32. This allows the front wall portion 31 to be made larger, reducing the impact feeling of the occupant against the lower connecting member 30, and also makes it easier for the front wall portion 31 to deform rearward in the event of a rear-end collision because the front wall portion 31 is long from its upper end to its lower end.

[0031] The rear wall 32 is a wall that connects to the side frame SF (inner extension 13) and connects and supports the lower connection member 30 to the side frame SF. Specifically, as shown in FIG. 4(a), the rear surface of the rear wall 32 is aligned with the front surface of the inner extension 13. As shown in FIG. 5, the inner extension 13 and the rear wall 32 are welded together along the inclined edge 13A of the inner extension 13. Because the inclined edge 13A is inclined relative to the vertical direction, even if the heightwise overlap between the inclined edge 13A and the rear wall 32 is small, the weld length can be increased to maintain the required weld strength. The angle γ of the inclined edge 13A is preferably 20 degrees or greater. An angle γ of 20 degrees or greater increases the weld length. The angle γ is more preferably 30 degrees or greater, and even more preferably 40 degrees or greater. Moreover, by setting the angle γ to 70 degrees or less, it is possible to prevent the inner extending portion 13 from forming an excessively acute angle. Furthermore, because the rear wall portion 32 is fixed to the side frame SF, the rearward movement of the rear wall portion 32 is suppressed in the event of a rear-end collision, and the connecting portion between the front wall portion 31 and the rear wall portion 32 becomes more likely to deform, making it easier to control the rearward movement of the front wall portion 31.

[0032] As described above, the lower connecting member 30 of this embodiment has a front wall portion 31 and a rear wall portion 32 connected to the front wall portion 31, so that it has higher rigidity against crushing in the left-right direction compared to a simple plate-shaped lower connecting member, and can efficiently transmit loads from the side to the center of the vehicle.

[0033] As shown in Figure 3, the upper wall portion 33 has a flat plate shape extending substantially in the front-to-rear direction. This allows the upper end of the front wall portion 31 and the upper end of the rear wall portion 32 to be separated appropriately in the front-to-rear direction, allowing for a large deformation stroke when the front wall portion 31 deforms rearward. The connecting portion between the front wall portion 31 and the upper wall portion 33 has a smooth, edgeless shape due to the natural R-shape created when the upper wall portion 33 and the front wall portion 31 are bent.

[0034] The lower flange 34 is bent rearward from the lower end of the front wall 31 below the shaft 3S and extends rearward. The connecting portion between the front wall 31 and the lower flange 34 also has a smooth, edgeless shape due to the natural R-shape created when bending between the lower flange 34 and the front wall 31. The lower flange 34 is not connected to the rear wall 32, and as a result, the lower connecting member 30 does not have a closed cross-sectional shape. In this way, the lower flange 34 and the rear wall 32 are not connected, and a gap exists between them, making it easy for the front wall 31 to deform rearward.

[0035] The folded flange 35 is formed by folding back forward from the lower side of the rear end of the lower flange 34, and the front end of the folded flange 35 is located rearward of the lower end of the front wall portion 31. In this way, by including the lower flange 34 and the folded flange 35 in the lower connecting member 30, the cross-sectional area of ​​the lower connecting member 30 is increased. This improves rigidity in the left-right direction and improves lateral load transmission. Furthermore, by positioning the front end of the folded flange 35 rearward of the lower end of the front wall portion 31 (the portion connecting the front wall portion 31 and the lower flange 34), the edge of the front end of the folded flange 35 does not hit the seatback cushion hard during a rear-end collision, thereby reducing the impact feeling of the lower connecting member 30 to the occupant and minimizing damage to the seatback cushion.

[0036] Through holes 38 are formed in two locations, left and right, in the rear wall 32 of the lower connecting member 30, more specifically, from the rear wall 32 to the upper wall 33. As shown in Fig. 6, the through holes 38 function as escape holes to prevent the tips of the clips 51 from interfering with the rear wall 32 of the lower connecting member 30 when the rear cover 5 is attached to the clip holes 13B with the clips 51. For this reason, the through holes 38 are provided at positions corresponding to the clip holes 13B.

[0037] 5, the lower connection member 30 does not reach the side wall portion 12A, and a small gap is provided between the lower connection member 30 and the side wall portion 12A. However, if there are no problems with manufacturing errors in the lower connection member 30 or the lower connection member 30 climbing up onto the corners of the lower member 12, the lower connection member 30 may be configured so that both ends abut against the side wall portion 12A.

[0038] The operation of the vehicle seat S configured as above during a rear-end collision will be described. As shown in Fig. 7, before a rear-end collision occurs, the lower end of the rotating member 45 is in a position where it has swung forward, and the pressure-receiving member 40 is in the forwardmost position within its movable range. Although the rotating member 45 is not shown in Fig. 7 to Fig. 9, in the normal state of Fig. 7, the lower end of the rotating member 45 is in the forward position.

