Seat back

Abstract

The present invention provides a seatback in which a pad covered with a cover is divided into three sections in the width direction of the seat and attached to the frame, and in which an airbag device can be installed without hindering the deployment of the airbag. [Solution] The device comprises a frame 4 and a cushion structure 5. The cushion structure 5 consists of a main structure 10 and side structures 20 on both sides of the main structure 10. The main structure 10 comprises a main pad 12, a main cover 13, and a main support member 11. The side structure 20 comprises a side pad 22, a side cover 23, and a side support member 21. The side support member 21 of the side structure 20, in which an airbag device 6 is disposed, is provided with a through hole 21a through which the airbag device 6 passes. A weakened portion 21d is formed at the lower edge of the through hole 21a, which ruptures when the airbag 61 is deployed.

Description

Technical Field

[0001] The present invention relates to a seat back. More specifically, it relates to a seat back in which an airbag device is disposed inside.

Background Art

[0002] Conventionally, in a seat back of a vehicle seat equipped in a vehicle such as an automobile, there is known a seat back in which a seat back pad covered with a seat back cover is divided into three parts in the seat width direction and attached to a seat back frame. Patent Document 1 discloses a seat back configured such that a seat back main part at the center in the seat width direction and a seat back side part disposed at a side of the seat back main part are attached to a seat back frame. Such a vehicle seat aims to have good assemblability and be easy to automate the assembly, and to be easy to replace only the seat back side part that is likely to deteriorate 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 automobile seat described in Patent Document 1 above, an insert wire or a plate for attachment to a seat back frame is incorporated in the seat side back part. As a result, it has been difficult to configure the airbag device to be disposed inside the seat side back part because the deployment of the airbag may be hindered by the insert wire or the seat back frame.

[0005] In view of these problems, the object of the present invention is to provide a seat back in which an airbag device can be installed without hindering the deployment of the airbag, in a seat back in which a seat pad covered with a seat cover is divided into three parts in the seat width direction and attached to a frame. [Means for solving the problem]

[0006] The first invention of the present invention is a seat back comprising a frame forming a skeleton and a cushion structure attached to the frame to elastically support 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 main support member which is attached to the frame side of the main pad and supports the main pad in a planar manner, wherein the side structure comprises a side pad which is a cushion body and a side cover which covers the side pad - and a side support member attached to the frame side of the side pad to support the side pad in a planar manner, wherein at least one of the side structures is provided with an airbag device that expands forward, and the side support member of the side structure in which the airbag device is provided is provided with a through hole through which the airbag device passes inward when the airbag device is attached to the frame, and a weakened portion is formed on the lower edge of the through hole that allows the through hole to rupture due to the deployment pressure when the airbag of the airbag device is deployed, thereby widening in the seat width direction.

[0007] According to the first invention, the side support member is provided with a through hole, and a weakened portion is formed on the lower edge of the through hole, which is ruptured by the deployment pressure when the airbag of the airbag device is deployed, allowing the through hole to expand in the seat width direction. This allows the side structure to be attached to the frame with the airbag device attached to the frame, and the airbag device to be placed inside the side structure. Furthermore, when the airbag is deployed, it can inflate forward without being hindered by the side support member. In addition, the airbag device can be attached to a split-type seat back comprising a main structure and each side structure without any reduction in functionality.

[0008] The second invention of the present invention is characterized in that, in the first invention described above, the weakened portion is formed at a position in which the rupture point that is destroyed during the deployment of the airbag of the airbag device does not interfere with the airbag.

[0009] According to the second invention, the weakened portion is formed in a position where the rupture point, which may form a sharp edge when the airbag is destroyed during deployment, does not interfere with the airbag, so that the airbag can be deployed without being damaged.

[0010] The third invention of the present invention is characterized in that, in the first invention or the second invention, the upper edge of the through hole in the side support member is formed in an R shape when viewed from the front.

[0011] According to the third invention, the weakened portion is destroyed during the airbag deployment process, and as the airbag deploys, the through-hole widens significantly downwards and outwards in the seat width direction. At this time, since the upper edge of the through-hole in the side support member is formed in an R shape when viewed from the front, the upper edge of the through-hole is less likely to be destroyed, and the risk of a part of the side support member scattering and injuring the seated occupant can be suppressed.

[0012] The fourth invention of the present invention is characterized in that, in the first invention or the second invention, the weakened portion is fixed to the frame by a clip or screw whose central axis extends in the front-rear direction.

