JP7421055B2 - seat back frame - Google Patents

Description

The present invention relates to a seat back frame for a vehicle seat.

Conventionally, it is known that a seat back frame for a vehicle seat is configured using a panel material made of a substantially rectangular metal plate and a frame material formed in a frame shape and joined to the panel material. (For example, see Patent Document 1, etc.).
Furthermore, as vehicles become lighter in weight in order to improve fuel efficiency and the like, vehicle seats are also required to be lighter.

Patent No. 6245294

By the way, in the seat back panel as described in Patent Document 1, the frame material made of metal pipes such as steel is arranged along the outer peripheral edge of the panel material, so the circular shape of the pipe is The contact area between the tubular shape and the flat panel material is small, and the rigidity of the entire seat back frame may not be sufficient.
In addition, if a pipe is used for the frame material of the seat back frame, the seat back frame becomes heavy, and the seat back panel described does not connect the side frame and lower frame, making it impossible to reduce the weight of the vehicle seat. There are cases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seat back panel for a vehicle seat that can maintain and improve rigidity while reducing weight.

In order to solve the above problems, the invention according to claim 1,
A seat back frame comprising a panel material and a frame material joined to at least an outer peripheral edge of the panel material,
The frame material has an open cross-sectional shape with a hat-shaped cross section having a flat part, and a pair of side wall parts rising from the flat part toward the panel material become wider toward the panel material. and a step is formed on each of the side walls, and the height of the step formed on one of the pair of side walls from the panel material is equal to the height of the step formed on one of the pair of side walls. The height of the step formed on the side wall portion is different from the panel material .

The invention according to claim 2 provides a seat back frame according to claim 1, in which a lower frame member, which is the frame member joined to a lower end portion of the panel member and extends in the left-right direction; The present invention is characterized in that it includes a connecting bracket that connects the side frame member, which is the frame member, that is joined to the end portion and extends in the vertical direction.

The invention according to claim 3 is the seat back frame according to claim 2 , in which each end portion of the connection bracket that contacts the lower frame material and the side frame material is arranged in a direction away from the panel material. It is characterized in that it is a protruding convex portion, and a central portion is a concave portion depressed toward the panel material side.

According to a fourth aspect of the invention, in the seat back frame according to the third aspect, the recessed portion of the connection bracket is formed to be recessed in an oval shape.

The invention according to claim 5 is the seat back frame according to any one of claims 2 to 4 , wherein the connection bracket protrudes toward the panel material at an end portion, and It is characterized in that a claw portion is formed to be joined to.

The invention according to claim 6 is the seat back frame according to any one of claims 1 to 5 , in which the upper frame material joined to the upper end portion of the panel material and extending in the left-right direction is A portion that is joined to the panel material and intersects with the frame material extending in the vertical direction is curved along the outer shape of the frame material extending in the vertical direction.

The invention according to claim 7 provides the seat back frame according to claim 6 , wherein the upper frame material is arranged so as to straddle at least one of the frame materials extending in the vertical direction. Features.

According to an eighth aspect of the invention, in the seat back frame according to the seventh aspect, the upper frame material has a bulging portion that bulges in a direction away from the panel material.

The invention according to claim 9 is the seat back frame according to claim 7 or 8 , wherein a headrest is attached to the upper frame material, and the headrest has an opening at least on a lower surface side. It is characterized by

The invention according to claim 10 is the seat back frame according to any one of claims 1 to 9 , wherein beads are formed in a plurality of geometric shapes in the panel material. It is characterized by

The invention according to claim 11 is characterized in that, in the seat back frame according to claim 10 , vertically adjacent geometric shapes among the plurality of geometric shapes are vertically symmetrical.

The invention according to claim 12 is characterized in that, in the seat back frame according to claim 10 or 11 , a hole is formed in a central portion of the geometric shape of the bead.

The invention according to claim 13 is the seat back frame according to any one of claims 10 to 12 ,
The panel material is divided into a plurality of sections by the frame material that is joined to the panel material and extends in the vertical direction,
The plurality of geometrical shapes of the beads in each of the sections are arranged at positions vertically shifted from each other in the adjacent sections.

According to the invention described in claim 1, the side wall portions of the frame material having a hat-shaped cross section are formed so as to become wider toward the panel material, and steps are formed on each side wall portion, thereby making the frame material lightweight. However, sufficient rigidity can be obtained.
Therefore, it is possible to reduce the weight of a seat back frame using such a frame material and a vehicle seat constructed using the same while maintaining and improving the rigidity.

According to the invention described in claim 2 , the rigidity of the corner portion of the seat back frame, particularly the rigidity against torsion, can be improved.

