Vehicle seat

Abstract

A vehicle seat (100) is provided with a seat cushion (11), a seat back (12), a tilt angle adjustment mechanism, a lumbar support mechanism (40), and a control unit (100) that pushes a support surface (12S) toward an occupant (60) by means of the lumbar support mechanism (40) when the seat back (12) is tilted backwards by a predetermined angle or more.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Japanese Patent Application No. 2024-139638, filed on August 21, 2024, the entire contents of which, including the specification, claims, drawings and abstract, are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the structure of a vehicle seat with a tilt adjustment mechanism. Background Technology

[0004] A vehicle seat designed to prevent the occupant's head from shifting relative to the headrest and to prevent the occupant's clothing from rolling up when the seat back is reclined.

[0005] For example, JP2006-160217A discloses a vehicle seat that includes a connecting rod rotatably connecting the lower part of the seat back to the rear end of the seat cushion, and a parallel connecting rod connecting the seat cushion to the floor. In this vehicle seat, when the seat back is tilted back, the rear end of the seat cushion moves upward and backward.

[0006] Additionally, JP2010-246599A discloses a vehicle seat in which the seat back and seat cushion are connected by a linkage mechanism including an L-shaped link. In this vehicle seat, when the seat back is tilted back, the seat cushion moves upward and forward.

[0007] In addition, JP2023-004166A discloses a vehicle seat that has a top plate drive section that mitigates the height difference between the top plate section and the seat back. When the seat back is tilted back, the top plate section that supports the buttocks of the occupant moves forward and upward. Summary of the Invention

[0008] The prior art vehicle seats described in JP2006-160217A, etc., allow the rotation center of the occupant's back to be close to the rotation center of the seat back. However, in this vehicle seat, the rotation center of the seat back is located away from the boundary between the seat back and the seat cushion, so when the seat back is tilted back, the lower end of the seat back is lower than the rear end of the seat cushion. Therefore, a height difference is created between the rear end of the seat cushion and the lower end of the seat back. As a result, the occupant may sometimes experience discomfort caused by the height difference, abdominal pressure caused by the buttocks resting on the height difference, or fatigue and discomfort caused by the uneven distribution of pressure on the back.

[0009] Therefore, the purpose of this disclosure is to reduce the discomfort of occupants when the seat back is reclined.

[0010] The vehicle seat disclosed herein includes a seat cushion frame, a seat back, a seat back frame, a tilt adjustment mechanism, a lumbar support mechanism, and a control unit. The seat cushion frame supports the seat cushion. The seat back has a support surface that supports the back of a seated occupant. The seat back frame supports the seat back. The tilt adjustment mechanism includes a curved bracket integrally formed with the seat back frame; the seat back tilts backward by the bracket moving in an arc relative to the seat cushion frame. The lumbar support mechanism pushes the support surface toward the occupant. The control unit adjusts the operation of the lumbar support mechanism. The control unit includes a processor for information processing, configured to push the support surface toward the occupant via the lumbar support mechanism when the seat back tilts backward by a predetermined angle or more.

[0011] Therefore, when the seat back is reclined, the lumbar support mechanism reduces the height difference between the rear end of the seat cushion and the lower end of the seat back, thus suppressing the occupant's discomfort.

[0012] In the vehicle seat disclosed herein, the processor may also adjust the extension position of the support surface according to the tilt angle of the seat back.

[0013] The height difference between the rear end of the seat cushion and the lower end of the seat back varies depending on the tilt angle of the seat back. Therefore, by adjusting the extension position of the support surface according to the tilt angle of the seat back, occupant discomfort can be suppressed regardless of the tilt angle of the seat back.

[0014] In the vehicle seat disclosed herein, the tilt adjustment mechanism may also include a curved track mounted on the seat cushion frame, the bracket being guided to move by the curved track, thereby causing the bracket to swing relative to the seat cushion frame.

[0015] Therefore, the center of rotation can be set close to the occupant's buttocks while the tilt adjustment mechanism is positioned away from the center of rotation. This prevents the occupant sitting in the vehicle seat from coming into contact with the tilt adjustment mechanism.

[0016] In the vehicle seat disclosed herein, the curved track may also be a curved shape with a varying radius of curvature.

[0017] Therefore, multiple rotation centers of the seat back can be set, enabling highly flexible tilt adjustment.

[0018] This invention can suppress the discomfort of occupants when the seat back is reclined. Attached Figure Description

[0019] Figure 1This is a system diagram showing the structure of a vehicle seat according to an embodiment.

