Seat back

Abstract

To provide a seat back which is capable of adequately controlling amount of travel when a back board is removed due to excessive load input received from side of a seating person.SOLUTION: A seat back 1 includes a back board 5 which is attached to a back frame 2 from reverse side of a seat. The seat back 1 includes an attachment part 6 which attaches a board upper part 5A and a board lower part 5B to the back frame 2 in attachment intensities which are different from each other so that attachment of the board lower part 5B is removed while maintaining attachment state of the board upper part 5A when a load with prescribed magnitude or more is applied from side front of the seat to the back board 5. In addition, the seat back 1 includes an elastic connection part 7 which connects a cushion bottom part C1 of a seat cushion SC with the board lower part 5B via a rubber band 7B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a seat back, and more particularly to a seat back having a back board attached to a back frame from the rear side of the seat. [Background technology]

[0002] Patent Document 1 discloses a configuration in which a backboard is provided on the rear of a seatback. In the event of a rear-end collision of the vehicle, the backboard is partially detached from the back frame when the seated occupant's body is pressed strongly against the seatback, allowing the occupant's body to sink deeper into the seatback. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-74625 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration described in Patent Document 1 does not have a configuration for controlling the amount of movement (opening amount) of the backboard when it is detached from the back frame. Therefore, the present invention provides a seat back that can appropriately control the amount of movement when the backboard is detached due to an excessive load input from the seated person. [Means for solving the problem]

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

[0006] That is, the first invention of the present invention is a seat back having a backboard attached to a back frame from the back side of the seat, and has an attachment portion that attaches the upper and lower parts of the board to the back frame with different attachment strengths so that when a load of a predetermined magnitude or more is applied to the backboard from the front side of the seat, the attachment state of the upper part of the board is maintained while the attachment of the lower part of the board is detached, and an elastic connecting portion that connects the lower part of the board to the cushion bottom of the seat cushion via an elastic member.

[0007] According to the first aspect of the present invention, when the lower part of the board is detached from the seat due to a load of a predetermined magnitude or greater applied from the front side of the seat, the movement of the lower part of the board toward the back side of the seat can be elastically restricted by the elastic connecting part, thereby making it possible to appropriately control the amount of movement of the lower part of the board.

[0008] The second invention of the present invention is a seat back according to the first invention, wherein the elastic connecting portion comprises a planar member that is joined so as to extend in the seat width direction along the lower part of the board, and a band-shaped rubber band as the elastic member that connects the planar member to the bottom of the cushion.

[0009] According to the second aspect of the present invention, movement of the board lower portion toward the rear side of the seat can be appropriately restricted over a wide range in the seat width direction of the board lower portion. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view illustrating a schematic configuration of a seat back according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. 2 is a schematic view of the seat back as seen from the left side. [Figure 4] 4 is a schematic diagram corresponding to FIG. 3 and illustrating a state in which the lower part of the board has been detached due to a load input. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] First Embodiment (Outline of seat back 1) First, the configuration of a seat back 1 according to a first embodiment of the present invention will be described with reference to Figures 1 to 4. In the following description, when directions such as front, back, up, down, left, and right are indicated, they refer to the directions shown in each figure.

[0013] Furthermore, when a direction, such as the "seat width direction," is indicated with the word "seat," it refers to the respective direction relative to the seat back 1. Furthermore, in the following description, when a specific reference drawing is not shown or when there is no reference symbol corresponding to the reference drawing, any of Figures 1 to 4 will be referred to as appropriate.

[0014] 1 and 2, a seat back 1 according to this embodiment is configured as a backrest portion of an automobile seat. The seat back 1 is provided so as to rise from the rear end portion of a seat cushion SC, which serves as a seating portion.

[0015] As shown in Fig. 2, the seat back 1 has a metal back frame 2 that forms the framework of the seat back, and a urethane foam back pad 3 that covers the front part of the back frame 2. The seat back 1 also has a fabric back cover 4 that covers the entire surface of the back pad 3, and a resin back board 5 that covers the rear surface of the seat back 1.

[0016] The seat back 1 also has mounting portions 6 that attach the upper board portion 5A and the lower board portion 5B of the back board 5 to the back frame 2 from the rear side of the seat (the back side). As shown in Fig. 1, the seat back 1 also has elastic connecting portions 7 that connect the lower board portion 5B and the cushion bottom portion C1, which is the bottom portion of the seat cushion SC, via rubber bands 7B.