According to the third aspect of the invention, the lower frame material and the side frame material are sandwiched between the convex portion of the connection bracket and the panel material, and the lower frame material and the side frame material are securely connected by the connection bracket. It becomes possible to do so. Therefore, it is possible to further improve the rigidity of the corner portions of the seat back frame.

According to the fourth aspect of the invention, the formability of the connection bracket is improved, and the connection bracket can be easily welded to the panel material.

According to the invention set forth in claim 5 , it becomes possible to accurately and easily join the connecting bracket to the panel material.

According to the invention described in claim 6 , it is possible to cross the upper frame material and other frame materials in a flat state without bulging the intersecting portion forward, and to firmly connect them. becomes possible. Therefore, it becomes possible to further improve the rigidity of the seat back frame.

According to the invention set forth in claim 7 , the upper frame material is not divided into two pieces and placed on the left and right sides of the frame material, but one upper frame material is placed so as to straddle the frame materials. Compared to the case where the upper frame material is divided into two pieces, since the upper frame material is composed of one piece, it is possible to improve the rigidity, and it is possible to further improve the rigidity of the seat back frame.

According to the invention set forth in claim 8 , by providing the upper frame material with a bulging portion that bulges in a direction away from the panel material, it is possible to further improve the rigidity of the upper frame material.

According to the invention described in claim 9 , since the headrest has an opening at least on the lower surface side, it is possible to reduce the weight of the headrest, and it is possible to reduce the weight of the seat back frame. . Furthermore, since the headrest can be formed by press working, it can be formed more inexpensively and lightweight.

According to the tenth aspect of the present invention, by forming beads in the panel material, deformation of the panel material is less likely to occur, thereby increasing the rigidity of the panel material and making it possible to improve the rigidity of the seat back frame.

According to the invention set forth in claim 11 , it becomes possible to further improve the rigidity of the panel material, and it becomes possible to improve the rigidity of the seat back frame.

According to the invention set forth in claim 12 , it is possible to reduce the weight of the panel material while maintaining the rigidity of the panel material due to the beads, and it is possible to reduce the weight of the seat back frame.

According to the invention set forth in claim 13 , it becomes possible to further improve the rigidity of the panel material against twisting and bending, and it becomes possible to further improve the rigidity of the seat back frame.

It is a front view showing the composition of the seat back frame concerning this embodiment. FIG. 3 is a front view showing the configuration of a seat back frame in which beads are arranged at vertically shifted positions in each section. (A) is a diagram showing the configuration of the side frame material according to the present embodiment, and (B) is a sectional view taken along the line XX in (A). (A) is a diagram showing the configuration of the lower frame material and middle frame material according to the present embodiment, and (B) is a sectional view taken along YY in (A). (A) to (D) are cross-sectional views showing the configurations of Comparative Examples 1 to 4. It is a perspective view showing the composition of the connection bracket concerning this embodiment. FIG. 3 is a plan view of an upper frame material of a portion of the seat back frame that seats two people. It is a perspective view showing the state where a headrest pillar is made to contact the curved surface of a recess formed in the front of an upper frame material, and is attached. (A) It is a perspective view showing an example of composition of a headrest, and (B) is a figure which looked at the headrest of (A) from slightly below. (A) It is a figure showing the figure showing another example of composition of a headrest seen from slightly below, and (B) is a top view of the headrest of (A). FIG. 10(A) is a side view of the headrest of FIG. 10(A). (A) It is a perspective view of the example of a structure of a striker, and (B) is a sectional view of the attachment part of the striker of (A). (A) It is an exploded perspective view of the attachment structure of the striker of another example of composition, and (B) is a sectional view of the attachment part of the striker of (A). FIG. 7 is a perspective view showing still another configuration example of the striker, its mounting structure, and the like.

Embodiments of the present invention will be described below with reference to the drawings. However, although the embodiments described below have various limitations that are technically preferable for implementing the present invention, the technical scope of the present invention is not limited to the embodiments and illustrated examples below. do not have.

FIG. 1 is a front view showing the configuration of a seat back frame according to this embodiment. Although not shown, the seat back frame 10 constitutes a seat back of a vehicle seat provided inside a vehicle.
Although not shown, the seat back is constructed by disposing a cushion pad in front of the seat back frame 10 and covering the cushion pad with an outer skin. The seating area for a passenger seated on the vehicle seat is divided by providing unevenness on the cushion pad or stitching the outer skin.

In addition, although FIG. 1 shows a case where the vehicle seat is a rear seat for three people and the seat back is separated into a two-seat part and a one-seat part, in the following explanation, In some cases, the seat back is described as if it were not separated (that is, as if the panel material 20 described below is one panel material).
The present invention also applies to cases where the seat back is not separated into a two-seat portion and a one-seat portion, but is formed as a single three-seater (or two-seater) seat back. Applicable. It is also applied to the seat back frame of a one-person vehicle seat.

