JP2010046162A - Frame structure of vehicle seat back and vehicle seat back with the structure - Google Patents

Abstract

[PROBLEMS] To achieve the weight reduction of the entire structure while ensuring the necessary strength for the seat back while being able to flexibly respond to the space constraints required for the frame structure without reducing the manufacturing efficiency. A vehicle seat back frame structure is provided.
In order to form a frame skeleton of a seat back, a vehicle seat back frame having a plate-like side frame 12 disposed so that a plate width is positioned in the front-rear direction of the vehicle in a pair of left and right seat backs. Each of the side frames 12 has a structure in which the plate-like side frame 12 is closed in a direction substantially orthogonal to the height direction at each of the front edge portion 22 and the rear edge portion 24 over the entire height direction. A vehicular seat back frame structure having a closed cross-section portion 26 which is cut in cross section.
[Selection] Figure 1

Description

The present invention relates to a frame structure for a vehicle seat back and a vehicle seat back having the structure, and more specifically, a vehicle seat that achieves weight reduction while securing the strength of the vehicle seat back in the vehicle seat. The present invention relates to a frame structure of a back and a vehicle seat back having the structure.

Conventionally, a vehicle seat has a seat cushion having a lower portion fixed to a passenger compartment floor portion, and a seat back having a lower portion supported by a rear portion of the seat cushion. A type that cannot be moved forward in an upright state has been adopted.

Such a vehicle seat back includes a seat back frame that forms a frame structure of the vehicle seat back, and a pad that covers the seat back frame, an outer trim, and the like are provided on the seat back frame.
The seat back frame structure is roughly classified into a type in which the whole is configured in a frame shape and a flat panel type.

With respect to the former type, conventionally, a frame structure of a vehicle seat back that employs a pair of side frames has been used. More specifically, the frame structure of such a vehicle seat back is such that the upper ends of a pair of side frames are spanned by an upper frame, and the lower ends are connected by a lower frame, so that the vehicle seat back as a whole A strength member is formed as a frame structure. Each of the pair of side frames is disposed so that the plate width faces the front-rear direction of the vehicle.
In such a frame structure of a vehicle seat back, for example, as disclosed in Patent Document 1, a so-called tailored blank material is known.
Here, the tailored blank material is a known press material that can be prepared by combining a plurality of steel materials according to the purpose by welding.

The frame structure of this type of vehicle seat back will be described in more detail. In the seat back frame structure, plate-like side frames are arranged at the left and right positions of the seat back. An upper frame is bridged around the upper end of the side frame and is rigidly connected to each other. On the other hand, a lower frame is similarly bridged at the lower end of the side frame, and these are similarly rigidly connected to each other. The lower side of the side frame is supported by a pivoting shaft (not shown) for reclining the seat back.

The side frame is formed by pressing a so-called tailored blank material in which side portions of a plurality of plates made of the same material or different materials are abutted and welded from the upper part of the seat back toward the lower part. More specifically, the front part of the abutting surface in the width direction of the abutting surface is abutted and welded in a state where it is inclined in the in-plane downward direction of the plate surface with respect to the rear side part, and the flange portion having a cross-sectional shape of "K" Have.
According to such a tailored blank material, since the abutting surfaces of the respective plate materials are joined by continuous wire welding, it is possible to obtain a high bond strength at each joint portion.
More specifically, the bending moment acting on the side frame is distributed so as to gradually increase from the upper part of the side frame toward the lower part (rotating shaft for seat reclining). By optimally arranging plate materials having a plate thickness (section modulus) that can correspond to the size, it is possible to provide each part with the required strength while limiting the amount of plate material used to the minimum necessary.

However, the frame structure of the vehicle seat back of this type has the following technical problems.

1stly, when employ | adopting a tailored blank material, it is necessary to prepare a some steel plate and to join each abutting surface by continuous wire welding. Therefore, the manufacturing efficiency of the frame structure of the vehicle seat back is lowered, and the manufacturing cost of the frame structure of the vehicle seat back is increased. In particular, since the abutting surfaces of a plurality of steel plates are joined by welding, it is necessary to butt weld each steel plate in an inclined state in order to increase the abutting area in order to ensure high bonding strength. is there. Such welding work further reduces the manufacturing efficiency of the frame structure of the vehicle seat back. This is especially true when a plurality of steel plates of different materials are used as the tailored blank material.