[0020] Figure 2 This indicates that the passengers are seated in Figure 1 An elevation view showing the condition of the vehicle's seats.

[0021] Figure 3 It means to make Figure 1 The diagram illustrates the movement of various parts when the seat back of a vehicle reclines.

[0022] Figure 4 This indicates that the passengers are seated in Figure 1 The image shows an elevation view of the vehicle seat with the backrest reclined.

[0023] Figure 5 It is an elevation view showing the seat back reclining when the occupants are seated in a proportional vehicle seat. Detailed Implementation

[0024] Hereinafter, the vehicle seat 100 according to the embodiments will be described with reference to the accompanying drawings. In addition, FR, UP, and RH in each figure represent the front, upper, and right sides of the vehicle seat 100, respectively. Furthermore, the opposite directions of FR, UP, and RH represent the rear, lower, and left sides, respectively. Hereinafter, only the front-back, left-right, and up-down directions will be used in the description, unless otherwise specified.

[0025] like Figure 1 As shown, the vehicle seat 100 includes a seat cushion 11, a seat back 12, a seat cushion frame 13, a seat back frame 14, a tilt adjustment mechanism 20, a lumbar support mechanism 40, and a control unit 50.

[0026] The seat cushion frame 13 is a metal plate-like component disposed at the left and right ends of the vehicle seat 100 and extending in the front-rear direction. The left and right seat cushion frames 13 are connected left and right by a plurality of crossbeams (not shown), and are mounted to the vehicle floor (not shown) via the front and rear leg sections 15 and 16. The seat cushion 11 is mounted on the left and right seat cushion frames 13. The seat cushion 11 has a buttocks 61 supporting the seated occupant 60 (see reference). Figure 2 ) ) seat surface 11S.

[0027] The seat back frame 14 is located on the upper rear side of the left and right seat cushion frames 13, and is a metal plate-like component extending in the vertical direction. The left and right seat back frames 14 are connected in the left-right direction by a connecting member (not shown). The left and right seat back frames 14 are connected to the left and right seat cushion frames 13 by a tilt adjustment mechanism 20. A seat back 12 is installed in front of the left and right seat back frames 14. The seat back 12 has a backrest 62 (see reference) that supports the seated occupant 60. Figure 2 The supporting surface 12S.

[0028] The tilt adjustment mechanism 20 includes a curved track 21, a slider 22, a bracket 23, a rod 31, a worm gear housing 32, a screw 33, and a motor 35. The tilt adjustment mechanism 20 tilts the seat back 12 back about a rotation center C. Here, the rotation center C is a position away from the tilt adjustment mechanism 20 and close to the hip point 65 (see reference 65), which is the center of rotation of the upper body of the occupant 60 when the seat back 12 is tilted back. Figure 4 The position of ).

[0029] The curved track 21 is an arc-shaped track with radius R that is bolted 24 to the side of the seat cushion frame 13. The slider 22 is guided by the curved track 21 and can move along it. The bracket 23 is a plate-shaped component with a curved lower part that is curved into an arc shape and an upper part that extends upward. The upper part of the bracket 23 is fixed to the lower side of the seat back frame 14 by bolts 26. Thus, the bracket 23 and the seat back frame 14 are integrated. In addition, the lower part of the bracket 23 is fixed to the slider 22 by bolts 25. Therefore, when the slider 22 is guided by the curved track 21 and moves in an arc shape, the lower part of the bracket 23 rotates relative to the seat cushion frame 13, and the seat back frame 14 rotates about the rotation center C. As a result, the seat back 12 tilts back. Here, the rotation center C is the center of curvature of the curved track 21.

[0030] Rod 31 is a round bar component supported on the left and right seat cushion frames 13 and extending in the left-right direction. The left and right ends of rod 31 pass through the left and right seat cushion frames 13 and extend to the outside of the left and right seat cushion frames 13. Worm gear housing 32 houses the worm gear and screw 33 connected to both ends of rod 31. The worm gear engages with screw 33 in worm gear housing 32. Worm gear housing 32 is mounted on the outside of seat cushion frames 13 in a manner that allows it to rotate around rod 31. The rear end of screw 33 is rotatably connected to the lower part of bracket 23 via fastening part 34. Electric motor 35 is disposed between the left and right seat cushion frames 13 and drives rod 31 to rotate. In addition, electric motor 35 detects the rotation angle position of rod 31 and outputs it.