Further, in the following, directions will be explained based on directions (front and rear, left and right, up and down) when the traveling direction of the vehicle is set as the front.
In addition, in FIG. 1, the seat cushion, etc. in the center part of the seat back can swing forward around shaft members 50, 50 provided at the lower end, and can be used as an armrest when folded forward. A case in which it is configured to function is shown.

The seat back frame 10 includes a panel material 20 and a frame material 30 joined to the outer peripheral edge of the panel material 20 and the like.
The panel material 20 (also referred to as a pan frame) is a metal plate made of steel, aluminum alloy, or the like, and is formed into a rectangular shape when viewed from the front. This panel material 20 is arranged so that each side of the rectangle faces in the left-right direction and the up-down direction.

Further, as the frame material 30, an upper frame material 31 and a lower frame material 32 extending in the left-right direction are attached to the upper and lower ends of the front surface of the panel material 20, respectively, and are joined to the panel material 20. Side frame members 33, 33 extending in the vertical direction are attached to both left and right ends of the front surface of the panel member 20, respectively, and are joined to the panel member 20.
Furthermore, middle frame members 34 , 34 , 34 extending in the vertical direction are attached to the front surface of the panel member 20 between the side frames 33 , 33 , respectively, and are joined to the panel member 20 .
Note that these frame members 30 (31 to 34) will be explained in detail later. Further, these frame members 30 are joined to the panel members 20 by laser welding, and this point will also be explained later.

In this embodiment, the panel material 20 is divided into a plurality of sections 20A to 20C by a side frame material 33 and a middle frame 34, and each section 20A to 20C of the panel material 20 has a plurality of geometric beads 21. formed into a shape.
Note that the bead is a protruding (rail-shaped) structure configured to bulge forward from the front surface of the panel material 20.

If the metal plate that constitutes the panel material 20 is in a flat state, it is likely to be deformed such as curving or bending, but by forming the convex beads 21 by plastic working, the panel material 20 is less likely to deform. It becomes possible to increase the rigidity of the panel material 20.
In addition, in this embodiment, as shown in FIG. 1, by arranging the beads 21 so that their geometric shape (in this embodiment, the shape is mainly a combination of trapezoids) is symmetrical in the vertical direction, the panel The rigidity of the material 20 is further improved.

Further, in this embodiment, a hole 22 is formed in the central portion of the geometric shape of each bead 21, respectively.
With this configuration, it is possible to reduce the weight of the panel material 20 while maintaining the rigidity of the panel material 20 due to the beads 21.

On the other hand, in FIG. 1, the plurality of geometrical shapes of the beads 21 in each section 20A to 20B of the panel material 20 are located at the same position in the vertical direction in each adjacent section (sections 20A and 20B and sections 20B and 20C). A case in which they are arranged like this is shown, and it is also possible to configure them like this.
Further, as shown in FIG. 2, the plurality of geometric shapes of the beads 21 in each section 20A to 20B of the panel material 20 are vertically shifted from each other in each adjacent section (sections 20A and 20B and sections 20B and 20C). It is also possible to configure it so that it is placed in a different position.
With this configuration, it is possible to further improve the rigidity of the panel material 20 against twisting and bending.

Note that it is also possible to form an outer peripheral flange (not shown) by bending the outer peripheral edge of the panel material 20 forward or backward. With this configuration, it is possible to further improve the rigidity of the panel material 20.
Further, on the lower side of the central section 20B of the panel material 20, as described above, there is a shaft member 50 that serves as a pivot axis when the seat cushion or the like in the center portion of the seat back is pivoted forward to form an armrest. , 50 are attached.

In this embodiment, the frame material 30 (31 to 34) is made of metal such as steel or aluminum alloy.
The frame material 30 (32 to 34) has an open cross-sectional shape with a hat-shaped cross section having a flat portion, and a pair of side wall portions rising from the flat portion toward the panel material 20 are connected to the panel material 20. It is formed so that it becomes wider toward the end, and a step is formed on each side wall.
This will be explained in detail below.

In this embodiment, the side frame material 33 has an open cross-sectional shape with a hat-shaped cross section, as shown in FIGS. 3(A) and 3(B). It has a flat portion 33A and a pair of side wall portions 33B, 33B that stand up from the flat portion 33A toward the panel material 20, and the side wall portions 33B, 33B become wider toward the panel material 20. It is formed to be.
Steps 33C, 33C are formed on each side wall portion 33B, 33B of the side frame material 33, respectively. Further, flange portions 33D, 33D for joining the side frame material 33 to the panel material 20 are formed at the end portions of the respective side wall portions 33B, 33B, respectively.

