Seat back

Abstract

To provide a seat back designed so as to cause a cushion body to appropriately follow forward / backward movement of a lumbar plate.SOLUTION: A seat back 2 includes: a cushion body 20 that elastically supports a seated person; a back frame that supports the cushion body 20 from a back side of a seat; and a lumbar plate 14 that is attached to the back frame, supports the cushion body 20 from the back side of the seat, and is adjustable in a position in a front-back direction of the seat. The cushion body 20 includes: a top-plate main pad serving as a cushion portion; and a top-plate main resin member 21C fixed to a back surface of the pad that is a surface on a back side of the seat of the top-plate main pad. The top-plate main resin member 21C has an engagement portion C13 that is directly engaged with the lumbar plate 14 so as to follow movement of the lumbar plate 14 toward behind the seat.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a seat back. More specifically, the present invention relates to a seat back having a cushion body that elastically supports a seated person and a seat frame that supports the cushion body from the back side of the seat.

Background Art

[0002] Patent Document 1 discloses a configuration in a vehicle seat in which a cushion body composed of a seat pad and a seat cover is divided into three parts in the seat width direction. Specifically, the cushion body is divided into a top plate main body forming a central portion in the seat width direction and each top plate side forming both side portions in the seat width direction. The top plate main body and each top plate side are individually assembled and fixed to the seat frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1, when a lumbar plate for adjusting the support position of the seated person's waist back and forth is provided on the seat back, there is a problem that the top plate main body is difficult to follow the movement of returning from the overhanging position of the lumbar plate. The reason is considered to be that since the top plate main body is separated from each top plate side, it is difficult to receive the action of the restoring force from each top plate side. However, such a problem can also occur even in a configuration where the cushion body is not divided. Therefore, the present invention provides a seat back capable of appropriately following the back-and-forth movement of the lumbar plate with the cushion body.

Means for Solving the Problems

[0005] To solve the above problems, the seat back of the present invention employs the following means.

[0006] In other words, the first invention of the present invention is a seat back having a cushion body that elastically supports a seated person, and a seat frame that supports the cushion body from the back of the seat, wherein the seat back has a lumbar plate attached to the seat frame that is adjustable in the front-rear direction of the seat and supports the cushion body from the back of the seat, and the cushion body has a seat pad that forms a cushion portion, and a support member fixed to the back surface of the pad which is the back surface of the seat pad, and the support member has an engagement portion that directly engages with the lumbar plate so as to follow the movement of the lumbar plate toward the rear of the seat.

[0007] According to the first invention, by moving the lumbar plate forward of the seat, the support position of the cushion body by the lumbar plate can be adjusted to the front of the seat. Furthermore, by moving the lumbar plate backward of the seat, the cushion body's support member can be directly engaged with the lumbar plate at the engagement portion, thereby allowing the cushion body to follow the lumbar plate and be appropriately moved backward of the seat.

[0008] The second invention of the present invention is that, in the first invention described above, the cushion body is made up of three dividing elements, which are divided into a main top plate that forms the central part in the seat width direction and each side top plate that forms both side parts in the seat width direction, and the support member is a seat back set on the back surface of the main top plate pad that forms the seat pad of the main top plate.

[0009] According to the second invention, even if the cushion body is separated into the main top plate and each side of the top plate, the main top plate can be made to appropriately follow the forward and backward movement of the lumber plate.

[0010] The third invention of the present invention is a seat back in which, in the first or second invention described above, the lumbar plate has a pair of hooks that protrude outward in the seat width direction on both edges in the seat width direction, and the engaging portion of the support member is directly engaged with the lumbar plate by hooking the pair of hooks onto the back surface of the seat.

[0011] According to the third invention, the configuration in which the engaging portion of the support member is directly engaged with the lumber plate can be realized in a way that functions properly by a simple configuration in which the engaging portion is hooked onto a pair of hooks that protrude from both edges of the lumber plate in the sheet width direction.

[0012] The fourth invention of the present invention is a seat back in which, in the third invention described above, the lumbar plate adjusts its protruding position by bending in an arc toward the front of the seat relative to the seat frame, and also allows for height adjustment.

[0013] According to the fourth invention, by configuring the lumber plate to have a pair of hooks extending from both edges in the sheet width direction, the engagement portion of the support member is hooked from the back side of the sheet, allowing for appropriate adjustment of the deflection and height position of the lumber plate through the sliding of the contact surfaces.

