Vehicle seats

Abstract

To provide a vehicle seat capable of suppressing a decrease in fatigue reduction effect even when seating time becomes long.SOLUTION: A pelvis support 18 provided in a seat body 10H can switch between the pressing state of pressing the pelvis Pp of a seated occupant P and the unpressing state of not pressing the pelvis Pp of the seated occupant P. In a state in which the occupant is seated on the seat body 10H, a control part 62 controls the pelvis support 18 so that the pressing state and the unpressing state can be alternately repeated. Additionally, the control part 62 controls the pelvis support 18 so that duration time in the first pressing state after the occupant is seated can be longer than duration time in the second pressing state and the pressing states after the second pressing state after the occupant is seated and can be in the range of 35-45 minutes.SELECTED DRAWING: Figure 4B

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat. [Background technology]

[0002] There is known a technology that provides a vehicle seat with a function of supporting the pelvis (see, for example, Patent Document 1 below). Such a prior art can contribute to reducing fatigue when sitting. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-56776 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the above-mentioned prior art, if the sitting time in a position where the pelvis is supported exceeds a certain period of time, the effect of reducing fatigue is significantly reduced, and there is room for improvement in this respect.

[0005] In consideration of the above, an object of the present invention is to provide a vehicle seat that can suppress a decrease in fatigue reduction effect even if the seating time is long. [Means for solving the problem]

[0006] The vehicle seat of the present invention described in claim 1 comprises a seat body for an occupant to sit on, the seat body including a seat cushion with a seat cushion pad placed on a seat cushion frame to support the buttocks and thighs of a seated occupant, and a seat back with a seat back pad placed on a seat back frame to support the back of the seated occupant, a cushion support provided on the seat cushion frame and capable of pressing only a rear portion of the seat cushion pad toward the upper side of the seat without pressing a front portion of the seat cushion pad toward the upper side of the seat, and a back lower support provided on the seat back frame and capable of pressing only a lower portion of the seat back pad toward the front side of the seat without pressing an upper portion of the seat back pad toward the front side of the seat, and the vehicle seat includes a pressing mechanism that is switchable between a pressing state in which the pelvis of the seated occupant is pressed and a non-pressing state in which the pelvis of the seated occupant is not pressed, and The cushion support and the back lower support are synchronized. and a control unit that controls the pressing mechanism so that the pressed state and the non-pressed state are alternately repeated.

[0007] According to the above configuration, in the seat body for an occupant to sit on, the seat cushion, which is made up of a seat cushion pad placed on a seat cushion frame, supports the buttocks and thighs of the seated occupant, and the seat back, which is made up of a seat back pad placed on a seat back frame, supports the back of the seated occupant. The pressing mechanism is composed of a cushion support and a back lower support, and the cushion support is provided on the seat cushion frame and is capable of pressing only the rear part of the seat cushion pad toward the seat upper side without pressing the front part of the seat cushion pad toward the seat upper side, and the back lower support is provided on the seat back frame and is capable of pressing only the lower part of the seat back pad toward the seat front side without pressing the upper part of the seat back pad toward the seat front side. The pressing mechanism composed of the cushion support and the back lower support is switchable between a pressing state in which it presses the pelvis of the seated occupant and a non-pressing state in which it does not press the pelvis of the seated occupant. Then, when the occupant is seated on the seat body, the control unit Synchronizing the cushion support and lower back supportThe pressing mechanism is controlled so that a pressed state and a non-pressed state are alternately repeated. When the state of the pressing mechanism is switched between the pressed state and the non-pressed state, the body pressure distribution around the pelvis of the seated occupant changes, so that even if the seated occupant stays seated for a long time, the reduction in fatigue reduction effect is suppressed.

[0008] The vehicle seat of the present invention described in claim 2 has the configuration described in claim 1, wherein the control unit further controls the pressing mechanism so that the duration of the first pressing state after the occupant sits down is longer than the duration of the second or subsequent pressing states after the occupant sits down, and is between 35 minutes and 45 minutes.

[0009] According to the above configuration, the duration of the first pressing state after the occupant sits down is longer than the duration of the second or subsequent pressing states after the occupant sits down, and is 35 to 45 minutes. This configuration can reduce fatigue in the early stages of the occupant's seating, and the pressing state is switched to the non-pressing state just before the seated occupant feels the need to release the pressure on their pelvis. Therefore, the fatigue reduction effect is suppressed.

[0010] The vehicle seat of the present invention described in claim 3 is the configuration described in claim 1, wherein the seat body is provided with a body pressure sensor in a portion corresponding to an area where the pressing mechanism presses the pelvis of the seated occupant, and the control unit further performs the following based on the detection result of the body pressure sensor: In the pressed state, a first state in which the area of ​​a portion of the detection range of the body pressure sensor on which the body pressure of the seated occupant acts is equal to or greater than a predetermined reference value and the maximum value of the body pressure is equal to or less than a predetermined value; In the non-pressurized state, The second state, which is not the first state, is switched at a preset timing. So that it repeats alternately The pressing mechanism is controlled.