[0031] The lumbar support mechanism 40 is disposed inside the seat back 12 and pushes the support surface 12S of the seat back 12 toward the occupant 60 and toward the front of the seat.

[0032] The control unit 50 is a computer that internally includes a CPU 51, which acts as a processor for information processing, and a memory 52, which stores programs and control data. The control unit 50 is connected to a motor 35, a lumbar support mechanism 40, and a tilt adjustment switch 53. The rotation angle of the lever 31 detected by the motor 35 and the operation signal of the tilt adjustment switch 53 are input to the control unit 50. Based on the input signals, the control unit 50 adjusts the operation of the motor 35 and the lumbar support mechanism 40.

[0033] like Figure 2 As shown, when the seat back 12 is in the upright position, the back 62 of the occupant 60 is approximately parallel to the surface 41 of the back side of the lumbar support mechanism 40. Furthermore, the amount of depression of the support surface 12S of the seat back 12 is approximately constant along the surface of the back 62, and the pressure applied to the back 62 from the support surface 12S is also approximately constant. This state is comfortable for the occupant 60.

[0034] Next, refer to Figure 3 , Figure 4 ,right Figure 1 , Figure 2 The operation of the seat back 12 of the vehicle seat 100 when it is reclined will be explained. Furthermore, the operation of the CPU 51 of the control unit 50 is achieved by the CPU 51 executing a program stored in the memory 52.

[0035] When the occupant 60 operates the tilt adjustment switch 53 and inputs the operation signal of the tilt adjustment switch 53 to the control unit 50, the CPU 51 causes the motor 35 of the tilt adjustment mechanism 20 to operate.

[0036] When the motor 35 causes the rod 31 to rotate, as Figure 3 As indicated by arrow 90, the worm gears connected to both ends of rod 31 rotate. Thus, as... Figure 3 As indicated by arrow 91, the screw 33, engaged with the worm gear, moves forward relative to the seat cushion frame 13. Accompanying this, the fastening portion 34 at the rear end of the screw 33 moves forward. When the fastening portion 34 moves forward, as... Figure 3 As indicated by arrow 92, the slider 22 moves in an arc along the curved track 21. Thus, as... Figure 3 As indicated by arrow 93, the seat back 12 rotates around the center of rotation C and tilts backward.

[0037] like Figure 3As indicated by arrow 94, when the seat back 12 is tilted back, the lower end 12D of the seat back 12 rotates to lie behind the rear end 11A of the seat cushion 11. Therefore, when the seat back 12 is tilted back, the lower end 12D of the seat back 12 is lower than the rear end 11A of the seat cushion 11, creating a height difference G between the lower end 12D and the rear end 11A.

[0038] When the seat backrest 12 begins to tilt backward, the CPU 51 calculates the tilt angle of the seat backrest 12 based on the rotation angle position of the lever 31 input from the motor 35. Furthermore, if the tilt angle of the seat backrest 12 exceeds a predetermined angle, the CPU 51... Figure 4 The lumbar support mechanism 40 is activated as shown. The specified angle can be freely set, but it can also be set, for example, between 30° and 60°. Thus, as... Figure 4 As indicated by the hollow arrow 98, surface 41 is pushed forward toward the occupant 60, and the support surface 12S of the seat back 12 is pushed forward toward the occupant 60. Furthermore, in Figure 4 In the diagram, the shaded area represents the state after the surface 41 of the lumbar support mechanism 40 has moved forward. As a result, the height difference G between the lower end 12D of the seat back 12 and the rear end 11A of the seat cushion 11 (see reference) increases. Figure 5 The difference between high and low points is reduced to H (refer to the elevation difference H). Figure 4 Therefore, it can prevent the rear of the occupant's buttocks 61 from entering the height difference G, and suppress the occupant's feeling of pressure on the abdomen.

[0039] Additionally, through the movement of the lumbar support mechanism 40, the surface 41 is pushed forward toward the occupant 60, thus... Figure 4 As shown in section A, the backrest 62 of the occupant 60 of the seat backrest 12 is approximately parallel to the surface 41. Therefore, similar to the case where the seat backrest 12 is upright, the amount of depression of the support surface 12S of the seat backrest 12 is approximately constant along the surface of the backrest 62, and the pressure applied to the backrest 62 from the support surface 12S is also approximately constant, resulting in a comfortable state for the occupant 60. This suppresses fatigue and discomfort caused by deviations in the pressure distribution of the backrest 62.