[0014] The fifth invention of the present invention is a seat back in which, in the third invention described above, the lumbar plate has fin portions at multiple locations in the height direction on both edges in the seat width direction that protrude outward in the seat width direction to expand the support surface, and the pair of hook portions are any of the multiple fin portions.

[0015] According to the fifth invention, by utilizing the fin configuration that expands the support surface of the lumber plate, the engaging portion of the support member can be rationally and appropriately hooked onto the lumber plate. [Brief explanation of the drawing]

[0016] [Figure 1] This is a perspective view showing the schematic configuration of the seat back according to the first embodiment. [Figure 2] It is a front view of the seat back. [Figure 3] It is an exploded perspective view of removing the cushion body from the back frame. [Figure 4] It is a front view of the back frame. [Figure 5] It is a rear view of the cushion body. [Figure 6] It is a perspective view showing the state of assembling the cushion body to the back frame. [Figure 7] It is a sectional view taken along line VII-VII of FIG. 2. [Figure 8] It is a perspective view showing the state of assembling the resin member on the outer top plate side to the side frame. [Figure 9] It is a sectional view taken along line IX-IX of FIG. 2.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0018] 《First Embodiment》 (Schematic Configuration of Seat Back 2) First, the configuration of the seat back 2 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 9. In the following description, when indicating directions such as front, rear, up, down, left, and right, the respective directions shown in each figure shall be referred to. Also, when indicating directions with "sheet" attached, such as "sheet width direction", it shall refer to the direction based on the orientation of the seat 1 described later. Further, in the following description, when no specific reference figure is shown, or when there is no reference symbol corresponding to the reference figure, any of FIGS. 1 to 9 shall be appropriately referred to.

[0019] As shown in FIG. 1, the seat back 2 according to the present embodiment is configured as a backrest portion of a single-seat 1 installed on the floor of an automobile. The seat 1 is configured as the right seat of the automobile, and includes a seat back 2 forming the backrest portion of the seated person, a seat cushion 3 forming the seating portion, and a headrest 4 forming the headrest portion.

[0020] As shown in FIG. 2, the seat back 2 includes a side airbag device 30 on the right side, which is the outer side in the vehicle width direction. The side airbag device 30 is a known device that, when a vehicle collision is detected, the airbag 31 breaks through the seat back 2 and bulges forward of the seat to protect the head and chest of the seated person from the collision.

[0021] As shown in FIG. 3, the seat back 2 has a metal back frame 10 forming its skeleton, and a cushion body 20 assembled to the front portion of the back frame 10 to elastically support the waist and back of the seated person. The seat back 2 also has a back board 40 assembled to the rear portion of the back frame 10 to cover the back surface of the seat back 2. Here, the back frame 10 corresponds to the "seat frame" of the present invention.

[0022] The cushion body 20 is composed of three divided elements, which are divided into a top plate main 21 forming the central portion in the seat width direction and each top plate side 22 forming both side portions in the seat width direction. The top plate main 21 is a portion that supports the waist and back of the seated person from behind.

[0023] Each top plate side 22 is a portion that supports the waist and back of the seated person from the rear obliquely outward. The front surface of each top plate side 22, which is the surface on the front side of the seat, has a surface shape that rises obliquely forward toward the outside in the seat width direction.

[0024] The main top panel 21 and each side top panel 22 are configured to be individually assembled to the back frame 10 from the front of the seat. More specifically, the main top panel 21 and each side top panel 22 are configured to be easily attached to and detached from the back frame 10 without removing the seat 1 from the floor. This will be described in detail later.

[0025] (Seatback 2 configuration) The specific configuration of each part of the seat back 2 will be described below. As shown in Figures 3 and 4, the back frame 10 has a pair of left and right side frames 11 that extend vertically along both the left and right sides of the seat back 2. The back frame 10 also has an upper frame 12 that spans between the upper ends of each side frame 11 and a lower frame 13 that spans between the lower ends.

[0026] Furthermore, the back frame 10 has a planar lumbar plate 14 that is provided in a spanner manner between the upper frame 12 and the lower frame 13. The lumbar plate 14 is provided in a spanner manner between the upper frame 12 and the lower frame 13 via a support spring 15 that is bent into a U shape when viewed from the front.

[0027] The support spring 15 has both upper ends of its U-shape passed through the upper frame 12 from below the seat. The lower edge of the support spring 15 is also elastically supported from behind the seat at the front of the lower frame 13 via a torsion spring (not shown). The lumbar plate 14 consists of a long, flat resin member.