Further, in this embodiment, the lower frame material 32 and the middle frame material 34 also have an open cross-sectional shape with a hat-shaped cross section, as shown in FIGS. 4(A) and 4(B). Although FIGS. 4A and 4B show the case of the middle frame material 34 as a representative example, the lower frame material 32 is also configured in the same manner.
A pair of side wall portions 34B, 34B rising from the flat portion 34A toward the panel material 20 are formed so as to become wider toward the panel material 20, and are formed with steps 34C, 34C, respectively. There is. Further, flange portions 34D, 34D are formed at the ends of each side wall portion 34B, 34B, respectively.

However, unlike the case of the side frame material 33, the middle frame material 34 (lower frame material 32) is configured such that the heights of the steps 34C and 34C from the panel material 20 are different from each other.
Note that the middle frame material 34 and the lower frame material 32 can also be configured so that the heights of the steps 34C and 34C from the panel material 20 are the same, similarly to the side frame material 33. Further, in the side frame material 33, it is also possible to configure the steps 33C and 33C so that the heights from the panel material 20 are different from each other, and an appropriate structure for the frame material 30 is appropriately selected.

Table I shows the results of a comparison between the case where the frame material 30 is configured as described above (Example) and the case where the frame material 30 is configured in other shapes (Comparative Examples 1 to 4).
In addition, as an example, a structure like the side frame material 33 shown in FIGS. 3(A) and (B) was used, and as comparative examples 1 to 4, the side frame material 33 shown in FIGS. 5(A) to (D) was used. The material having the cross-sectional shape shown is general cold rolled steel plate (SPCC). In addition, the torsional rigidity was measured by the second polar moment. Note that FIGS. 5(A) to 5(D) show cross-sectional shapes, and actual values of thickness etc. are not reflected.

As can be seen from the above results, the frame material 30 (Example) according to the present embodiment has a thinner plate thickness (0.6 mm) and a lighter weight than Comparative Examples 1 to 4 (0.189 kg). ), the same or better section modulus (strength against bending) and torsional rigidity than Comparative Examples 1 to 4 can be obtained. Note that similar good results can be obtained even if the frame material 30 is configured as shown in FIGS. 4(A) and 4(B).
The frame material 30 is then joined and attached to the panel material 20 by laser welding via the flange portion 33D (34D).

Therefore, the seatback frame 10 according to the present embodiment using the frame material 30 as described above can be made lightweight while maintaining or further improving the rigidity.
Further, a vehicle seat configured using such a seat back frame 10 can also be made lighter while maintaining and improving rigidity.

By the way, when joining the lower frame material 32 as described above to the lower end of the panel material 20 and joining the side frame materials 33 to the left and right ends of the panel material 20, they are attached to the lower left and right corners of the panel material 20. If the corners of the seat back frame 10 are configured to be connected reliably at the corners, the rigidity of the corner portions of the seat back frame 10, particularly the rigidity against torsion, can be further improved.
Therefore, as shown in FIG. 1, it is possible to provide a configuration in which connection brackets 40 for connecting the lower frame material 32 and the side frame materials 33 are provided at the left and right corners of the lower side of the panel material 20.

Note that the connection bracket 40 is used not only to connect the lower frame material 32 and the side frame material 33, but also to connect the lower frame material 32 and the middle frame material 34, as shown as 40A in FIG. It is also possible to provide it in parts.
Further, it is also possible to configure the connecting bracket 40 to be provided at a portion where the upper frame member 31 and the side frame member 33 or the middle frame member 34 are connected.

The connecting bracket 40 is made of metal, and as shown in FIG. 6, it has a convex portion 41 that protrudes forward (that is, in the direction away from the panel material 20; the same applies hereinafter) at either the left or right (left side in FIG. 6) end portion. A convex portion 42 that protrudes forward is provided at the upper end portion.
Further, the connecting bracket 40 has a central portion formed as a recessed portion 43 that is recessed toward the panel material 20 side (that is, toward the rear). In this embodiment, the recessed portion 43 of the connection bracket 40 is formed in an oval shape.
Furthermore, a claw portion 44 that protrudes toward the panel material 20 is formed at an end portion of the connection bracket 40.