[0040] Next, refer to Figure 5 The following describes the situation where the seat back 12 is reclined while the occupant 60 is seated in the comparative vehicle seat 110. Here, even when the seat back 12 of the comparative vehicle seat 110 is reclined, the control unit 50 does not activate the lumbar support mechanism 40. Other than this, the structure is the same as that of the vehicle seat 100.

[0041] like Figure 5As shown, in the vehicle seat 110, when the occupant 60 operates the tilt adjustment switch 53 and the seat back 12 tilts back, as previously referred to... Figure 4 As explained, the lower end 12D of the seat back 12 is lower than the rear end 11A of the seat cushion 11, creating a height difference G between the lower end 12D and the rear end 11A (see reference). Figure 5 (Part B). Therefore, the rear side of the occupant's buttocks 61 enters the height difference G, and sometimes the occupant feels a pressure caused by the bending of the abdomen. In addition, the back 62 of the occupant 60 is not roughly parallel to the surface 41 of the back of the lumbar support mechanism 40, and the amount of sinking of the support surface 12S of the seat back 12 is not roughly constant along the surface of the back 62. Therefore, the occupant 60 sometimes feels fatigue and discomfort caused by the deviation in the pressure distribution of the back 62.

[0042] In contrast, in the embodiment of the vehicle seat 100, when the tilt angle of the seat back 12 is above a predetermined angle, the lumbar support mechanism 40 pushes the support surface 12S forward of the seat, thereby creating a height difference G (refer to) between the lower end 12D of the seat back 12 and the rear end 11A of the seat cushion 11. Figure 5 The reduction is to the height difference H (refer to) Figure 4 ( ), which can suppress the aforementioned discomfort of the occupants 60.

[0043] Furthermore, the vehicle seat 100 can have its rotation center C positioned close to the hip point 65 of the occupant 60, and the tilt adjustment mechanism 20 positioned away from the rotation center C. This prevents the occupant 60 seated in the vehicle seat 100 from contacting the tilt adjustment mechanism 20.

[0044] The above description explains that when the tilt angle of the seat back 12 is above a predetermined angle, the CPU 51 of the control unit 50 pushes the support surface 12S towards the occupant 60 and forward of the seat via the lumbar support mechanism 40. However, the operation of the CPU 51 of the control unit 50 is not limited to this. The CPU 51 of the control unit 50 can also adjust the rearward position of the support surface 12S according to the tilt angle of the seat back 12. For example, the amount of forward pushing of the support surface 12S towards the seat can be increased as the tilt angle of the seat back 12 increases.

[0045] The height difference G between the lower end 12D of the seat back 12 and the rear end 11A of the seat cushion 11 varies depending on the tilt angle of the seat back 12. Therefore, by adjusting the extension position of the support surface 12S according to the tilt angle of the seat back 12, the discomfort of the occupant 60 can be suppressed regardless of the tilt angle of the seat back 12.

[0046] Furthermore, while the above description indicates that the curved track 21 is an arc-shaped track, its shape is not limited to this. For example, the curved track 21 can also be a curved shape with multiple radii of curvature. In this case, the curved track 21 has multiple centers of curvature, allowing multiple rotation centers C of the seat back 12 to be set. This enables highly flexible tilt adjustment.

[0047] Furthermore, while the above description states that the bracket 23 is fixed to the seat back frame 14 by bolts 26, the bracket 23 is not limited to this structure as long as it is integrally formed with the seat back frame 14. For example, a seat back frame assembly in which the seat back frame 14 and the bracket 23 are integrally formed can also be used.

Claims

1. A vehicle seat, comprising: Seat cushion frame, supporting the seat cushion; The seat back has a support surface to support the back of the seated occupant. A seat back frame that supports the seat back; The tilt adjustment mechanism tilts the seat back by moving a curved bracket integrally formed with the seat back frame in an arc relative to the seat cushion frame. A lumbar support mechanism extends the support surface toward the occupant; and The control unit adjusts the movement of the waist support mechanism. The control unit includes a processor for information processing. The processor is configured to push the support surface toward the occupant via the lumbar support mechanism when the seat back is tilted at a predetermined angle or more.

2. The vehicle seat according to claim 1, wherein, The processor is configured to adjust the extension position of the support surface according to the tilt angle of the seat back.

3. The vehicle seat according to claim 1 or 2, wherein, The tilt adjustment mechanism has a curved track mounted on the seat cushion frame. The bracket is guided to move by the curved track, thereby causing the bracket to swing relative to the seat cushion frame.

4. The vehicle seat according to claim 3, wherein, The curved track is a curved shape with a varying radius of curvature.

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