JP7734033B2 - Vehicle seats - Google Patents

Description

The present invention relates to a vehicle seat.

Patent Document 1 below discloses technology related to an automobile seatback frame made of aluminum alloy. In this prior art, one frame and the other frame in the seatback frame are joined at the joints using mechanical joining means such as rivets, screws, bolts, or tapping bolts. This improves the joint strength at the joints, and prevents the seatback frame from undergoing large deformation when a large load is applied to the seatback frame during a vehicle collision, sudden braking, or other such event.

Japanese Patent Application Laid-Open No. 2001-17263

In vehicles with rear seats that are split across the width of the vehicle, a hinge is provided at the lower inside edge of the rear seat in the width direction of the vehicle, and the seat back is retractable via the hinge. At this hinge, the seat back frame must be secured to or unlocked from the vehicle body, and a bracket for the hinge is attached to the seat back frame. Therefore, when a large load is applied to the seat back frame, part of the large load is transmitted to the seat back frame via the bracket at the hinge.

In consideration of the above, the present invention aims to provide a vehicle seat that can suppress large deformation of the seatback frame when a large load is input to the seatback frame.

The vehicle seat according to the first aspect of the present invention comprises a frame-shaped seatback frame that forms the framework of a seatback supporting the upper body of a seated occupant, and brackets that are fixed to a vehicle body and are joined to the front or rear surfaces of vertical and horizontal members that intersect at corners of the seatback frame in a manner that overlaps the front or rear surfaces in the vehicle fore-and-aft direction, so as to conceal the outline of the front or rear surfaces, the brackets including a fixing piece fixed to the vehicle body, a joining piece connected to the fixing piece and positioned outward in the vehicle width direction of the seatback frame and joined to the seatback frame, through holes formed in the joining piece, and welded parts that are welded to the seatback frame through the through holes, the through holes being provided at multiple positions along the extension direction of the vertical members , and the through holes are also provided at positions that overlap the horizontal members, and the number of through holes provided on the vertical member side is greater than the number of through holes provided on the horizontal member side.

The vehicle seat according to the invention of claim 1 comprises a seatback frame and a bracket. The seatback frame forms the framework of the seatback, supporting the upper body of a seated occupant, and is formed in a frame shape. The bracket is fixed to the vehicle body and joined to the corners of the seatback frame. Vertical and horizontal members intersect at the corners of the seatback frame, and the bracket is joined to the seatback frame in a state where it overlaps the front or rear of the vertical and horizontal members so as to hide the outline of the front or rear faces in the fore-and-aft direction of the vehicle.

Note that the term "front or rear" here is used to include cases where the bracket is joined to the front of the seatback frame in the fore-and-aft direction of the vehicle, and cases where the bracket is joined to the rear of the seatback frame in the fore-and-aft direction of the vehicle. In the former case, the bracket is joined to the front of the seatback frame with the bracket overlapping the front of the seatback frame so as to hide the outline of the front of the seatback frame. On the other hand, in the latter case, the bracket is joined to the rear of the seatback frame with the bracket overlapping the rear of the seatback frame so as to hide the outline of the rear of the seatback frame.

Here, as a comparative example, the phrase "the outer shape of the front of the seatback frame (vertical and horizontal members) is not hidden at the corner (joint) between the bracket and the seatback frame" refers to a situation where the bracket only covers a portion of the front of the seatback frame, with the remaining portion of the front of the seatback frame protruding (exposed) beyond the outer edge of the bracket.

In the comparative example, at the joint, the front surface of the seatback frame is provided with both areas where the brackets overlap (are hidden) and areas where the brackets do not overlap (are exposed). Therefore, when a large load is transmitted to the seatback frame via the brackets, the large load is transmitted via the brackets to the areas where the brackets overlap on the front surface of the seatback frame at the joint, but the large load is not transmitted directly to the areas where the brackets do not overlap.

As a result, when a large load is transmitted to the seatback frame via the bracket, stress is concentrated at the boundary between the area on the front of the seatback frame where the large load is transmitted and the area where it is not transmitted, potentially causing the seatback frame to deform significantly from that boundary.

In contrast, in the present invention, the bracket overlaps the front surface of the seatback frame at the corner (joint) between the bracket and the seatback frame, hiding (covering) the outline of the front surface of the seatback frame. This allows the present invention to increase the contact area between the bracket and the front surface of the seatback frame compared to the comparative example.

As a result, in the present invention, when a large load is transmitted to the seat back frame via the bracket, the large load is transmitted across almost the entire front surface of the seat back frame where the bracket overlaps at the joint.

