Vehicle seating system with lumbar support

Abstract

Vehicle seat systems that offer lumbar support require improvement. [Solution] The seat device has multiple plate members as lumbar support members, and an expandable and contractible bag is provided on the back side of the lumbar support members. The bag expands when the seat back is upright relative to the seat cushion, pushing the multiple plate members from the back side and forming a surface shape for lumbar support on the multiple plate members. The bag contracts when the seat back is reclined relative to the seat cushion, allowing the multiple plate members to individually sink into the back side of the seat back.

Description

Technical Field

[0001] This application mainly discloses a seat device for a vehicle capable of supporting a lumbar.

Background Art

[0002] In a seat back on which an occupant in a vehicle sits, a plate-shaped lumbar support member that bulges at the rear side of the waist is provided to stabilize the waist and upper body of the occupant sitting on the seat (Patent Documents 1 to 3). In a seat back having a lumbar support member, the waist portion of an occupant sitting on the seat cushion can be supported from the rear side by the lumbar support member. The upper body of the occupant sitting on the seat is more likely to maintain an S-shaped curve above the waist portion by maintaining the state where the waist portion stands up, and the occupant is less likely to get tired even during a long drive. The lumbar support member can support the waist of the occupant from the rear side during the running of the vehicle and reduce the fatigue of the occupant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0005] Thus, improvements are needed in the seat systems of vehicles that offer lumbar support. [Means for solving the problem]

[0006] A vehicle seat device capable of providing lumbar support according to one embodiment of the present invention comprises a seat cushion on which a vehicle occupant sits, a seat back that can be inverted at the rear of the seat cushion, a lumbar support member provided on the seat back and having a plurality of plate members, and an expandable and contractible bag provided on the rear side of the lumbar support member on the seat back, wherein the bag expands when the seat back is upright relative to the seat cushion, pushing the plurality of plate members from the rear side to form a surface shape for lumbar support on the plurality of plate members, and contracts when the seat back is tilted relative to the seat cushion, allowing the plurality of plate members to individually sink into the rear side of the seat back. [Effects of the Invention]

[0007] In one embodiment of the present invention, a vehicle seat device capable of providing lumbar support has a plurality of plate members as lumbar support members provided on the seat back. Furthermore, expandable and contractible bag bodies are provided on the back side of the plurality of plate members for lumbar support. When the seatback is upright relative to the seat cushion, the bag expands due to the fluid supplied from the supply device. When the seatback is upright, the expanded bag pushes from the rear, forming a surface shape for lumbar support. While the vehicle is in motion with the seatback upright relative to the seat cushion, the multiple plate members can form a surface shape for lumbar support. When an occupant is seated on the seat cushion, their lumbar region, including the sacrum, is supported from the rear by the lumbar support surface, making them less prone to fatigue even during long journeys. Because the occupant's lumbar region, including the sacrum, is supported from the rear, forward sliding of the lumbar region is less likely to occur while the vehicle is in motion, making it easier to maintain the position and posture of the lumbar region when seated on the seat cushion. Conversely, when the seatback is reclined relative to the seat cushion, the bag-like structure shrinks. The lumbar support component is not a single plate, but is divided into multiple plate-like components. When the seatback is reclined, the weight of the occupant acts on these multiple plate-like components, allowing them to individually sink towards the back of the seatback. As the multiple plate-like components sink individually in the reclined seatback, the occupant can rest in a comfortable posture with their entire body, including their lower back, in contact with the seat surface. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram illustrating a vehicle according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating the front seat of the vehicle shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram illustrating the state of the front seat with the seatback of Figure 2 reclined. [Figure 4] Figure 4 is an explanatory diagram of a vehicle seat device provided in the front seat in the first embodiment. [Figure 5] Figure 5 is a schematic diagram illustrating the lumber support member and bag shown in Figure 4, viewed from the left side. [Figure 6]Figure 6 is an explanatory diagram showing the state in which the lumbar support member shown in Figure 4 forms a surface shape for lumbar support when the seat back is in an upright position. [Figure 7] Figure 7 is an explanatory diagram illustrating the state of the lumbar support member in Figure 4 when the seat back is reclined for comfort. [Figure 8] Figure 8 is a schematic diagram illustrating the first embodiment with the front seat back folded down. [Figure 9] Figure 9 is an example of a flowchart for lumbar support control by the control unit shown in Figure 4. [Figure 10] Figure 10 is an explanatory diagram of a vehicle seat device provided in the front seat in the second embodiment. [Figure 11] Figure 11 is a schematic diagram illustrating the lumbar support member shown in Figure 10, viewed from the upper left front side. [Figure 12] Figure 12 is an explanatory diagram showing the state in which the lumbar support member shown in Figure 11 forms a surface shape for lumbar support when the seat back is in an upright position. [Figure 13] Figure 13 is an explanatory diagram illustrating the state of the lumbar support member in Figure 11 when the occupant's weight is applied in a relaxed position with the seat back reclined. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in the following order with reference to the drawings. In the first embodiment, an overview of the first embodiment will be described first. Then, specific examples of the seat device, lumbar support state, comfort state, and lumbar support control will be described. In the second embodiment, first, an overview of the second embodiment will be described. Then, the main differences from the above-described embodiment will be explained regarding specific examples of the seat device, lumbar support state, and comfortable state. The following description of embodiments and drawings are examples of the invention disclosed in this application and do not limit the invention disclosed in this application.