[0028] The lumbar plate 14 is assembled so that its upper and lower ends can slide vertically along the left and right sides of the U-shape of the support spring 15. The lumbar plate 14 is configured so that its upper and lower ends move vertically along the sides of the support spring 15 by a drive unit (not shown) assembled to the back frame 10.

[0029] The lumbar plate 14 is moved so that the distance between its upper and lower ends is reduced, causing the middle section between the upper and lower ends to bend in an arc towards the front of the seat. As a result, the support position (lumbar support position) of the lower half of the main top plate 21 of the cushion body 20 by the lumbar plate 14 is pushed forward of the seat. This increases the support pressure on the seated person's lumbar region by the main top plate 21. In addition, the lumbar plate 14 can be adjusted vertically by moving its upper and lower ends up and down together.

[0030] The lumber plate 14 has a shape in which both its left and right edges have multiple fin portions 14A that protrude outwards in a wave-like manner to the left and right (outward in the sheet width direction). The lumber plate 14 has a shape in which it has a pair of left and right vertical surfaces that extend in a planar manner in the vertical direction along each side of the U-shape of the support spring 15. Each fin portion 14A has a shape in which it protrudes outwards in a wave-like manner from the outer edge of each vertical surface of the lumber plate 14. As a result, each fin portion 14A is configured to extend a wave-like support surface to the area outside the side of the U-shape of the support spring 15.

[0031] Plate-shaped fastening brackets 11A are welded to the rear edge of each side frame 11, extending diagonally backward inward in the sheet width direction. Each fastening bracket 11A has its front surface (overlapping surface), which faces diagonally forward, positioned toward the installation space of the main top plate 21. Fastening portions C25 extending from the top plate side resin members 22C on the underside of the sheet of each corresponding top plate side 22 are fastened to these fastening brackets 11A via a plug-in fastening structure.

[0032] A bracket with a round-shaped engagement hole 11B is attached to the outer part of the lower end of each side frame 11. A fitting clip C24, which is attached to the lower part of the top plate side resin member 22C on the underside of the seat of each corresponding top plate side 22, engages with these engagement holes 11B by snap-fitting when inserted from the front of the seat.

[0033] Support brackets 12A, which extend vertically in a rectangular tubular shape, are welded to the left and right sides of the upper frame 12, passing through them vertically. Each support bracket 12A is inserted and welded to the top and bottom plates of the upper frame 12, passing through them vertically. More specifically, the upper ends of each support bracket 12A are provided to protrude from the top plate of the upper frame 12 above the seat.

[0034] Each support bracket 12A functions as a mounting part for inserting and attaching the headrest 4, as described in Figure 1, to the top of the seat back 2 from above the seat. Each support bracket 12A is fitted with a headrest support (not shown) that can be inserted and attached from above the seat to a pair of left and right headrest stays (not shown) that hang down from the headrest 4.

[0035] Each of the left and right ends (shoulder sections) of the upper frame 12 has a fitting hole 12B formed through it so that the top plate section penetrates vertically. The upper end fitting portion C22 formed on the upper part of the top plate side resin member 22C on the underside of the sheet of the corresponding top plate side 22 is fitted into each fitting hole 12B by hooking from above the sheet.

[0036] (Main 21-piece configuration on the top panel) Next, the configuration of the main top plate 21 and each of the side top plates 22 that constitute the cushion body 20 will be described. First, the configuration of the main top plate 21 will be described. As shown in Figures 3, 5, and 7, the main top plate 21 has a main top plate pad 21A which is the cushion part, a main top plate cover 21B made of fabric that covers the main top plate pad 21A, and a main top plate resin member 21C which is provided on the back surface of the pad, which is the back surface of the main top plate pad 21A. Here, the main top plate pad 21A corresponds to the "seat pad" of the present invention. The main top plate resin member 21C corresponds to the "support member" and "main top plate support member" of the present invention.

[0037] As shown in Figures 5 and 7, the top main pad 21A is made of a polyurethane foam molded body. As shown in Figure 3, the top main pad 21A has a mat-like shape that is placed over the upper frame 12 and lumbar plate 14 of the back frame 10 from the front of the seat. More specifically, the top main pad 21A has a canopy portion on its upper part that is placed over the top of the upper frame 12 from above the seat.

