Seat back

Abstract

To disclose one example of a seat back on which a lumber support device capable of exhibiting sufficient support power is mounted.SOLUTION: In a lumber support device 7, a pressure reception plate 12 is bent at a connection part 11C and protrudes toward a seat front side when the pressure reception plate 12 exists at a support position. By this, the device can exhibit sufficient support power compared to a conventional one which is bent into a circular arc shape. Further, it is desirable for the pressure reception plate 12 that a first pressure reception part 11A, a second pressure reception part 11B nd the connection part 11C are integrated.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a seatback having a so-called "lumbar support" function.

Background Art

[0002] For example, the lumbar support device described in Patent Document 1 supports a pressure receiving plate by curving it in an arc shape so as to press the waist of a seated person.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the lumbar support device described in Patent Document 1 is configured to curve the pressure receiving plate in an arc shape, it is difficult to exhibit sufficient supporting force. The present disclosure discloses an example of a seatback made in view of the above point.

Means for Solving the Problems

[0005] A seat back that supports the back of a seated person preferably has at least one of the following constituent elements. That is, the constituent element comprises a pressure-receiving member (11) having a first pressure-receiving part (11A) that supports the lumbar region of the seated person, and a second pressure-receiving part (11B) connected above the first pressure-receiving part (11A) and cooperating with the first pressure-receiving part (11A) to support the back of the seated person, and a drive mechanism (13) that displaces the pressure-receiving member (11) between a support position where the pressure-receiving member (11) is located on the seated person's side and a non-support position where the pressure-receiving member (11) is located on the rear side compared to the support position, and it is preferable that when the pressure-receiving member (11) is in the support position, the pressure-receiving member (11) bends at the connection part (11C) between the first pressure-receiving part (11A) and the second pressure-receiving part (11B) so that it protrudes toward the front of the seat.

[0006] As a result, in the seat back, when the pressure-receiving member (11) is in the support position, the pressure-receiving member (11) bends at the connecting portion (11C) between the first pressure-receiving portion (11A) and the second pressure-receiving portion (11B), becoming convex toward the front of the seat. This makes it possible to exert sufficient support force compared to conventional designs that are curved in an arc shape.

[0007] The seatback may also have the following configuration, for example: In other words, the pressure-receiving member (11) is configured to have a pressure-receiving plate (12) in which a first pressure-receiving portion (11A), a second pressure-receiving portion (11B), and a connecting portion (11C) are integrated, and furthermore, it is desirable that the connecting portion (11C) is an elastically deformable portion with lower bending rigidity than the first pressure-receiving portion (11A) and the second pressure-receiving portion (11B).

[0008] Furthermore, the pressure receiving plate (12) is provided with a support member (9) that rotatably supports one end of the pressure receiving plate (12) in the vertical direction. The portion of the pressure receiving plate (12) rotatably supported by the support member (9) is defined as the rotation center (O1), and the other end of the pressure receiving plate (12) in the vertical direction is defined as the rotation end (P1). The distance from the rotation center (O1) to the rotation end (P1) is defined as the pressure receiving plate length (Lo). When the pressure receiving plate (12) is in the support position, the position of the rotation end (P1) is located closer to the seated person than when the pressure receiving plate (12) is in the non-support position. It is also desirable that the pressure receiving plate length (Lo) when the pressure receiving plate (12) is in the support position is smaller than the pressure receiving plate length (Lo) when the pressure receiving plate (12) is in the non-support position.

[0009] Furthermore, the drive mechanism (13) is configured to have a rotating arm (13A) with one end rotatably connected to the pressure plate (12) and the other end rotatably connected to the support member (9), the rotating arm (13A) having one end connected to a part of the pressure plate (12) on the rotating end (P1) side from the connecting part (11C), and an actuator (13B) that rotates the rotating arm (13A) around the connection point with the support member (9), and the rotating arm (13A) and the pressure plate (1 When the distance from the connection point (P2) to the center of rotation (O1) is defined as the arm end radius (R1), and the distance from the connection point (P3) between the rotating arm (13A) and the support member (9) to the center of rotation (O1) is defined as the center end radius (R2), it is desirable that the difference between the arm end radius (R1) and the center end radius (R2) when the pressure plate (12) is in the support position is smaller than the difference between the arm end radius (R1) and the center end radius (R2) when the pressure plate (12) is in the non-support position.