[0010] [First Embodiment] (Overview) A lumbar support member is provided on the seat back of the seat on which the occupant sits in the vehicle. The lumbar support member is formed in a surface shape that follows the shape from the waist to the back of the occupant sitting on the seat cushion. However, if a lumbar support member with a surface shape that follows the shape from the waist to the back of the seated occupant is provided on the seat back in this way, it is difficult for the occupant to take a comfortable posture when reclining the seat back and resting on it. When the body hits the lumbar support member, a part of the occupant's body such as the waist will float from the seat surface. In this embodiment, the lumbar support member for forming a predetermined surface shape is configured by dividing it into a plurality of plate members. Here, the plurality of plate members are individually fixed to, for example, the frame of the seat back and are connected to each other by a telescopic member. Also, a bag body that can be expanded and contracted by a fluid supplied from a supply device is provided on the back side of the plurality of plate members as the lumbar support member. The bag body is provided so as to be expandable and contractible, for example, between a support wire and the plurality of plate members that constitute the frame of the seat back. When the bag body expands in a state where the seat back stands against the seat cushion, the plurality of plate members are pushed from the back side by the expanding bag body, and a surface shape for lumbar support can be formed in the standing seat back. Also, when the fluid is discharged from the bag body and the bag body is in a contracted state and the weight of the occupant acts, the plurality of plate members can sink into the back side of the seat back. The occupant can take a comfortable posture in which the body is entirely supported by the seat surface on the seat with the seat back reclined and rest. In this embodiment, an example will be described in which a lower plate member and an upper plate member connected by a telescopic member are used as the plurality of plate members for lumbar support and are arranged vertically. Here, the telescopic member may be, for example, extensible by the weight of the occupant.

[0011] (Specific examples of vehicle seats) Figure 1 is a schematic explanatory diagram of a vehicle 1 according to the first embodiment of the present invention. The vehicle 1 in Figure 1 has a body 2 that is either wagon-shaped or SUV (Sport Utility Vehicle)-shaped. The passenger compartment 3 of the vehicle body 2 is equipped with a front seat 4 and a rear seat 5. Below, we will use the front, back, left, right, up, and down directions, based on the state shown in Figure 1.

[0012] Figure 2 is a schematic diagram illustrating the front seat 4 of vehicle 1 in Figure 1. The front seat 4 in Figure 2 is designed for one occupant of the vehicle 1 to sit in. The front seat 4 in Figure 2 has a seat cushion 11, a seat back 12, and a headrest 13. The seat cushion 11 comprises a seat cushion frame 14 and a cushioning material (not shown). The cushioning material may be provided on the upper side of the seat cushion frame 14. The occupants of the vehicle 1 sit on the seat cushion 11. The seat back 12 includes a seat back frame 15, a lumbar support member 20, and a cushioning material (not shown). The cushioning material may be provided on the front side of the seat back frame 15. The lumbar support member 20 is provided on the seat back 12, for example, attached to the front side of the seat back frame 15. The lumbar support member 20 supports the lower back of the occupant seated on the seat cushion 11 of the front seat 4 from the rear. As a result, the lumbar region of the occupant seated on the front seat 4, including the hip bones 51, stands upright on the seat cushion 11. The spine 52 of the occupant seated on the front seat 4 forms an S-curve on the upright hip bones 51. The upper body of the occupant seated on the front seat 4 maintains an upright position at the waist, allowing the spine 52 to maintain an S-curve above the waist. This makes it less tiring for the occupant even during long journeys in the vehicle 1. The lumbar support member 20 can support the occupant's lower back from the rear while the vehicle 1 is in motion, thereby reducing occupant fatigue.

[0013] The lower end of the seat back frame 15 is rotatably attached to the rear end of the seat cushion frame 14 by a shaft member 16. The seat back frame 15 is inverted at the rear of the seat cushion frame 14. In Figure 2, the seat back frame 15 is upright relative to the seat cushion 11 for the occupant while the vehicle 1 is in motion. The occupant can obtain a desired seating position suitable for driving the vehicle 1, for example, by adjusting the angle of the seat back frame 15. In addition, the lumbar support member 20 can stabilize the occupant's seating position.

[0014] Incidentally, the occupants can sometimes recline the reversible seatback 12 and rest on the front seat 4. However, if a lumbar support member 20 is provided on the seat back 12, a part of the occupant's body, such as the lower back, will be lifted away from the seat surface of the front seat 4 when the seat back 12 is reclined. The occupant cannot assume a comfortable posture on the front seat 4 even when the seat back 12 is reclined. The occupant cannot take a comfortable rest. Figure 3 is a schematic diagram illustrating the state in which the seatback 12 of the front seat 4 in Figure 2 is reclined. In the dashed circle A of Figure 3, the occupant's waist is separated from the seat surface of the front seat 4. Thus, improvements are needed in the seat device 19 of the vehicle 1 that is capable of lumbar support.

[0015] (Specific example of a seat device) Figure 4 is an explanatory diagram of the seat device 19 of the vehicle 1 provided on the front seat 4 in the first embodiment. The sheet device 19 in Figure 4 includes a lumber support member 20 divided into multiple plate members, an expandable and contractible bag body 39, a compressor 33, an exhaust valve 34, an operating unit 31, a DMS (Driver Monitoring System) 32, and a control unit 35. The seat device 19 may also be provided in a similar configuration for the seats of the vehicle 1 other than the front seat 4.