[0038] The upper canopy portion of the top main pad 21A has a pair of left and right rectangular support through holes A11 that penetrate vertically. When the canopy portion of the top main pad 21A is placed over the top plate portion of the upper frame 12 via the top main resin member 21C, which will be described later, each support through hole A11 is passed through the upper end of the corresponding support bracket 12A and set on the top plate portion.

[0039] The top panel main cover 21B is placed over the top panel main pad 21A from the front of the seat, and its top, bottom, left, and right peripheral edges are pulled in and secured to the back surface of the top panel main pad 21A. Specifically, as shown in Figure 5, the ends of the peripheral edges of the top panel main cover 21B that are pulled in to the back surface of the pad are hooked onto the top panel main resin member 21C, which is a frame-shaped component when viewed from the rear and is provided on the back surface of the pad, and are secured to it.

[0040] The above hooks allow the top panel main cover 21B to be stretched over the entire outer surface of the top panel main pad 21A. The top panel main resin member 21C is fixed in place by being pressed against the back surface of the top panel main pad 21A through the hooks at each end of the top panel main cover 21B. In the overhang area of ​​the top panel main cover 21B that covers the overhang portion of the top panel main pad 21A, rectangular support through-holes B11 are formed that penetrate vertically, allowing each support through-hole A11 to communicate with the outside.

[0041] As shown in Figure 7, the top main cover 21B is secured by being suspended from the front of the sheet into a suspension groove A12 formed at a corresponding position on the top main pad 21A, at the upper and lower intermediate portion of the area that covers the front of the top main pad 21A. Specifically, on the back surface of the suspended intermediate portion of the top main cover 21B, a suspension portion B12 is formed, which includes a tubular suspension cotton cloth sewn to extend in the sheet width direction along the intermediate portion, and a suspension wire passed along the suspension cotton cloth.

[0042] The suspension portion B12 is pulled in from the front of the sheet into a suspension groove A12 formed in the top main pad 21A so as to penetrate the pad thickness direction (front-to-back direction of the sheet). Then, on the back surface of the pad, the suspension portion B12 is hooked onto each hook CL1 of four fastening clips CL that are arranged in the sheet width direction and attached to the clip locking portion C14 of the top main resin member 21C. As a result, the top main cover 21B is stretched so that its middle portion is in close contact with the outer surface of the top main pad 21A.

[0043] The fastening clip CL is made of a resin injection molded product having a hook CL1 for hooking the suspension part B12 and a seat part CL2 that serves as an attachment part to the main resin member 21C of the top plate. The fastening clip CL is snap-fitted into place by inserting each hook CL1 into the corresponding holes drilled in the main resin member 21C of the top plate from the rear of the seat, so that the clip locking parts C14, which are elastic claws formed around each hole in the main resin member 21C of the top plate, are in contact with the rear surface of the seat parts CL2.

[0044] As a result, the seat portion CL2 is attached in a state where it is pressed in the front-to-back direction between the rear surface of the main resin member 21C of the top plate and the clip locking portion C14. With this attachment, each fastening clip CL is set so that the hook CL1 protrudes from the main resin member 21C of the top plate forward of the seat, and the hook CL1 is inserted into the suspension groove A12 of the main pad 21A of the top plate.

[0045] As shown in Figure 5, the main resin component 21C of the top plate is made of an injection-molded product that is molded to form a frame shape when viewed from the rear, extending along the outer peripheral edge of the back surface of the main pad 21A of the top plate. Cover latches C11 are formed on the left, right, and upper sides of the frame-shaped portion of the main resin component 21C when viewed from the rear, for securing the ends that are pulled into the back surface of the main pad of the top plate. The main resin component 21C of the top plate is integrally fixed to the back surface of the main pad 21A of the top plate via the main pad 21B by securing the ends of the main pad 21B to the cover latches C11 of the main resin component 21C.

[0046] In the canopy area of ​​the main resin component 21C of the top plate, which is superimposed on the back surface of the canopy portion of the main pad 21A, rectangular support through-holes C12 are formed that penetrate vertically, connecting each support through-hole A11 of the main pad 21A to the area below the sheet.

[0047] As shown in Figure 3, the main top plate 21 is assembled to the back frame 10 from above the seat as follows. First, the overhang portion of the main top plate 21 that extends to the rear of the seat is placed over the upper frame 12. At this time, each support through hole C12 of the main top plate resin member 21C is set to pass through the upper end of the corresponding support bracket 12A on the upper frame 12. As a result, the overhang portion of the main top plate 21 is hooked onto the upper end of each support bracket 12A and set in a fixed position.