[0010] Furthermore, it is desirable to include a bending restricting portion (14) that bends the pressure receiving plate (12) so that it becomes convex toward the front side of the sheet when the pressure receiving plate (12) is displaced from a non-supported position to a supported position.

[0011] This makes it possible to reliably bend the pressure plate (12) so that it is convex toward the front of the sheet. Incidentally, the symbols in each of the parentheses above are just examples showing the correspondence with the specific configurations etc. described in the embodiments described later, and this disclosure is not limited to the specific configurations etc. indicated by the symbols in the parentheses above. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a vehicle seat according to the first embodiment. [Figure 2] This is an exploded view of the lumbar support device according to the first embodiment. [Figure 3] This is a diagram showing a pressure receiving plate according to the first embodiment. [Figure 4] This figure shows the pressure plate in a non-supported position. [Figure 5] This diagram shows the pressure-receiving plate located in the support position. [Figure 6] This figure shows the main parts of the lumbar support device according to the second embodiment. [Modes for carrying out the invention]

[0013] The following "Embodiments of the Invention" are examples of embodiments that fall within the technical scope of this disclosure. In other words, the features defining the invention as described in the claims are not limited to the specific configurations and structures shown in the embodiments below.

[0014] This embodiment is an example in which the seat back according to this disclosure is applied to a seat installed in a vehicle or other vehicle (hereinafter referred to as a vehicle seat). The arrows and diagonal lines indicating direction in each figure are included to facilitate understanding of the relationships between the figures and the shapes of the members or parts.

[0015] Therefore, the seat back is not limited to the orientation shown in each figure. The orientations shown in each figure are those of the vehicle seat according to this embodiment when it is installed in a vehicle. Diagonal lines do not necessarily indicate a cross-sectional view.

[0016] At least one member or portion described with a reference numeral is provided, unless otherwise specified with a limitation such as "one". That is, unless a limitation such as "one" is specified, two or more of the subject member may be provided. The seat back disclosed in the present disclosure includes at least one of the components such as members or portions described with at least reference numerals, and the structural portions illustrated in the drawings.

[0017] (First Embodiment) <1. Overview of Vehicle Seat> As shown in Figure 1, the vehicle seat 1 at least includes a seat cushion 3, a seat back 5 and the like. The seat cushion 3 is a portion for supporting the buttocks of a seated person. The seat back 5 is a portion for supporting the back of the seated person.

[0018] The seat back 5 is provided with a lumbar support device 7. The lumbar support device 7 is a device for supporting the lumbar region of a seated person, and is a device capable of switching between a support state and a non-support state.

[0019] The support state refers to a state in which the lumbar region of the seated person is pressed to support the lumbar region. The non-support state refers to a state where the support state is released. Therefore, in the non-support state, the lumbar support device 7 does not actively press the lumbar region of the seated person.

[0020] <2. Details of Lumbar Support Device> As shown in Figure 2, the lumbar support device 7 at least includes a frame 9, a pressure receiving member 11, a drive mechanism 13 and the like. The frame 9 is a member that constitutes a part of the skeleton of the seat back 5. The frame 9 according to the present embodiment is formed of a wire-shaped steel material.

[0021] <2.1 Pressure Receiving Member (Pressure Receiving Plate)> The pressure receiving member 11 is a portion that receives a load from the back of a seated person. Specifically, the pressure receiving member 11 is configured to have a pressure receiving plate 12 in which a first pressure receiving portion 11A, a second pressure receiving portion 11B, and a connecting portion 11C are integrated.

[0022] The first pressure-receiving part 11A is a plate-shaped part that supports the lower back of the seated person. The second pressure-receiving part 11B is a plate-shaped part that is connected above the first pressure-receiving part 11A and works in cooperation with the first pressure-receiving part 11A to support the back of the seated person.

[0023] The connecting portion 11C is the part that connects the first pressure-receiving portion 11A and the second pressure-receiving portion 11B. In this embodiment, the first pressure-receiving portion 11A, the second pressure-receiving portion 11B, and the connecting portion 11C are all made from a single resin plate.

[0024] Furthermore, as shown in Figure 3, a flange 11D is provided on the back side of the second pressure-receiving portion 11B, protruding from the back side. The flange 11D is a reinforcing portion that increases the bending rigidity of the second pressure-receiving portion 11B compared to the first pressure-receiving portion 11A.

