JP2020117217A - Seat frame - Google Patents

Abstract

To allow both parts of a closed cross sectional structure part and an opened cross sectional structure part to be appropriately provided in side frames.SOLUTION: Side frames 10 provided at both end parts in a width direction of a vehicular seat include: a closed cross sectional structure part 10a constituting one end part in a frame extension direction and an opened cross sectional structure part 10b constituting a part continuous to the closed cross sectional structure part 10a in the frame extension direction. Further, a clearance formed resulting from discontinuity of the continuous part in a cross section of the opened cross sectional structure part 10b becomes larger in a separated region 10y disposed at a position separated from the closed cross sectional structure part 10a in the frame extension direction than in an adjacent region 10x adjacent to the closed cross sectional structure part 10a in the frame extension direction, of the opened cross sectional structure part.SELECTED DRAWING: Figure 6

Description

The present invention relates to a seat frame of a vehicle seat, and more particularly to a seat frame lighter than a conventional product.

In order to reduce the weight of a vehicle seat, it is generally considered to reduce the thickness of each part of the seat frame. However, the thinner the thickness of each part of the seat frame, the lower the rigidity of the part. On the other hand, when ensuring rigidity in the seat frame, it is conceivable that the cross-sectional structure of the portion where the rigidity and the like should be ensured is a closed cross-sectional structure. To explain with an example, in the seat frame described in Patent Document 1, the side frame of the seat back frame has a closed cross-section structure.

JP, 2014-88133, A

The seat frame described in Patent Document 1 will be described in detail. The side frame (strictly speaking, the side frame of the seat back frame) has a closed cross-section structure from the upper end to the lower end. With such a configuration, the rigidity of the side frame can be secured, but it is difficult to sufficiently reduce the weight of the seat frame. Therefore, as a structure for ensuring both rigidity and weight reduction, it is conceivable to have a closed cross-section structure part and an open cross-section structure part in the side frame. However, if the cross-sectional shape changes abruptly at the boundary between the closed cross-section structure and the open cross-section structure, problems such as a significant decrease in rigidity and stress concentration may occur at the boundary.

In addition, some seat frames include a frame (connection frame) that connects the side frames. In such a seat frame, when the closed cross-section structure part and the open cross-section structure part are present together in the side frame, the connection frame should be properly attached to the side frame while considering the positional relationship between the connection frame and the side frame. Is required.

In addition, other members such as a support member for supporting an occupant and a power cloth attachment member for attaching a power cloth of an airbag may be attached to the side frame. When the above-mentioned members are attached to the side frame in a configuration in which the closed cross-section structure part and the open cross-section structure part coexist in the side frame, it is required to be attached at a position suitable for smooth attachment work. ..

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a seat frame capable of appropriately coexisting a closed cross-section structure part and an open cross-section structure part in a side frame. Especially.
Another object of the present invention is to be able to appropriately attach a connecting frame for connecting between side frames to a side frame in which a closed cross-section structure part and an open cross-section structure part are appropriately present. To provide a seat frame.
Further, a third object of the present invention is to attach a support member for supporting an occupant and a power cloth for an airbag to a side frame in which a closed cross-section structure part and an open cross-section structure part are appropriately present. An object of the present invention is to provide a seat frame to which a force cloth attachment member can be appropriately attached.

According to the seat frame of the present invention, the problem is a seat frame having side frames provided at both ends in the width direction of the vehicle seat, wherein the side frame has one end in the extending direction of the side frame. And a closed cross-section structure part having a closed cross-section structure that crosses the extension direction, and a part that is continuous with the closed cross-section structure part in the extension direction, and the cross-section has an open cross-section structure. An open cross-section structure part, and a gap formed by a continuous part of the cross-section of the open cross-section structure part is interrupted in the extending direction of the open cross-section structure part. This is solved by the fact that it is larger in the spaced area in the position distant from the closed cross section structure in the extension direction than in the adjacent area in the position adjacent to the closed cross section structure.

In the seat frame of the present invention configured as described above, the closed cross-section structure part and the open cross-section structure part coexist in the side frame. In addition, the gap formed by the discontinuity of the continuous portion in the cross section of the open cross-section structure part is located at a position farther from the closed cross-section structure part than the adjacent region located at the position adjacent to the closed cross-section structure part. It becomes larger in the separated area. That is, the degree of opening in the cross section of the open cross-section structure portion is larger in the separated region than in the adjacent portion. With such a configuration, it is possible to prevent the cross-sectional shape from abruptly changing in the boundary portion between the closed cross-section structure portion and the open cross-section structure portion in the side frame, and reduce the rigidity due to the abrupt change in the cross-sectional shape It is possible to suppress stress concentration.

Further, in the seat frame described above, it is preferable that the gap in the adjacent region becomes larger as it is located farther from the closed cross-section structure portion in the extending direction.
In the above configuration, the gap in the adjacent region (in other words, the opening degree of the cross section) gradually increases as the distance from the closed cross section structure section increases. This makes it possible to more effectively suppress changes in the cross-sectional shape at the boundary between the closed cross-section structure and the open cross-section structure.

Further, in the seat frame, the separation area has a pair of end portions that are adjacent to the gap in a portion that is continuous in the cross section, and the pair of ends that the separation area has. It is preferable that at least one end of the portion has two portions that are folded back and overlap each other in the width direction, and that the two portions are joined to form a closed space.
In the above configuration, at least one of the pair of end portions of the separated region is folded back. Further, the end portion has two portions that are folded back and overlap each other in the width direction, and further, the two portions are joined to form a closed space. This makes it possible to improve the strength of the separated region.

The seat frame may include a connecting frame that connects the side frames, and the connecting frame may include a first extending portion extending in the width direction and the first extending portion in the width direction. Second extension portions located on both sides of the portion and extending toward the side frame, and the second extension portion is inserted inside one end portion of the closed cross-section structure portion in the extension direction. Therefore, it is preferable that the adjacent region is adjacent to the other end of the closed cross-section structure portion in the extending direction.
In the above configuration, the second extending portion of the connecting frame is inserted inside the one end portion in the extending direction of the closed cross section structure portion, and the adjacent region is adjacent to the other extending direction end portion of the closed cross section structure portion. ing. With such a positional relationship, it is possible to appropriately arrange the connecting frames and connect the side frames favorably by the connecting frame.

Further, in the seat frame described above, it is preferable that a portion of the second extending portion that is inside the one end of the closed cross-section structure portion in the extending direction is joined to the closed cross-section structure portion.
In the above configuration, the portion of the second extending portion that is inside the one end portion in the extending direction of the closed cross-section structure portion is joined to the closed cross-section structure portion. With such a configuration, the connecting frame can be attached to the side frame more appropriately.

Further, in the seat frame, the length of the adjacent region in the extending direction may be shorter than the length of the closed cross-section structure portion in the extending direction.
According to the above configuration, the length of the adjacent region having lower rigidity among the adjacent regions is set to be shorter, so that the rigidity of the side frame can be improved.

Further, in the above seat frame, the adjacent region has a pair of end portions located in a position adjacent to the gap in a continuous portion in the cross section, and the width direction in order to support an occupant. In, the support member installed between the side frames is attached to the side frame, the attachment position of the support member is the same position as the adjacent region in the extending direction, and the adjacent region is It is preferable that the positions are apart from the pair of end portions that have.
In the above configuration, the attachment position of the support member on the side frame is the same position as the adjacent region in the extending direction, and the position is apart from the pair of end portions of the adjacent region. With such a positional relationship, the support member can be appropriately attached to the side frame without interfering with the pair of end portions of the adjacent region.