Secondly, when the tailored blank material is employed, it is difficult to ensure the degree of freedom in designing the vehicle seat back. More specifically, in the case of a tailored blank material, the required strength is realized by selecting the thickness or material of each of a plurality of steel plates. However, it is strongly desired that a design parameter for determining the strength can be ensured by ensuring a parameter other than the plate thickness or the material, so that a flexible design can be performed.
In particular, since the space itself occupied by the frame structure of the vehicle seat back has a great influence on the vehicle interior space, the space required for the frame structure is ensured while ensuring the strength required for the frame structure of the vehicle seat back. There is a need to provide a frame structure that can be flexibly handled according to the constraints.
JP 2006-51272 A

In view of the above technical problems, the object of the present invention is to ensure the necessary strength for the seat back while allowing flexibility to meet the space constraints required for the frame structure without reducing the manufacturing efficiency. However, an object of the present invention is to provide a frame structure for a vehicle seat back that achieves weight reduction of the entire structure.

In order to solve the above problems, a frame structure of a vehicle seat back according to the present invention includes:
For a vehicle having a plate-like side frame having a uniform plate thickness, which is arranged so that a plate width is positioned in the front-rear direction of the vehicle in order to form a frame skeleton of the seat back. A seat back frame structure,
Each of the side frames has a closed cross-sectional portion in which a plate-shaped side frame is closed in a direction substantially orthogonal to the height direction at each of the front edge portion and the rear edge portion over the entire height direction. It is configured.

According to the frame structure of the vehicle seat back having such a configuration, the pair of left and right side frames functioning as strength members does not have a uniform thickness on the safety side over the entire thickness. In addition, for example, only the left and right edges that are effective in securing the bending rigidity acting in the front-rear direction of the vehicle are closed in the direction perpendicular to the height direction over the entire height direction. By providing the part, it is possible to reduce the weight while securing the required strength or necessary rigidity of the vehicle seat back through securing the section modulus corresponding to the position necessary to ensure the necessary rigidity for strength. Can be achieved.

When selecting the shape of the closed cross section, for example, if the closed cross section is a rectangular cross section, select the height or width to meet the space constraints required for the frame structure of the vehicle seat back. By doing so, it is possible to respond flexibly to the design.

The closed section has a rectangular cross section, and presses the edge of the plate-like side frame in a multi-step manner so that one surface portion of the edge of the plate-like side frame is formed. It is good to form in the form which abuts the other surface part of a plate-shaped side frame.
Furthermore, the height and width of the rectangular cross section may be adjusted independently of each other by selecting a mold used for multi-step pressing.
Furthermore, it is preferable that one surface portion of the edge portion of the plate-like side frame is fixed to the other surface portion of the plate-like side frame by welding in the butt portion.
In addition, an upper frame is bridged over the upper ends of the pair of left and right side frames,
A lower frame is bridged between lower ends of the pair of left and right side frames,
A lower arm is attached to each lower end portion of the pair of left and right side frames via a recliner,
The lower arm is a plate-like shape arranged so that the plate width is positioned in the front-rear direction in the pair of left and right seat backs,
Each of the lower arms may have a closed cross-sectional portion in which a plate-shaped lower arm is closed in a direction substantially orthogonal to the height direction at each of the front edge portion and the rear edge portion over the entire height direction. .

In addition, the closed section of the lower arm has a rectangular cross section, and by pressing the edge of the plate-like lower arm in multiple stages, one surface portion of the edge of the plate-like lower arm It is good to form in the form which butts the other surface part of a plate-shaped lower arm.
Furthermore, the height and width of the rectangular cross section of the closed section of the lower arm can be adjusted independently of each other by selecting a die used for multi-step pressing. Is good.
Furthermore, it is preferable that the pair of left and right side frames have a trapezoidal shape in which the plate width increases toward the upper end.
Further, each of the pair of left and right side frames may have a plurality of openings aligned in a height direction between closed cross-sectional portions provided at front and rear edges.

In order to solve the above-described problems, a vehicle seat according to the present invention includes:
A vehicle seat back having the frame structure according to any one of claims 1 to 8, and a seat cushion having a lower portion fixed to a passenger compartment floor.