[0039] In the event of a relatively weak rear-end collision, as shown in FIG. 8, the center portion of the seatback cushion 50 (the portion against which the occupant P's back rests) moves rearward, and the seatback cushion 50 pushes the pressure-receiving member 40 rearward, causing the pressure-receiving member 40 to move rearward. At this time, the lower end of the rotating member 45 swings rearward. Also, the inner surface of the lower portion of the seatback cushion 50 (the portion against which the occupant P's buttocks and other parts rests) rests against the front surface 31A of the lower connecting member 30, causing it to deform somewhat. However, because the front surface 31A has a wide surface and is inclined slightly upward relative to the connecting portion 21B and the rear wall portion 32, the reaction force that the occupant P's buttocks and other parts receive from the lower connecting member 30 acts as a small pressure, and the impact that the occupant P receives from the lower connecting member 30 is soft. In addition, the connecting portion of the lower connecting member 30 between the front wall portion 31 and the upper wall portion 33 and the connecting portion of the front wall portion 31 and the lower flange 34 have gently curved surfaces, so the occupant P does not feel a strong impact from the lower connecting member 30. Furthermore, because the front end of the folded flange 35 is located rearward of the lower end of the front wall portion 31, the edge of the front end of the folded flange 35 does not hit the inner surface of the seatback cushion 50 hard, thereby preventing damage to the seatback cushion 50. In addition, because the front wall portion 31 is located forward of the shaft 3S, the seatback cushion 50 does not directly hit the shaft 3S. Therefore, the occupant P does not feel a strong impact from the shaft 3S.

[0040] In the event of a relatively strong rear-end collision, as shown in FIG. 9 , the center portion of the seatback cushion 50 moves significantly rearward, and accordingly, the pressure-receiving member 40 also moves significantly rearward as the connecting wire 41 elastically deforms. At this time, the seatback cushion 50 strongly hits the front surface 31A of the lower connecting member 30, and the lower connecting member 30 bends and deforms at the connection portion between the front wall portion 31, including the upper wall portion 33, and the rear wall portion 32. Therefore, even if a strong force is applied to the seatback cushion 50 from the buttocks or the like of the occupant P, the front wall portion 31 of the lower connecting member 30 moves rearward to absorb the impact, and the occupant P does not feel a strong impact on the buttocks or the like. In particular, in the vehicle seat S of this embodiment, the flat upper wall portion 33 extending substantially in the front-to-rear direction is provided between the front wall portion 31 and the rear wall portion 32, and therefore a space is secured between the front wall portion 31 and the rear wall portion 32, thereby increasing the stroke of the rearward deformation of the front wall portion 31, i.e., the amount of impact absorption.

[0041] As in the case of a minor rear-end collision, the connecting portion of the lower connecting member 30 between the front wall portion 31 and the upper wall portion 33 and the connecting portion of the front wall portion 31 and the lower flange 34 are gently curved, making it less likely that the occupant P will feel a strong impact from the lower connecting member 30. In addition, because the front end of the folded flange 35 is located rearward of the lower end of the front wall portion 31, the edge of the front end of the folded flange 35 will not strongly hit the inner surface of the seatback cushion 50, thereby suppressing damage to the seatback cushion 50. Furthermore, because the front wall portion 31 is located forward of the shaft 3S, the seatback cushion 50 will not directly hit the shaft 3S, thereby mitigating the impact of the shaft 3S on the occupant P.

[0042] Furthermore, in the vehicle seat S of this embodiment, the lower connecting member 30 is not flat as in the conventional case, but has a front wall portion 31 and a rear wall portion 32 connected to each other at the upper portion, thereby improving the overall rigidity against bending loads in the fore-and-aft direction. Therefore, in the conventional case, during a rear-end collision, the center of the lower frame is displaced rearward relative to the side frames, bending in a V-shape in plan view, and there is a risk that the side frames also deform (change their orientation) so that their front ends move inward to the left and right. However, in the vehicle seat S of this embodiment, such deformation is unlikely to occur. In other words, although the lower connecting member 30 is likely to deform so that the front wall portion 31 approaches the rear wall portion 32, it is unlikely to deform overall so as to be V-shape in plan view, thereby suppressing deformation of the side frames SF. Furthermore, because the lower connecting member 30 is provided so as to span the left and right side frames SF, when a load is applied that tends to deform the side frames SF inward, the front wall portion 31 comes into contact with the inner surfaces of the side frames SF, thereby suppressing deformation of the side frames SF.

[0043] Furthermore, in the vehicle seat S of this embodiment, the lower connecting member 30 is disposed across the left and right side frames SF, and the front wall portion 31, rear wall portion 32, upper wall portion 33, lower flange 34, and folded flange 35 provide a sufficient cross-sectional area. Therefore, when the vehicle is subjected to a side collision load, the vehicle seat S is prevented from being crushed in the lateral direction and the lateral load can be transmitted to the center of the vehicle. In particular, the lower connecting member 30 is welded to the inner extension portion 13 of the side frame SF at the inclined edge portion 13A, and is therefore fixed to the side frame SF with sufficient strength through a long weld length. This increases the rigidity of the seatback frame 1 and allows the lateral load to be transmitted efficiently to the center of the vehicle. In other words, the lateral rigidity of the vehicle seat S can be increased by increasing the weld length between the lower connecting member 30 and the inner extension portion 13 without increasing the vertical size of the lower connecting member 30.