In this way, in the present invention, the seatback frame can distribute the large load transmitted to the front surface of the seatback frame by increasing the contact area between the seatback frame and the bracket. As a result, the present invention can suppress the concentration of stress in the seatback frame, making it possible to suppress large deformation of the seatback frame. Note that the same effect can be achieved when the bracket is joined to the rear surface of the seatback frame in the vehicle's fore-and-aft direction.

Here, "contactable" includes cases where the bracket and seatback frame come into contact when at least a large load is input (transmitted). Before a large load is input, the bracket does not necessarily have to be in surface contact with the seatback frame when the bracket overlaps the front of the seatback frame so as to hide the outline of the front of the seatback frame. The same applies when the bracket is joined to the rear surface of the seatback frame in the fore-and-aft direction of the vehicle.

In addition, in the present invention , the bracket is configured to include a fixed piece and a connecting piece, the fixed piece is fixed to the vehicle body, and the connecting piece is connected to the fixed piece and is disposed on the outer side of the seat back frame in the vehicle width direction and connected to the seat back frame. In other words, by connecting the connecting piece to the front or rear surface of the seat back frame, the connecting piece overlaps the front or rear surface of the seat back frame so as to hide the outer shape of the front or rear surface of the seat back frame.

The bracket further includes a through hole and a welded portion, and the connecting piece is formed with a through hole, and the connecting piece is welded to the seat back frame through the through hole (welded portion). Here, the through holes are provided at a plurality of positions along the extension direction of the vertical member. Note that the "through hole" also includes a notch in which a portion of the hole is opened.

As mentioned above, in the bracket, the connecting piece is connected to the fixed piece, is positioned outside the seatback frame in the vehicle width direction, and is joined to the seatback frame. Therefore, when a large load is input to the seatback frame due to, for example, a vehicle collision (rear-end collision), the large load is transmitted from the vehicle body via the fixed portion of the fixed piece to the connecting piece, and is then input (transmitted) to the seatback frame via the connecting piece.

In the present invention, a through hole is provided in the joining piece of the bracket, and a weld is provided in the through hole, thereby joining (welding) the bracket to the seat back frame. On the other hand, as a comparative example, a weld may be provided on the outer edge of the bracket, and the bracket may be joined to the seat back frame via the weld.

Because the through-hole is formed inside the outer edge of the bracket, the present invention allows the welded portion to be closer to the fixed portion (fixed piece) than the comparative example. In this way, the present invention allows the moment generated in the bracket during a vehicle collision to be smaller than the comparative example by the amount that the welded portion is closer to the fixed portion.
Furthermore, in the present invention, the through holes are also provided at positions that overlap with the horizontal members, and the number of through holes provided on the vertical member side is greater than the number of through holes provided on the horizontal member side.
The vehicle seat according to the invention described in claim 2 is a vehicle seat according to the invention described in claim 1, wherein the through hole provided on the lateral member side has a larger area than the through hole provided on the vertical member side.
The vehicle seat of the invention described in claim 3 is a vehicle seat of the invention described in claim 1, wherein the through hole provided on the lateral member side is provided further outward in the seat width direction than the through hole provided on the vertical member side.

A vehicle seat according to a fourth aspect of the present invention is the vehicle seat according to the first aspect of the present invention, wherein the welded portion is formed continuously and includes opposing portions of the through hole.

In the vehicle seat according to the invention described in claim 4 , the welded portion is formed continuously, including the opposing portions in the through hole, so that the weld length can be made longer compared to a comparative example in which the welded portion is provided in only a portion of the through hole (not including the opposing portions in the through hole).

As a result, the present invention can improve the joint strength between the bracket and the seat back frame compared to the comparative example, and can increase the welding area between the bracket and the seat back frame, making it possible to distribute the load transmitted from the bracket to the seat back frame in the event of a vehicle collision.

A vehicle seat according to a fifth aspect of the present invention is the vehicle seat according to the fourth aspect of the present invention, wherein the welded portion has a closed shape.

In the vehicle seat according to the invention described in claim 5 , the shape of the welded portion is closed, so that the weld length can be made longer than when the shape of the welded portion is open.

This allows for greater joint strength between the bracket and the seat back frame than when the welded portion is open-shaped, and also allows for a greater weld area between the bracket and the seat back frame, making it possible to further distribute the load transmitted from the bracket to the seat back frame in the event of a vehicle collision.