Further, in the above seat frame, the adjacent region has a pair of end portions located at positions adjacent to the gap in a continuous portion in the cross section, and is for attaching a sack cloth of an airbag. A force cloth attachment member is attached to the side frame, an attachment position of the force cloth attachment member is the same position as the adjacent region in the extending direction, and the pair of end portions included in the adjacent region. It is good to be a position away from.
In the above configuration, the attachment position of the webbing attachment member on the side frame is the same position as the adjacent region in the extending direction, and is also a position apart from the pair of end portions of the adjacent region. With such a positional relationship, it is possible to properly attach the webbing attachment member to the side frame without interfering with the pair of end portions of the adjacent region.

Further, in the above seat frame, the attachment position of the webbing attachment member may be a position facing one end of the pair of end portions of the adjacent region in the width direction.
In the above configuration, the attaching position of the webbing attaching member on the side frame is a position facing one end of the pair of end portions of the adjacent region in the width direction. With such a positional relationship, it is possible to effectively utilize the space adjacent to the one end portion in the width direction to attach the webbing attachment member.

Further, in the seat frame, the separation area has a pair of end portions that are adjacent to the gap in a portion that is continuous in the cross section, and the pair of ends that the separation area has. Of the parts, at least one end has two parts that overlap in the width direction by being folded back, and a force cloth attachment member for attaching the energy cloth of the airbag is attached to the side frame, The attaching position of the webbing attachment member may be a position deviating from one of the two portions.
In the above configuration, at least one of the pair of end portions of the separated region is folded back to have two portions that overlap in the width direction. This makes it possible to improve the strength of the separated region. Further, in the above configuration, the attachment position of the webbing attachment member on the side frame is a position deviated from one of the two portions. With such a configuration, it is possible to appropriately attach the webbing attachment member to the side frame without interfering with the one portion.

Further, in the above seat frame, the webbing attachment member is attached to a peripheral position of the one portion of the side frame, and the one portion is formed to intersect the webbing attachment member. It is good if a relief part is provided.
In the above configuration, the escape portion is formed in one of the two portions that overlap each other in at least one end of the separated region. With such a configuration, it is possible to more effectively avoid the interference with the one portion and appropriately attach the webbing attachment member to the side frame.

Further, in the seat frame, the separation area has a pair of end portions that are adjacent to the gap in a portion that is continuous in the cross section, and the pair of ends that the separation area has. At least one end of the portion has two portions that are folded back and overlap in the width direction, and the side frame has a reinforcing portion formed at the same position as the two portions in the extending direction. And a fragile portion formed at a position rearward of the reinforcing portion.
In the above configuration, the reinforcing portion for increasing the strength of the side frame is provided at the same position as the position where one end of the separated region in the extending direction is folded back. With such a positional relationship, it is possible to more effectively exert the reinforcing effect of the reinforcing portion. Further, by providing the fragile portion at the rear of the reinforcing portion, for example, when a load is input at the time of a vehicle rear collision, the side frame is deformed with the fragile portion as the base point so that the impact can be mitigated.

ADVANTAGE OF THE INVENTION According to the seat frame of this invention, it suppresses that a cross-sectional shape changes suddenly in the boundary part of a closed cross-section structure part and an open cross-section structure part in a side frame, and rigidity reduction resulting from the sudden change of the said cross-section shape is suppressed. It is possible to suppress stress concentration.
Further, according to the seat frame of the present invention, the gap in the adjacent region gradually increases as the distance from the closed cross-section structure increases, so that the change in cross-sectional shape at the boundary between the closed cross-section structure and the open cross-section structure can be further suppressed. It can be effectively suppressed.
Further, according to the seat frame of the present invention, the strength of the separated area can be improved.
Further, according to the seat frame of the present invention, it is possible to appropriately arrange the connecting frames and connect the side frames favorably by the connecting frames.
Further, according to the seat frame of the present invention, of the second extending portion, the portion of the second extending portion that has entered inside the one end portion in the extending direction of the closed cross-section structure portion is joined to the closed cross-section structure portion, thereby connecting the connecting frame to the side. It becomes possible to more appropriately attach to the frame.
Further, according to the seat frame of the present invention, it is possible to improve the rigidity of the side frame by setting the length of the adjacent region having lower rigidity in the adjacent regions to be shorter.
Further, according to the seat frame of the present invention, it becomes possible to properly attach the supporting member to the side frame.
Further, according to the seat frame of the present invention, it is possible to appropriately attach the webbing attachment member to the adjacent region of the side frame.
Further, according to the seat frame of the present invention, it is possible to effectively utilize the space in the adjacent region to attach the webbing attachment member.
Further, according to the seat frame of the present invention, it is possible to appropriately attach the webbing attachment member to the separated region of the side frame.
Further, according to the seat frame of the present invention, it is possible to effectively avoid a part of the spacing area from interfering with the power cloth mounting member when the power cloth mounting member is properly mounted to the spacing area of the side frame. It becomes possible.
Further, according to the seat frame of the present invention, while effectively exerting the reinforcing effect by the reinforcing portion, when a load is input at the time of a vehicle rear collision, the side frame is deformed with the weak portion as a base point to generate an impact. Can be alleviated.

1 is an overall view of a vehicle seat according to an embodiment of the present invention. It is a figure when the seat frame concerning one embodiment of the present invention is seen from the slanting front. It is a figure when the seat frame concerning one embodiment of the present invention is seen from diagonally back. It is a schematic cross section which shows the location where the pillar guide is welded in the connection frame. It is a figure when the side frame concerning one embodiment of the present invention is seen from the side. It is a figure when one part which constitutes a side frame is seen from the side. It is a figure when other parts which constitute a side frame are seen from the side. It is a figure when the side frame concerning one embodiment of the present invention is seen from the slanting front. It is a figure which shows the AA cross section in FIG. It is a figure which shows the BB cross section in FIG. It is a figure which shows the CC cross section in FIG. It is a figure which shows the DD cross section in FIG. It is a figure which shows the 1st modification. It is a figure which shows the 2nd modification. It is a figure which shows a reclining device and its attachment components.

An embodiment of the present invention will be described below. The embodiments described below are merely examples for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be modified and improved without departing from the spirit of the invention, and it goes without saying that the present invention includes equivalents thereof. Furthermore, in the following description, the content regarding the material, shape, and size of each device and its components is merely one of the specific examples, and does not limit the present invention. That is, the materials, shapes, and sizes of the devices and their components can be freely designed as long as they meet the specific requirements of the present invention.

Further, in the following description, the “front-back direction” means the front-back direction of the vehicle seat, and specifically, the direction that matches the traveling direction of the vehicle. Further, the “width direction” means the width direction of the vehicle seat, and is specifically a direction that coincides with the vehicle width direction (left-right direction).

Further, in the following description, it is assumed that the vehicle seat is in a use state (a state in which a seated person can sit down) unless otherwise specified. That is, in the following description, the postures, positions, and positional relationships of each part of the vehicle seat with respect to other members are the contents when the vehicle seat is in use.