[0025] Specifically, the flange 11D consists of multiple wall-like portions protruding from the back surface of the second pressure-receiving portion 11B. As a result, the bending rigidity of the second pressure-receiving portion 11B is greater than that of the first pressure-receiving portion 11A and the connecting portion 11C, which do not have the flange 11D, etc.

[0026] Note that bending stiffness refers to the bending stiffness around an axis parallel to the sheet width direction (left-right direction of the paper). At least one (multiple in this embodiment) hook-shaped hinges 12A are provided on one end (upper end in this embodiment) of the pressure receiving member 11, that is, the pressure receiving plate 12.

[0027] As shown in Figure 2, the frame 9 is provided with the same number of shaft portions 9A as the hinges 12A. Each shaft portion 9A is a round bar or cylindrical part to which the corresponding hinge 12A is rotatably locked, and its axial direction is parallel to the sheet width direction. The shaft portions 9A are provided on resin blocks 9B fixed to the frame 9.

[0028] When each hinge 12A is locked to each shaft portion 9A, the upper end of the pressure plate 12 is rotatably supported by the frame 9 via the shaft portion 9A. In this embodiment, each hinge 12A is roughly U-shaped with an open upper end.

[0029] Each shaft portion 9A is fitted into the hinge 12A through the upper opening of the hinge 12A. At this time, since the lower side of the pressure plate 12 is supported by the rotating arm 13A (see Figure 4), each hinge 12A will not fall out of each shaft portion 9A.

[0030] <2.2 Drive Mechanism> The drive mechanism 13 is a mechanism for deforming and displacing the pressure plate 12 between a support position (see Figure 5) and a non-support position (see Figure 4). The support position is the position in which the pressure plate 12 is located closer to the seated person compared to the non-support position, and the pressure plate 12 is in a supported state.

[0031] The non-supported position is the position where the pressure receiving plate 12 is located on the rear side compared to the supported position, and the pressure receiving plate 12 is in a non-supported state. When the pressure receiving plate 12 is in the supported position, it bends at the connecting portion 11C and becomes convex toward the front side of the sheet (see Figure 5).

[0032] In other words, the second pressure-receiving section 11B has greater bending rigidity than the first pressure-receiving section 11A and the connecting section 11C because it is provided with multiple flanges 11D. The first pressure-receiving section 11A has greater bending rigidity than the connecting section 11C because it is provided with a hinge 12A as shown in Figure 3.

[0033] Therefore, the connecting portion 11C is an elastically deformable portion with lower bending rigidity compared to the first pressure-receiving portion 11A and the second pressure-receiving portion 11B. Consequently, when a force that compresses the pressure-receiving plate 12 in the vertical direction is applied to the pressure-receiving plate 12, the pressure-receiving plate 12 will buckle at the connecting portion 11C.

[0034] In other words, when the pressure plate 12 is in the support position, the pressure plate 12 is bent at the connecting portion 11C. Therefore, the pressure plate length Lo (see Figure 5) when the pressure plate 12 is in the support position is smaller than the pressure plate length Lo (see Figure 4) when the pressure plate 12 is in the non-support position.

[0035] The pressure plate length Lo refers to the distance from the center of rotation O1 to the rotating end P1 of the pressure plate 12. The center of rotation O1 refers to the part of the pressure plate 12 that is rotatably supported by the frame 9, that is, the central axis of the shaft portion 9A.

[0036] The rotating end P1 of the pressure plate 12 refers to the end of the pressure plate 12 opposite to the center of rotation O1 in the vertical direction (in this embodiment, the lower end of the pressure plate 12). The position of the rotating end P1 in the support state is located closer to the seated person, i.e., closer to the front of the seat, compared to the position of the rotating end P1 in the non-support state.

[0037] The drive mechanism 13 is configured to include at least a rotating arm 13A and an actuator 13B, as shown in Figure 4. The rotating arm 13A is a member in which one end is rotatably connected to the pressure plate 12 and the other end is rotatably connected to the frame 9. In this embodiment, the one end is the lower end and the other end is the upper end.

[0038] The connection point between the rotating arm 13A and the pressure plate 12 is located on the rotating end P1 side of the connecting portion 11C (see Figure 5). The connection point between the rotating arm 13A and the frame 9 is located between the connecting portion 11C and the rotating end P1. In other words, the upper end of the rotating arm 13A is located lower than the connecting portion 11C and higher than the lower end of the pressure plate 12.