The vehicle seat according to the invention of claim 6 is a vehicle seat according to the invention of any one of claims 1 to 5 , wherein the seatback frame is divided into two in the vehicle width direction and includes an inner skeletal member that is rectangular tubular and arranged along the seat height direction, and a lower skeletal member that is rectangular tubular and connected to the inner skeletal member and arranged along the seat width direction, and the joining piece that is joined to the seatback frame at the bracket includes an upper part that hides the front or rear side of the inner skeletal member in the longitudinal direction of the vehicle, and a lower part that is formed below the upper part in the vertical direction of the vehicle and is formed so as to protrude outward in the vehicle width direction more than the upper part, hiding the front or rear side of the lower skeletal member in the longitudinal direction of the vehicle.

In a vehicle seat according to a sixth aspect of the present invention, the seatback frame is divided into two parts in the vehicle width direction, and includes an inner skeleton member and a lower skeleton member each having a rectangular cylindrical shape. The inner skeleton member is provided along the seat height direction, and the lower skeleton member is connected to the inner skeleton member and provided along the seat width direction.

On the other hand, the bracket's joint pieces are formed on the top and bottom of the vehicle in the vertical direction and include an upper part that conceals the front or rear side of the inner frame member in the vehicle's fore-and-aft direction, and a lower part that conceals the front or rear side of the lower frame member in the vehicle's fore-and-aft direction, with the lower part of the joint piece being formed so that it protrudes outward in the vehicle width direction more than the upper part.

In other words, the lower part of the connecting piece has a larger contact area with the seat back frame than the upper part of the connecting piece. In this way, by increasing the contact area between the bracket and the front or rear of the seat back frame, it is possible to distribute the large load transmitted to the front of the seat back frame during a vehicle collision. This makes it possible to prevent stress concentration in the seat back frame and prevent large deformation of the seat back frame.

As described above, according to the vehicle seats set forth in claims 1 to 3 , when a large load is input to the seat back frame, large deformation of the seat back frame can be suppressed.

According to the vehicle seat of the fourth aspect, the welding length can be increased, and the load transmitted from the bracket to the seat back frame can be dispersed.

According to the vehicle seat of the fifth aspect, the welding length can be further increased, and the load transmitted from the bracket to the seat back frame can be further dispersed.

According to the vehicle seat of the sixth aspect, a large load transmitted to the front or rear surface of the seat back frame can be dispersed, and large deformation of the seat back frame can be suppressed.

1 is a front view including a seat back frame of a rear seat to which a vehicle seat according to the present embodiment is applied. 2 is an enlarged view of a center hinge portion of the seat back frame shown in FIG. 1 . FIG. FIG. 3 is a front view showing a bracket used in the center hinge portion shown in FIG. 2 . 4 is a cross-sectional view taken along line AA in FIG. 3. 4 is a cross-sectional view taken along line BB in FIG. 3. 3A is a front view showing residual strain when a large load is input to the bracket and seat back frame shown in FIG. 2, and FIG. 3B is a front view showing the state in which the bracket has been removed. FIG. 4 is a front view corresponding to FIG. 3 and shows a modification of the bracket shown in FIG. 3 . FIG. 4 is a front view of a comparative example, corresponding to FIG. 3 . FIG. 4 is a front view of a comparative example, corresponding to FIG. 3 . 10A is a front view showing residual strain when a large load is input to the bracket and seat back frame shown in FIG. 9, and FIG. 10B is a front view showing the state with the bracket removed.

The following describes a rear seat 10 as a vehicle seat according to an embodiment of the present invention, using the drawings. Note that the arrows FR, RH, and UP shown as appropriate in each figure indicate the forward, rightward, and upward directions of the rear seat 10, respectively. Furthermore, in this embodiment, the front-rear, left-right, top-bottom directions of the rear seat 10 coincide with the front-rear, left-right, top-bottom directions of the vehicle (automobile) in which the rear seat 10 is installed. Hereinafter, when the front-rear, left-right, top-bottom directions are used in the description, they refer to the front and back of the seat in the front-rear direction, the left and right of the seat in the left-right direction (seat width direction), and the top and bottom of the seat in the up-down direction.

<Configuration of vehicle seat>
First, the configuration of a rear seat to which the vehicle seat according to this embodiment is applied will be described.

Figure 1 shows a front view of the seatback frame 25, which indicates the framework of the seatback 11 of the rear seat 10. As shown in Figure 1, in this embodiment, the rear seat 10 is, for example, a second- or third-row seat, and is a two- or three-seater seat. The rear seat 10 is also divided into left and right halves, broadly divided into a right-side rear seat 12 located on the right side and a left-side rear seat 14 located on the left side. Note that the seatback frame 25 does not necessarily have to be divided into left and right halves.