Positioning pins (not shown) are provided at the corners of the panel material 20, and these pins are inserted into positioning holes 45 provided in the recesses 43 of the connecting bracket 40. When the back side of the concave portion 43 is brought into contact with the panel material 20, the pin and the hole 45 are engaged, and the connecting bracket 40 is positioned with respect to the panel material 20.
Then, when the back side of the concave portion 43 of the connecting bracket 40 is brought into contact with the panel material 20, the convex portion 41 of the connecting bracket 40 comes into contact with the lower frame material 32, and as shown in FIG. The lower frame member 32 is sandwiched between the lower frame member 20 and the lower frame member 32. Further, the convex portion 42 of the connection bracket 40 comes into contact with the side frame material 33, and the side frame material 33 is sandwiched between the convex portion 42 and the panel material 20.
Further, when the back side of the recess 43 of the connection bracket 40 is brought into contact with the panel material 20, the claw portion 44 of the connection bracket 40 is brought into contact with the panel material 20.

Therefore, by joining the concave portions 43 and claw portions 44 of the connecting bracket 40 to the panel material 20 by laser welding, the connecting bracket 40 is joined to the panel material 20, and the convex portions 41 and 42 of the connecting bracket 40 are joined to the panel material 20. Since the lower frame material 32 and the side frame material 33 are sandwiched between the lower frame material 32 and the side frame material 33, it becomes possible to reliably connect the lower frame material 32 and the side frame material 33 with the connection bracket 40.

Further, since the lower frame material 32 and the side frame material 33 are reliably connected at the corner of the panel material 20, it is possible to further improve the rigidity of the corner of the seatback frame 10, especially the rigidity against torsion. .
Note that by forming the concave portion 43 of the connection bracket 40 in an oval shape as in this embodiment, the formability of the connection bracket 40 is improved, and the connection bracket 40 can be easily laser welded to the panel material 20. It becomes possible to do so.

On the other hand, in this embodiment, the upper frame material 31 has a U-shaped cross section with a flange portion as shown in FIG. is formed.
However, the upper frame material 31 may also be configured as shown in FIGS. 3(A), (B) and FIGS. 4(A), (B) like the lower frame 32, side frame 33, middle frame 34, etc. is also possible.

The upper frame material 31 is made of metal such as steel or aluminum alloy, and is configured as shown in FIG. 7 in this embodiment.
FIG. 7 is a plan view of the upper frame material 31 of the two-seater portion of the seat back frame 10.
This will be explained in detail below.

As shown in FIG. 1, the upper frame material 31 intersects with the side frame material 33 and the middle frame material 34 at the upper end of the front surface of the panel material 20.
Therefore, the upper frame material 31 is configured such that portions A to C that intersect with the side frame materials 33 and the middle frame materials 34 are curved forward along the outer shapes of the side frame materials 33 and the middle frame materials 34. .
In FIG. 7, the symbol A represents a portion where the upper frame material 31 and the side frame material 33 intersect, and the symbols B and C represent the portions where the upper frame material 31 and the middle frame material 34 intersect.

With this configuration, it becomes possible to intersect the upper frame material 31, the side frame material 33, and the middle frame material 34 in a flat state without causing the intersecting portions A to C to swell forward.
Furthermore, since the upper frame material 31 is curved along the outer shapes of the side frame materials 33 and the middle frame materials 34, the upper frame materials 31 and the side frame materials 33 and the middle frame materials 34 cannot be joined by laser bonding or the like. This makes it possible to firmly connect them, thereby making it possible to further improve the rigidity of the seat back frame 10.

In addition, in the part indicated by the symbol B, the upper frame material 31 is not divided into two parts and placed on the left and right sides of the middle frame material 34, but one upper frame material 31 is arranged so as to straddle the middle frame material 34. (See Figures 1 and 7).
With this configuration, compared to the case where the upper frame material 31 is divided into two pieces, since the upper frame material 31 is composed of one piece, it is possible to improve the rigidity, and the rigidity of the seat back frame 10 is further improved. It becomes possible to do so.

Further, as shown in FIG. 1, a headrest pillar holding portion 51 for holding a headrest pillar of a headrest (not shown) may be attached to the upper frame material 31.
At that time, as shown in FIG. 7, the part D of the upper frame material 31 to which the headrest pillar holding part 51 etc. are attached is bulged out forward, and the headrest pillar holding part 51 is attached to the bulged part D. It becomes possible to attach the headrest pillar holding portion 51 and the like to the frame material 31 easily and accurately. Further, by providing the bulging portion D, it is possible to further improve the rigidity of the upper frame material 31.

Further, as shown in FIG. 1, the headrest pillar 52 may be directly attached to the upper frame material 31 in some cases.
In this case, for example, as shown in FIG. 7, the front surface of the upper frame material 31 is depressed to form concave curved surfaces E, E, and the headrest pillar 52 is brought into contact with the concave curved surfaces E, E as shown in FIG. It is possible to configure it so that it can be attached by laser welding or the like.