[0013] According to the fourth invention, when the airbag deploys, the direction of the force applied to the weakened portion is in the direction of the seat width, so there is almost no force acting to pull out the clip or screw whose central axis extends in the front-rear direction in the central axis direction. This prevents the weakened portion from separating from the frame and the side support member from flying off. [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] This is a front view of the seat back shown above. Because it is symmetrical, only the right side is shown. Furthermore, only the frame and the side support members of the side structure are shown. [Figure 4] This is a cross-sectional view taken along the line IV-IV in Figure 3. It shows the side structure including the back pad, back cover, and main structure. [Figure 5] Figure 3 is a cross-sectional view taken along the VV arrow. It shows the side structure including the back pad, back cover, and main structure. [Modes for carrying out the invention]

[0015] Based on Figures 1 to 5, 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 FIGS. 1 and 2, the seat back 3 has a frame 4 that forms a 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 pair of left and right airbag devices 6.

[0018] As shown in FIGS. 1 and 2, the frame 4 has a pair of left and right side frames 41 that extend in the vertical direction on both left and right sides of the seat back 3, an upper frame 42 that connects the upper end portions of each side frame 41, and a lower frame 43 that connects the lower end portions of each side frame 41. The frame 4 is formed in a substantially rectangular frame shape when viewed from the front. A lumbar plate 44 is disposed between the upper frame 42 and the lower frame 43 of the frame 4. This lumbar plate 44 is the same as the one disclosed in JP-A-2015-209062.

[0019] As shown in FIGS. 1 to 5, 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 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 with respect to the frame 4, and a main cover 13 that covers the main pad 12 from the front side.

[0021] The main support member 11 is fixed to the upper rear surface portion with respect to the upper frame 42, fixed to the rear surface portion at substantially the central portion in the vertical direction with respect to the lumbar plate 44, and fixed to the lower rear surface portion with respect to the lower frame 43.

[0022] The main pad 12 is an elastic body made of a foamed molded body of a polyurethane resin, and has substantially the same outer shape as the main support member 11 when viewed from the front. The main cover 13 is a bag-shaped cover member that is formed by integrating a plurality of pieces by sewing and opens rearward. The main cover 13 is covered from the front with respect to the main pad 12 disposed on the front side of the main support member 11, and the main structure 10 is formed by locking the terminal portion of the rear opening to the rear surface portion of the outer peripheral edge of the main support member 11.

[0023] As shown in FIGS. 2 to 5, the side structure 20 includes a resin side support member 21, a side pad 22 that is disposed on the front side of the side support member 21 and is supported by the side support member 21 with respect to the frame 4, and a side cover 23 that covers the side pad 22 from the front.

[0024] As shown well in FIG. 3, the side support member 21 is a member that extends in the vertical direction, and a through hole 21a that extends in the vertical direction and penetrates in the front-rear direction is formed at a substantially central portion in the left-right direction. The left side (inside the seat) of the through hole 21a is a base portion 21b that extends vertically along the front side of the side frame 41 of the frame 4, and the right side (outside the seat) of the through hole 21a is a deformed portion 21c. The deformed portion 21c is formed in a substantially U shape whose horizontal cross section opens rearward (see FIGS. 4 and 5). A weakened portion 21d that connects the lower end portion side of the base portion 21b and the lower end portion side of the deformed portion 21c is formed below the through hole 21a. Above the through hole 21a, the upper end portion of the deformed portion 21c is gradually curved leftward (in the seat inner side direction) as it goes upward with respect to the upper end portion side of the base portion 21b and is connected, and an R portion 21e having an R shape when viewed from the front is formed between the base portion 21b and the deformed portion 21c. The side support member 21 is fixed to the frame 4 at the rear surface portion (not shown) of the substantially central portion in the vertical direction of the base portion 21b and the weakened portion 21d.

[0025] As clearly shown in Figures 3 and 5, the weakened portion 21d has a rectangular mounting portion 21g when viewed from the front, and a bent portion 21h with a Z-shaped cross-section when cut in a horizontal plane. The upper end of the bent portion 21h is connected to the deformed portion 21c, and the lower end of the bent portion 21h is connected to the right end of the mounting portion 21g. The outer bent portion 21k, which is the folded portion on the right side (outside the seat) of the bent portion 21h, is thin and is designed to easily break due to the load applied to the deformed portion 21c in the rightward direction (outward direction of the seat) when the airbag deploys. The mounting portion 21g is fixed to the bracket 41a of the side frame 41 by a clip 21m passed through a clip hole (not shown). Here, the outer bent portion 21k corresponds to the "break point" in the claims.