The right rear seat 12 is equipped with a right seat cushion (not shown) that supports the thighs and waist of the seated occupant, and a right seatback 16 that is located at the rear end of the seat cushion and supports the upper body of the seated occupant. Similarly to the right rear seat 12, the left rear seat 14 is equipped with a left seat cushion (not shown) that supports the thighs and waist of the seated occupant, and a left seatback 18 that is located at the rear end of the seat cushion and supports the upper body of the seated occupant.

The right seat back 16 and the left seat back 18 are adjacent to each other in the left-right direction of the seat (vehicle width direction) and can rotate independently of each other around an axis along the seat width direction. In this embodiment, the dimensional ratio of the right seat back 16 to the left seat back 18 in the vehicle width direction is set to, for example, 60:40.

A left headrest 20 is connected to the upper end of the left seatback 18 so that it can be raised and lowered. A right headrest 22 is connected to the upper right end of the right seatback 16 so that it can be raised and lowered, and a center headrest 24, located between the right headrest 22 and the left headrest 20, is connected to the upper left end of the right seatback 16 so that it can be raised and lowered. Note that in the case of a two-seater seat, the center headrest 24 is not necessary.

(seat back)
Here, we will explain the configuration of the right seatback 16. The left seatback 18 has substantially the same configuration as the right seatback 16, so the same components as those in the right seatback 16 are denoted by the same reference numerals and will not be explained further.

The right-side seat back 16 includes a frame-shaped seat back frame 26 that forms the outer edge of the right-side seat back 16, and a plate-shaped seat back panel 28 attached to the back surface of the seat back frame 26. The seat back panel 28 is formed, for example, by press-molding a metal plate, and is attached to the back surface of the seat back frame 26 by welding or other means.

(seat back frame)
In this embodiment, the seatback frame 26 includes an upper frame 26A, a lower frame (horizontal member, lower skeleton member) 26B, an outer side frame 26C, and an inner side frame (vertical member, inner skeleton member) 26D. Note that the right-side seatback 16 in this embodiment is further provided with a reinforcement 26E between the outer side frame 26C and the inner side frame 26D.

The outer side frame 26C, reinforcement 26E, and inner side frame 26D are welded to the upper frame 26A and lower frame 26B, respectively. As a result, the upper frame 26A, lower frame 26B, outer side frame 26C, reinforcement 26E, and inner side frame 26D are integrated to form the seatback frame 26.

The upper frame 26A is provided at the upper end of the seatback frame 26 along the seat width direction, and a pair of retaining members 30, 32 that hold the right headrest 22 and center headrest 24, which support the head of a seated occupant, are attached to the upper frame 26A.

The lower frame 26B is provided at the lower end of the seatback frame 26 along the seat width direction, and a reclining hinge portion 34 is attached to the lower frame 26B, which rotates the right seatback 16 relative to the seat cushion (not shown).

The outer side frame 26C is provided along the seat height direction on the outer side of the seatback frame 26 in the vehicle width direction, and a locking bracket 36 (not shown) is attached to the outer side frame 26C to secure it to the vehicle body.

The inner side frame 26D is provided on the seat back frame 26, inside the vehicle width direction, along the seat height direction. A center hinge portion 38 (described below) that allows the right seat back 16 to fold down is provided on the inner side frame 26D side.

In this embodiment, the upper frame 26A, lower frame 26B, outer side frame 26C, inner side frame 26D, and reinforcement 26E are each made of aluminum alloy to reduce the weight of the seatback frame and for cost reasons. These frames use hollow square pipes, and when cut along the width direction perpendicular to the longitudinal direction of each frame, a closed cross section is formed.

The shape of the seatback frame is not limited to a hollow structure (rectangular prism structure); a cylindrical or solid structure may be used as long as the required strength and configuration of the seatback frame are ensured. However, if the seatback frame is cylindrical or columnar, the connecting piece 44 of the bracket 40 (described below) is formed in an arc shape to fit the outer periphery of the seatback frame, although this is not shown in the figures.

In addition, the upper frame 26A and lower frame 26B require higher rigidity than the outer side frame 26C, inner side frame 26D, and reinforcement 26E. For this reason, the width dimensions of the square pipes in the upper frame 26A and lower frame 26B are set to be larger than those of the outer side frame 26C, inner side frame 26D, and reinforcement 26E.