With this configuration, compared to the case where the headrest pillar 52 is attached to the flat upper frame material 31 (that is, the upper frame material 31 in which the concave curved surfaces E and E are not formed), the upper frame material 31 and the headrest pillar 52 are The contact area becomes larger.
Therefore, the headrest pillar 52 can be reliably attached to the upper frame material 31.

Note that the case where the headrest pillar holding part 51 and the headrest pillar 52 are attached to the upper frame material 31 has been described above, but for example, as shown in FIGS. 60 can also be configured to be directly attached.
In this case, the headrest 60 can be formed into a box shape in which the front surface 61, the top surface 62, the side surfaces 63, etc. are integrally formed by press working, etc., using a metal plate such as steel or aluminum alloy. It is possible to provide a configuration in which a mounting portion 64 for attaching to the panel material 20 is provided at the rear side of the left and right side surfaces 63, and mounting portions 65 for attaching to the upper frame material 31 are provided on the rear sides of the left and right side surfaces 63, respectively.

Further, as shown in FIGS. 9A and 9B, for example, if the headrest 60 is configured to have a hole 66 on the front surface 61 or the like or an opening 67 on the bottom side, the weight of the headrest 60 can be reduced. This makes it possible to reduce the weight of the seat back frame 10. Furthermore, since the headrest 60 can be formed by press working, it can be formed inexpensively and lightweight.

It is also possible to configure the headrest 60 as shown in FIGS. 10(A) and 10(B) and FIG. 11. FIG. 10(A) is a view of a configuration example of this headrest 60 viewed from slightly below, and FIGS. 10(B) and 11 are a plan view and a side view of the configuration example of this headrest 60.
Also in this configuration example of the headrest 60, an opening 67 is provided on the lower surface side. A flange 68 extending inward is formed at the lower end portions of the front surface 61 and the left and right side surfaces 63. By forming the flanges 68 facing inward at the lower ends of the front surface 61 and left and right side surfaces 63 of the headrest 60 in this manner, the rigidity of the headrest 60 can be improved.

Further, in this configuration example, cutouts 69 are formed in the headrest 60 from the front surface 61 to the flange 68 and from the side surface 63 to the flange 68, respectively.
In this way, by providing the notch 69 from the front surface 61 and side surface 63 of the headrest 60 to the flange 68, it is possible to prevent wrinkles from forming in the flange 68 portion when bending the headrest 60 to form the flange 68. It becomes possible to do so. Note that although FIG. 10A and the like show the case where the notch 69 is provided on both the front surface 61 and the side surface 63 of the headrest 60, it is possible to provide the notch 69 only on the front surface 61 or only on the side surface 63 of the headrest 60. It is also possible to provide one. Further, the number of notches 69 provided on the front surface 61 and the side surfaces 63 can be determined as appropriate.

Further, as shown in FIG. 10(B) and FIG. 11, it is also possible to form a bead 71 in the connecting portion 70 between the upper surface 62 of the headrest 60 and the attachment portion 64 to the panel material 20. Note that, as shown in FIG. 11, the connecting portion 70 is formed so as to draw an arc forward and upward from the attachment portion 64, and is continuous with the upper surface 62 of the headrest 60.
Then, by forming beads 71 on the connecting portion 70 by, for example, bulging upward at several locations on the connecting portion 70, it is possible to improve the rigidity of the connecting portion 70.

Note that if the upper end of the bead 71 is higher than the upper end of the upper surface 62 of the headrest 60, the bead 71 may get in the way when installing the headrest 60, so as shown in FIG. It is desirable that the upper end is formed below the upper end of the upper surface 62 of the headrest 60.
Furthermore, an appropriate number of welding jig positioning holes 72 (see FIG. 10(B)) provided on the upper surface 62 of the headrest 60 are provided at appropriate positions on the upper surface 62.

By the way, although not shown in the drawings, the seatback frame 10 can be further reduced in weight by providing holes or openings in the portion of the upper frame material 31 to which the headrest 60 is attached.

Note that FIG. 1 shows a case where a seat belt attachment portion 53 for attaching a seat belt for an occupant seated in the center row of a vehicle seat is attached to the upper frame member 31.
The seatbelt attachment part 53 is attached to a predetermined attachment position F of the upper frame material 31 (see FIG. 7). It is also possible to provide a bulge or a recess.

On the other hand, in this embodiment, strikers 54 and 56 are attached to the seat back frame 10. The strikers 54 and 56 are used to maintain the posture of the seatback frame 10 and the seatback by engaging with a locking mechanism (not shown) provided on the vehicle body.
In this embodiment, the strikers 54 and 56 are attached to the seat back frame 10 in the following manner.

