Seat back

Abstract

In a seatback in which the seatback structure is divided into three parts in the seat width direction and attached to a seatback frame, the present invention provides a seatback that suppresses the deterioration of the function of the lumbar support device. [Solution] The cushion has a frame 4, a cushion structure 5, and a lumbar support device 6. The cushion structure 5 consists of a main structure 10 and side structures 20 on both sides. The main structure 10 has a main pad 12, a main cover 13, and a main support member 11. The lumbar support device 6 is capable of locally adjusting the pressing force in the vertical direction. The main support member 11 is formed in a frame shape with a lower opening 113, and a plurality of curved portions 114 are formed in the side frame portion 111. The protrusions 123 of the main pad 12 abut against the curved portions 114 that are passed through the slits 13b of the terminal portion 13a of the main cover 13, thereby suppressing the outward movement of the curved portions 114 in the sheet width direction.

Description

Technical Field

[0001] The present invention relates to a seat back. More specifically, the present invention relates to a seat back in which a seat back structure is divided into three parts in the seat width direction and attached to a seat back frame.

Background Art

[0002] Conventionally, in the seat back of a vehicle seat equipped in a vehicle such as an automobile, a seat back structure that elastically supports the body of a seated occupant is known to be divided into three parts in the seat width direction and attached to a seat back frame. Patent Document 1 discloses a seat back configured to be divided into a seat back main part at the center in the seat width direction and seat back side parts arranged on both sides of the seat back main part. The seat back main part is configured to be attached to a main support member that supports it in a planar shape with a main pad, which is a cushion body, covered with a main cover, which is a skin material. A vehicle seat having such a seat back aims to have good assembly properties and be easy to automate the assembly, and to be easy to replace only the seat back side parts that are prone to deterioration when the occupant gets on and off.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the seat back described in Patent Document 1 above, the main part of the seat back has a structure in which the main support member abuts against a lumbar support device attached to the seat back frame. As a result, when the lumbar support device is activated, it presses against the main pad via the main support member, and although it is possible to press against the seated occupant's lower back over a relatively wide area, it is difficult to press against a specific area. Therefore, there was a need to locally adjust the pressing force of the lumbar support device in a seat back structure that is divided into three sections in the seat width direction.

[0005] In view of these demands, the object of the present invention is to provide a seat back in which the seat back structure is divided into three parts in the seat width direction and attached to a seat back frame, and which suppresses the deterioration of the function of the lumbar support device. [Means for solving the problem]

[0006] The first invention of the present invention is a seat back comprising a frame forming the skeleton, a lumbar support device attached to the frame, and a cushion structure attached to the frame for elastically supporting a seated occupant, wherein the cushion structure consists of a main structure in the center in the width direction of the seat and a pair of left and right side structures arranged on both sides of the main structure, wherein the main structure comprises a main pad which is a cushion body, a main cover which covers the main pad, and a substantially plate-shaped main support member which is attached to the frame side of the main pad and supports the main pad, wherein the lumbar support device is capable of locally adjusting the pressing force in the forward direction in the vertical direction and is arranged on the rear side of the main structure, and the main support member is such that the lumbar support device is the main support member The main pad is formed in a frame shape with an opening that allows it to directly contact the rear surface of the pad, and the outer peripheral frame portion in the seat width direction of the opening has a plurality of curved portions that curve and extend inward in the seat width direction, and the rear surface of the main pad has a plurality of projections that protrude toward the rear and are positioned on the outside in the seat width direction of the curved portions when in contact with the main support member, and the end of the main cover in the seat width direction has a plurality of slits that allow the curved portions of the main support member, when in contact with the rear surface of the main pad, to pass through in the seat width direction and lock the main cover to the main support member, and the projections contact the curved portions when they are passed through the slits and suppress the movement of the curved portions toward the outside in the seat width direction.

[0007] According to the first invention, the main support member is formed in a frame shape having an opening that allows the lumbar support device to directly contact the rear surface of the main pad. The lumbar support device is capable of locally adjusting the forward pressing force in the vertical direction. This allows the lumbar support device to directly press the main pad and apply locally different pressing forces in the vertical direction to the lumbar region of the seated occupant. Furthermore, with the main cover locked to the main support member by passing the curved portion of the main support member through a slit provided at the seat width end of the main cover, the projection can contact the curved portion to suppress its movement outward in the seat width direction. This allows the main structure to be securely attached to the main support member while suppressing a decrease in the function of the lumbar support device.