[0044] Furthermore, in the vehicle seat S of this embodiment, the rear wall 32 of the lower connecting member 30 has the through hole 38 as a relief portion, which prevents interference between the clip 51 and the rear wall 32 when attaching the cover 5 to the back of the seat back S1, facilitating assembly work. In other words, even if there is some error in the size or shape of the rear wall 32, interference between the clip 51 and the rear wall 32 can be prevented, so there is no need to pay excessive attention to assembling the lower connecting member 30 and the side frame SF or attaching the clip 51, making the work easier. Furthermore, since the relief portion is the through hole 38, when manufacturing the lower connecting member 30 made of sheet metal by press working, the relief portion can be easily formed by blanking, facilitating manufacturing.

[0045] Although the embodiment of the present invention has been described above, the present invention can be practiced by appropriately modifying it as shown in the following other embodiments.

[0046] For example, in the above embodiment, the lower connecting member 30 has a flat upper wall portion 33, but the upper wall portion 33' connecting the front wall portion 31 and the rear wall portion 32 may be bent at a single R as shown in Figure 10.

[0047] In the above embodiment, the relief portion of the lower connecting member 30 is configured as a through hole 38, but it may also be configured as a recess 38' as shown in Fig. 11. By using a recess 38' instead of a through hole 38, the relief portion can be configured without reducing the strength of the rear wall portion 32, and interference between the clip 51 and the rear wall portion 32 can be avoided.

[0048] In the above embodiment, the front surface 31A of the front wall portion 31 is inclined upward relative to the extending direction of the pipe of the connection portion 21B in a side view, but may be parallel to the extending direction of the pipe.

[0049] In the above embodiment, the pressure-receiving member 40 is provided to actively push the occupant P into the seat back S1 during a rear-end collision, but the present invention may also be applied to a seat that does not have a pressure-receiving member 40. However, when the pressure-receiving member 40 is present, the lower connecting member 30 and the occupant P are more likely to come closer to each other, so the present invention can be effectively used in such cases.

[0050] In the above embodiment, the inclined edge portion 13A of the inner extension portion 13 was inclined relative to the vertical direction so that the inner end portion went from inside to outside as it went from top to bottom, but conversely, it may be inclined relative to the vertical direction so that the inner end portion went from outside to inside as it went from top to bottom.

[0051] In the above embodiment, the pressure-receiving member 40 is supported on the side frame SF by the connecting wire 41, but it may also be supported on the side frame SF by other connecting members such as rubber or a belt.

[0052] In the above embodiment, the cover on the rear surface of the seat back is given as an example of the part to be attached, but the part to be attached can also be a harness, switches operated from the rear seat, a pocket on the rear surface of the seat back, etc. Furthermore, the mounting hole is not limited to a simple hole, but can also be a hole for threading a tapping bolt or a female screw hole, and the fixing member can also be a bolt, a tapping bolt, a rivet, etc.

[0053] Furthermore, in the above embodiment, a vehicle seat S is shown as an example of application of a vehicle seat, but the vehicle seat of the present invention can also be applied to other vehicle seats, for example, seats for ships or aircraft. [Explanation of symbols]

[0054] 1 Seat back frame 2 seating frame 3 Reclining mechanism 3S shaft 5 Cover 10 Side Plate 11 Upper Member 12 Lower Member 12A Side wall part 13 Inner extension 13A Sloped Edge 13B Clip hole 21 Upper frame 21A Upper connection part 21B Connection 23 Pillar support 30 Lower connecting member 31 Front wall 31A Front 32 Rear wall 33 Upper wall 33′ Upper wall 34 Lower flange 35 Folded flange 38 Through Hole 38' Recess 40 Pressure-receiving member 50 Seatback cushion 51 clips Front seat frame S vehicle seat S1 seat back S2 seating area S3 Headrest SF Side Frame

Claims

[Claim 1] A seat back frame is a frame of a vehicle seat, and is supported by a seat frame, which is a frame of a seating portion on which an occupant sits, The seat back frame includes side frames arranged spaced apart on the left and right sides, and a lower connection member arranged to bridge between lower parts of the left and right side frames and connect the left and right side frames, the lower connecting member is made of sheet metal and includes: a front wall portion disposed on the occupant side and receiving a load from the occupant's buttocks in the event of a rear collision; a rear wall portion connected to the rear of the front wall portion and connected to the side frame; and a connecting portion connecting the front wall portion and the rear wall portion, a front end of a front wall portion of the lower connecting member is located forward of a lower end of a pressure-receiving member disposed between the left and right side frames, The left and right side frames each have a side wall portion and an inner extension portion extending inward in the left-right direction from the side wall portion, the lower connection member and the inner extension portion are joined by a weld, The rear wall portion is provided with a through hole, The seat back frame is characterized in that an upper end of the through hole is positioned above a lower end of the welded portion.

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