12(A) is a perspective view of the striker 54, and FIG. 12(B) is a sectional view of the attachment portion of the striker 54.
The striker 54 is formed by bending a single wire made of a round metal rod into a frame shape, and both ends 54A and 54B are pressed into a flat plate shape.

Further, as shown in FIG. 1 and FIG. 12(B), a notch 20a is formed in the panel material 20 so as to extend from the end of the panel material 20 to the lower side of the upper frame material 31. A reinforcing plate 55 is attached to the front side of the panel material 20 on the lower side of the upper frame material 31 so as to cover the notch 20a. Note that the reinforcing plate 55 may be formed integrally with the upper frame material 31 by, for example, extending the flange portion of the upper frame material 31 downward.
The lower end 54A of the striker 54 is joined to the front surface of the reinforcing plate 55 by laser welding, and the striker 54 is inserted into the opening of the reinforcing plate 55 or the notch 20a of the panel material 20, and It extends behind 20.

Further, the striker 54 has an upper portion routed forward from the rear of the panel material 20 through the notch 20a, and an upper end portion 54B joined to the front surface of the upper frame material 31 by laser welding. There is.
In this embodiment, the striker 54 is thus attached to the upper portion of the seat back frame 10 so as to protrude rearward.

Note that, as described later, the end portion 54B of the striker 54 is joined to the upper frame material 31 by laser welding from the back side of the upper frame material 31. At this time, when the upper frame material 31 is viewed from directly behind (that is, when viewed in the laser irradiation direction (direction from the rear to the front)), the joining position of the end 54B of the striker 54 and the upper frame material 31 is , overlaps the engaging portion 54C of the striker 54 with the locking mechanism (see FIGS. 12(A) and 12(B)), it becomes difficult to irradiate the joining position with the laser.
Therefore, in this embodiment, as shown in FIGS. 1 and 12(A), the upper end 54B of the striker 54 is not directed downward but diagonally downward. With this configuration, the joining position between the end 54B of the striker 54 and the upper frame material 31 does not overlap with the engaging part 54C of the striker 54 with the locking mechanism, and the laser can be easily and precisely directed to the joining position. It becomes possible to irradiate.

FIG. 13(A) is an exploded perspective view of the mounting structure of the striker 56, and FIG. 13(B) is a sectional view of the mounting portion of the striker 54.
Like the striker 54, the striker 56 is also formed by bending a single wire rod made of a round metal rod into a frame shape, and both ends 56A and 56B are pressed into a flat plate shape.

An opening 20b is provided in the upper part of the panel material 20.
Further, the upper frame material 31 has projecting portions 31b, 31b formed in which the flange portion 31a of the portion corresponding to the opening 20b of the panel material 20 projects in the vertical direction, respectively.

Then, as shown in FIG. 13(B), the lower end 56A and the upper end of the striker 56 are attached to the front surface of the overhanging parts 31b, 31b of the upper frame material 31 joined to the front surface of the panel material 20. 56B, respectively, and the striker 56 is inserted through the opening 20b of the panel material 20 and extends to the rear of the panel material 20.
In this embodiment, the striker 56 is thus attached to the upper portion of the seat back frame 10 so as to protrude rearward.

Note that the manner in which the strikers 54 and 56 are attached to the seat back frame 10 is not limited to the manner in which they are attached in this embodiment.
Furthermore, the structure of the strikers 54 and 56 is not limited to the structure of the present embodiment, in which a single wire made of a round metal bar is bent and both ends are pressed into a flat plate shape. Other structures are possible.

For example, as shown in FIG. 14, a striker 57 is formed by bending a frame-shaped flat plate with an opening in the center, and has a locking mechanism engaging portion 57A and a flange portion 57B for attachment to the panel material 20. It is possible to configure
Then, by providing a notch 20c in the panel material 20, fitting the striker 57 into the notch 20c of the panel material 20, and joining the back side of the flange portion 57B to the panel material 20, the striker 57 is attached to the panel material 20. It can be configured to be attached.

In this case, the upper frame member 31 (not shown) is attached from the front side of the panel member 20 to which the striker 57 is attached.
At that time, the upper frame material 31 is recessed by recessing the panel material 20 by the thickness of the flange portion 57B of the striker 57, or by recessing the upper frame material 31 by the thickness of the flange portion 57B of the striker 57. It is desirable that the striker 57 is configured to be reliably joined to the panel material 20 and to be properly attached to the panel material 20.

In this way, the striker 57 can be attached to the upper portion of the seat back frame 10 so as to protrude rearward.
With this configuration, the striker 57 can be formed by press working, so it can be formed at a lower cost and lighter weight than when the striker is formed from a metal round bar or the like.