According to the vehicle seat having such a configuration, in the pair of left and right side frames functioning as strength members, the plate thickness is not uniform and thick on the safety side over the entire strength, for example, To provide a closed section that is closed in the direction perpendicular to the height direction over the entire height direction only on the left and right edges, which are effective to ensure bending rigidity acting in the longitudinal direction of the vehicle. Therefore, it is possible to achieve weight reduction while ensuring the necessary strength or necessary rigidity of the vehicle seat back through securing the section modulus corresponding to the position necessary to ensure the necessary rigidity for strength. it can.
When selecting the shape of the closed cross section, for example, if the closed cross section is a rectangular cross section, select the height or width to meet the space constraints required for the frame structure of the vehicle seat back. By doing so, it is possible to respond flexibly to the design.

According to the frame structure of the vehicle seat back and the vehicle seat back having the structure according to the present invention, in the plate-like side frame functioning as the strength member, the plate thickness is set on the safety side in terms of strength over the entire flat plate. The required strength or necessary strength of the vehicle seat back is ensured by ensuring the section modulus by making the closed section corresponding to the position necessary to ensure the rigidity necessary for strength without making it uniform thick. Weight reduction can be achieved while ensuring rigidity.

The embodiment of the vehicle seat according to the present invention will be described in detail below with reference to the drawings, taking as an example a case where the vehicle seat is applied to a rear seat of an automobile.
FIG. 1 is a schematic perspective view of a frame structure of a vehicle seat back according to an embodiment of the present invention. FIG. 2 is a side view of the side frame of the frame structure of the vehicle seat back according to the embodiment of the present invention. 3 is a cross-sectional view taken along line AA in FIG. 4 is a cross-sectional view taken along line BB in FIG. FIG. 5 is a cross-sectional view taken along the line CC of FIG. 6 is a cross-sectional view taken along the line DD in FIG. FIG. 7 is a schematic view of a mold used for the drawing process when the side frame is closed. FIG. 8 is a schematic view of a mold used for the first flange down process when the side frame is closed. FIG. 9 is a schematic view of a mold used in the second flange down process when the side frame is closed. FIG. 10 is a schematic view of a mold used in the cam bending process when the side frame is closed. FIG. 11 is a closed cross section of the panel processed in the cam bending process of FIG. FIG. 12 is a schematic view of a mold used in the shaping process when the panel is closed.

The vehicle rear seat according to the present invention has a seat cushion whose lower part is fixed to the passenger compartment floor part, and a seat back whose lower part is supported at the rear part of the seat cushion. Reclining is possible.
The vehicle rear seat includes a pad (not shown) attached to the front side of the vehicle seat back frame structure so as to cover the entire front surface of the vehicle seat back frame structure, which will be described later, and a vehicle seat back frame structure and pad. And a bag-like skin (not shown) are provided.

As shown in FIG. 1, the vehicle seat back frame structure includes a plate-like side frame 12 that is disposed such that a plate width is positioned in the front-rear direction of the vehicle with a pair of left and right seat backs. Each side frame 12 is made of steel, for example, SPFC980Y (plate thickness 1.0 mm). Since the bending moment acting on each side frame 12 increases toward the lower side, each side frame 12 has a trapezoidal shape in which the plate width increases toward the upper side, as shown in FIG. An upper frame 14 is bridged between the upper ends of the pair of left and right side frames 12 and is rigidly coupled at each upper end, while a lower frame 16 is bridged between the lower ends of the pair of left and right side frames 12 at It is rigidly connected. The upper frame 14 and the lower frame 16 are made of steel, like the side frame 12, and examples thereof include PFC780Y (plate thickness 0.8 mm). As described above, the pair of left and right side frames 12, the upper frame 14, and the lower frame 16 constitute a vehicle seat back frame structure that functions as a strength member.

As shown in FIG. 1, regarding the upper frame 14 arranged in an inverted U-shape, unlike the side frame 12, the upper frame 14 is not formed from a single plate material having a uniform plate thickness. As shown in FIGS. 3 and 4, it is formed by pressing two plate members 29 having a uniform plate thickness. FIG. 3 shows a cross section of the horizontal portion 31, while FIG. 4 shows a cross section of the vertical portion 33. As shown in FIGS. 3 and 4, the horizontal portion 31 is formed of a rectangular cross section 26 by two plates 29, while the vertical portion 33 has a cross-sectional “U” shape. On the other hand, the other plate material 29 is pressed so as to have a rectangular concave and convex concave section, and these plate materials 29 are welded to have closed cross-section portions 27A and B on both edges. That is, closed cross sections 27 </ b> A and 27 </ b> B are formed by covering the open portions of the recesses with one plate material 29 with respect to the recesses provided on both edge portions of the other plate material 29. Thereby, as will be described later, it is possible to similarly fix the upper end surface of the side frame 12 having the closed cross-sectional portions 35 at both edges by butt welding.