[0008] The second invention of the present invention is characterized in that, in the first invention described above, the curved portion is configured to be twisted and deformed in the front-rear direction by pressure when the lumbar support device is activated.

[0009] According to the second invention, even if the curved portion is positioned overlapping the front of a part of the lumbar support device, it twists and deforms in the front-rear direction due to the pressure from the rear when the lumbar support device is operated, so the pressure area in the seat width direction by the lumbar support device can be widened.

[0010] The third invention of the present invention is characterized in that, in the second invention described above, notches are formed at the upper and lower base portions of the curved portion in the outer peripheral frame portion, serving as weakening portions that make the curved portion more susceptible to twisting deformation.

[0011] According to the third invention, when the lumbar support device is activated, the curved portion can be more easily twisted and deformed by the pressure from the rear.

[0012] The fourth invention of the present invention is characterized in that, in the first invention or the second invention, ribs extending in the sheet width direction are erected on the front side of the curved portion.

[0013] According to the fourth invention, since the rigidity of the curved portion is maintained, it is possible to easily pass the curved portion through the slit in the main cover when assembling the main structure. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view of an automotive seat with a seatback attached according to one embodiment of the present invention. [Figure 2] The above is an exploded perspective view of the seat back. [Figure 3] The above is a front view of the seatback. The side structures have been omitted. [Figure 4] This is a cross-sectional view taken along the line IV-IV in Figure 3. [Figure 5] This is a cross-sectional view taken along the line of arrow VV in Figure 3. [Figure 6] This is a cross-sectional view taken along the line VI-VI in Figure 3. [Figure 7] This is an exploded perspective view of the frame and main structure. [Figure 8] This diagram illustrates the assembly procedure for the main structure. [Figure 9] This diagram illustrates the assembly procedure for the main structure. [Figure 10] This diagram illustrates the assembly procedure for the main structure. [Figure 11] This diagram illustrates the assembly procedure for the main structure. [Modes for carrying out the invention]

[0015] Based on Figures 1 to 11, the seat back 3 of the automobile seat 1 according to one embodiment of the present invention will be described. In the following description, the description of direction will be based on the up, down, front, back, left, and right directions shown in each figure. Here, the up, down, front, back, left, and right directions are defined based on the automobile seat 1 when it is mounted on the floor F of the automobile. The left and right direction coincides with the seat width direction.

[0016] As shown in Fig. 1, the vehicle seat 1 has a seat cushion 2 that supports the buttocks and thighs of the seated occupant, and a seat back 3 that supports the waist and back of the seated occupant.

[0017] As shown in Fig. 2, the seat back 3 has a frame 4 that forms the skeleton, a cushion structure 5 that has a cushion function and is attached on the frame 4 to define the outer shape of the seat back 3, and a lumbar support device 6 attached to the frame 4.

[0018] As shown in Fig. 2, the frame 4 has a pair of left and right side frames 41 that extend vertically on both left and right sides of the seat back 3, an upper frame 42 that connects the upper end sides of each side frame 41, and a lower frame 43 that connects the lower end sides of each side frame 41. The frame 4 is formed in a substantially rectangular frame shape when viewed from the front. A lumbar support device 6 is disposed between the upper frame 42 and the lower frame 43 of the frame 4. This lumbar support device 6 is the same as the one disclosed in JP-A-2016-172487, in which a plurality of bag bodies 61 extending in the left-right direction are arranged vertically in parallel, and air supply and exhaust to each bag body 61 can be performed individually.

[0019] As shown in Figs. 1 and 2, the cushion structure 5 has a main structure 10 at the center in the seat width direction, and a pair of left and right side structures 20 on both side portions of the main structure 10. The main structure 10 is a portion that supports the waist and back of the seated occupant from behind, and the pair of left and right side structures 20 are portions that support the waist and back of the seated occupant from the sides.

[0020] The main structure 10 has a resin-made substantially plate-shaped main support member 11, a main pad 12 that is disposed on the front side of the main support member 11 and is supported by the main support member 11 against the frame 4, and a main cover 13 that covers the main pad 12 from the front side.