<<Basic configuration of vehicle seat and seat frame>>
First, a basic configuration of a vehicle seat (hereinafter, the present seat S) and a seat frame F forming a skeleton thereof according to the present embodiment will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the seat S has a seat back S1, a seat cushion S2, and a headrest S3. The seat back S1 and the seat cushion S2 are configured by placing the pad material P on the seat frames illustrated in FIGS. 2 and 3 and covering the surface of the pad material P with the skin material W. The headrest S3 is configured by disposing a pad material P on a core material (not shown) and covering the surface of the pad material P with a skin material W. A pair of headrest pillars (not shown) extending downward are provided below the headrest S3. The headrest S3 is supported by the upper end of the seatback S1 (strictly speaking, the seatback frame F1) via the pair of headrest pillars.

As shown in FIGS. 2 and 3, the seat S includes a seat back frame F1 included in the seat back S1 and a seat cushion frame F2 included in the seat cushion S2. The seat cushion frame F2 is connected to the upper rail RU of the slide rail device R arranged below the seat cushion frame F2. With this configuration, when the upper rail RU moves along the lower rail RL fixed to the vehicle body floor, the entire main seat S including the seat cushion frame F2 slides.

In the present embodiment, the seat cushion frame F2 is connected to the upper rail RU via the rotation link XL as shown in FIG. The rotation link XL is a link member arranged on both sides of the seat cushion S2 in the width direction, and rotates about a rotation axis along the width direction. Then, the rotation link XL rotates together with the seat cushion S2, whereby the position of the seat cushion S2 in the vertical direction is adjusted.

The lower end of the seat back frame F1 is connected to the rear end of the seat cushion frame F2 via a reclining device 80. By this reclining device 80, the seat back S1 including the seat back frame F1 is connected to the seat cushion S2 in a state in which the tilt angle with respect to the seat cushion S2 can be adjusted. That is, the seat back S1 can rotate relatively to the seat cushion S2 about the reclining shaft 81 extending in the width direction.

The seat S is different from the conventional general vehicle seat in the structure of the seat frame. Hereinafter, the configuration of the seat back frame F1 as a seat frame included in the seat S will be described in detail. The configuration described below (particularly the structure of the side frame 10) is applicable not only to the seat back frame F1 but also to the seat cushion frame F2.

<<Detailed structure of seat back frame>>
The configuration of the seat back frame F1 of the seat S will be described in detail with reference to FIGS. 2 and 3 and FIGS. As shown in FIG. 2, the seat back frame F1 has a rectangular frame shape when the seat frame F is viewed from the front. Further, the seat back frame F1 is lighter in weight than a seat back frame included in a conventional general vehicle seat. More specifically, as a material forming the seat back frame F1 (for example, a steel plate forming a side frame 10 described later), a material lighter than a material used in a conventional seat back frame is used. .. Further, when the components forming the seatback frame F1 are fastened/connected, fasteners such as bolts/nuts or screws are not used, but the components are fastened/connected by laser welding. By adopting such a configuration, the seat back frame F1 according to the present embodiment is lighter in weight.

The structure of the seat back frame F1 will be described. The seat back frame F1 has a pair of side frames 10 provided at both ends in the width direction, as shown in FIGS. 2 and 3. Further, as shown in the figure, the seat back frame F1 has an upper frame 30 which is attached to the upper end of each side frame 10 to connect the side frames 10 to each other. Further, the seat back frame F1 has a lower member frame 50 that connects the side frames 10 by being attached to the lower end portions of the side frames 10 as shown in FIG. Further, between the side frames 10, an S spring 60 as a support member for supporting the back of the occupant from behind is installed.

Hereinafter, the upper frame 30, the lower member frame 50, and the side frame 10 will be described in this order.
The upper frame 30 is a component formed in a downward U shape in a front view, and corresponds to a connecting frame. In addition, in the present embodiment, the upper frame 30 is configured by a metal hollow pipe member. However, the present invention is not limited to this, and the upper frame 30 may be formed of a solid member. As shown in FIG. 2, the upper frame 30 includes a horizontal portion 31 as a first extending portion extending in the width direction and second extending portions located on both sides of the horizontal portion 31 in the width direction. And a downward extension portion 32 of Each downward extension portion 32 extends downward toward the side frame 10, and a lower end portion 32 a thereof is joined to an upper portion of the side frame 10.

In addition, in the downward extending portion 32, a portion located below the lower end portion 32a (hereinafter, the skewed portion 32b) is slanted so as to spread outward in the width direction as it goes downward. Further, as shown in FIGS. 2 and 3, a connecting plate 33 extending in the width direction is provided between the lower ends of the oblique portions 32b. Both ends in the width direction of the connecting plate 33 are fixed to the oblique portion 32b by laser welding. Further, both end portions in the width direction of the connecting plate 33 are curved so as to shift rearward from the portion fixed to the oblique portion 32b toward the inner side in the width direction.

On the front surface of the horizontal portion 31 of the upper frame 30, a prismatic pillar guide 34 that supports the headrest pillar is attached. A pair of the pillar guides 34 are provided at intervals in the width direction. Further, of the horizontal portion 31, the portion to which the pillar guide 34 is attached is crushed so that the front surface thereof becomes a flat surface. The pillar guide 34 is fixed to the crushed and flat portion.

As shown in FIG. 4, a portion of the horizontal portion 31 to which the pillar guide 34 is fixed is orthogonal to the width direction, and as shown in FIG. 31a) is formed. In this embodiment, the pillar guide 34 is fixed by utilizing the raised portion 31a. More specifically, by irradiating the welding laser from the rear of the raised portion 31a with the front surface of the raised portion 31a and the rear surface of the pillar guide 34 in contact with each other, the raised portion 31a and the pillar guide 34 are laser-welded. There is. By the way, in FIG. 4, in order to make the description easy to understand, the raised portion 31a is shown to be slightly larger than the actual size.

Next, the lower member frame 50 will be described. The lower member frame 50 is formed by processing a sheet metal, and is installed between the lower end portions of the side frame 10 (strictly speaking, between the lower end portions of the rear wall portion 14 of the outer part 11 described later). Further, the upper edge portion and the lower edge portion of the lower member frame 50 are respectively bent forward to form flanges.

Next, the side frame 10 will be described with reference to FIGS. 5A is a diagram showing the side frame 10 according to the present embodiment, and FIGS. 5B and 5C are diagrams showing each part that constitutes the side frame 10, both of which are viewed from the inside in the width direction. It is a figure of time.

The side frame 10 has a spindle-shaped outer shape in a side view as shown in FIG. 5A. That is, when the side frame 10 is viewed from the side, the front end portion of the side frame 10 bulges in an arc shape from the midway position in the vertical direction. When the seat S is in use (more strictly, when the seat back S1 is at the reference position), the side frame 10 is along a direction slightly inclined (backwardly inclined) with respect to the vertical direction. It has been extended for a long time. Incidentally, below, the extension direction of the side frame 10 will be referred to as a “frame extension direction”.

Further, the lower end portion 32 a of the lower extension portion 32 of the upper frame 30 is joined to one end portion (upper end portion) of the side frame 10 in the extending direction. Here, in the state where the lower end portion 32a is joined to the upper end portion of the side frame 10, the extending direction of the lower extending portion 32 is substantially coincident with the frame extending direction. In this sense, it can be said that the frame extending direction corresponds to the extending direction of the downward extending portion 32.

In the present seat S, the length of the portion of the lower end portion 32a of the downward extending portion 32 joined to the upper end portion of the side frame 10 is shorter than that of the conventional vehicle seat. This is to make the seat S lighter than the conventional vehicle seat. Further, in the present embodiment, the thickness of the steel plate forming the side frame 10 is smaller than the thickness of the pipe forming the upper frame 30.