[0026] As shown in Figures 2, 4, and 5, the side pad 22 is an elastic body made of foamed polyurethane resin and has an external shape that is almost the same as that of the side support member 21 when viewed from the front. The portion of the side support member 21 corresponding to the through hole 21a is formed to cover the front part of the airbag device 6 which is positioned to close the through hole 21a, and no hole is provided that penetrates in the front-to-back direction. The side cover 23 is a bag-shaped cover member that opens toward the rear and is formed by integrating a plurality of pieces by sewing together. The side structure 20 is formed when the side cover 23 is placed over the side pad 22 which is 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. As shown in Figure 4, the side cover 23 has a first cover portion 23a that covers the front and right sides of the side pad 22 and a second cover portion 23b that covers the right side of the side support member 21. The right end of the first cover portion 23a and the upper right end of the second cover portion 23b are connected by the first sewing portion 23c. The upper left end of the second cover portion 23b is connected to the resin plate 23e by the second sewing portion 23d, together with the upper left end of the connecting reinforcement fabric 67, which will be described later.

[0027] The airbag device 6 is attached to the outer surface of the seat on the left and right side frames 41. Since it is roughly symmetrical, the right airbag device 6 will be described as a representative example. As shown in Figures 2 to 5, the airbag device 6 is formed in a vertically elongated box shape that extends in a long length in the vertical direction, and when viewed from the front, its external shape is designed to substantially match the shape of the through hole 21a of the side support member 21. The airbag device 6 has an airbag 61, an inflator 62, a case 63, and a reinforcing cloth 64. The airbag device 6 receives a vehicle collision detection signal from the vehicle's ECU (not shown), injects gas from the inflator 62 into the airbag 61, inflating the airbag 61 and deploying it toward the front of the seat.

[0028] Case 63 is a vertically elongated box-shaped container that houses the airbag 61 and the inflator 62, with its left side fixed to the side frame 41. When the airbag 61 inflates and deploys, Case 63 is pushed open through a slit (not shown) to inflate and deploy the airbag 61 forward.

[0029] The reinforcing fabric 64 is a guide fabric that does not stretch easily and restricts the deployment direction of the airbag 61, and has a front reinforcing fabric 65 disposed on the front side and a rear reinforcing fabric 66 disposed on the rear side. The right end of the front reinforcing fabric 65, the right end of the first cover portion 23a, the upper right end of the second cover portion 23b, and the right end of the rear reinforcing fabric 66 are overlapped in this order and connected by the first sewing portion 23c. The upper left end of the second cover portion 23b is connected to the resin plate 23e by the second sewing portion 23d. The right side of the side cover 23 is fixed to the side support member 21 by the resin plate 23e being positioned on the inner part of the U-shape of the deformed portion 21c of the side support member 21. The left end of the front reinforcing fabric 65 is fixed to the frame 4 by a fixing member (not shown). The left end of the rear reinforcing fabric 66 is fixed to the frame 4 by a fixing member 66a.

[0030] The assembly procedure for the seat back 3 will now be described. First, as shown in Figures 3 to 5, the airbag device 6 is attached to the outer surface of each side frame 41 on the frame 4. Next, the pre-assembled left and right side structures 20 are attached to the frame 4. At this time, the airbag device 6 is positioned inside each side structure 20 so that it passes through each through-hole 21a of each side support member 21 in each side structure 20. At this time, the left end of the front reinforcement fabric 65 is fixed to the frame 4 by a fixing member (not shown), and the left end of the rear reinforcement fabric 66 is fixed to the frame 4 by a fixing member 66a. Next, the main structure 10 is attached to the frame 4. Note that when removing the main structure 10 and each side structure 20 from the frame 4, the reverse procedure of the above is followed. Finally, a backboard (not shown) is attached to the rear side of the frame 4 to conceal the rear side of the frame 4.