[0021] As shown in Figures 2 to 4, the main support member 11 has an upper part 11c which is approximately the upper half, and a lower part 11d which is approximately the lower half. The upper part 11c and the lower part 11d are formed in a surface shape that abuts against the rear surface 12b, which is the opposite side of the front surface 12a, which is the side of the main pad 12 facing the seated person. The upper part 11c has a rectangular upper opening 11e that penetrates in the front-to-back direction, approximately in the center when viewed from the front. The lower part 11d has a pair of left and right side frame parts 111 that extend downward from the lower left and right ends of the upper part 11c, and a lower frame part 112 that connects the lower ends of each side frame part 111. The area enclosed by the lower end of the upper part 11c, each side frame part 111, and the lower frame part 112 is a lower opening 113 that penetrates in the front-to-back direction. The lower opening 113 is set to be larger than the upper opening 11e. Each side frame 111 has a pair of left and right curved sections 114 that curve and protrude inward in the seat width direction, arranged vertically. Each curved section 114 is formed in a roughly C-shape with an opening on the outside in the seat width direction when viewed from the front, and three ribs 115 extending in the left-right direction are erected on the front part opposite the C-shaped opening. In detail, as is clearly shown in Figure 5, the ribs 115 have a mountain shape when viewed from above, with the central part in the left-right direction protruding forward. When viewed from the front, the three ribs 115 extend parallel to each other in the left-right direction, and the vertical distance between the uppermost rib 115 and the lowermost rib 115 is set to be approximately equal to the vertical length dimension of the protrusion 123 of the main pad 12, which will be described later. At the upper and lower base portions of each curved section 114 on the inside in the seat width direction of each side frame 111, notches 116 are formed to facilitate twist deformation of each curved section 114 in the out-of-plane direction, which is the front-rear direction. The main support member 11 has its upper part 11c's rear surface fixed to the upper frame 42, and its lower part 11d's rear surface approximately in the vertical center fixed to the lumbar support device 6. Here, the side frame portion 111 and the lower opening 113 correspond to the "outer peripheral frame portion" and "opening" in the claims, respectively.

[0022] As shown in Figures 2 to 7, the main pad 12 is an elastic body made of foamed polyurethane resin, and has an external shape that is almost the same as that of the main support member 11 when viewed from the front. A molded felt body 121 is integrally molded on the rear surface 12b of the main pad 12. As is clearly shown in Figure 5, this felt body 121 is for forming a supply passage 122 for conditioned air supplied from an air conditioning unit (not shown) installed inside the seat back 3. On the rear side of the felt body 121, which constitutes a part of the rear surface 12b of the main pad 12, there are vertically extending protrusions 123 that abut the outer side in the seat width direction of each curved portion 114 when the front surface of the main support member 11 is in contact with the rear surface 12b of the main pad 12. The height dimension of the protrusions 123 in the front-rear direction is set to about three times the thickness of the curved portion 114, and the length dimension in the vertical direction is set to about half the length dimension of the curved portion 114. Each protrusion 123 abuts against the outer side in the sheet width direction of each curved portion 114 of the main support member 11 when the main structure 10 is formed, preventing each curved portion 114 from moving outward in the sheet width direction. Here, the protrusion 123 corresponds to the "projection" in the claims.

[0023] As shown in Figures 2 to 7, the main cover 13 is a bag-shaped cover member that opens towards the rear, formed by sewing together multiple pieces of a planar body made by cutting a thin urethane slab pad laminated onto a fabric. The main structure 10 is formed when the main cover 13 is placed over the main pad 12, which is positioned in front of the main support member 11, from the front 12a side, and the rear-opening end portion is locked to the side frame portion 111 of the main support member 11. Specifically, as is clearly shown in Figure 7, vertically extending slits 13b are formed at positions corresponding to the curved portions 114 of the main support member 11 on the left and right end portions 13a of the main cover 13. With the main support member 11 in contact with the rear surface 12b of the main pad 12, the main cover 13 is placed over the main pad 12 from the front 12a side, and the main structure 10 is formed by wrapping the end portions 13a around to the rear surface 12b of the main pad 12 and passing each curved portion 114 through each slit 13b. In this case, the curved section 114 is provided with three ribs 115 extending in the left-right direction, which increases its rigidity and makes it easier to pass through the slit 13b.