[0048] Next, using the hooked canopy as a pivot point, the main top plate 21 is dropped onto the lumber plate 14 from the front of the sheet. Then, in conjunction with this, as shown in Figure 6, the middle fin portions 14A (hooking portions 14B) of the fin portions 14A that protrude from the left and right sides of the lumber plate 14 are hooked onto the front surfaces of the engaging portions C13 that protrude from the inner edges of the left and right frame sides of the main top plate resin member 21C.

[0049] As a result, the fin portions 14A (hooking portions 14B) that are hooked onto each engaging portion C13 are pressed against the rear surfaces of the left and right frame sides of the main resin top plate member 21C. Consequently, the frame sides of the main resin top plate member 21C are pressed and sandwiched between these fin portions 14A.

[0050] The main top panel 21 is further constructed such that the end of the main top panel cover 21B, which extends from its lower part downwards towards the seat, is pulled under the lower frame 13 of the back frame 10 and secured to the rear surface of the lower frame 13. With the above assembly, the main top panel 21 is set so that its upper, lower, and middle sections are engaged with the back frame 10 or the lumber plate 14, respectively.

[0051] With the above assembly, the main top plate 21 moves in the front-to-back direction of the seat, following the movement of the lumbar plate 14 when the lumbar plate 14 is bent in an arc shape forward of the seat, and when the curvature is returned to its original position backward of the seat. In addition, when the position of the lumbar plate 14 is adjusted in the vertical direction, the main top plate 21 is designed to appropriately release the movement by sliding each fin portion 14A up and down along the main top plate resin member 21C.

[0052] (Each top panel has a 22-sided configuration.) Next, the configuration of each top panel side 22 will be described with reference to Figures 3, 5, and 9. Each top panel side 22 includes a top panel side pad 22A which serves as a cushion, a fabric top panel side cover 22B which covers the top panel side pad 22A, and a top panel side resin member 22C provided on the back surface of the top panel side pad 22A.

[0053] Each top panel side 22 has a substantially identical basic structure, but because a side airbag device 30 is provided on the right side of the seat back 2, the configuration differs in terms of the presence or absence of a path for deploying the airbag 31 and the shape that secures the installation space for the side airbag device 30.

[0054] As shown in Figure 9, the top plate side pad 22A is made of a polyurethane foam molded body. The top plate side pad 22A is formed with a pad surface, which is the surface facing the sheet, having a ridge-like protrusion that rises diagonally from the inside to the outside in the sheet width direction, towards the front of the sheet.

[0055] The top panel side pad 22A has a concave curved surface shape, formed by hollowing out the back surface of the pad so as to be recessed along the aforementioned embankment-like protrusion. As shown in Figures 3 and 5, the top panel side pad 22A also has a shape with an overhang portion on its upper part that covers the top panel of the upper frame 12 from above the sheet.

[0056] The top panel side cover 22B is placed over the top panel side pad 22A from the front of the seat, and its top, bottom, left, and right edges are pulled in and secured to the back surface of the top panel side pad 22A. Specifically, the top, bottom, left, and right ends of the top panel side cover 22B that are pulled in to the back surface of the pad are hooked onto and secured to the curved plate-shaped top panel side resin member 22C provided along the back surface of the pad.

[0057] The above hooks allow the top panel side cover 22B to be stretched over the entire outer surface of the top panel side pad 22A. In addition, the top panel side resin member 22C is fixed in place by being pressed against the back surface of the top panel side pad 22A through the hooks at each end of the top panel side cover 22B.

[0058] As shown in Figures 5 and 9, the top plate side resin member 22C is made of an injection-molded product molded to match the concave curved surface on the back surface of the top plate side pad 22A. The top plate side resin member 22C has a side support portion C26 formed in which it diagonally supports the embankment-shaped protrusion of the top plate side pad 22A from the back surface of the pad along the protrusion. This side support portion C26 supports the embankment-shaped protrusion of the top plate side pad 22A in a planar manner from the back surface of the pad, enabling the top plate side pad 22A to properly support the side of the seated person's body.

[0059] The peripheral edge of the top plate side resin member 22C has cover latching claws C21 formed therein for securing each end that is pulled into the back surface of the top plate side cover 22B pad. Also, as shown in Figure 5, the canopy area of ​​the top plate side resin member 22C that overlaps with the back surface of the canopy portion of the top plate side pad 22A has an upper end fitting portion C22 that protrudes downward from the sheet.