[0016] The lumber support member 20 has multiple plate members, including a lower plate member 21 and an upper plate member 22. The lower plate member 21 has the same width in the left-right direction as the seat back frame 15. The lower plate member 21 is fixed to the seat back frame 15 at two points on the left and right sides of its lower edge by fasteners 29. The upper plate member 22 is provided above the lower plate member 21. The upper plate member 22 has the same width in the left-right direction as the seat back frame 15. The upper plate member 22 is fixed to the seat back frame 15 at two points on the left and right of its upper edge by fasteners 29. In this way, the lower plate member 21 and the upper plate member 22 are fixed to the seat back frame 15 at all four corners of their entirety. The lower plate member 21 and the upper plate member 22 are connected at two points on the left and right by multiple expandable members 28. The expandable members 28 may be made of elastic material such as a flexible spring material or rubber. The expandable members 28 may also be expandable by the weight of the occupant on the seat back 12.

[0017] As a result, the lower plate member 21 and the upper plate member 22 are connected by the expandable member 28 on the front side of the seat back frame 15, so that they are aligned vertically, and can function as multiple plate members for lumbar support. Here, the lower plate member 21 and the upper plate member 22 may be, for example, two halves of a plate material formed from a resin material or the like into a desired plate shape for lumbar support. The plate shape for lumbar support is basically a plate shape that protrudes forward to support the lower back portion, including the hip bones 51 of the occupant seated in the front seat, from the rear. The plate shape for lumbar support may further include a plate shape that supports the back portion, including the spine 52 of the occupant seated in the front seat, from the rear. In the drawings, the lower plate member 21 and the upper plate member 22 are shown as flat plates for illustrative purposes. Cushioning material may be attached to the front surface of each plate material. Furthermore, the lower plate member 21 and the upper plate member 22, both made of plate material, may have elastic rubber material attached to their entirety. The elastic rubber material that connects the lower plate member 21 and the upper plate member 22 as a whole functions as an elastic member 28.

[0018] Figure 5 is a schematic explanatory diagram showing the lumbar support member 20 and bag body 39 of Figure 4, viewed from the left side. The seat back frame 15 in Figure 5 has multiple support wires 17 stretched between the left and right vertical frames. The multiple support wires 17 function as the part of the seat back frame 15 that supports the occupant's back. The lower plate member 21 and the upper plate member 22 are then attached to the front side of the seat back frame 15.

[0019] The expandable bag 39 is provided between the support wire 17 of the seat back frame 15 and the lower plate member 21 and the upper plate member 22. The expandable bag 39 is provided on the rear side of the lumbar support member 20 in the seat back 12. The bag 39 may be made of a base fabric similar to that of an airbag, sewn in a way that allows it to be expanded into a desired shape. The bag 39 in Figure 5 is expandable and contractible into a disc shape between the support wire 17 of the seat back frame 15 and the multiple plate members 21-22 for lumbar support.

[0020] In Figure 4, the exhaust valve 34 is an on / off valve connected to the bag 39. When the exhaust valve 34 opens, it exhausts the air from the bag 39 to the passenger compartment 3. The compressor 33 is connected to the bag 39. With the exhaust valve 34 closed, it supplies air from the vehicle compartment 3 to the bag 39. The fluid supplied to the bag 39 may be a gas other than air, such as nitrogen gas, or a liquid such as water.

[0021] The control unit 31 is for the occupant of the vehicle 1 to adjust the amount of air in the bag 39 and control the state of the lumbar support. The control unit 31 may have an operation button for the compressor 33, an opening and closing button for the exhaust valve 34, and so on. The DMS32 images the occupants of vehicle 1 to identify individual occupants and monitor their condition. Because the DMS32 images the interior of the vehicle, it can detect the inverted state of the seatback 12 and the seated state of the occupants. The control unit 35 is connected to the operating unit 31, DMS 32, compressor 33, and exhaust valve 34. The control unit 35 may have input / output ports to which a CPU (Central Processing Unit), memory, and peripheral devices are connected, for example. The CPU reads and executes a program stored in memory. In this way, the CPU functions as the control unit 35 that controls the operation of the seat device 19. The memory may record past lumbar support settings for each occupant.

[0022] (Specific examples of lumbar support) Figure 6 is an explanatory diagram showing the state in which the lumbar support member 20 shown in Figure 4 forms a surface shape for lumbar support as illustrated in Figure 2, when the seat back 12 is in an upright position. When the seat back 12 is upright relative to the seat cushion 11, the compressor 33 operates under the control of the control unit 35 and supplies air to the bag 39 with the exhaust valve 34 closed. The compressor 33 may operate for a time corresponding to the operating time of the operating unit 31, for example, and supply an amount of air to the bag 39 corresponding to the operating time. The bag-like body 39 expands between the support wires 17 of the seat back frame 15 and the lower plate member 21 and the upper plate member 22. Because the support wires 17 of the seat back frame 15 are located behind the bag-like body 39, the bag-like body 39 expands forward, pushing the lower plate member 21 and the upper plate member 22 forward from the rear side of the seat back. As a result, the expandable member 28 extends. Since the lower part of the lower plate member 21 is fixed, the upper part extends forward beyond the lower part. Since the upper part of the upper plate member 22 is fixed, the lower part extends forward beyond the upper part. As a result, the lumbar support member 20 takes on a convex shape for lumbar support, with its vertical center part extending forward. As described above, the lumbar support member 20, which is provided at the bottom of the seat back 12, has a surface shape in which the central part is raised forward more than the upper and lower parts, so that the lumbar bones 51, including the sacrum of the occupant sitting on the seat cushion 11, are supported in an upright position on the seat cushion 11. In addition, the occupant's spine 52 forms an S-shape on the upright lumbar bones 51. The lumbar support member 20 can support the lumbar region, including the lumbar bones 51 of the occupant sitting on the seat cushion 11, from the rear to prevent it from falling backward.