Further, in the present embodiment, the side frame 10 is made of a thin steel plate, more specifically, an ultra-high tensile steel plate having a thickness of 1 mm or less. Further, the side frame 10 according to the present embodiment is configured by joining a plurality of frame pieces, specifically two frame pieces. More specifically, each side frame 10 has an outer part 11 shown in FIG. 5B and an inner part 12 shown in FIG. 5C as constituent parts. Each of these parts is formed by processing an ultra high strength steel plate.

The outer part 11 corresponds to one frame piece among a plurality of frame pieces forming the side frame 10, and mainly forms a portion of the side frame 10 on the outer side in the width direction. The inner part 12 corresponds to another frame piece, and mainly constitutes a widthwise inner portion of the side frame 10. Then, as shown in FIG. 6, the outer part 11 and the inner part 12 are joined by laser welding in a state where they are partially overlapped with each other to form the side frame 10. It should be noted that in FIG. 6, welding traces obtained by laser welding are shown by thick broken lines.

Hereinafter, the structure of the side frame 10 will be described in more detail with reference to FIGS. 6 to 10 together with FIG. 3 and FIGS. First, in describing the structure of the side frame 10, the respective configurations of the outer part 11 and the inner part 12 will be described.

The outer part 11 has a substantially U-shaped cross section that intersects the frame extending direction, and has a side wall portion 13 and a rear wall portion 14 as shown in FIGS. The side wall portion 13 is a portion of the side frame 10 located at an end portion on the outer side in the width direction. The end surface of the side wall portion 13 defines the end surface of the side frame 10 on the outer side in the width direction. That is, the outer shape of the side wall portion 13 corresponds (substantially matches) to the outer shape of the side frame 10, as can be seen by comparing FIGS. 5A and 5B. Further, the front end portion of the side wall portion 13 includes a flange portion 13a formed by bending the side wall portion 13 toward the inner side in the width direction at a substantially right angle. The flange portion 13a is formed in a wide range from the middle portion of the side wall portion 13 to the lower end portion in the frame extending direction.

Further, as shown in FIG. 5B, the side wall portion 13 is formed with a plurality of rectangular holes and circular holes. An end portion of an S spring 60 described later and a webbing attachment clip 70 are inserted into and engaged with these holes. The details of the holes will be described later.

Further, as shown in FIG. 5B, a mounting hole 13b for mounting the reclining device 80 is formed in the lower portion of the side wall portion 13. The reclining device 80 is mounted on the side wall portion 13 so that the reclining shaft 81 passes through the mounting hole 13b. In this embodiment, a plurality of attachment parts are used to attach the reclining device 80 to the side wall portion 13. The mounting parts and the like of the reclining device 80 will be described later.

The rear wall portion 14 is a portion provided so as to be substantially orthogonal to the rear end portion of the side wall portion 13, and extends toward the inner side in the width direction as shown in FIG. 6. The rear wall portion 14 extends long in the frame extending direction, and the end positions (upper end position and lower end position) of the rear wall portion 14 in the same direction are substantially aligned with the end positions of the side wall portion 13. A flange portion 14a formed by bending the rear wall portion 14 inward in the width direction is bent at a substantially right angle toward the front. The flange portion 14a is formed in a wide range from the upper end portion to the lower end portion of the rear wall portion 14 in the frame extending direction. As shown in FIG. 6, the flange portion 14a is interrupted at a position directly above the lower member frame 50 in the frame extending direction in order to attach the lower member frame 50 to the lower end portion of the rear wall portion 14.

Further, on the rear surface of the rear wall portion 14, as shown in FIG. 3, a bead formed along the frame extending direction (hereinafter, a rear wall portion bead 14b) is formed. The rear wall bead 14b is provided to improve the rigidity of the rear wall 14 (in particular, the rigidity with respect to the load acting in the front-rear direction), and the widthwise central portion of the rear wall 14 is recessed forward. Has been formed. In the present embodiment, the rear wall bead 14b is formed so that its lower end reaches the position directly above the lower member frame 50.

As shown in FIG. 5C, the inner part 12 has a curved shape according to the outer shape of the side frame 10, and has an upper part 15, a central part 16 and a lower part 17 of the part as shown in FIG. .. The upper part 15 constitutes the upper end of the inner part 12, and has a substantially U-shaped cross section that intersects the frame extending direction, as shown in FIG. 7. Then, as shown in FIGS. 6 and 7, the upper part 15 of the outer frame 11 is combined with and joined to the upper part of the outer part 11 to form the closed cross-section structure part 10 a of the side frame 10. The closed section structure portion 10a will be described in detail later.

The part central portion 16 constitutes a part of the inner part 12 adjacent to the lower end of the upper part 15 of the inner part 12, and extends downward from the lower end of the upper part 15 of the part. Further, as shown in FIG. 8, the cross section of the central part 16 of the part that intersects the frame extending direction is substantially V-shaped. Then, as shown in FIGS. 6 and 7, the part central portion 16 constitutes an open cross-section structure portion 10b of the side frame 10 by being combined and joined to an intermediate portion of the outer part 11 in the frame extending direction. ing. Strictly speaking, the part central part 16 is joined to the front end part of the side wall part 13 of the outer part 11 so that the part adjacent to the closed cross-section structure part 10a in the frame extending direction of the open cross-section structure part 10b. The adjacent region 10x located at 1 is formed. The open cross-section structure portion 10b and the adjacent region 10x will be described in detail later.

The part lower part 17 constitutes a part of the inner part 12 located below the part central part 16 and extends downward from the lower end of the part central part 16 while curving in an arc shape. Further, as shown in FIG. 9, the cross section of the lower part 17 of the part that intersects the frame extending direction is substantially S-shaped. The part lower part 17 is formed so as to be slightly narrower in the front-back direction than the part upper part 15. Then, as shown in FIGS. 6, 9 and 10, the lower part 17 of the part is combined with the lower part of the outer part 11 to form an open cross-section structure part 10 b of the side frame 10. Strictly speaking, the part lower part 17 is joined to the front end part of the side wall part 13 of the outer part 11, so that the part lower part 17 is located at a position apart from the closed cross section structure part 10a in the frame extension direction in the open cross section structure part 10b. The existing separation area 10y is formed. In particular, the parts lower portion 17 constitutes only the front end portion of the separated region 10y in the side frame 10. The separated area 10y will be described in detail later.

Next, the structure of the side frame 10 will be described. As shown in FIG. 6, a closed cross-section structure 10a is formed at the upper end of the side frame 10. As shown in FIG. 7, the closed cross-section structure portion 10a is a portion having a closed cross-section structure in a cross section that intersects the frame extending direction.

Then, the lower end 32a of the lower extension 32 of the upper frame 30 is inserted inside the upper end (one end in the frame extension direction) of the closed cross section structure 10a, and the lower end 32a is further closed cross section structure. It is joined to the portion 10a. That is, the end portion of the side frame 10 located on the same side as the downward extending portion 32 in the frame extending direction forms the closed cross-section structure portion 10a. On the other hand, the downward extending portion 32 enters inside the upper end portion of the closed cross-section structure portion 10a and is joined to the upper end portion. As a result, the upper frame 30 can be properly assembled to the side frame 10, and as a result, the side frames 10 are favorably connected to each other by the upper frame 30. In the present embodiment, the downward extension 32 and the upper end of the closed cross-section structure 10a are joined by being irradiated with a laser for welding from outside the upper end.