[0060] The upper end fitting portion C22 is inserted from above the seat into the corresponding fitting holes 12B formed at the left and right ends (shoulders) of the upper frame 12 when assembling the top plate side 22 to the back frame 10 (see Figure 3). This insertion causes the upper part of the top plate side 22 to hook onto the upper frame 12 and be set in a fixed position.

[0061] As shown in Figure 5, a base portion C23 is formed at the lower part of the top plate side resin member 22C, which protrudes to the rear of the seat, and a fitting clip C24 is attached to its tip. When assembling the top plate side 22 to the back frame 10 (see Figure 3), the fitting clip C24 is inserted with a snap fit into the corresponding round hole-shaped engagement hole 11B formed on the rear edge of the lower end of each side frame 11. This insertion engages the lower part of the top plate side 22 with the lower part of each side frame 11, setting it in a fixed position.

[0062] Furthermore, a plate-shaped fastening portion C25 is formed in the middle of the top plate side resin member 22C in the vertical direction, extending diagonally backward from its inner edge in the sheet width direction toward the inside in the sheet width direction. As shown in Figure 8, the fastening portion C25 is set so as to overlap with the front surface (overlapping surface facing diagonally forward) of the fastening bracket 11A that extends inward diagonally backward from each side frame 11 when the top plate side 22 is assembled to the back frame 10.

[0063] After setting up as described above, bolt B, which is a push-in type fastening structure, is inserted into the fastening part C25 and the fastening bracket 11A using a fastening tool (impact) not shown and fastened. As a result, the fastening part C25 is fastened to the upper surface of the fastening bracket 11A in an overlapping manner.

[0064] (Configuration of the side airbag system 30) Next, the configuration of the side airbag device 30 will be explained with reference to Figure 9. The side airbag device 30 is attached to the right side (outer side) of the side frame 11 on the right side (outer side in the vehicle width direction). The side airbag device 30 is formed in a vertically elongated box shape that extends vertically along the right side frame 11 (see Figure 4).

[0065] Specifically, the side airbag device 30 includes an airbag 31, an inflator 32, a case 33, a guide plate 34, and a reinforcing cloth 35. The side airbag device 30 receives a vehicle collision detection signal input from a vehicle ECU (not shown), and injects gas from the inflator 32 into the airbag 31, causing the airbag 31 to inflate and deploy in front of the seat. The airbag 31 inflates and deploys to form a vertically elongated bag shape in front of the seat, piercing the seatback 2 over a wide area in the vertical direction.

[0066] Case 33 is a vertically elongated box-shaped container that houses the airbag 31 and the inflator 32. Case 33 is bolted to the right side of the right side frame 11 at two points on its inner surface, top and bottom. Case 33 has an open cross-section structure with a vertically elongated slit at its right front corner. When the airbag 31 inflates and deploys, the deployment pressure pushes open the right front corner of Case 33, causing the airbag 31 to inflate and deploy forward of the seat.

[0067] As described above, case 33 is positioned on the back side of the top panel side resin member 22C. Therefore, the top panel side resin member 22C has an opening C27 that opens up the deployment area of ​​the airbag 31 in order to secure a deployment path for the airbag 31 that inflates from case 33 located on its back side. As shown in Figure 5, the opening C27 is formed in a vertically elongated rectangular shape so as to open up almost the entire area directly facing case 33.

[0068] The guide plate 34 consists of a metal plate-like member with a vertically elongated, L-shaped cross-section. The guide plate 34 is fixed to the rear side of the case 33 and is provided to cover the right side. The guide plate 34 is provided to extend forward from the right side of the case 33 through the opening C27 of the top plate side resin member 22C to the front of the seat. As a result, when the airbag 31 inflates and deploys, the guide plate 34 covers the edge of the opening C27 from the inside, protecting the airbag 31 from direct contact with the edge of the opening C27.

[0069] The reinforcing cloth 35 is configured as a vertically elongated guide cloth that guides the deployment direction of the airbag 31. The reinforcing cloth 35 is made from a single piece of cloth. The reinforcing cloth 35 wraps around the case 33 from the rear of the seat, and each end of the wrapped cloth is sewn through the opening C27, through the slit A21 of the top side pad 22A, and to the stitching ends B21 of each cover piece of the top side cover 22B, where the stitching is broken by the deployment pressure of the airbag 31.