[0023] (Specific examples of euthanasia) Figure 7 is an explanatory diagram illustrating the state of the lumbar support member 20 in Figure 4 when the seat back 12 is reclined to a comfortable position. When the seat back 12 is reclined against the seat cushion 11, the exhaust valve 34 opens under the control of the control unit 35. As a result, the bag 39 shrinks by expelling air. In particular, the weight of the occupants can cause the bag 39 to shrink so as to expel all the air. As the bag body 39 shrinks, the lower plate member 21 and the upper plate member 22 are no longer pushed forward from the seat back frame 15. The expandable member 28 extends due to the weight of the occupant. Since the lower part of the lower plate member 21 is fixed, the upper part is lower than the lower part due to the weight of the occupant. Since the upper part of the upper plate member 22 is fixed, the lower part is lower than the upper part due to the weight of the occupant. As a result, the lower plate member 21 and the upper plate member 22 may sink down so as to fit between the seat back frame 15, and their vertical central parts may take on a concave shape with a sloping apex.

[0024] Figure 8 is a schematic diagram illustrating the state in which the seatback 12 of the front seat 4 is folded down in the first embodiment. As shown in Figure 7, the lower plate member 21 and the upper plate member 22 have a concave shape, so that the occupant's lower back, when attempting to assume a comfortable posture in the front seat 4 with the seat back 12 reclined as shown in Figure 8, can come into contact with the seat surface of the front seat 4 and be supported by the seat surface of the front seat 4. In addition, the occupant's lower back can be reclined on the seat surface of the front seat 4, and the spine 52 can also be curved in an arch shape. The occupant can obtain a comfortable posture in which the entire upper body, including the lower back, is supported by the seat surface of the front seat 4.

[0025] (Specific example of lumbar support control) Figure 9 is an example of a flowchart of lumbar support control by the control unit 35 in Figure 4. The control unit 35 repeatedly executes the lumbar support control shown in Figure 9. The control shown in Figure 9 is an example where the inverted state of the seat back 12 is detected, and if the seat back 12 is upright, the compressor 33 is activated for a predetermined time. If the seat back 12 is reclined, the control unit 35 opens the exhaust valve 34 for a predetermined time. In addition, for example, the compressor 33 or exhaust valve 34 may operate for a duration corresponding to the occupant's operation time to the control unit 31, or it may operate for a duration pre-set by the individual occupant or the last set duration recognized by the DMS 32. The individual occupant's pre-set or last set duration may be recorded in the memory of the control unit 35 or the memory of the DMS 32.

[0026] In step ST1, the control unit 35 determines whether or not an occupant in the vehicle 1 is seated in the front seat 4. The control unit 35 may determine whether or not an occupant is seated in the front seat 4 based on detection of seating in the front seat 4 by the DMS 32, detection of seating sensors (not shown) provided on the seat cushion 11 of the front seat 4, detection of the operation of fastening the seat belt of the front seat 4, etc. If an occupant is seated in the front seat 4, the control unit 35 proceeds to step ST2. If no occupant is seated in the front seat 4, the control unit 35 terminates this control.

[0027] In step ST2, the control unit 35 detects the inverted state of the seat back 12 of the front seat 4 in which the occupant is seated. Based on the detection of the inverted state of the seat back 12 of the front seat 4 by the DMS 32, the detection by the seat back 12 inversion sensor (not shown), etc., the control unit 35 detects the inverted state of the seat back 12 of the front seat 4 in which the occupant is seated.

[0028] In step ST3, the control unit 35 determines whether the seat back 12 of the front seat 4 in which the occupant is seated is upright or not. If the seatback 12 of the front seat 4 is upright, the control unit 35 proceeds to step ST4 for lumbar support. If the seatback 12 of the front seat 4 is upright, that is, if the seatback 12 of the front seat 4 is reclined, the control unit 35 proceeds to step ST7 in order to ensure a comfortable state. In addition, the control unit 35 may determine in step ST3 whether or not the seatback 12 of the front seat 4 in which the occupant is seated is reclined.

[0029] In steps ST4 to ST6, the control unit 35 performs processing for lumbar support. First, in step ST4, the control unit 35 operates the compressor 33 with the exhaust valve 34 closed. In step ST5, the control unit 35 determines whether a predetermined time has elapsed. The elapsed time may be measured by a timer (not shown) of the control unit 35. If the predetermined time has not elapsed since the compressor 33 was operated, the control unit 35 repeats this process. Once the predetermined time has elapsed, the control unit 35 proceeds to step ST6. In step ST6, the control unit 35 stops the compressor 33. After that, the control unit 35 terminates this control. As a result, the bag 39 expands as air is supplied by the compressor 33 operating for a predetermined time. The lower plate member 21 and the upper plate member 22, which are the lumbar support members 20, can have the convex shape for lumbar support shown in Figure 6. Thus, when the seat back 12 is upright relative to the seat cushion 11, the bag 39 expands due to the air supplied from the compressor 33. The bag 39 can press the multiple plate members 21-22 from the rear side to form a surface shape for lumbar support on the multiple plate members 21-22.