[0017] 2, the mounting portion 6 has first clips 6A that are integrally attached to the front surface of the upper board portion 5A at multiple locations along the periphery of the board in the seat width direction and seat height direction. The mounting portion 6 also has second clips 6B that are integrally attached to the front surface of the lower board portion 5B at multiple locations along the periphery of the board in the seat width direction and seat height direction.

[0018] Each of the first clips 6A and each of the second clips 6B is attached integrally to a bracket or a resin frame (not shown) that is integrally joined to the back frame 2, simply by inserting it from the back side of the seat. As shown in Figures 3 and 4, each of the first clips 6A is configured to have a high removal force that enables it to maintain its attachment to the bracket (not shown) even if a load of a predetermined magnitude or more is applied to the back board 5 from the front side of the seat.

[0019] On the other hand, each second clip 6B is configured to have a low removal force that causes it to detach from the resin frame (not shown) when a load of a predetermined magnitude or greater is applied to the backboard 5 from the seat front side (see FIG. 4). Here, the "load of a predetermined magnitude or greater" applied to the backboard 5 refers to an excessive load that would be applied to the backboard 5 when the body of a seated occupant is pressed hard against the seat back 1 in the event of a rear-end collision of the vehicle.

[0020] That is, each of the first clips 6A and each of the second clips 6B is configured to attach the upper board 5A and the lower board 5B to the back frame 2 with different attachment strengths. Therefore, as shown in Fig. 4, when a rear-end collision of the vehicle occurs and the body of the seated occupant is pressed strongly against the seat back 1, the upper board 5A remains attached to the back frame 2, while the lower board 5B is detached from the back frame 2 to the back side (rear side) of the seat.

[0021] As a result, the lumbar region of the seated person can be pushed deeper into the seat back 1. The configuration in which the lower board portion 5B is disengaged from the back of the seat due to the action of an excessive load input is the same as the known configuration disclosed in documents such as JP 2023-74625 A. Therefore, a detailed description of this configuration will be omitted.

[0022] When the board lower part 5B is disengaged from the back of the seat due to the excessive load input described above, the elastic connecting part 7 that connects the board lower part 5B to the cushion bottom part C1 of the seat cushion SC is pulled toward the back of the seat by the board lower part 5B. As a result, the elastic connecting part 7 stretches the rubber band 7B against its elastic force, and applies a force that elastically restricts the movement of the board lower part 5B toward the back of the seat.

[0023] This restricts the amount of movement of the board lower portion 5B so that it does not move excessively toward the rear of the seat, thereby preventing the board lower portion 5B from coming into contact with surrounding structures or cracking due to excessive deformation.

[0024] 1, the elastic connecting portion 7 is composed of a carpet 7A that is joined so as to extend in the seat width direction along the lower edge of the board lower portion 5B, and a U-shaped rubber band 7B that is joined to the front portion of the carpet 7A that is pulled under the front of the carpet 7A. The upper portion of the carpet 7A that is joined along the lower edge of the board lower portion 5B has a width that is approximately the same as the lower edge of the board lower portion 5B.

[0025] The upper part of this carpet 7A is integrally joined over the entire width of the seat by welding to the front part of the lower edge of the lower board part 5B. Note that the upper part of the carpet 7A may be integrally joined by providing a plurality of claws (not shown) aligned in the width direction of the seat on the front part of the lower edge of the lower board part 5B, and by hooking the hook holes from above onto each claw.

[0026] The front part of carpet 7A that is pulled downwards is narrower in width than the upper part that is joined to the above-mentioned lower board part 5B. Rubber band 7B is bent into a U-shape when viewed from the bottom and attached to the front part of carpet 7A with a narrower width, and both ends of the U-shape are sewn together.

[0027] The portion of the rubber band 7B extending between both ends of the U-shape is fixed to a support spring (not shown) that forms the cushion bottom C1. This support spring (not shown) elastically supports the cushion pad (not shown) of the seat cushion SC from below. The support spring (not shown) spans between the front and rear frame portions of a cushion frame that has a frame shape in plan view.

[0028] Therefore, by being fixed to this support spring (not shown), the rubber band 7B is indirectly attached to a cushion frame (not shown) of the seat cushion SC. Therefore, when the rubber band 7B is pulled toward the back side of the seat by the board lower part 5B, the part of the rubber band 7B fixed to the cushion bottom part C1 can be appropriately fixed in position so that it is not pulled toward the back side (rear side) of the seat.