A lower arm 20 is attached to the lower ends of the pair of left and right side frames 12 via a recliner 18 so that the back seat can be moved forward from the upright position with respect to the seat cushion. The seat cushion can be moved backward from the upright position while being locked at an adjustment pitch of 2 °. Since such a recliner structure is conventionally known, detailed description thereof is omitted here.
The characteristics of the pair of left and right side frames 12 will be described. Each side frame 12 extends in the direction substantially perpendicular to the height direction at each of the front edge portion 22 and the rear edge portion 24 over the entire height direction. The plate-like side frame 12 has closed cross-section portions 35A and B26 that have a closed cross-section. More specifically, FIG. 5 shows a cross-sectional view of the upper part of the side frame 12, and FIG. 6 shows a cross-sectional view of the lower part of the side frame 12. As shown in FIGS. 5 and 6, each of the closed cross-section portions 35A and 35B has a rectangular cross section, and the edge of the plate-like side frame 12 is pressed in a multi-step manner to form a plate shape. One surface portion of the edge portion of the side frame 12 is abutted against the other surface portion of the plate-like side frame 12, and one surface portion is fixed to the other surface portion by, for example, laser welding. The A detailed manufacturing method will be described later.

The height h and width w of the rectangular closed cross-section portions 35A, B are, for example, the section modulus required for the strength closed cross-section portions 35A, B in view of space restrictions on the frame structure of the seat back. The height h and the width w may be adjusted while ensuring the above. In this respect, for example, the degree of freedom in design can be ensured as compared with a case where strength is ensured by locally thickening the edge of the side frame 12.

Each of the pair of left and right side frames 12 has a trapezoidal shape in which the plate width increases toward the upper end, and a plurality of openings 30 aligned in the height direction between the closed cross-section portions 35A and 35B provided at the front and rear edges. Have The plane portion between the front and rear edge portions of the side frame 12 is not critical in strength as compared with the front and rear edge portions. Therefore, by providing a plurality of openings 30 aligned in the height direction at the portion, the weight can be further reduced. Can be achieved. Note that the shape, size, or number of the openings 30 may be appropriately selected within a range that does not cause a problem in strength.

As shown in FIG. 6, the lower arm 20 has closed cross sections 37 </ b> A and 37 </ b> B, like the side frame 12. More specifically, each of the lower arms 20 has a closed cross section in which the plate-like lower arm 20 is closed in a direction substantially perpendicular to the height direction at each of the front edge portion and the rear edge portion over the entire height direction. Parts 37A and 37B. More specifically, the closed cross sections 37A and B have a rectangular cross section, and the edge of the plate-like lower arm 20 is formed by pressing the edge of the plate-like lower arm 20 in multiple steps. The one surface portion is abutted against the other surface portion of the plate-like lower arm 20, and the one surface portion is fixed to the other surface portion by, for example, laser welding.

As clearly shown in FIG. 6, the closed section of the side frame 12 and the closed section of the lower arm 20 are in a back-to-back positional relationship via the recliner 18, in other words, the recliner 18. The flat surface portion of the side frame 12 is abutted against one of the surfaces, and the flat surface portion of the lower arm 20 is abutted with the other surface of the recliner 18.
As shown in FIGS. 1 and 6, from the viewpoint of reducing the weight while ensuring a predetermined strength, the closed cross-section portion of the side frame 12 and the closed cross-section portion of the lower arm 20 are arranged in the height direction. Are not overlapped, and the closed cross sections 37A, B of the lower arm 20 extend downward from the end heights of the closed cross sections 35A, B of the side frame 12.