In this embodiment, for example, the lower frame 26B requires higher rigidity than the outer side frame 26C, which in turn requires higher rigidity than the upper frame 26A. Furthermore, the upper frame 26A requires higher rigidity than the inner side frame 26D and the reinforcement 26E. For this reason, the width dimensions of the square pipes are set so that the lower frame 26B is the largest, followed by the outer side frame 26C and then the upper frame 26A, and are smallest for the inner side frame 26D and the reinforcement 26E.

The material for the seatback frame is not limited to aluminum alloy; as long as it can provide the strength and rigidity required for the seatback frame, it goes without saying that non-ferrous metals other than aluminum alloys may also be used.

(Center hinge part)
Here, the center hinge portion 38 will be described.

The center hinge portion 38 is equipped with a hinge bracket (bracket) 40 that is fixed to the vehicle body (not shown) and joined to the seatback frame 26. The hinge bracket 40 is made of the same material as the seatback frame 26, which in this embodiment is an aluminum alloy.

As shown in FIG. 3, the hinge bracket 40 has a rectangular plate shape when viewed from the front, and includes a fixed piece 42 that is fixed to the vehicle body (not shown), and a joining piece 44 that is joined to the seat back frame 26. The fixed piece 42 and joining piece 44 are arranged along the vehicle width direction, and as shown in FIG. 1, the joining piece 44 is provided on the outside of the fixed piece 42 in the vehicle width direction.

As shown in Figures 3 and 4, an inclined surface 46 is provided between the fixed piece 42 and the connecting piece 44. The inclined surface 46 slopes toward the rear of the vehicle as it extends from the connecting piece 44 to the fixed piece 42, and has an inflection point to smoothly connect the connecting piece 44 and the fixed piece 42. This inclined surface 46 positions the fixed piece 42 rearward of the connecting piece 44.

Furthermore, as shown in FIG. 3, the fixing piece 42 has two circular fixing holes 48, 50 arranged in the vertical direction. As shown in FIG. 2, a bolt 52 can be inserted into each of these fixing holes 48, 50, and the fixing piece 42 is fastened (fixed) to a bracket fixed to the vehicle body (not shown) via the bolt 52 and nut 54 (fixing portion 55).

As shown in Figures 3 and 5, a protrusion 56 is provided between the fixing holes 48 and 50, extending in an arc shape toward the front of the vehicle and in the vertical direction of the vehicle. Furthermore, a flange 58 is formed on the inner edge 42A of the fixing piece 42, located opposite the joining piece 44, and extends toward the front of the vehicle. By forming the protrusion 56 and flange 58 in this way, the rigidity of the fixing piece 42 itself can be improved compared to when it is simply formed in a flat plate shape.

On the other hand, as shown in FIG. 3, the joining piece 44 is formed so that its width dimension D1 along the vehicle width direction is larger than the width dimension D3 of the fixing piece 42, and it is formed so that it protrudes downward beyond the lower edge 42B of the fixing piece 42. Also, as shown in FIG. 4, the lower portion 44B of the joining piece 44 protrudes further toward the front of the vehicle than the upper portion 44A of the joining piece 44.

Specifically, between the upper portion 44A and the lower portion 44B of the joining piece 44, there is an inclined surface 60 that slopes toward the front of the vehicle as it moves from the upper portion 44A to the lower portion 44B, and has inflection points 60A and 60B, providing a smooth connection between the upper portion 44A and the lower portion 44B of the joining piece 44.

As mentioned above, the lower frame 26B is designed so that the width dimension of the square pipe is larger than that of the inner side frame 26D. Therefore, the front surface 26B1 of the lower frame 26B is located further forward of the vehicle than the front surface 26D1 of the inner side frame 26D. Because the inclined surface 60 is formed between the upper and lower portions 44A and 44B of the joint piece 44, the upper portion 44A of the joint piece 44 overlaps the front surface 26D1 of the inner side frame 26D in surface contact, and the lower portion 44B of the joint piece 44 overlaps the front surface 26B1 of the lower frame 26B in surface contact.

As shown in Figure 3, the flange portion 58 formed on the fixing piece 42 is formed continuously on the lower edge portion 44B1 of the joining piece 44. This improves the rigidity of the joining piece 44 itself. The lower portion 44B of the joining piece 44 is also formed to protrude outward in the vehicle width direction more than the upper portion 44A of the joining piece 44.

On the other hand, two through holes 62, 64 are formed in the upper part 44A of the joining piece 44, arranged in the vertical direction. Furthermore, a through hole 66 is formed in the lower part of the joining piece 44. The through holes 62, 64 are roughly rectangular with the longitudinal direction being the vertical direction, and the through hole 66 is roughly pentagonal, like a triangle with the opposing apexes cut off.