[0024] The assembly procedure for the main structure 10 will be explained using Figures 8 to 11. First, as shown in Figure 8, with the front surface of the main support member 11 in contact with the rear surface 12b of the main pad 12, the main cover 13 is placed over the main pad 12 from the front surface 12a side. Then, as shown in Figure 9, the end portion 13a of the main cover 13 is wrapped around the rear surface 12b of the main pad 12, and each curved portion 114 is passed through each slit 13b. As a result, as shown in Figure 10, each curved portion 114 that protrudes from each slit 13b comes out behind the end portion 13a and presses the end portion 13a against the rear surface 12b of the main pad 12 via the three ribs 115. As shown in Figure 11, the upper and lower ends of each curved portion 114 engage with the upper and lower ends of each slit 13b, and the ribs 115 press against each end portion 13a, thereby maintaining the main cover 13 in a state of covering the main pad 12. At this time, each protrusion 123 of the main pad 12 abuts against the outer side in the seat width direction of each curved portion 114 of the main support member 11, preventing each curved portion 114 from moving outward in the seat width direction.

[0025] As shown in Figure 2, the side structure 20 includes a resin side support member 21, a cushioning body, a side pad 22, positioned in front of the side support member 21 and supported by the side support member 21 against the frame 4, and a side cover 23 that covers the side pad 22 from the front. The side support member 21 is a roughly plate-shaped resin member similar to the main support member 11. The side pad 22 is an elastic body made of a foamed polyurethane resin molded body similar to the main pad 12, and has almost the same external shape as the side support member 21 when viewed from the front. The side cover 23 is a bag-shaped cover member that opens towards the rear, formed by sewing together multiple pieces of a planar body made by cutting a thin urethane slab pad laminated onto a fabric similar to the main cover 13. The side structure 20 is formed when the side cover 23 is placed over the side pad 22 positioned in front of the side support member 21 from the front and the end portion of the rear opening is locked to the rear outer edge of the side support member 21.

[0026] The assembly procedure for the seat back 3 will now be described. First, as shown in Figures 3 to 5, the lumbar support device 6 is positioned between the upper frame 42 and the lower frame 43, between each side frame 41 of the frame 4. Next, the pre-assembled left and right side structures 20 are attached to the frame 4 by fixing the predetermined positions of the side support members 21 with screws. Then, the pre-assembled main structure 10 is attached to the frame 4 by fixing the upper part 11c of the main support member 11 to the upper frame 42 and fixing the approximately central part of the lower part 11d in the vertical direction to the rear surface of the lower frame 43. As a result, each bag 61 of the lumbar support device 6 is positioned so that a portion of the left and right ends overlaps the rear side of each curved portion 114 of the main support member 11, and most of the central part is in direct contact with the rear surface 12b of the main pad 12.

[0027] As shown in Figures 4 to 6, when the lumbar support device 6 is activated, the seat back 3 assembled as described above is inflated with air supplied to each bag 61, as shown by the dashed lines, and the main pad 12 and main cover 13 also inflate forward as shown by the dashed lines. At this time, since the air supplied to each bag 61 can be adjusted independently, the rear surface 12b of the main pad 12 at a specific point in the vertical direction can be pressed more strongly than other parts. In addition, since most of the central part of each bag 61 is in direct contact with the rear surface 12b of the main pad 12, localized vertical pressure can be applied to the lumbar region of the seated occupant. Furthermore, although parts of the left and right ends of each bag 61 overlap the curved portions 114 of the main support member 11, each curved portion 114 is easily twisted and deformed in the front-rear direction, so the lumbar region of the seated occupant can be pressed over a wider area in the seat width direction.

[0028] As described above, this embodiment provides the following effects. The main support member 11 is formed in a frame shape with a lower opening 113 that allows the lumbar support device 6 to directly contact the rear surface 12b of the main pad 12. The lumbar support device 6 can locally adjust the forward pressing force in the vertical direction by independently adjusting the air supplied to each bag 61. This allows the lumbar support device 6 to directly press the main pad 12 and apply locally different pressing forces in the vertical direction to the lumbar region of the seated occupant. Furthermore, with the main cover 13 locked to the main support member 11 by passing the curved portion 114 of the main support member 11 through the slit 13b provided at the end portion 13a of the main cover 13, the protrusion 123 contacts the curved portion 114, suppressing the outward movement of the curved portion 114 in the seat width direction. This allows the main structure 10 to be securely attached to the main support member 11 with the main cover 13 while suppressing a decrease in the function of the lumbar support device 6.