When the closed cross-section portions 35A and 35B of the side frame 12 have a closed cross-section of a plate material having a constant thickness with respect to the height (h1, h2) and / or width (w1, w2) of the closed cross-section portions 35A and B In addition, the height or the width may be appropriately selected so as to meet other constraints within a range in which a necessary section modulus is ensured. For example, when the extension of the side frame 12 in the left-right direction is restricted due to space restrictions, the height of the closed cross-section portions 35A and 35B is limited, and the width is secured accordingly. It is also possible. Conversely, when the space in the front-rear direction of the side frame 12 is restricted due to space restrictions, the width of the closed cross-sections 35A, B is limited and the height is secured accordingly. It is also possible to deal with it. As described above, only the plate material having a uniform plate thickness is prepared for the side frame 12, and the whole is aligned with the plate thickness of the critical portion in terms of strength by providing the closed cross-section portions 35A and 35B by pressing it. Without conversely, after aligning the thickness of the part where there is no problem in strength, by providing the closed cross-section 35A, B locally, while securing the necessary strength while achieving weight reduction as a whole It becomes possible to do.

Here, the manufacturing method of the side frame 12 having such a closed cross-sectional structure will be schematically described below. The manufacturing method of the side frame 12 includes a drawing process, a first flange down process, a second flange down process, a cam bending process, and a shaping process. The side cross-section processing of the side frame 12 is performed on the flat side frame 12 before the opening 30 is provided.
First, in the squeezing step, as shown in FIG. While the side frame 12 is positioned between the presser 92 and the spring 94 is contracted, the upper die 96 is lowered toward the lower die 90 to form a step portion D1 on the side frame 12.

Next, in the first flange down process, as shown in FIG. 8, the side frame 12 formed with the stepped portion is mounted on another first flange down mold 100. The first flange down mold 100 is engaged with the lower mold 102, the presser 104 installed above the lower mold 102, and the presser 104 via the spring 106. And an upper mold 104 having the same oblique portion. The lower mold 102 includes a first oblique portion 106 that coincides with the step portion D1 formed on the side frame 12, a second oblique portion 108 formed at the end, a first oblique portion 106, and a second oblique portion 108. And a horizontal portion 110 formed between the two. Using such a first flange down mold 100, the side frame 12 is positioned between the presser 104 and the lower mold 102 so that the step portion D of the side frame 12 is aligned with the first oblique portion 106. While the spring 106 is contracted, the upper die 104 is lowered toward the lower die 102 to form an oblique portion D2 at the end of the side frame 12.

Next, in the second flange down process, as shown in FIG. 9, the side frame 12 in which the oblique portion D <b> 2 is formed is attached to another second flange down mold 112. The second flange down mold 112 includes a lower mold 114, a presser 116 that is installed above the lower mold 114, and an upper mold 120 that engages the presser 116 via a spring 118. The lower die 114 has the same configuration as the first oblique portion 106, the horizontal portion 110, and the second oblique portion 108 of the lower die of the first flange down mold, and further continues to the second oblique portion 108 at the end. The vertical portion 122 is provided. On the other hand, the upper mold 120 has a recess 124, and a vertical portion 126 is formed in the recess 124. Using the second flange down mold 112, the side frame 12 is positioned between the presser 116 and the lower mold 114 so that the side frame 12 is aligned with the first oblique portion, the horizontal portion, and the second oblique portion. In this state, the upper mold 120 is lowered toward the lower mold 114 while the spring 118 is contracted to form the vertical portion D3 at the end of the side frame 12.

Next, in the cam bending step, as shown in FIG. 10, the side frame 12 in which the vertical portion D <b> 3 is formed is attached to another cam bending die 128. The cam bending die 128 includes a first lower die 130, a presser 132 installed above the first lower die 130, an upper die 136 that engages the presser 132 via a spring 134, and the upper die 136. A second lower mold 138 engaged with the second lower mold 138. On the lower surface of the presser 132, a shape complementary to the first oblique portion, the horizontal portion, and the second oblique portion is formed. The upper mold 136 has a concave portion 140, and the vertical portion 142 of the concave portion 140 is disposed so as to face the end portion of the presser 132. The upper mold 136 has an oblique portion 144 below the vertical portion 142 of the recess 140. The second lower mold 138 has an upper surface 146 and an oblique portion 148 having an inclination similar to that of the oblique portion 144 of the upper mold 136, and the oblique portions are in surface contact with each other. Thereby, when the upper mold | type 136 is moved below, the 2nd lower mold | type 138 is comprised so that it may move to a horizontal direction via an oblique part. Using such a cam bending mold 128, the side frame 12 is positioned between the presser 132 and the first lower mold 130 so that the side frame 12 is aligned with the first oblique portion, the horizontal portion, and the second oblique portion. In this state, when the upper die 136 is moved downward while the spring 134 is contracted, the second lower die 138 is moved in the horizontal direction, so that the vertical portion of the end portion of the side frame 12 is moved to the second lower die 138. Bent by the right side. In order to make the bending portion formed in this way approach 90 ° bending, the same process is performed twice using such a cam bending die 128. FIG. 11 shows the shape of the side frame 12 when the same process is performed twice.