In this embodiment, as shown in FIG. 2, plug welding is performed through the through holes 62, 64, and 66. This plug welding joins (welds) the joint piece 44 of the hinge bracket 40 to the joint (corner) 68 where the inner side frame 26D and the lower frame 26B are integrated by welding in the seatback frame 26 (welds 70, 72, and 74).

The welds 70, 72, and 74 are welded in a roughly U-shape, opening outward in the vehicle width direction, following the shape of the through holes 62, 64, and 66. In other words, the welds 70, 72, and 74 are formed continuously, including opposing portions of the through holes 62, 64, and 66 (for example, the opposing portions of weld 70 are 70A and 70B). In addition to plug welding, fillet welding (weld 76) is also performed at the joint 68.

Here, the width dimension D1 of the joining piece 44 is set to be larger than the width dimension D2 of the inner side frame 26D, and the vertical dimension H1 of the lower part 44B of the joining piece 44 is set to be larger than the width dimension (vertical dimension) H2 of the lower frame 26B.

For this reason, with the joint piece 44 of the hinge bracket 40 welded to the joint 68 between the inner side frame 26D and the lower frame 26B, the hinge bracket 40 overlaps the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B at the joint 68 so that the outlines of the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B are hidden.

<Functions and Effects of Vehicle Seat>
Next, the operation and effects of the rear seat 10 to which the vehicle seat according to this embodiment is applied will be described.

In this embodiment, as shown in FIG. 1, the seatback frame 26 is composed of an upper frame 26A, a lower frame 26B, an outer side frame 26C, an inner side frame 26D, and a reinforcement 26E. At the joint 68 between the inner side frame 26D and the lower frame 26B, the hinge bracket 40 overlaps the front face 26D1 of the inner side frame 26D and the front face 26B1 of the lower frame 26B, as described above, so as to hide the outlines of the front face 26D1 of the inner side frame 26D and the front face 26B1 of the lower frame 26B.

As a comparative example, Figures 8 and 9 show a case where the hinge bracket 100 only partially covers the outer shape of the seat back frame 104 at the joint 106 between the hinge brackets 100, 102 and the seat back frame 104.

Specifically, as shown in FIG. 8, a portion of the front surface 104A1 of the lower frame 104A protrudes (is exposed) from the lower edge 100A of the hinge bracket 100. Also, as shown in FIG. 9, a portion of the front surface 104B1 of the inner side frame 104B protrudes (is exposed) from the outer edge 102A of the hinge bracket 102.

In other words, in the comparative example, as shown in FIG. 8, at the joint 106, the front surface 104A1 of the lower frame 104A has both an area where the hinge bracket 100 overlaps (is hidden) and an area where the hinge bracket 100 does not overlap (is exposed). Similar to the lower frame 104A, as shown in FIG. 9, at the joint 106, the front surface 104B1 of the inner side frame 104B has both an area where the hinge bracket 102 overlaps and an area where the hinge bracket 102 does not overlap.

For example, when a large load is transmitted to the seat back frame 104 via the hinge bracket 102, the large load is transmitted via the hinge bracket 102 to the area where the hinge bracket 102 overlaps on the front surface 104B1 of the seat back frame 104 at the joint 106, but the large load is not directly transmitted to the area where the hinge brackets 100, 102 do not overlap.

For example, Figures 10(A) and (B) show the residual strain in the hinge bracket 102 and seat back frame 104 when a large load is transmitted to the seat back frame 104 via the hinge bracket 102, with darker dots indicating greater strain. Note that Figure 10(A) shows the state in which the hinge bracket 102 is joined to the seat back frame 104, while Figure 10(B) shows the state in which the hinge bracket 102 has been removed. Figures 6(A) and (B), described below, are similar to Figures 10(A) and (B).

As shown in Figures 10(A) and (B), when a large load is transmitted to the seatback frame 104 via the hinge bracket 102, stress is concentrated at the boundary Q on the front surface 104B1 of the seatback frame 104 between the area where the large load is transmitted and the area where it is not transmitted. Therefore, in the comparative example, although not shown, there is a possibility that the seatback frame 104 may deform significantly starting from the boundary Q.

In contrast, in this embodiment, as shown in FIG. 2, at the joint 68 between the hinge bracket 40 and the seatback frame 26, the hinge bracket 40 overlaps the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B so that the outlines of these surfaces are hidden.