On the other hand, as described above, in the present sheet S, in order to reduce the weight, the length of the portion of the downward extension portion 32 joined to the upper end portion of the side frame 10 (hereinafter, joining length) is It is shorter than conventional vehicle seats. Here, if the joining length is shortened, the supporting rigidity of the side frame 10 is reduced accordingly. Here, the supporting rigidity of the side frame 10 means the stability of the supporting state of the side frame 10 when an external force acts on the side frame 10.

On the other hand, in the present embodiment, the upper end portion of the side frame 10 to which the downward extending portion 32 is joined is the closed cross-section structure portion 10a. Since the closed cross-section structure portion 10a has a closed cross-section structure, support rigidity is ensured. As shown in FIG. 6, the closed cross-section structure 10a extends so that the lower end of the closed cross-section structure 10a is located below the lower end of the downward extension 32 in the frame extending direction. That is, in the side frame 10, the portion positioned below the downward extending portion 32 (that is, the portion that is not joined to the downward extending portion 32) has the closed cross-section structure portion 10a, so that the supporting rigidity is increased. Is secured.

As described above, in the present embodiment, the upper end of the side frame 10 is the closed cross-section structure 10a, and the downward extension 32 of the upper frame 30 is joined to the closed cross-section structure 10a. 10a extends below the lower end of the downward extension portion 32. As a result, it becomes possible to compensate for the support rigidity that is lost by shortening the joining length.

In the present embodiment, as shown in FIG. 7, the upper section of the outer part 11 and the upper section 15 of the inner part 12 are joined together by laser welding to form the closed cross-section structure section 10a. Has been done. More specifically, in the upper part of the outer part 11, the side wall part 13 and the flange part 14a of the rear wall part 14 overlap the part upper part 15 of the inner part 12. The upper portion of the outer part 11 and the upper portion 15 of the inner part 12 are joined by irradiating the overlapping portion with a laser for welding along the frame extending direction. By constructing the closed cross-section structure part 10a by stacking the two parts as described above, the strength of the closed cross-section structure part 10a is further increased, and the supporting rigidity of the side frame 10 can be further secured.

Further, in this embodiment, the thickness of the steel plate forming the side frame 10 is smaller than the thickness of the pipe forming the upper frame 30. Thereby, even if the joint length is shortened and the closed cross-section structure portion 10a extends below the lower end of the downward extension portion 32, the weight increase of the side frame 10 is suppressed (specifically, the conventional product). It is possible to reduce the weight).

By the way, if the side frame 10 as a whole has a closed cross-section structure, the weight of the side frame 10 increases accordingly. Therefore, in the present embodiment, only the upper end of the side frame 10 is the closed cross-section structure 10a, and the portion located below it is the open cross-section structure 10b. Here, the open cross-section structure portion 10b is a portion of the side frame 10 that is continuous with the closed cross-section structure portion 10a in the frame extension direction and that has a cross section that intersects the frame extension direction. That is, in the open cross-section structure portion 10b, as shown in FIGS. 8 and 9, a gap Q is formed by discontinuing a continuous portion in the cross section.

As described above, in the present embodiment, only the upper end portion of the side frame 10 has the closed cross-section structure portion 10a, so that the supporting rigidity of the side frame 10 is ensured and the weight of the seatback frame F1 including the side frame 10 is further increased. It is possible to reduce the weight.

Further, in the present embodiment, the open cross-section structure portion 10b is located adjacent to the closed cross-section structure portion 10a in the frame extending direction, and the adjacent area 10x is located apart from the closed cross-section structure portion 10a. It is divided into 10y.

The adjacent region 10x is a region of the open cross-section structure 10b that is adjacent to the lower end (the other end in the frame extending direction) of the closed cross-section structure 10a. The adjacent region 10x is configured by laser welding in a state where the central portion of the outer part 11 and the central portion 16 of the inner part 12 in the frame extending direction overlap each other. More specifically, in the central portion of the outer part 11, the flange portion 13a of the side wall portion 13 overlaps with the central portion 16 of the inner part 12. The central portion of the outer part 11 and the central portion 16 of the inner part 12 are joined by irradiating the overlapping portion with a welding laser along the frame extending direction. An adjacent region 10x is formed by the central portion of the outer part 11 and the central portion 16 of the inner part 12 that are joined together.

In addition, as shown in FIG. 8, the adjacent region 10x has a pair of end portions 10s and 10t located at positions adjacent to the above-described gap Q in the continuous portion in the cross section. In addition, as shown in FIG. 8, each of the pair of end portions 10s and 10t included in the adjacent region 10x extends so that the tip of each end faces the gap Q in the cross section.

The separation region 10y is a region located below the adjacent region 10x in the open section structure portion 10b. The separated region 10y is formed by laser welding the lower part of the outer part 11 and the lower part 17 of the inner part 12 in the frame extending direction so as to overlap each other. More specifically, of the lower part of the outer part 11, the flange part 13 a of the side wall part 13 overlaps with the part lower part 17 of the inner part 12. By irradiating the overlapping portion with a laser for welding along the frame extending direction, the lower portion of the outer part 11 and the lower portion 17 of the inner part 12 are joined. The lower portion of the joined outer part 11 and the lower part 17 of the inner part 12 form a separated region 10y.

Further, as shown in FIG. 9, the separation region 10y has a pair of end portions 10s and 10t located at positions adjacent to the above-described gap Q in the continuous portion in the cross section. Of the pair of end portions 10s and 10t included in the separated region 10y, the end portion 10s located on the front side is folded back in the front-rear direction, as shown in FIG. That is, the end portion 10s located on the front side has two portions that overlap in the width direction (hereinafter, overlapping portions 10v and 10w). As described above, in the present embodiment, by folding back the end portion 10s located on the front side of the pair of end portions 10s and 10t included in the separation region 10y, the strength of the open cross-section structure portion 10b including the separation region 10y is increased. Has been.

In the present embodiment, the end portion 10s located on the front side of the pair of end portions 10s and 10t included in the separated region 10y is folded back, but the present invention is not limited to this, and the end portion 10s is located on the rear side. The positioned end 10t may be folded back.

Furthermore, as shown in FIG. 9, the end portion 10s located on the front side forms a closed space C by joining the two overlapping portions 10v and 10w. More specifically, the end portion 10s located on the more front side is folded back in the front-rear direction as described above, but particularly in the present embodiment, it is folded back like a bag. That is, of the folded back end 10s, the rearward region is narrowed with respect to the frontward region, and the overlapping portions 10v and 10w are in contact with each other. Then, the two overlapping portions 10v, 10w that are in contact with each other are irradiated with a laser for welding, so that the two overlapping portions 10v, 10w are joined. As a result, the end portion 10s located on the front side forms the closed space C. As described above, in the present embodiment, the end portion 10s located on the front side forms the closed space C, so that the strength of the open cross-section structure portion 10b including the separated region 10y is further increased.

In joining the two overlapping portions 10v and 10w, a welding laser is irradiated from the inside in the width direction (in other words, of the two overlapping portions 10v and 10w, the overlapping portion 10w on the inside in the width direction is irradiated. It is supposed to irradiate the laser).

Further, in the present embodiment, the two overlapping portions 10v and 10w are joined by laser welding, and the end portion 10s located on the more front side forms the closed space C, but the present invention is not limited to this. Not something. As shown in FIG. 11, two overlapping portions 10v and 10w may be spaced apart from each other (that is, the end portion 10s located on the front side is not closed).