[0030] In steps ST7 to ST10, the control unit 35 performs processing for achieving a comfortable state. First, in step ST7, the control unit 35 confirms that the seat back 12 is reclined. Step ST7 may be omitted. Next, in step ST8, the control unit 35 opens the exhaust valve 34. In step ST9, the control unit 35 determines whether a predetermined time has elapsed. The elapsed time may be measured by a timer (not shown) of the control unit 35. If the predetermined time has not elapsed since the exhaust valve 34 was opened, the control unit 35 repeats this process. Once the predetermined time has elapsed, the control unit 35 proceeds to step ST10. In step ST10, the control unit 35 closes the exhaust valve 34. After that, the control unit 35 terminates this control. As a result, air is exhausted from the bag 39. The bag 39 shrinks. The lower plate member 21 and the upper plate member 22, which are the lumbar support members 20, can be in the comfortable position shown in Figure 7. In this way, when the seat back 12 is tilted relative to the seat cushion 11, the bag 39 opens the exhaust valve 34 to expel air from the bag 39. After expelling the air, the bag 39 shrinks, allowing the multiple plate members 21-22 to sink into the back side of the seat back 12.

[0031] (effect) In one embodiment of the present invention, the seat device 19 of the vehicle 1 has a plurality of plate members 21 to 22 as lumbar support members provided on the seat back 12. Furthermore, a bag body 39 that can be expanded and contracted by a fluid supplied from a compressor 33 as a supply device is provided on the back side of the plurality of plate members 21 to 22 for lumbar support. When the seat back 12 is upright relative to the seat cushion 11, the bag 39 expands due to the fluid supplied from the compressor 33. As a result, the multiple plate members 21-22 are pressed from the rear side by the expanded bag 39 on the upright seat back 12, forming a surface shape for lumbar support. While the vehicle 1 is in motion with the seat back 12 upright relative to the seat cushion 11, the multiple plate members 21-22 form a surface shape for lumbar support. When an occupant sits on the seat cushion 11, the lumbar region, including the sacrum, is supported from the rear by the surface shape for lumbar support, making it less tiring even during long journeys. Because the occupant's lumbar region, including the sacrum, is supported from the rear, forward sliding of the waist is less likely to occur while the vehicle 1 is in motion, making it easier to stabilize the position and posture of the waist when sitting on the seat cushion 11. Conversely, when the seatback 12 is reclined relative to the seat cushion 11, the bag 39 releases fluid and shrinks. This allows the multiple plate members 21-22 to sink into the back of the reclined seatback 12. Moreover, the lumbar support member is not a single plate, but is divided into multiple plate members 21-22. Each of the multiple plate members 21-22 sinks individually into the back of the seatback 12 according to the load acting on each, and does not maintain the surface shape for lumbar support in the sunk state. The occupant can rest comfortably on the front seat 4 with the seatback 12 reclined, by allowing the multiple plate members 21-22 to sink individually under their own weight, so that no part of their body, such as their waist, is lifted off the front seat 4.

[0032] In this embodiment, the multiple plate members 21-22 for the lumbar support have a lower plate member 21 and an upper plate member 22 connected by an expandable member 28 so as to be arranged vertically. The lower part of the lower plate member 21 is fixed to the seat back frame 15. The upper part of the upper plate member 22 is fixed to the seat back frame 15. The bag 39 is then provided in an expandable and contractible manner between the support wire 17 of the seat back frame 15 and the multiple plate members 21-22 for lumbar support. As a result, the expanded bag-like body 39 pushes forward, causing the central portions of both the lower plate member 21 and the upper plate member 22, which are connected by the expandable member 28, to protrude forward, forming a surface shape for lumbar support. The lower plate member 21 and the upper plate member 22, which are divided in the vertical direction, can form a surface shape for lumbar support that rises on the upper rear side of the hip bone 51. In particular, the lower plate member 21 and the upper plate member 22 are connected by an expandable member 28 above the hip bone 51 of the occupant seated on the seat cushion 11, when they are forming a surface shape for lumbar support. The lower plate member 21 and the upper plate member 22 are pushed forward by the expanded bag 39, causing them to bend above the hip bone 51 of the occupant seated on the seat cushion 11, thereby forming a good surface shape for lumbar support. An occupant seated on the seat cushion 11 may have their lower back supported by the lumbar support of the seat back 12. Conversely, when the bag body 39 is contracted, the lower plate member 21 and the upper plate member 22 become less likely to bulge out to support the pelvic bones 51 from the rear. The lower plate member 21 and the upper plate member 22 become movable so that the space between them sinks down. The lower plate member 21 and the upper plate member 22 can support the area from the occupant's waist to their back in a rounded position on the support wire 17. The occupant can then stabilize in a comfortable position on the front seat 4 with the seat back 12 reclined.

[0033] In this embodiment, the expandable member 28 is expandable by the weight of the occupant. As a result, the multiple plate members 21 to 22 can sink towards the back of the seat back 12 when the seat back is reclined, due to the weight of the occupant. Furthermore, the bag-like body 39 expands, thereby extending the expandable member 28. When the lower plate member 21 and the upper plate member 22 form the surface shape for lumbar support, the expanded bag-like body 39 and the extended expandable member 28 are in a balanced state. Therefore, even if the weight of the occupant is applied or changes, the surface shape for lumbar support will not easily change. As the surface shape for lumbar support is stabilized, the occupant's waist and upper body can be stably supported while driving.

[0034] [Second Embodiment] (Overview) In the embodiment described above, an example was described in which a lower plate member 21 and an upper plate member 22 are used as multiple plate members for the lumber support. In this embodiment, an example is described in which a left lower plate member 23, a right lower plate member 24, a left upper plate member 25, and a right upper plate member 26 are used as multiple plate members for the lumbar support. The four plate members 23-26, consisting of a left lower plate member 23, a right lower plate member 24, a left upper plate member 25, and a right upper plate member 26, which are arranged in a vertical and horizontal line, are connected by an expandable / contractible member 28. The following will mainly explain the differences from the embodiments described above.