Specifically, in this embodiment, the hinge bracket 40 is configured to include a fixed piece 42 and a connecting piece 44. The fixed piece 42 is fixed to the vehicle body, and the connecting piece 44 is positioned outside the fixed piece 42 in the vehicle width direction, connected to the fixed piece 42, and joined to the seat back frame 26.

The joint piece 44 of the hinge bracket 40 is joined to the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B, so that the joint piece 44 overlaps the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B, hiding the outer shapes of the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B.

As a result, in this embodiment, the contact area between the joint piece 44 of the hinge bracket 40 and the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B can be increased compared to the comparative example.

For this reason, in this embodiment, when a large load is transmitted to the seatback frame 26 via the hinge bracket 40, as shown in FIG. 6(A), the large load is transmitted at the joint 68 across substantially the entire front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B, with which the hinge bracket 40 overlaps.

In this way, by increasing the contact area between the seatback frame 26 and the hinge bracket 40, the large load transmitted to the front surface 26D1 of the inner side frame 26D and the front surface 26B1 of the lower frame 26B can be dispersed. As a result, as shown in FIG. 6(B), stress concentration in the seatback frame 26 can be suppressed, making it possible to suppress large deformation of the seatback frame 26.

Furthermore, in this embodiment, as shown in FIG. 2, the hinge bracket 40 is configured to include through holes 62, 64, 66 and welds 70, 72, 74. Roughly rectangular through holes 62, 64, 66 are formed in the joint piece 44 of the hinge bracket 40, and the joint piece 44 is welded to the seat back frame 26 through the through holes 62, 64, 66 and via the welds 70, 72, 74.

As mentioned above, in the hinge bracket 40, the connecting piece 44 is positioned outside the fixed piece 42, which is fixed to the vehicle body, in the vehicle width direction. Therefore, for example, when a large load is input to the seatback frame 26 due to a vehicle collision, the large load is transmitted from the vehicle body via the fixed portion 55 of the fixed piece 42 to the connecting piece 44, and the large load is then input (transmitted) to the seatback frame 26 via the connecting piece 44.

In this embodiment, through holes 62, 64, and 66 are provided in the joint piece 44 of the hinge bracket 40, and welds 70, 72, and 74 are provided in the through holes 62, 64, and 66, thereby joining (welding) the hinge bracket 40 to the seat back frame 26.

On the other hand, as a comparative example, as shown in Figure 9, welds 108, 110, 112, and 114 may be provided on the outer edge 102A of the hinge bracket 102, and the hinge bracket 102 may be joined to the seat back frame 104 via these welds 108, 110, 112, and 114.

In contrast, in this embodiment, as shown in FIG. 2, through holes 62, 64, and 66 are formed in the joint piece 44 of the hinge bracket 40, and the joint piece 44 is welded to the seat back frame 26 via welds 70, 72, and 74 through the through holes 62, 64, and 66. Because the through holes 62, 64, and 66 are formed inward from the outer edge 40A of the hinge bracket 40, in this embodiment, the welds 70, 72, and 74 can be positioned closer to the fixing portion 55 than in the comparative example.

In this way, in this embodiment, by positioning the welded portions 70, 72, and 74 closer to the fixed portion 55, it is possible to reduce the moment generated in the hinge bracket 40 during a vehicle collision compared to the comparative example. As a result, in this embodiment, it is possible to reduce the strain generated in the seat back frame 26.

Note that plug welding is not necessarily required at the joint 68 between the hinge bracket 40 and the seat back frame 26; fillet welding is also acceptable. However, if fillet welding is used, it is not necessary to form through holes 62, 64, and 66 in the joint piece 44 of the hinge bracket 40.

In addition, in this embodiment, the lower portion 44B of the joining piece 44 is formed to protrude further outward in the vehicle width direction than the upper portion 44A of the joining piece 44. As a result, in this embodiment, the lower portion 44B of the joining piece 44 has a larger contact area with the seat back frame 26 than the upper portion 44A of the joining piece 44.

In this way, by increasing the contact area between the hinge bracket 40 and the seatback frame 26, it is possible to distribute the large load transmitted to the inner side frame 26D and lower frame 26B of the seatback frame 26 during a vehicle collision. This makes it possible to reduce the concentration of stress in the seatback frame 26 and prevent large deformation of the seatback frame 26.

In addition, in this embodiment, the through holes 62, 64, 66 are generally rectangular, and the welded portions 70, 72, 74 are generally U-shaped, with the opening on the outer side in the vehicle width direction, following the shape of the through holes 62, 64, 66, i.e., so-called open shapes, and are formed continuously, including the opposing portions of the through holes 62, 64, 66.