By the way, in the seat back frame 10 according to the present embodiment, the thickness of the panel material 20 is reduced to the extent that rigidity etc. are not impaired in order to reduce the weight. It became possible to join each member.
Therefore, although not shown in the drawings, in the manufacturing process of the seat back frame 10 according to the present embodiment, each frame material 30 (upper frame material 31, lower frame material 31, etc.) is frame material 32, side frame material 33, middle frame material 34, etc.), connection bracket 40, necessary parts (headrest pillar holding part 51, headrest pillar 52 (or headrest 60), seat belt attachment part 53, striker 54, 56, etc.) are placed at each predetermined position using a jig (not shown), and the seat back frame 10 is manufactured by irradiating a laser from the back side of the panel material 20 to perform laser welding at predetermined welding points at once. It has become.

With this configuration, it becomes possible to quickly and accurately weld each member to the panel material 20 having a relatively large area.
At this time, it is also possible to use, for example, arc welding together with racer welding. In addition, when welding the headrest pillar holding part 51 to the upper frame material 31, if there is a panel material 20 behind it, it will be difficult to perform laser welding (or laser welding will not be possible). It is possible to configure the panel material 20 so that it does not get in the way of laser welding by appropriately providing the like.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention.
For example, holes, cutouts, etc. may be provided in the panel material 20, each frame material 30, the connecting bracket 40, necessary parts, etc. to reduce the weight, as long as the rigidity of the seat back frame 10 is not impaired. is also possible.

10 Seat back frame 20 Panel materials 20A to 20C Section 21 Bead 22 Hole 30 Frame material 31 Upper frame material 32 Lower frame material 33 Side frame material (side frame material, frame material extending in the vertical direction)
33A, 34A Plane portions 33B, 34B Side wall portions 33C, 34C Step 34 Middle frame material (frame material extending in the vertical direction)
40 Connection brackets 41, 42 Convex portion 43 Concave portion 44 Claw portion 60 Headrest 67 Opening portion D Swelling portion

Claims (13)

A seat back frame comprising a panel material and a frame material joined to at least an outer peripheral edge of the panel material,
The frame material has an open cross-sectional shape with a hat-shaped cross section having a flat part, and a pair of side wall parts rising from the flat part toward the panel material become wider toward the panel material. and a step is formed on each of the side wall portions,
The height of the step formed on one of the pair of side walls from the panel material is different from the height of the step formed on the other side wall from the panel material. Features a seat back frame. a lower frame material which is the frame material joined to the lower end of the panel material and extends in the left-right direction; and a side frame material which is the frame material joined to the left-right end of the panel material and extends in the vertical direction. The seat back frame according to claim 1, further comprising a connecting bracket that connects the seat back frame. The connecting bracket has a convex portion that protrudes in a direction away from the panel material at each end portion that contacts the lower frame material and the side frame material, respectively, and a recessed portion that is depressed toward the panel material in the center portion. The seat back frame according to claim 2 , characterized in that: The seat back frame according to claim 3 , wherein the recessed portion of the connection bracket is formed in an oval shape. According to any one of claims 2 to 4 , the connecting bracket has a claw portion formed at an end portion thereof to protrude toward the panel material and to be joined to the panel material. Seat back frame as described. The upper frame material, which is joined to the upper end of the panel material and extends in the left-right direction, has a portion that intersects with the frame material, which is joined to the panel material and extends in the vertical direction, to the frame material, which extends in the vertical direction. The seat back frame according to any one of claims 1 to 5 , wherein the seat back frame is curved along the outer shape of the material. The seat back frame according to claim 6 , wherein the upper frame material is arranged so as to straddle at least one of the frame materials extending in the vertical direction. The seat back frame according to claim 7 , wherein the upper frame material has a bulging portion that bulges in a direction away from the panel material. The seat back frame according to claim 7 or 8 , wherein a headrest is attached to the upper frame material, and the headrest has an opening at least on a lower surface side. The seat back frame according to any one of claims 1 to 9 , wherein the panel material has beads formed in a plurality of geometric shapes. The seat back frame according to claim 10 , wherein vertically adjacent geometric shapes among the plurality of geometric shapes are vertically symmetrical. The seat back frame according to claim 10 or 11, wherein a hole is formed in a central portion of the geometric shape of the bead. The panel material is divided into a plurality of sections by the frame material that is joined to the panel material and extends in the vertical direction,
Any one of claims 10 to 12 , wherein the plurality of geometrical shapes of the beads in each of the sections are arranged at vertically shifted positions from each other in each of the adjacent sections. Seat back frame as described in .

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