[0039] Furthermore, the difference between the arm end radius R1 (see Figure 5) and the center end radius R2 (see Figure 5) when the pressure plate 12 is in the support position is smaller than the difference between the arm end radius R1 and the center end radius R2 when the pressure plate 12 is in the non-support position.

[0040] The arm end radius R1 refers to the distance from the connection point P2 between the rotating arm 13A and the pressure plate 12 to the center of rotation O1. The center end radius R2 refers to the distance from the connection point P3 between the rotating arm 13A and the frame 9 to the center of rotation O1.

[0041] The actuator 13B is a mechanism that rotates the rotating arm 13A around the connection point P3 with the frame 9. Specifically, as shown in Figure 4, it is configured to include a slider cam 13C and a motor 13D, etc.

[0042] The slider cam 13C is a component that slides and displaces vertically while making sliding contact with the rotating arm 13A. The motor 13D uses the principle of a screw to slide and displace the slider cam 13C.

[0043] When the slider cam 13C is displaced toward the connection point P3, the lower end of the rotating arm 13A is displaced toward the seated person, i.e., toward the front of the seat (see Figure 5). When the slider cam 13C is displaced downward, the lower end of the rotating arm 13A is displaced toward the rear of the seat (see Figure 4).

[0044] When the lower end of the rotating arm 13A rotates toward the front of the seat, the rotating arm 13A applies a force to the pressure plate 12 that compresses it in the vertical direction. Consequently, the rotation of the rotating arm 13A causes the pressure plate 12 to bend and buckle.

[0045] <3. Features of the vehicle seat (particularly the lumbar support device) according to this embodiment> In this embodiment, when the pressure plate 12 is in the support position, the pressure plate 12 bends at the connecting portion 11C and becomes convex toward the front of the seat. Therefore, compared to conventional devices that are curved in an arc shape, it is possible to exert sufficient support force.

[0046] (Second Embodiment) As shown in Figure 6, this embodiment is provided with a bending restricting portion 14. The bending restricting portion 14 is a member that ensures the pressure receiving plate 12 bends so that it becomes convex toward the front of the sheet when the pressure receiving plate 12 is displaced from a non-supported position to a supported position.

[0047] In other words, the bending restricting portion 14 restricts the bending of the pressure receiving plate 12 so that it becomes convex toward the rear side of the seat when the pressure receiving plate 12 is displaced from a non-supported position to a supported position. In other words, if the pressure receiving plate 12 were to bend so that it becomes convex toward the rear of the seat, the pressure receiving plate 12 would come into contact with the bending restricting portion 14, thus preventing the pressure receiving plate 12 from bending so that it becomes convex toward the rear of the seat.

[0048] Furthermore, this embodiment may also have the following configuration, for example. In other words, the configuration includes a contact portion provided on the pressure plate 12 that can contact the shaft portion 9A and constitutes a bending restriction portion. The contact portion is spaced apart from the shaft portion 9A when the pressure plate 12 is in a non-supported position, and furthermore, the contact portion contacts the shaft portion 9A while the pressure plate 12 is displaced from the non-supported position to the supported position.

[0049] In this configuration, when the central perpendicular is defined as a virtual line perpendicular to the central axis of rotation at the connection point (P2) between the rotating arm 13A and the pressure plate 12, it is desirable that the contact point between the contact portion and the shaft portion 9A be located on the pressure plate 12 side with respect to the central perpendicular.

[0050] (Other embodiments) In the above-described embodiment, the pressure receiving plate 12 was configured with a first pressure receiving portion 11A, a second pressure receiving portion 11B, and a connecting portion 11C integrated into one. However, the disclosure is not limited thereto. That is, the disclosure may also include a configuration in which, for example, the first pressure receiving portion 11A and the second pressure receiving portion 11B are made of separate members, and the connecting portion 11C is formed by a hinge.

[0051] In the embodiment described above, a plurality of flanges 11D were provided on the back surface of the second pressure-receiving portion 11B. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a configuration in which the thickness dimension of the second pressure-receiving portion 11B is greater than the thickness dimension of the first pressure-receiving portion 11A.