As a result, in this embodiment, the weld length can be made longer than in a comparative example (not shown) in which a weld is provided only in a portion of the through hole (not including the opposing portion of the through hole).

Therefore, in this embodiment, compared to the comparative example, the joint strength between the hinge bracket 40 and the seatback frame 26 can be improved, and the welding area between the hinge bracket 40 and the seatback frame 26 can be increased, making it possible to distribute the load transmitted from the hinge bracket 40 to the seatback frame 26 in the event of a vehicle collision.

As shown in Figure 7, the through holes 62, 64, 66 may of course be closed, as shown by welds 78, 80, 82. Depending on the size of the through holes 62, 64, 66, the through holes 62, 64, 66 may be closed by welds 78, 80, 82.

In this way, by forming the welds 78, 80, and 82 in a closed shape, the weld length can be made even longer than when the welds are open, as in the case of the welds 70, 72, and 74 shown in Figure 2. This further improves the joint strength between the hinge bracket 40 and the seat back frame 26.

In addition, by increasing the weld length, the weld area between the hinge bracket 40 and the seat back frame 26 can be further increased, making it possible to further distribute the load transmitted from the hinge bracket 40 to the seat back frame 26 in the event of a vehicle collision.

In this embodiment, as shown in FIG. 1, the hinge bracket 40 used in the center hinge portion 38 has been described, but it can also be applied to a bracket joined to the seatback frame 26. Therefore, it is not necessarily limited to the hinge bracket 40. For example, it may also be applied to a locking bracket 36 for fixing to the vehicle body. Furthermore, the seatback frame 25 does not necessarily have to be divided into left and right halves.

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

10 Rear seat (vehicle seat)
11 Seat back 12 Right rear seat (vehicle seat)
14 Left rear seat (vehicle seat)
16 Right seat back (seat back)
18. Left seat back (seat back)
25 Seat back frame 26 Seat back frame 26B1 Front surface 26B Lower frame (seat back frame, horizontal member, lower frame member)
26D Inner side frame (seat back frame, vertical member, inner framework member)
26D1 Front 40 Hinge bracket (bracket)
42 Fixing piece (bracket)
44 Joint piece (bracket)
44A Upper part (joint piece)
44B Lower part (joint piece)
62 Through hole 64 Through hole 66 Through hole 68 Joint part (corner part)
70 Welded portion 72 Welded portion 74 Welded portion 78 Welded portion 80 Welded portion 82 Welded portion

Claims (6)

a seat back frame formed in a frame shape and forming a framework of the seat back that supports the upper body of a seated occupant;
a bracket that is fixed to the vehicle body and is joined to the front or rear surface of the vertical member and the horizontal member that intersect at the corner of the seat back frame in a state where the bracket overlaps the front or rear surface in the vehicle fore-and-aft direction so as to hide the outer shape of the front or rear surface;
Equipped with
The bracket is
a fixing piece fixed to the vehicle body side;
a joining piece connected to the fixing piece, arranged on the outer side of the seat back frame in the vehicle width direction, and joined to the seat back frame;
a through hole formed in the joining piece;
a welded portion welded to the seat back frame through the through hole;
The invention comprises:
The through holes are provided at a plurality of positions along the extending direction of the vertical member,
Furthermore, the through holes are also provided at positions that overlap with the horizontal member, and the number of through holes provided on the vertical member side is greater than the number of through holes provided on the horizontal member side . 2. The vehicle seat according to claim 1, wherein the through-holes provided on the lateral member side have a larger area than the through-holes provided on the vertical member side. The vehicle seat according to claim 1 , wherein the through-holes provided on the lateral member side are provided outward in the seat width direction than the through-holes provided on the vertical member side. The vehicle seat according to claim 1 , wherein the welded portion is formed continuously including opposing portions of the through hole . The vehicle seat according to claim 4 , wherein the welded portion has a closed shape . The seat back frame is divided into two in the vehicle width direction, and
an inner framework member having a rectangular cylindrical shape and provided along the seat height direction;
a lower framework member having a rectangular cylindrical shape, connected to the inner framework member, and provided along the seat width direction;
and
The joining piece joined to the seat back frame in the bracket is
an upper portion that hides a front or rear side of the inner framework member in the vehicle longitudinal direction;
a lower portion formed below the upper portion in the vehicle up-down direction and formed to protrude outward in the vehicle width direction relative to the upper portion, and hiding a front or rear side of the lower framework member in the vehicle longitudinal direction;
The vehicle seat according to any one of claims 1 to 5, comprising :