By the way, in the present embodiment, as shown in FIG. 6, the opening degree of the cross section in the adjacent region 10x of the open cross section structure portion 10b becomes larger as it goes downward. That is, the pair of end portions 10s, 10t included in the adjacent region 10x are spaced apart from each other in the frame extending direction as they are farther from the closed cross-section structure portion 10a, and a larger gap Q is formed therebetween. Further, in the present embodiment, as can be seen by comparing FIGS. 8 and 9, the gap Q (that is, the opening degree of the cross section) in the cross section of the open cross section structure portion 10b becomes larger in the separated area 10y than in the adjacent area 10x. ing. With such a configuration, it is possible to prevent the cross-sectional shape from abruptly changing at the boundary between the closed cross-section structure portion 10a and the open cross-section structure portion 10b. As a result, it is possible to suppress a decrease in the rigidity of the side frame 10 and a stress concentration due to a sudden change in the cross-sectional shape.

Further, as described above, the above-mentioned gap Q in the adjacent region 10x is gradually increased as the distance from the closed cross-section structure portion 10a is increased in the frame extending direction. Thereby, it becomes possible to more effectively suppress the abrupt change of the cross-sectional shape at the boundary portion between the closed cross-section structure portion 10a and the open cross-section structure portion 10b.

Explaining in more detail the structure of the side frame 10 according to the present embodiment, as shown in FIG. 5A, the length of the adjacent region 10x in the frame extending direction is shorter than the length of the closed cross-section structure portion 10a in the same direction. ing. That is, in the present embodiment, the adjacent region 10x having a rigidity lower than that of the closed cross-section structure 10a is shorter than the closed cross-section structure 10a in the frame extending direction. As a result, in the present embodiment, the side frame 10 has a higher rigidity than in the case where the adjacent region 10x is configured to be longer than the closed cross-section structure portion 10a.

Further, as shown in FIGS. 2, 3 and 7, the side frame 10 is provided with a recess formed by being recessed inward in the width direction. This recess is formed in the side wall portion 13 of the outer part 11 that constitutes the side frame 10, more specifically, in the central portion of the side wall portion 13 in the frame extending direction and in the portion corresponding to the lower half. As described above, in the present embodiment, since the side wall portion 13 is provided with the concave portion, the strength of the side frame 10 is enhanced. The number of recesses provided in the side wall portion 13 and the location where the recesses are provided are not particularly limited.

By the way, of the recesses formed in the side frame 10, the recess formed in the central portion of the side wall portion 13 (hereinafter referred to as the first recess 20) is a substantially triangular recess when viewed from the side. Further, as can be seen by comparing FIGS. 5A, 5B, and 5C, the first recess 20 is arranged so that the upper end of the first recess 20 is located above the lower end of the closed cross-section structure 10a in the side frame 10. It is provided.

By the way, when the concave portion is provided in the side frame 10, the section modulus of the portion where the concave portion is provided is decreased, and particularly, the section modulus at the upper end of the concave portion is remarkably changed. On the other hand, in the present embodiment, the portion of the side frame 10 where the upper end of the first recess 20 is located is the closed cross-section structure 10a. With such a configuration, it is possible to suppress a decrease in the section modulus in the portion of the side frame 10 where the upper end of the first recess 20 is located.

Further, among the recesses formed in the side frame 10, the recesses (hereinafter, second recesses 21) formed in the lower half of the side wall portion 13 are the outer surface of the side wall portion 13 (the surface on the outer side in the width direction). Surface). Here, a part of the second concave portion 21 forms the end portion 10s located on the front side of the pair of end portions 10s and 10t included in the separated region 10y. Strictly speaking, of the two overlapping portions 10v and 10w formed by folding back the end portion 10s, the overlapping portion 10v located on the outer side in the width direction is the second concave portion 21 as shown in FIG. It is located inside.

The overlapping portion 10v located inside the second recess 21 is joined to the overlapping portion 10w facing the overlapping portion 10v by laser welding. As described above, in the present embodiment, one of the two overlapping portions 10v and 10w to be joined is located in the second recess 21, that is, in the range where the strength of the side frame 10 is increased. This makes it possible to secure the joining strength when joining the two overlapping portions 10v and 10w by laser welding. Here, the joining strength means the stability of the contact state between the two overlapping portions 10v and 10w at the stage of joining them.

Further, in the lower half portion of the side wall portion 13 of the side frame 10, as shown in FIG. 3 and FIG. 5B, a floating island-shaped bead portion surrounded by the second concave portion 21 (hereinafter, convex bead portion). 22) has been formed. The convex bead 22 corresponds to a reinforcing portion, and is provided at the lower end of the side frame 10 so that the rigidity of the side frame 10 (especially, the rigidity against the load input to the upper portion of the seat back S1 by the occupant during a vehicle rear collision). ) Is provided. The convex bead 22 is formed by bulging a predetermined portion of the side frame 10 outward, and in the present embodiment, is formed so as to linearly extend in the front-rear direction.

In addition, the convex bead 22 may be formed so that the position of each part of the bead is lowered as it goes toward the rear end. More preferably, the convex bead 22 is formed so as to extend in the direction along the input direction of the load input to the upper portion of the seat back S1 at the time of a vehicle rear collision. Further, in the present embodiment, the convex bead 22 is formed at the same height as the end portion 10s on the folded side of the pair of end portions 10s and 10t included in the separated region 10y. More specifically, the formation position of the convex bead 22 is substantially the same as the two overlapping portions (overlapping portions 10v, 10w) in the folded back end 10s in the frame extending direction. With such a positional relationship, in the present embodiment, the folding of the end portion 10s and the formation of the convex bead 22 are combined, and the strength of the side frame 10 is effectively increased.

Further, the convex bead 22 is not limited to the configuration provided on the side wall portion 13, and may be provided on the rear wall portion 14 as shown in FIG. 11. Explaining the configuration illustrated in FIG. 11, a fragile portion 23 along the width direction is formed at the lower end portion of the rear wall portion 14. The fragile portion 23 is a portion serving as a deformation base point when the side frame 10 is bent due to an impact load of a predetermined magnitude or more when a vehicle rear collision occurs, and is configured by a hole portion, a concave portion, or the like. The fragile portion 23 is provided behind the convex bead 22 provided on the side wall portion 13. More specifically, as shown in FIG. 11, it may be formed at a position straddling a boundary portion (corner portion) between the side wall portion 13 and the rear wall portion 14. In the above-described configuration, the second convex bead 22 extending in the direction intersecting the fragile portion 23 is provided in the portion of the rear wall portion 14 located above or below the fragile portion 23. Good.

<<Installation position of S spring on side frame>>
As shown in FIGS. 2 and 3, the seatback frame F1 according to the present embodiment includes an S spring 60 that is provided between the side frames 10 in the width direction. On the other hand, the S spring 60 extends meandering in the vertical direction along the width direction. Further, the extension direction end of the S spring 60 is hooked in an engagement hole 13x formed in the side wall portion 13 of the outer part 11 of the side frame 10. Thereby, the S spring 60 is attached to the side frame 10.