[0070] The slit A21 formed in the top side pad 22A is a hole for allowing the airbag 31 to pass through when it inflates and deploys, as it expands forward from the opening C27. The slit A21 is formed to penetrate through the top side pad 22A in a long, elongated shape, extending almost the entire length in the vertical direction directly opposite the case 33 of the top side pad 22A.

[0071] The airbag 31, upon receiving gas injection from the inflator 32, expands forward of the seat, pushing open the case 33 and passing through the opening C27 of the top side resin member 22C, while pushing open the slit A21 of the top side pad 22A from the back side of the pad. The airbag 31 then expands forward of the seat through the gaps between the stitching ends B21 of the top side cover 22B, which are sewn to each end of the reinforcing fabric 35 and form the burst line BL, due to the pressure of its deployment.

[0072] (How to assemble seatback 2) Next, we will explain how to assemble the cushion body 20 to the back frame 10. Referring to Figure 3, the cushion body 20 is first assembled to the back frame 10 by attaching each top panel side 22 before the top panel main 21 (top panel side assembly process). The method for attaching each top panel side 22 to the back frame 10 is as described above.

[0073] After assembling each tabletop side 22, the tabletop main 21 is then assembled to the back frame 10 (tabletop main assembly process). Following this procedure, the cushion body 20, which consists of three divided elements, can be easily and appropriately assembled to the back frame 10. The procedure for removing the cushion body 20 from the back frame 10 is the reverse of the above procedure.

[0074] In summary, the seat back 2 according to this embodiment has the following configuration. The reference numerals in parentheses below correspond to the respective configurations shown in the above embodiment.

[0075] In other words, the seat back (2) has a cushion body (20) that elastically supports the occupant, and a seat frame (10) that supports the cushion body (20) from the back of the seat. The seat back (2) further has a lumbar plate (14) that is attached to the seat frame (10) and is adjustable in the front-rear direction of the seat, which supports the cushion body (20) from the back of the seat. The cushion body (20) has a seat pad (21A) that forms the cushion part, and a support member (21C) that is fixed to the back surface of the pad, which is the back surface of the seat pad (21A). The support member (21C) has an engagement part (C13) that directly engages with the lumbar plate (14) so ​​as to follow the movement of the lumbar plate (14) toward the rear of the seat.

[0076] With the above configuration, by moving the lumbar plate (14) forward of the seat, the support position of the cushion body (20) by the lumbar plate (14) can be adjusted forward of the seat. Furthermore, by moving the lumbar plate (14) backward of the seat, the support member (21C) of the cushion body (20) directly engages with the lumbar plate (14) at the engagement portion (C13), allowing the cushion body (20) to follow the lumbar plate (14) and move appropriately backward of the seat.

[0077] Furthermore, the cushion body (20) is composed of three dividing elements: a main top plate (21) which forms the central part in the seat width direction, and each top plate side (22) which forms the side parts in the seat width direction. The support member (21C) is set on the back surface of the top plate main pad (21A) which forms the seat pad (21A) of the top plate main (21). With the above configuration, even if the cushion body (20) is configured to be separated into the top plate main (21) and each top plate side (22), the top plate main (21) can be appropriately made to follow the forward and backward movement of the lumbar plate (14).

[0078] Furthermore, the lumber plate (14) has a pair of hooks (14B) on both edges in the sheet width direction that protrude outward in the sheet width direction. The engaging portion (C13) of the support member (21C) is directly engaged with the lumber plate (14) by hooking the pair of hooks (14B) onto the back surface of the sheet.

[0079] According to the above configuration, the configuration in which the engaging portion (C13) of the support member (21C) is directly engaged with the lumber plate (14) can be realized in a proper function by a simple configuration in which the engaging portion (C13) is hooked onto a pair of hooking portions (14B) that protrude from both edges of the lumber plate (14) in the sheet width direction.

[0080] Furthermore, the lumbar plate (14) can adjust its protrusion position by bending in an arc forward relative to the seat frame (10), and its position in the height direction can also be adjusted. With the above configuration, the engagement portion (C13) of the support member (21C) is hooked from the back side of the seat to a pair of hook portions (14B) that protrude from both edges of the lumbar plate (14) in the seat width direction, thereby appropriately allowing the bending and height position adjustment of the lumbar plate (14) to be adjusted by the sliding of the contact surfaces.