[0031] As described above, the assembled seat back 3 is attached to the seat cushion 2 as shown in Figure 1 to form the automobile seat 1 and is fixed to the floor F. In this state, when a vehicle collision detection signal is received from the vehicle's ECU, gas is injected from the inflator 62 into the airbag 61, inflating the airbag 61 and deploying it toward the front of the seat. At this time, as shown in Figure 3, as the airbag 61 deploys and reaches the deployed state 61E, the outer bent portion 21k (see Figure 5) of the weakened portion 21d breaks, causing the deformed portion 21c of the side support member 21 to rotate to the right around its upper end and reach the deformed state 21cE. In parallel, as the airbag 61 deploys and reaches the deployed state 61E, the tensile force applied by the front reinforcing fabric 65 and the rear reinforcing fabric 66 causes the first stitched portion 23c to break, and the airbag 61 deploys toward the front of the seat back 3 from between the first cover portion 23a and the second cover portion 23b.

[0032] As described above, this embodiment provides the following effects. The side support member 21 is provided with a through hole 21a, and a weakened portion 21d is formed on the lower edge of the through hole 21a, which is ruptured by the deployment pressure when the airbag 61 is deployed, allowing the through hole 21a to expand outward from the seat. The shape of the through hole 21a is such that it substantially matches the external shape of the airbag device 6 when viewed from the front. This allows the side structure 20 to be attached to the frame 4 with the airbag device 6 attached to the side frame 41, and the airbag device 6 to be placed inside the side structure 20. Furthermore, when the airbag 61 is deployed, it can inflate forward without being hindered by the side support member 21. In addition, the airbag device 6 can be attached to a split-type seat back 3 comprising a main structure 10 and each side structure 20 without any reduction in functionality.

[0033] Furthermore, although the weakened portion 21d may break at the outer bent portion 21k, potentially forming a sharp edge, the outer bent portion 21k, where the break occurs, is positioned far from the airbag 61 during deployment and does not interfere with the airbag 61. This reduces the risk of the airbag 61 coming into contact with the outer bent portion 21k during deployment, allowing the airbag 61 to deploy without being damaged.

[0034] Furthermore, an R-shaped R-section 21e is formed on the upper edge of the through-hole 21a in the side support member 21 when viewed from the front. As a result, when the weakened portion 21d is destroyed during the deployment process of the airbag 61 and the airbag 61 deploys, the deformed portion 21c rotates and deforms so that the lower side expands significantly outward in the seat width direction, centered on the upper end. At this time, the action of the R-section 21e prevents the upper edge of the through-hole 21a from being destroyed, thus reducing the risk of part of the side support member 21 flying off and injuring the seated occupant.

[0035] In addition, since the weakened portion 21d is fixed to the frame 4 by a clip 21m whose central axis extends in the front-rear direction, when the airbag 61 deploys, the direction of the force applied to the weakened portion 21d is in the seat width direction, and there is almost no force acting to pull the clip 21m, whose central axis extends in the front-rear direction, in the direction of the central axis. This prevents the weakened portion 21d from separating from the frame 4 and the side support member 21 from flying off.

[0036] 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.

[0037] 1. In the above embodiment, airbag devices 6 are provided on both the left and right sides, but the seatback is not limited to this, and may have airbag devices 6 provided on only one side, either the left or the right.

[0038] 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 in railway vehicles. [Explanation of Symbols]

[0039] 1. Automotive seats 3 Seatback 4 frames 5. Cushion structure 6. Airbag system 10 Main Structure 11 Main support member 12 Main Pad 13 Main Cover 20 Side Structures 21 Side support member 21a Through hole 21b Base section 21c Deformed part 21d Weakening section 21e R section 21k Outer bend (break point) 21m clip 22 Side Pads 23 Side cover 61 Airbags

Claims

1. It is a seat back, It has a frame that forms the skeleton 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 main support member which is attached to the frame side of the main pad and supports the main pad in a planar manner. The side structure comprises a side pad which is a cushioning body, a side cover which covers the side pad, and a side support member which is attached to the frame side of the side pad and supports the side pad in a planar manner. At least one of the side structures is equipped with an airbag device that expands forward. The side support member of the side structure on which the airbag device is installed is provided with a through hole through which the airbag device passes inward when the airbag device is attached to the frame. A seat back having a weakened portion formed on the lower edge of the through-hole, which allows the through-hole to rupture under the deployment pressure when the airbag of the airbag device deploys, thereby widening in the seat width direction.

2. In claim 1, The weakened portion is a seatback in which the rupture point that is destroyed during the deployment of the airbag in the airbag device does not interfere with the airbag.

3. In claim 1 or claim 2, The upper edge of the through hole in the side support member is formed in an R shape when viewed from the front.

4. In claim 1 or claim 2, The weakened portion is a seat back fixed to the frame by a clip or screw whose central axis extends in the front-rear direction.

Images