[0035] (Specific example of a seat device) Figure 10 is an explanatory diagram of the seat device 19 of the vehicle 1 provided on the front seat 4 in the second embodiment. The seat device 19 in Figure 10 has a left lower plate member 23, a right lower plate member 24, a left upper plate member 25, and a right upper plate member 26 as multiple plate members for lumbar support. Here, the four plate members 23-26 may be made by forming a resin material or the like into a desired plate shape for lumber support, and then dividing it into four sections vertically and horizontally. Figure 11 is a schematic explanatory diagram of the lumbar support member 20 of Figure 10, viewed from the upper left front side. Here, the four plate members 23-26, which constitute the lumbar support member 20, are shown as rectangular flat plates for ease of visibility.

[0036] The left lower plate member 23 and the right lower plate member 24 divide the width of the seat back frame 15 in the left-right direction. The left lower plate member 23 is fixed to the seat back frame 15 at the lower left corner by fasteners 29. The right lower plate member 24 is fixed to the seat back frame 15 at the lower right corner by fasteners 29. The upper left plate member 25 and the upper right plate member 26 divide the width of the seat back frame 15 in the left-right direction. The upper left plate member 25 is fixed to the seat back frame 15 at its upper left corner by fasteners 29. The upper right plate member 26 is fixed to the seat back frame 15 at its upper right corner by fasteners 29. In this way, the four plate members 23-26 are fixed to the seat back frame 15 at all four corners. If the plate members need to be restrained around the fasteners 29, each plate member may be fixed to the seat back frame 15 by multiple fasteners 29. The left lower plate member 23 and the right lower plate member 24 are connected by an expandable member 28. The left upper plate member 25 and the right upper plate member 26 are connected by an expandable member 28. The left lower plate member 23 and the left upper plate member 25 are connected by an expandable member 28. The right lower plate member 24 and the right upper plate member 26 are connected by an expandable member 28. As a result, the four plate members 23-26, which are arranged in a vertical and horizontal line, are interconnected by multiple expandable members 28 to form a single plate-like outer shape. The four plate members 23-26 can function as multiple plate members for lumbar support on the front side of the seat back frame 15.

[0037] The bag-like structure 39 is provided in an expandable and contractible manner between the seat back frame 15 or support wire 17 and the four plate members 23-26 for lumbar support.

[0038] (Specific examples of lumbar support) Figure 12 is an explanatory diagram showing the state in which the lumbar support member 20 shown in Figure 11 forms a surface shape for lumbar support when the seat back 12 is in an upright position. When the seat back 12 is upright relative to the seat cushion 11, the bag 39 expands due to the supply of air from the compressor 33. The expanded bag 39 pushes forward the left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26, which are connected by the expandable member 28. As a result, the four plate members 23-26 form a convex shape for lumber support, with the central portions of the four plate members 23-26 protruding forward, as shown in Figure 12.

[0039] In other words, the upper right portion of the lower left plate member 23 is positioned in front of the lower left portion. The upper left portion of the lower right plate member 24 is positioned in front of the lower left portion. The lower right portion of the upper left plate member 25 is positioned in front of the upper left portion. The lower left portion of the upper right plate member 26 is positioned in front of the upper left portion. As shown in Figure 11, the left lower plate member 23 and the left upper plate member 25 are connected by an expandable / contractable member 28 above the hip bones 51 of the occupant seated on the seat cushion 11. Furthermore, the right lower plate member 24 and the right upper plate member 26 are connected by an expandable / contractable member 28 above the hip bones 51 of the occupant seated on the seat cushion 11. As a result, the four plate members 23-26, with their convex shapes for lumbar support, can support the occupant's hip bones 51 and spine 52 from the rear when seated on the seat cushion 11. The expanding bag 39 can deform under the occupant's weight. The occupant's hip bones 51 and spine 52 are stably supported by the four plate members 23-26, which are pressed by the expanding bag 39. The occupant's hip bones 51, including the sacrum, are supported to stand upright on the seat cushion 11. The occupant's spine 52 also forms an S-shape on top of the standing hip bones 51. The lumbar support member 20 can support the occupant's lower back, including the hip bones 51, to prevent it from tilting backward when seated on the seat cushion 11.

[0040] (Specific examples of euthanasia) Figure 13 is an explanatory diagram illustrating the state of the lumbar support member 20 in Figure 11 when the occupant's weight is applied in the relaxed position with the seat back 12 reclined. When the seat back 12 is reclined relative to the seat cushion 11, the exhaust valve 34 opens, and the bag 39 deflates and contracts. Furthermore, when the weight of the occupant is applied, the bag 39 may contract to deflate all the air. When the bag body 39 shrinks, the four plate members 23-26 no longer protrude from the seat back frame 15. Then, the telescopic member 28 extends due to the weight of the occupants. The lower left plate member 23 is fixed at its lower left end, so when the weight of the occupants acts on it, the upper right end sags below the lower left end. The lower right plate member 24 is fixed at its lower right end, so when the weight of the occupants acts on it, the upper left end sags below the lower right end. The upper left plate member 25 is fixed at its upper left end, so when the weight of the occupants acts on it, the lower right end sags below the upper left end. The upper right plate member 26 is fixed at its upper right end, so when the weight of the occupants acts on it, the lower left end sags below the upper right end. As a result, the four plate members 23-26 are positioned so as to fit between the seat back frame 15, and are angled downwards towards the back of the seat back 12. The four plate members 23-26 may have a concave shape with their vertical central portions angled downwards. As a result, as shown in Figure 8, the lumbar region of an occupant attempting to assume a comfortable posture in the front seat 4 with the seatback 12 reclined can come into contact with and be supported by the seat surface of the front seat 4. Furthermore, the occupant's lumbar region can recline on the seat surface of the front seat 4, and the spine 52 can also be curved in an arched shape. The occupant can achieve a comfortable posture in which their entire upper body, including their lumbar region, is supported by the seat surface of the front seat 4.