[0081] Furthermore, the lumber plate (14) has fin portions (14A) at multiple locations in the height direction on both edges in the sheet width direction, which protrude outward in the sheet width direction to expand the support surface. A pair of hook portions (14B) are made up of any of the multiple fin portions (14A). With the above configuration, the engagement portion (C13) of the support member (21C) can be rationally and appropriately hooked onto the lumber plate (14) by utilizing the configuration of the fin portions (14A) that expand the support surface of the lumber plate (14).

[0082] Regarding other embodiments: Although the embodiments of the present invention have been described above using one embodiment, the present invention can be implemented in various forms other than those described above.

[0083] 1. The seat back of the present invention may be configured as a seat back for seats installed in vehicles other than automobiles, such as trains, as well as in vehicles other than automobiles, such as aircraft and ships. Furthermore, the cushion body may consist of three divided elements, divided into a main top plate and each top plate side, or it may consist of a single undivided structure.

[0084] 2. The support member provided on the back surface of the seat pad and fixed to the seat frame may be made of metal in addition to resin. Alternatively, the support member may be made of a backing material made of nonwoven fabric or the like, which is integrally impregnated and hardened with the back surface of the seat pad by integral foam molding with the seat pad.

[0085] The engagement portion that directly engages the support member with the lumber plate may consist of an engagement structure other than a hook, such as a connection by a hook fastener, a snap-fit ​​fitting by a clip, a press-fit fitting by a pin, or a structure that slides into an elongated hole. The engagement portion may engage the support member with both sides or one side of the edge of the lumber plate, or it may engage with the middle part of the lumber plate. Furthermore, the engagement points of the engagement portion with the lumber plate may be one or multiple points.

[0086] 3. The main top cover and the side top covers may be made of leather, in addition to fabric. [Explanation of Symbols]

[0087] 1 sheet 2 seatbacks 3 Seat cushions 4 headrests 10. Back frame (seat frame) 11 Side Frames 11A Fastening Bracket 11B Engagement hole 12 Upper Frame 12A Support Bracket 12B Fitting hole 13 Lower Frame 14 Lumbar Plate 14A Fin section 14B Hook 15 Support spring 20 cushion body 21 Main top panel 21A Top panel main pad (seat pad) A11 Support through hole A12 Hanging groove 21B Top Panel Main Cover B11 Support through-hole B12 Suspension section 21C Main resin component for tabletop (support component, main support component for tabletop) C11 Cover latch C12 Support through-hole C13 Engagement part C14 Clip locking part CL fastening clip CL1 Hook CL2 seat 22 Tabletop side 22A Top Panel Side Pad A21 Slit 22B Top panel side cover 1 B21 Suture Terminal 22C Top panel side resin component C21 Cover latch C22 Upper end fitting part C23 Base C24 Mating Clip C25 fastening part C26 Side Support Section C27 opening 30 Side airbag system 31 Airbags 32 Inflator 33 cases 34 Guide Plate 35 Rikifu 40 Backboard B bolt BL Burst Line

Claims

1. A seat back comprising a cushion body that elastically supports the occupant, and a seat frame that supports the cushion body from the back of the seat, The seat frame has a lumbar plate that is attached to the seat frame and supports the cushion body from the back of the seat, and is adjustable in the front-to-back direction of the seat. The cushion body comprises a seat pad that forms the cushion portion, and a support member fixed to the back surface of the seat pad, which is the back surface of the seat pad. The support member has an engagement portion that directly engages with the lumbar plate so as to follow the movement of the lumbar plate toward the rear of the seat.

2. A seat back according to claim 1, The cushion body is composed of three dividing elements: a main top plate that forms the central part in the seat width direction, and each side top plate that forms the sides in the seat width direction. The support member is a seat back that is set on the back surface of the main pad of the top plate, which forms the seat pad of the main top plate.

3. A seat back according to claim 1 or claim 2, The lumber plate has a pair of hooks on both edges in the sheet width direction that protrude outward in the sheet width direction, A seat back in which the engaging portion of the support member is directly engaged with the lumbar plate by hooking the pair of hooks onto the back surface of the seat.

4. A seat back according to claim 3, The lumbar plate is designed to bend in an arc forward relative to the seat frame, thereby adjusting its protrusion position, and also allowing for height adjustment of the seat back.

5. A seat back according to claim 3, The lumber plate has fins at multiple locations in the height direction on both edges in the sheet width direction, which protrude outward in the sheet width direction to expand the support surface. A seat back in which a pair of the aforementioned hooking portions are one of a plurality of aforementioned fin portions.

Images