Next, in the shaping step, as shown in FIG. 12, an upper mold 152 having a recess 150 that opens downward in a shape that matches the closed cross-sectional shape of the side frame 12, and a lower mold 154 that has a flat upper surface. A side frame 12 having a bent portion is mounted on a mold 156, and pressing is performed again to adjust the shape and form a desired closed cross-sectional shape.

Thus, a closed cross-sectional structure is formed on one side of the side frame 12. In order to form a closed cross-sectional structure on the other side, the same process as described above may be performed. Note that a butt portion between one surface of the end of the side frame 12 and the other surface portion of the side frame 12 may be fixed by, for example, welding. This completes the manufacture of the panel. Incidentally, when the closed cross section 26 is provided in the lower arm 20, it may be separately performed by the same method as described above.

When changing the width of the closed cross-section structure to be formed, the length of the horizontal portion 110 of the lower mold 102 of the first flange down mold 100 and the presser 104 having a shape corresponding thereto are changed, and the one is formed. In order to change the height of the closed cross-sectional structure, the depth of the concave portion 140 of the upper die 136 of the cam bending die 128 may be changed. What is necessary is just to select a required metal mold | die according to the width | variety and height of a structure.

As described above, by using the side frame 12 having a uniform plate thickness, the left and right side portions are each processed to have a closed cross section, so that the cross section of the closed cross section 26 corresponds to the bending moment acting on the side frame 12. By adjusting the coefficient and reducing the overall weight while ensuring the required strength, there is no need to increase the overall thickness of the plate, so the optimal plate thickness can be set. Is possible. Since it is possible to ensure the required rigidity or strength by such a simplified structure, it is possible to avoid the complexity of the structure or the increase in the number of parts, thereby enabling the dimensional accuracy and production of each part. It is also possible to improve the performance.

As a modification, a configuration of the side frame 12 in which a conventional tailored blank material and a closed cross section are combined may be employed.
According to such a configuration, by providing closed cross-section portions having different sizes in the height direction of the side frame 12, the outer shape of the side frame 12 is a trapezoidal shape having a narrow width in the height direction as described above. Instead, it can be rectangular.

More specifically, a plurality of, for example, three types of tailored blank materials having a common thickness are prepared with the plate width of the side frame 12 being constant, and the closed cross-section portions 35A and 35B are provided for each tailored blank material. The heights of the tailored blank materials are different from each other in the order of the tailored blank materials having the closed cross-section portions 35A and 35B having a large width W, that is, having a large section modulus. It is a configuration that accumulates. In this case, each tailored blank material can be abutted at the plate width portion of the side frame 12 and the outer flange portion that constitutes a part of the closed cross-section portions 35A and 35B before and after that, and is firmly fixed by welding. It is possible.
As described above, by providing different closed cross-section portions 35A and B in the height direction, it is possible to adopt a rectangular shape having a constant plate width in the height direction as the overall shape of the side frame 12.

Although the embodiments of the present invention have been described in detail above, various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention. For example, in the present embodiment, the closed cross-section portions provided on the front and rear edges of the side frame 12 have been described on the premise that the closed cross-section portions have a rectangular shape with respect to the height and width. For example, a trapezoidal shape or the like is applicable without being limited to the rectangular shape.
Furthermore, when the vehicle seat is a rear seat, a reinforcing frame fixed to the frame structure may be separately provided in order to withstand the load caused by the movement of the luggage placed in the luggage compartment. According to the present invention, it is possible to substantially cancel the increase in weight associated with the installation of such a reinforcing frame.