[0041] (effect) In one embodiment of the present invention, the seat device 19 of the vehicle 1 has a plurality of plate members 23 to 26 as lumbar support members provided on the seat back 12. Furthermore, a bag 39 that can be expanded and contracted by a fluid supplied from a compressor 33 is provided on the back side of the plurality of plate members 23 to 26 for lumbar support. When the seat back 12 is upright relative to the seat cushion 11, the bag 39 expands due to the fluid supplied from the compressor 33. As a result, the multiple plate members 23-26 are pressed from the rear side by the expanded bag 39 on the upright seat back 12, forming a surface shape for lumbar support. While the vehicle 1 is in motion with the seat back 12 upright relative to the seat cushion 11, the multiple plate members 23-26 form a surface shape for lumbar support. When an occupant sits on the seat cushion 11, the lumbar region, including the sacrum, is supported from the rear by the surface shape for lumbar support, making it less tiring even during long journeys. Because the occupant's lumbar region, including the sacrum, is supported from the rear, forward sliding of the waist is less likely to occur while the vehicle 1 is in motion, making it easier to stabilize the position and posture of the waist when sitting on the seat cushion 11. Conversely, when the seatback 12 is reclined relative to the seat cushion 11, the bag 39 releases fluid and shrinks. This allows the multiple plate members 23-26 to sink into the back of the reclined seatback 12. Moreover, the lumbar support member is not a single plate, but is divided into multiple plate members 23-26. Each of the multiple plate members 23-26 sinks individually into the back of the seatback 12 according to the load acting on it, and does not maintain the surface shape for lumbar support in the sunk state. The occupant can rest comfortably on the front seat 4 with the seatback 12 reclined, with the multiple plate members 23-26 sinking individually due to their own weight, so that no part of their body, such as their waist, is lifted off the front seat 4.

[0042] In this embodiment, the multiple plate members 23 to 26 for the lumbar support include a left lower plate member 23, a right lower plate member 24, a left upper plate member 25, and a right upper plate member 26, which are connected by an expandable member 28 so as to be arranged vertically and horizontally. The left lower plate member 23 has its lower left portion fixed to the seat back frame 15. The right lower plate member 24 has its lower right portion fixed to the seat back frame 15. The left upper plate member 25 has its upper left portion fixed to the seat back frame 15. The right upper plate member 26 has its upper right portion fixed to the seat back frame 15. The bag body 39 is then provided in an expandable and contractible manner between the seat back frame 15 or support wire 17 and a plurality of plate members 23-26 for lumbar support. As a result, the expanded bag 39 pushes forward, causing the left lower plate member 23, right lower plate member 24, left upper plate member 25, and right upper plate member 26, which are connected by the expandable member 28, to have their central portions move forward, forming a surface shape for lumbar support. The left lower plate member 23, right lower plate member 24, left upper plate member 25, and right upper plate member 26, which are divided in the up, down, left, and right directions, can form a surface shape for lumbar support that bulges out on the posterior side of the waist and on the posterior side of the spine 52. In particular, the left lower plate member 23 and the left upper plate member 25, when forming a surface shape for lumbar support, are connected to other plate members by an expandable member 28 above the hip bones 51 of the occupant seated on the seat cushion 11. Similarly, the right lower plate member 24 and the right upper plate member 26, when forming a surface shape for lumbar support, are connected to other plate members by an expandable member 28 above the hip bones 51 of the occupant seated on the seat cushion 11. As a result, the left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26 are pushed forward by the expanded bag 39, causing them to bend above the hip bones 51 of the occupant seated on the seat cushion 11 and protrude along the spine 52, thereby forming a good surface shape for lumbar support. An occupant seated on the seat cushion 11 can have their lower back and spine 52 supported by the lumbar support of the seat back 12. Conversely, when the bag body 39 is contracted, the left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26 are less likely to bulge out to support the posterior sides of the hip bones 51 and the spine 52 from behind. The left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26 become movable so that the space between them sinks down. The left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26 can support the area from the occupant's waist to their back in a rounded state in the vertical and horizontal directions on the support wire 17. The occupant can then stabilize in a comfortable position on the front seat 4 with the seat back 12 reclined.

[0043] In this embodiment, the expandable member 28 is expandable by the weight of the occupant. As a result, the multiple plate members 23 to 26 can sink towards the back of the seat back 12 when the seat back is reclined, due to the weight of the occupant. Furthermore, the bag-like body 39 expands, thereby extending the expandable member 28. When the left lower plate member 23, the right lower plate member 24, the left upper plate member 25, and the right upper plate member 26 form a surface shape for lumbar support, the expanded bag-like body 39 and the extended expandable member 28 are in a balanced state. Therefore, even if the weight of the occupant is applied or changes, the surface shape for lumbar support will not easily change. As the surface shape for lumbar support is stabilized, the occupant's waist and upper body can be stably supported while driving.