[0029] As a result, as shown in Figure 4, the elastic connecting portion 7 including the rubber band 7B can elastically restrict movement of the board lower portion 5B toward the back side (rear side) of the seat by gradually increasing the restricting force. With this configuration, the amount of movement of the board lower portion 5B toward the back side (rear side) of the seat can be appropriately controlled. Here, the carpet 7A corresponds to the "planar member" of the present invention, and the rubber band 7B corresponds to the "elastic member" of the present invention.

[0030] As shown in Figure 1, the elastic connecting portion 7 is composed of the carpet 7A, which extends from the board lower portion 5B so as to be pulled downward and forward as described above, and the rubber band 7B, which connects the carpet 7A to the cushion bottom portion C1. With this configuration, the area below the board lower portion 5B can be covered with the carpet 7A in a way that looks good to the outside. Furthermore, the rubber band 7B, which connects the carpet 7A to the cushion bottom portion C1, can elastically restrict movement of the board lower portion 5B toward the back of the seat (rearward) by gradually increasing the restricting force.

[0031] To summarize the above, the seat back 1 according to this embodiment has the following configuration: Note that the reference numerals in parentheses below correspond to the respective components shown in the above embodiment.

[0032] That is, the seat back (1) has a back board (5) attached to the back frame (2) from the backside of the seat. The seat back (1) has attachment parts (6) that attach the board upper part (5A) and the board lower part (5B) to the back frame (2) with different attachment strengths so that when a load of a predetermined magnitude or more is applied to the back board (5) from the front side of the seat, the attachment state of the board upper part (5A) is maintained while the attachment of the board lower part (5B) is detached. The seat back (1) also has an elastic connecting part (7) that connects the board lower part (5B) and the cushion bottom part (C1) of the seat cushion (SC) via an elastic member (7B).

[0033] According to the above configuration, when the lower board portion (5B) is released due to a load of a predetermined magnitude or more applied from the front side of the seat, the movement of the lower board portion (5B) toward the back side of the seat can be elastically restricted by the elastic connecting portion (7), thereby making it possible to appropriately control the amount of movement of the lower board portion (5B).

[0034] The elastic connecting portion 7 includes a planar member 7A that is connected to the board lower portion 5B so as to extend in the seat width direction, and a band-like rubber band 7B that serves as an elastic member 7B that connects the planar member 7A to the cushion bottom portion C1. With this configuration, movement of the board lower portion 5B toward the back of the seat can be appropriately restricted over a wide range in the seat width direction of the board lower portion 5B.

[0035] Other Embodiments Although one embodiment of the present invention has been described above, the present invention can be embodied in various forms other than the above embodiment.

[0036] 1. The seat back of the present invention is applicable to seats installed in vehicles such as automobiles and trains, as well as seats installed in vehicles other than vehicles such as airplanes and ships. The seat back is also applicable to seats other than vehicles.

[0037] 2. The mounting portion for mounting the backboard to the back frame may be made of other mounting means such as hooks or screws in addition to clips.

[0038] 3. The elastic connecting portion may be configured to connect the lower portion of the board and the bottom of the cushion only with an elastic member. The elastic member may be a rubber band or a spring such as a tension spring. Furthermore, if the elastic connecting portion has a planar member connected to extend in the seat width direction along the lower portion of the board, the planar member may be made of a planar material other than carpet, such as woven fabric, knitted fabric, or leather. [Explanation of symbols]

[0039] 1 seat back 2 Back Frame 3 Back Pad 4 Back cover 5 Backboard 5A Top of the board 5B Bottom of the board 6 Mounting part 6A First Clip 6B 2nd clip 7 Elastic connection part 7A Carpet (surface-shaped material) 7B Rubber band (elastic material) SC seat cushion C1 Cushion bottom

Claims

1. A seat back having a backboard attached to a back frame from the back side of the seat, a mounting portion that mounts the upper and lower board portions to the back frame with different mounting strengths so that the lower board portion is detached while the upper board portion is maintained in a mounted state when a load of a predetermined magnitude or more is applied to the back board from the seat surface side; The seat back has an elastic connecting portion that connects the lower portion of the board and the cushion bottom of the seat cushion via an elastic member.

2. 2. The seat back according to claim 1, The seat back has a planar member to which the elastic connecting portion is connected so as to extend in the seat width direction along the lower part of the board, and a band-shaped rubber band as the elastic member that connects the planar member to the cushion bottom.

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