The frame structure of a panel-type vehicle seat back according to the present invention and the vehicle seat back having the structure are used not only for automobiles but also for general vehicles that are transported in the state where a person such as a railway vehicle or an airplane is seated on the seat. In a flat panel frame that can be applied and functions as a strength member, the rigidity required for strength can be obtained without making the thickness of the flat plate uniform over the entire plate. It is possible to ensure the section modulus by the closed section structure corresponding to the position required to secure the vehicle, and in this respect, weight reduction while ensuring the necessary strength or necessary rigidity of the vehicle seat back To achieve.

1 is a schematic perspective view of a frame structure of a vehicle seat back according to an embodiment of the present invention. It is a side view of the side frame 12 of the frame structure of the vehicle seat back which concerns on embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which follows the CC line of FIG. It is sectional drawing which follows the DD line | wire of FIG. It is the schematic of the metal mold | die used for a drawing process in making the closed cross section of the side frame 12. FIG. It is the schematic of the metal mold | die used for a 1st flange down process in the case of making the closed cross section of the side frame 12. FIG. It is the schematic of the metal mold | die used for a 2nd flange down process in making the closed cross section of the side frame 12. FIG. It is the schematic of the metal mold | die used for a cam bending process in making the closed cross section of the side frame 12. FIG. It is the closed cross-section part 26 of the panel processed at the cam bending process of FIG. It is the schematic of the metal mold | die used for a shaping process in making the closed cross section of a panel.

Explanation of symbols

h Height w Width 12 Side frame 14 Upper frame 16 Lower frame 18 Recliner 20 Lower arm 22 Front edge portion 24 Rear edge portion 30 Opening 31 Horizontal portion 33 Vertical portion 35 Closed section 37 Closed section 98 Drawing die 100 First Flange down mold 112 Second flange down mold 128 Cam bending mold 156 Shaping mold

Claims (10)

For a vehicle having a plate-like side frame having a uniform plate thickness, which is arranged so that a plate width is positioned in the front-rear direction of the vehicle in order to form a frame skeleton of the seat back. A seat back frame structure,
Each of the side frames has a closed cross-sectional portion in which a plate-shaped side frame is closed in a direction substantially orthogonal to the height direction at each of the front edge portion and the rear edge portion over the entire height direction.
A vehicle seat back frame structure.     The closed section has a rectangular cross section, and one surface portion of the edge of the plate-like side frame is plate-like by pressing the edge of the plate-like side frame in multiple steps. The frame structure of the vehicle seat back according to claim 1, wherein the frame structure is formed to abut against the other surface portion of the side frame.     3. The vehicle seat back according to claim 2, wherein the height and width of the rectangular cross section can be adjusted independently of each other by selecting a mold used for multi-step pressing. Frame structure.     4. The vehicle seat back according to claim 2, wherein at the abutting portion, one surface portion of the edge portion of the plate-like side frame is fixed to the other surface portion of the plate-like side frame by welding. Frame structure. An upper frame is bridged over the upper ends of the pair of left and right side frames,
A lower frame is bridged between lower ends of the pair of left and right side frames,
A lower arm is attached to each lower end portion of the pair of left and right side frames via a recliner,
The lower arm is a plate-like shape arranged so that the plate width is positioned in the front-rear direction in the pair of left and right seat backs,
Each of the lower arms has a closed cross-sectional portion obtained by closing the plate-like lower arm in a direction substantially perpendicular to the height direction at each of the front edge portion and the rear edge portion over the entire height direction.
The frame structure of the vehicle seat back according to any one of claims 1 to 4.     The closed cross-section portion of the lower arm has a rectangular cross section, and by pressing the edge of the plate-like lower arm in multiple stages, one surface portion of the edge of the plate-like lower arm is plated The frame structure of the vehicle seat back according to claim 5, wherein the frame structure is formed so as to abut against the other surface portion of the shaped lower arm.     The height and width of the rectangular cross section of the closed section of the lower arm can be adjusted independently of each other by selecting a mold used for multi-stage pressing. 6. The frame structure of the vehicle seat back according to 6.     The frame structure of the vehicle seat back according to any one of claims 1 to 7, wherein each of the pair of left and right side frames has a trapezoidal shape in which a plate width increases toward an upper end.     The vehicle according to any one of claims 1 to 8, wherein each of the pair of left and right side frames has a plurality of openings arranged in a height direction between closed cross-section portions provided at front and rear edges. Seat back frame structure. A vehicle seat comprising: a vehicle seat back having the frame structure according to any one of claims 1 to 9; and a seat cushion having a lower portion fixed to a passenger compartment floor.

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