[0052] The actuator 13B in the above-described embodiment was configured to rotate the rotating arm 13A by sliding the slider cam 13C using the principle of a screw. However, the disclosure is not limited to this. That is, the disclosure may also be configured to rotate the rotating arm 13A using, for example, a link mechanism.

[0053] In the embodiment described above, the upper end of the pressure plate 12 was rotatably connected to the frame 9. However, the disclosure is not limited thereto. That is, the disclosure may also include a configuration in which, for example, the lower end of the pressure plate 12 is rotatably connected to the frame 9.

[0054] The drive mechanism 13 according to the above embodiment was configured to include a rotating arm 13A and an actuator 13B, etc. However, the disclosure is not limited thereto. That is, the disclosure may, for example, bend the pressure plate 12 using a drive mechanism that utilizes a rotating cam.

[0055] In the embodiments described above, the vehicle seat according to this disclosure was applied to a vehicle. However, the application of the invention disclosed herein is not limited to this. That is, the disclosure can be applied, for example, to seats used in vehicles such as railway cars, ships and aircraft, as well as to stationary seats used in theaters, homes, etc.

[0056] Furthermore, this disclosure is not limited to the embodiments described above, but is sufficient to be consistent with the intent of the disclosures described in the embodiments described above. Therefore, it may be a configuration in which at least two of the embodiments described above are combined, or a configuration in which any of the illustrated components or components described with reference numerals in the embodiments described above are omitted. [Explanation of Symbols]

[0057] 1… Vehicle seat 3… Seat cushion 5… Seat back 7... Lumbar support device 9... Frame 9A... Shaft 9B… Block 11… Pressure-receiving member 11A… First pressure-receiving section 11B… Second pressure receiving section 11C… Connecting section 11D… Flange 12… Pressure plate 12A… Hinge 13A… Rotating arm 13… Drive mechanism 13C… Slider cam 13D… Motor

Claims

1. In a seat back that supports the back of a seated person, A pressure-receiving member having a first pressure-receiving part that supports the lumbar region of a seated person, and a second pressure-receiving part connected above the first pressure-receiving part and cooperating with the first pressure-receiving part to support the back of the seated person, The system includes a drive mechanism that displaces the pressure-receiving member between a support position where the pressure-receiving member is located on the side of the seated person and a non-support position where the pressure-receiving member is located on the rear side compared to the support position. When the pressure-receiving member is in the support position, the pressure-receiving member bends at the connection between the first pressure-receiving portion and the second pressure-receiving portion, becoming convex toward the front side of the sheet. The pressure-receiving member is configured to have a pressure-receiving plate in which the first pressure-receiving portion, the second pressure-receiving portion, and the connecting portion are integrated. The connecting portion is an elastically deformable portion with lower bending rigidity compared to the first pressure-receiving portion and the second pressure-receiving portion. Furthermore, the system includes a support member that rotatably supports one end of the pressure receiving plate in the vertical direction, When the portion of the pressure-receiving plate rotatably supported by the support member is defined as the center of rotation, the other end of the pressure-receiving plate in the vertical direction is defined as the end of rotation, and the distance from the center of rotation to the end of rotation is defined as the length of the pressure-receiving plate, When the pressure-receiving plate is in the support position, the position of the rotating end is located closer to the seated person than when the pressure-receiving plate is in the non-support position, A seatback in which the length of the pressure-receiving plate when it is in the support position is smaller than the length of the pressure-receiving plate when it is in the non-support position.

2. The aforementioned drive mechanism is A rotating arm having one end rotatably connected to the pressure plate and the other end rotatably connected to the support member, wherein the one end is connected to the part of the pressure plate closer to the rotating end than the connecting portion, and The rotating arm is configured to have an actuator that rotates it about the connection point with the support member, When the distance from the connection point between the rotating arm and the pressure plate to the center of rotation is defined as the arm end radius, and the distance from the connection point between the rotating arm and the support member to the center of rotation is defined as the center end radius, The seat back according to claim 1, wherein the difference between the arm end radius and the center end radius when the pressure receiving plate is in the support position is smaller than the difference between the arm end radius and the center end radius when the pressure receiving plate is in the non-support position.

3. The seat back according to claim 2, further comprising a bending restricting portion that bends the pressure receiving plate so that it becomes convex toward the front of the seat when the pressure receiving plate is displaced from the non-supported position to the supported position.

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