Here, the formation position of the engagement hole 13x will be described. As can be seen by comparing FIGS. 5A and 5C, the engagement hole 13x is formed at the same position as the adjacent region 10x in the frame extending direction. The engagement hole 13x is formed between the pair of end portions 10s and 10t included in the adjacent region 10x in the front-rear direction. That is, in the present embodiment, the attachment position of the S spring 60 is the same position as the adjacent region 10x in the frame extending direction, and is a position apart from the pair of end portions 10s and 10t of the adjacent region 10x. There is. Due to such a positional relationship, in the present embodiment, the S spring 60 is appropriately attached to the side frame 10 so as not to interfere with the pair of end portions 10s and 10t of the adjacent region 10x.

<<About the attachment position of the power cloth attachment clip on the side frame>>
In the seat back frame F1 according to the present embodiment, the side cloth 10 closer to the vehicle door is attached with the power cloth attachment clip 70 shown in FIG. The power cloth attachment clip 70 corresponds to a power cloth attachment member and is a component for attaching a power cloth of an airbag (not shown). On the other hand, in the side frame 10 of the outer frame 11 of the side frame 10, rectangular insertion holes 13y and 13z for inserting the force cloth attachment clips 70 are formed. Then, as shown in FIG. 10, the force cloth attachment clip 70 is attached to the side frame 10 by partially inserting the force cloth attachment clip 70 into the insertion holes 13 y and 13 z.

Further, in this embodiment, as shown in FIG. 5B, two insertion holes 13y and 13z are formed at different positions in the frame extending direction. Hereinafter, the formation positions of the respective insertion holes 13y and 13z will be described. In the following, the insertion hole 13y located higher in the frame extension direction will be referred to as the "upper insertion hole 13y", and the insertion hole 13z located further down will be referred to as the "lower insertion hole 13z". ..

As can be seen by comparing FIGS. 5A and 5B, the upper insertion hole 13y is formed at the same position as the adjacent region 10x in the frame extending direction. Further, the upper insertion hole 13y is formed at a position displaced in the width direction from each of the pair of end portions 10s and 10t of the adjacent region 10x. Specifically, the upper insertion hole 13y is formed at a position facing the end 10s located on the front side in the width direction, of the pair of ends 10s and 10t included in the adjacent region 10x. That is, in the present embodiment, the attachment position of the force cloth attachment clip 70 to be inserted into the upper insertion hole 13y is the same position as the adjacent region 10x in the frame extension direction, and the pair of end portions of the adjacent region 10x have. It is located away from 10s and 10t. Due to such a positional relationship, in the present embodiment, the force cloth attachment clip 70 is appropriately attached to the side frame 10 so as not to interfere with the pair of end portions 10s and 10t included in the adjacent region 10x. Further, among the pair of end portions 10s and 10t included in the adjacent region, a space is formed inside the end portion 10s located on the front side in the width direction. In the present embodiment, the webbing attachment clip 70 is attached by effectively utilizing this space.

In the present embodiment, the upper insertion hole 13y is, as shown in FIG. 5B, a portion of the side wall portion 13 where the above-described recesses (first recess 20 and second recess 21) are not formed, That is, it is formed in a portion (non-concave portion) located on the outer side in the width direction. Further, in the present embodiment, the upper insertion hole 13y is located in front of the engagement hole 13x formed for mounting the S spring 60, as shown in FIG. 5B. In other words, in the seat back frame F1 according to the present embodiment, the S spring 60 is arranged behind the force cloth attachment clip 70 that is inserted into the upper insertion hole 13y.

As can be seen by comparing FIGS. 5A and 5B, the lower insertion hole 13z is formed at the same position as the spacing region 10y in the frame extending direction. Further, the lower insertion hole 13z is formed in the vicinity of the end of the pair of ends 10s and 10t of the separated region 10y that is folded back (that is, the end 10s located on the front side). There is. More specifically, as shown in FIG. 10, the end portion 10s has two portions (overlapping portions 10v, 10w) that are folded back and overlap each other in the width direction. On the other hand, the lower insertion hole 13z is formed behind the inner overlapping portion 10w of the two portions 10v and 10w. More specifically, as shown in FIG. 5A, the lower insertion hole 13z is formed immediately behind the inner overlapping portion 10w. Further, in the present embodiment, the inner portion of the overlapping portion 10w, which is located immediately in front of the lower insertion hole 13z, is notched to form the escape portion 10u, as shown in FIG. .. The escape portion 10u is a portion formed at the inner side overlapping portion 102 so as to intersect the webbing attachment clip 70.

That is, in the present embodiment, the attachment position of the force cloth attachment clip 70 inserted into the lower insertion hole 13z is the same position as the spacing region 10y in the frame extending direction, and one end portion of the spacing region 10y has. In 10s, the position is out of the overlapping portion 10w located on the inner side in the width direction. Due to such a positional relationship, in the present embodiment, the force cloth attachment clip 70 is appropriately attached to the side frame 10 so as not to interfere with the overlapping portion 10w.

The force cloth attachment clip 70 inserted into the lower insertion hole 13z is attached to the side frame 10 at a position around the overlapping portion 10w. On the other hand, a cutout-shaped escape portion 10u is formed in the overlapping portion 10w. This makes it possible to more effectively avoid the interference with the overlapping portion 10w when the force cloth attachment clip 70 inserted into the lower insertion hole 13z is attached to the side frame 10.

In the present embodiment, the folded end 10s of the pair of ends 10s and 10t included in the separated region 10y is relatively short in order to avoid interference with the webbing attachment clip 70. ing. Further, the above-mentioned end portion 10s forms the closed space C by joining the two overlapping portions 10v and 10w, but since the above-mentioned escape portion 10u is formed in the vicinity of the lower insertion hole 13z. As shown in FIG. 10, it is not closed space C but opened. However, the present invention is not limited to this, and the formation position of the lower insertion hole 13z is shifted rearward from the position shown in FIG. 10, and the closed space C is formed in the vicinity of the lower insertion hole 13z. It may be.

Further, in the present embodiment, the lower insertion hole 13z is a non-concave portion in which the above-mentioned concave portions (the first concave portion 20 and the second concave portion 21) are not formed in the side wall portion 13, as shown in FIG. 5B. Is formed in.

<<Installation of reclining device>>
In the present embodiment, the reclining device 80 is attached to the lower end portion of the seatback frame F1, more specifically, to the lower end portion of the side wall portion 13 of the outer part 11 forming the side frame 10. More specifically, a mounting hole 13b for mounting the reclining device 80 is formed in the lower end portion of the side wall portion 13. As shown in FIG. 13, the mounting hole 13b has a substantially inverted keyhole shape in a side view. That is, the lower portion of the mounting hole 13b is circular and the upper portion is substantially rectangular.

Further, in the present embodiment, the first bracket 82 is interposed between the side wall portion 13 and the reclining device 80 in the width direction, and the reclining device 80 is attached to the side wall portion 13 via the first bracket 82. There is. The first bracket 82 is made of a relatively thick steel plate, and as shown in FIG. 13, has a substantially inverted keyhole-shaped base portion 82a and a protruding portion 82b protruding outward in the width direction from the upper end portion of the base portion 82a. Have. One end of the spiral spring 85 is engaged with the projecting portion 82b. That is, the urging force of the spiral spring 85 directly acts on the projecting portion 82b.