[0044] The embodiments described above are examples of preferred embodiments of the present invention, but the present invention is not limited thereto, and various modifications or changes are possible without departing from the spirit of the invention.

[0045] In the embodiments described above, the lumbar support member 20 is divided into two or four sections. The lumbar support member 20 may be divided into any other number of parts. Also, not all of the multiple plate members that make up the lumbar support member 20 have to be fixed to the seat back frame 15. Some of the plate members may be held in place by being connected to other plate members that are fixed to the seat back frame 15 by an expandable member 28. However, it is preferable that the lumbar support member 20 be divided into two or more parts, at least in the vertical direction. This allows the lumbar support member 20 to sink properly into the rear side of the seat back frame 15 when the weight of the occupant is applied while the bag body 39 is contracted.

[0046] In the embodiments described above, the multiple plate members are described as multiple divisions of a convex shape for lumber support. In this case, each of the multiple plate members basically has an uneven plate shape. In addition, for example, each of the multiple plate members may be formed in a substantially flat shape and bend or deform when pressed by the expanding bag 39 to form a convex shape for lumbar support. By forming grooves for bending and curving in the substantially flat plate members, the plate members can be deformed from a flat shape to a three-dimensional shape by the force of the expanding bag 39. Furthermore, each of the multiple plate members can return to a substantially flat shape when the bag 39 shrinks or when the weight of the occupants is applied. Furthermore, since each of these deformable plate members is made up of multiple sections of the convex shape for lumbar support, it is thought that when the bag 39 shrinks, it will easily return to a state where it does not protrude from the seat back frame 15 smoothly. This also helps the stretched telescopic member 28 to return to its natural length. In contrast, if the entire convex shape for lumbar support is formed by deforming a single plate member, it is thought that even if the bag 39 shrinks, it will be difficult for it to return to a state where it does not protrude from the seat back frame 15 solely by that.

[0047] In the embodiment described above, the compressor 33 is directly connected to the bag 39. In addition, for example, a three-way branch valve may be provided between the compressor 33 and the bag 39. The control unit 35 can change the direction of the three-way branch valve to direct the flow of fluid such as air from the compressor 33 to the bag 39, or from the bag 39 to the outside air. In this case, the exhaust valve 34 is not necessary. Furthermore, although the compressor 33 is designed so that the supplied fluid does not flow back, if fluid leakage is a concern, the control unit 35 may change the valve direction of the three-way branch valve to prevent fluid from leaking out of the bag 39. The three-way branch valve can switch the input and output of the fluid in the bag 39. [Explanation of Symbols]

[0048] 1...Vehicle, 2...Vehicle body, 3...Passenger compartment, 4...Front seat, 5...Rear seat, 11...Seat cushion, 12...Seat back, 13...Headrest, 14...Seat cushion frame, 15...Seat back frame, 16...Axle member, 17...Support wire, 19...Seat device, 20...Lumbar support member, 21...Lower plate member, 22...Upper plate member, 23...Left lower plate member, 24...Right lower plate member, 25...Left upper plate member, 26...Upper right plate member, 28...Extendable member, 29...Fastener, 31...Operating unit, 32...DMS, 33...Compressor, 34...Exhaust valve, 35...Control unit, 39...Bag body, 51...Waist bone, 52...Spine

Claims

1. The seat cushion on which the vehicle's occupants sit, The rear side of the aforementioned seat cushion includes a seat back that can be inverted, A lumbar support member having a plurality of plate members is provided on the seat back, The seat back is provided on the rear side of the lumbar support member and comprises an expandable and contractible bag, It has, The bag body is The seat back expands while standing upright relative to the seat cushion, and pushes the multiple plate members from the rear side, causing the multiple plate members to form a surface shape for lumbar support. The seat back is retracted while tilted relative to the seat cushion, allowing the multiple plate members to individually sink into the back side of the seat back. A vehicle seat system that provides lumbar support.

2. The multiple plate members for the lumbar support have a lower plate member and an upper plate member connected by an expandable member so as to be arranged vertically. The lower plate member is fixed to the frame of the seat back at its lower end. The upper part of the upper plate member is fixed to the frame of the seat back, The lower plate member and the upper plate member, connected by the aforementioned expandable member, are pushed forward by the expanded bag-like body to form a surface shape for lumbar support. A vehicle seat device capable of providing lumbar support, as described in claim 1.

3. The aforementioned expandable member is capable of being extended by the weight of the occupants. The bag body is By expanding, the expandable member is extended to form a surface shape for lumbar support on the lower plate member and the upper plate member. A vehicle seat device capable of providing lumbar support, as described in claim 2.

4. The lower plate member and the upper plate member are connected by the expandable member above the hip bones of the occupant seated on the seat cushion, in a state where they form a surface shape for lumbar support. A vehicle seat device capable of providing lumbar support, according to claim 2 or 3.

5. The multiple plate members for the lumbar support include a left lower plate member, a right lower plate member, a left upper plate member, and a right upper plate member, which are connected by expandable members so as to be arranged vertically and horizontally. The left lower plate member is fixed to the frame of the seat back at its lower left portion. The right lower plate member is fixed to the frame of the seat back at its lower right portion. The upper left plate member is fixed to the frame of the seat back at its upper left portion. The upper right plate member is fixed to the frame of the seat back at its upper right portion. The left lower plate member, the right lower plate member, the left upper plate member, and the right upper plate member, which are connected by the aforementioned expandable member, are pushed forward by the expanded bag body to form a surface shape for lumbar support. A vehicle seat device capable of providing lumbar support, as described in claim 1.

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