[0029] Furthermore, the curved portion 114 is configured to twist and deform in the front-rear direction due to the pressure when the lumbar support device 6 is activated. As a result, even if the curved portion 114 is positioned overlapping the front of a part of the lumbar support device 6, it will twist and deform in the front-rear direction due to the pressure from the rear when the lumbar support device 6 is activated, thus widening the pressing area in the seat width direction by the lumbar support device 6.

[0030] Furthermore, notches 116 are formed at the upper and lower bases of the curved portion 114 in the side frame portion 111, serving as weakening sections that make the curved portion 114 more susceptible to twisting deformation in the front-rear direction. This makes it possible to make the curved portion 114 more susceptible to twisting deformation due to the pressure from the rear when the lumbar support device 6 is operated.

[0031] In addition, three ribs 115 extending in the sheet width direction are erected on the front side of the curved section 114. This maintains the rigidity of the curved section 114, making it easier to pass the curved section 114 through the slit 13b of the main cover 13 when assembling the main structure 10.

[0032] Although specific embodiments have been described above, the present invention is not limited to their appearance and configuration, and various modifications, additions, and deletions are possible without altering the essence of the invention. For example, the following can be made.

[0033] 1. In the above embodiment, the lumbar support device 6 is configured such that multiple bag bodies 61 extending in the left-right direction are arranged vertically, and each bag body 61 can be supplied with and vented individually. However, it is not limited to this configuration, and may also be configured as a mechanical device in which strip-shaped plate members arranged vertically can be individually moved and adjusted in the front-rear direction.

[0034] 2. In the above embodiment, the present invention was applied to the seat back 3 of an automobile seat 1, but it is not limited to this and can also be applied to seats of airplanes, railway vehicles, or ships. [Explanation of symbols]

[0035] 1. Automotive seats 3 Seatback 4 frames 5. Cushion structure 6. Lumbar support device 10 Main Structure 11 Main support member 12 Main Pad 12a front 12b Rear 13 Main Cover 13a Terminal section 13b Slit 20 Side Structures 61 Bag body 111 Side frame section (outer frame section) 113 Lower opening (opening) 114 Curved section 115 Rib 116 Notch 123 Protrusion (protrusion)

Claims

1. It is a seat back, It comprises a frame that forms the skeleton, a lumbar support device attached to the frame, and a cushion structure attached to the frame that elastically supports the seated occupant. The cushion structure consists of a main structure in the center in the width direction of the seat, and a pair of left and right side structures positioned on both sides of the main structure. The main structure comprises a main pad which is a cushioning body, a main cover which covers the main pad, and a substantially plate-shaped main support member which is attached to the frame side of the main pad and supports the main pad. The lumbar support device is capable of locally adjusting the forward pressing force in the vertical direction and is located on the rear side of the main structure. The main support member is formed in a frame shape having an opening that allows the lumbar support device to directly contact the rear surface of the main pad. The outer periphery of the opening in the sheet width direction has multiple curved portions formed therein that curve and extend inward in the sheet width direction, The rear surface of the main pad has a plurality of projections that protrude toward the rear and are positioned on the outer side of the curved portion in the width direction of the seat, while in contact with the main support member. Multiple slits are formed at the end of the main cover in the seat width direction, allowing the curved portion of the main support member, which is in contact with the rear surface of the main pad, to pass through in the seat width direction and lock the main cover to the main support member. The aforementioned projection abuts against the curved portion while it is passed through the slit, thereby suppressing the outward movement of the curved portion in the seat width direction of the seat back.

2. In claim 1, The curved portion of the seatback is configured to be able to twist and deform in the front-rear direction when pressed by the lumbar support device when it is activated.

3. In claim 2, A seat back in which notches are formed at the upper and lower base portions of the curved portion in the outer frame portion, serving as weakening portions that make the curved portion more susceptible to twisting deformation.

4. In claim 1 or claim 2, A seat back with ribs extending in the width direction of the seat erected on the front side of the curved portion.

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