The base portion 82a includes a ring-shaped lower portion and a rectangular frame-shaped upper portion, and is welded to the outer surface (the surface facing the width direction outer side) of the side wall portion 13. More specifically, of the outer side surface of the side wall portion 13, while the base portion 82a is in contact with the edge portion of the mounting hole 13b, by irradiating the laser for welding from the width direction inner side of the side wall portion 13, the base portion 82a is welded to the outer surface of the side wall portion 13. In addition, at the time of laser irradiation, laser is irradiated along the outer edge of the substantially inverted keyhole type mounting hole 13b. This makes it possible to increase the welding strength as compared with the case of irradiating the laser in a simple circular shape. Further, in the case of irradiating the laser as described above, welding can be performed at a position distant from the reclining shaft 81 as compared with the case of irradiating the laser in a simple circular shape. Further, by irradiating the laser as described above, welding is performed up to the upper end portion of the base portion 82a. As a result, the welding strength at the upper end of the base portion 82a provided with the projecting portion 82b is increased, and the supporting state of the projecting portion 82b that receives the biasing force from the spiral spring 85 can be stabilized.

Further, a reclining device 80 (strictly speaking, a casing of the reclining device 80) is welded to a surface of the base portion 82a located on the side opposite to the side wall portion 13. Further, the spiral spring 85 is arranged outside the reclining device 80 in the width direction. Furthermore, in the present embodiment, the second bracket 83 and the third bracket 84 are interposed between the reclining device 80 and the spiral spring 85 in the width direction.

The second bracket 83 is joined (welded) to the reclining device 80 on the side opposite to the first bracket 82. Further, as shown in FIG. 13, the second bracket 83 is formed with a through hole 83a having a circular hole shape. A portion of the reclining shaft 81 that protrudes outward in the width direction from the casing of the reclining device 80 is inserted into the through hole 83a.

As shown in FIG. 13, the third bracket 84 has a ring-shaped base portion 84a and a protruding portion 84b protruding outward in the width direction from the upper end portion of the base portion 84a. The base portion 84a is welded to the outer surface of the second bracket 83 (the surface opposite to the side where the reclining device 80 is welded). More specifically, of the outer surface of the second bracket 83, the laser beam for welding is emitted from the outer side in the width direction of the second bracket 83 in a state where the base portion 84a is in contact with the edge portion of the through hole 83a. By doing so, the base portion 84 a is welded to the outer surface of the second bracket 83. The other end of the spiral spring 85 is locked to the projecting portion 82b. One end of the spiral spring 85 is locked to the protruding portion 82b of the first bracket 82 and the other end is locked to the protruding portion 84b of the third bracket 84, so that the seat back S1 is moved forward. Is urged to.

With the configuration described above, in the present embodiment, the reclining device 80 is properly attached to the side frame 10 made of a relatively thin steel material.

10 side frame 10a closed cross-section structure part 10b open cross-section structure part 10s, 10t end part 10v, 10w overlapping part (two parts)
10u Escape part 10x Adjacent area 10y Separation area 11 Outer part 12 Inner part 13 Side wall part 13a Flange part 13b Mounting hole 13x Engagement hole 13y, 13z Insert hole 14 Rear wall part 14a Flange part 14b Rear wall bead 15 Parts upper part 16 parts Central part 17 Lower part 20 First recess (recess)
21 Second recess (recess)
22 Convex Bead 23 Weak Section 30 Upper Frame (Connecting Frame)
31 Horizontal part (first extension part)
31a Protuberance 32 Downward extension (second extension)
32a Lower end part 32b Oblique part 33 Connecting plate 34 Pillar guide 50 Lower member frame 60 S spring (supporting member)
70 Power cloth mounting clip (power cloth mounting member)
80 Reclining device 81 Reclining shaft 82 First bracket 82a Base part 82b Overhanging part 83 Second bracket 83a Through hole 84 Third bracket 84a Base part 84b Overhanging part 85 Swirl spring C Closed space F1 Seat back frame F2 Seat cushion frame Q Gap RL Lower rail RU Upper rail S Main seat (vehicle seat)
S1 Seat back S2 Seat cushion S3 Headrest P Pad material W Skin material XL Rotation link

Claims (12)

A seat frame having side frames provided at both ends in the width direction of a vehicle seat,
The side frame is
A closed cross-section structure portion that forms one end in the extension direction of the side frame and has a closed cross-section structure in a cross section that intersects the extension direction;
An open cross-section structure part forming a continuous part with the closed cross-section structure part in the extending direction, wherein the cross-section is an open cross-section structure,
A gap formed by a continuous portion of the open cross-section structure section being interrupted is adjacent to the open cross-section structure section at a position adjacent to the closed cross-section structure section in the extending direction. A seat frame, which is larger than a region in a separated region located at a position away from the closed cross-section structure portion in the extending direction. The seat frame according to claim 1, wherein the gap in the adjacent region is larger as it is farther from the closed cross-section structure portion in the extending direction. The separation region has a pair of end portions located in a position adjacent to the gap, in a continuous portion in the cross section,
At least one end portion of the pair of end portions of the separation region has two portions that overlap by being folded back in the width direction, and a closed space is formed by joining the two portions. The seat frame according to claim 1 or 2, wherein the seat frame is provided. A connecting frame for connecting between the side frames,
The connecting frame has a first extending portion extending in the width direction, and second extending portions located on both sides of the first extending portion in the width direction and extending toward the side frame, Equipped with
The second extending portion is inserted inside the one end portion in the extending direction of the closed cross-section structure portion,
The seat frame according to any one of claims 1 to 3, wherein the adjacent region is adjacent to the other end portion of the closed cross-section structure portion in the extending direction. The part of the second extending portion that has entered the inside of one end of the closed cross-section structure part in the extension direction is joined to the closed cross-section structure part. Seat frame. The seat frame according to claim 3, wherein a length of the adjacent region in the extending direction is shorter than a length of the closed cross-section structure portion in the extending direction. The adjacent region has a pair of end portions located in a position adjacent to the gap in a continuous portion in the cross section,
A supporting member, which is installed between the side frames in the width direction to support an occupant, is attached to the side frame,
7. The mounting position of the support member is the same position as the adjacent region in the extending direction, and is a position apart from the pair of end portions of the adjacent region. The seat frame according to any one of 1. The adjacent region has a pair of end portions located in a position adjacent to the gap in a continuous portion in the cross section,
A force cloth attachment member for attaching the energy cloth of the airbag is attached to the side frame,
The mounting position of the webbing mounting member is the same position as the adjacent region in the extending direction, and is a position apart from the pair of end portions of the adjacent region. The seat frame according to any one of items 1 to 7. 9. The seat frame according to claim 8, wherein an attachment position of the webbing attachment member is a position facing one end of the pair of end portions of the adjacent region in the width direction. .. The separation region has a pair of end portions located in a position adjacent to the gap, in a continuous portion in the cross section,
At least one end portion of the pair of end portions of the separation region has two portions that are folded back and overlap each other in the width direction,
A force cloth attachment member for attaching the energy cloth of the airbag is attached to the side frame,
The seat frame according to any one of claims 1 to 7, wherein a mounting position of the brace cloth mounting member is a position deviated from one of the two parts. The webbing attachment member is attached to a peripheral position of the one portion of the side frame,
The seat frame according to claim 10, wherein the one portion is provided with an escape portion formed to intersect with the webbing attachment member. The separation region has a pair of end portions located in a position adjacent to the gap, in a continuous portion in the cross section,
At least one end portion of the pair of end portions of the separation region has two portions that are folded back and overlap each other in the width direction,
The side frame includes a reinforcing portion formed at the same position as the two portions in the extending direction, and a fragile portion formed at a position rearward of the reinforcing portion. The seat frame according to any one of 1 to 11.