[0011] According to the above-mentioned configuration, the seat body is provided with a body pressure sensor in a portion corresponding to the area where the pressing mechanism presses the pelvis of the seated occupant. Then, the control unit further determines, based on the detection result of the body pressure sensor, In the pressed state,a first state in which the area of ​​a portion of the detection range of the body pressure sensor on which the body pressure of the seated occupant acts is equal to or greater than a predetermined reference value and the maximum value of the body pressure is equal to or less than a predetermined value; In the non-pressurized state, The second state, which is not the first state, is switched at a preset timing. So that it repeats alternately The pressure mechanism is controlled to prevent the body pressure distribution around the pelvis of the seated occupant from remaining the same for an excessive period, thereby minimizing the reduction in fatigue. [Effects of the Invention]

[0012] As described above, the vehicle seat of the present invention has the excellent effect of preventing a decrease in fatigue reduction effect even if the seating time is long. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view showing a vehicle seat according to a first embodiment of the present invention. [Figure 2] 2 is a perspective view showing a skeletal structure of a seat back in the vehicle seat of FIG. 1. FIG. [Figure 3] 2 is a perspective view showing a skeletal structure of a seat cushion in the vehicle seat of FIG. 1. FIG. [Figure 4A] 2 is a schematic side view showing the vehicle seat of FIG. 1 in which the pelvis support is in a non-pressing state. FIG. [Figure 4B] 2 is a schematic side view showing the vehicle seat of FIG. 1 in which the pelvis support is in a pressed state. FIG. [Figure 5] 3 is an exploded perspective view showing the skeletal structure of the seat back of FIG. 2 disassembled into a seat back frame and a back lower support. FIG. [Figure 6] FIG. 6 is an exploded perspective view showing the back lower support of FIG. 5 in an exploded state. [Figure 7A] FIG. 6 is a perspective view showing a state before the back lower support of FIG. 5 is actuated. [Figure 7B] FIG. 6 is a side view showing the state before the back lower support of FIG. 5 is actuated. [Figure 8A]FIG. 6 is a perspective view showing a state after the back lower support of FIG. 5 has been activated. [Figure 8B] FIG. 6 is a side view showing a state after the back lower support of FIG. 5 has been activated. [Figure 9] 4 is an exploded perspective view showing a state in which a part of the skeletal structure of the seat cushion of FIG. 3 is disassembled. FIG. [Figure 10] 4 is a perspective view showing the cushion support of FIG. 3 in a state after activation, as viewed obliquely from above. FIG. [Figure 11A] 4 is a perspective view showing the cushion support of FIG. 3 in a state before activation, as viewed obliquely from below. FIG. [Figure 11B] 4 is a perspective view showing the cushion support of FIG. 3 in a state after activation, as viewed obliquely from below. FIG. [Figure 12A] 4B is a diagram showing the body pressure distribution on the seat cushion side of the seated occupant in the state of FIG. 4A. FIG. [Figure 12B] FIG. 4C is a diagram showing the body pressure distribution on the seat cushion side of the seated occupant in the state of FIG. 4B. [Figure 13] 2 is a diagram showing a time cycle of the operation of the pelvic support in the vehicle seat of FIG. 1. FIG. [Figure 14] FIG. 10 shows the time cycles tried in tests to determine the duration of the initial pressure state. [Figure 15] 15 is a bar graph showing comfort ratings corresponding to each time cycle shown in FIG. 14, the ratings being made one hour after the start. [Figure 16] 15 is a bar graph showing comfort ratings corresponding to each time cycle shown in FIG. 14, the ratings being made two hours after the start. [Figure 17] FIG. 10 is a diagram showing the time cycle tested in a test to determine the duration of the second and subsequent pressing states. [Figure 18] 18 is a bar graph showing comfort ratings corresponding to each time cycle shown in FIG. 17, the ratings being made two hours after the start. [Figure 19] FIG. 4 is a perspective view showing a vehicle seat according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] [First embodiment] A vehicle seat according to a first embodiment of the present invention will be described with reference to Figures 1 to 18. Note that in these figures, an arrow FR indicates the front side of the seat, an arrow UP indicates the upper side of the seat, and an arrow W indicates the width direction of the seat.

[0015] FIG. 1 shows a perspective view of a vehicle seat 10 according to this embodiment. The vehicle seat 10 has a seat body 10H on which an occupant sits. The seat body 10H includes a seat cushion 12 that supports the buttocks and thighs of the seated occupant, a seat back 14 that supports the back of the seated occupant, and a headrest 16 that supports the head of the seated occupant. The seat cushion 12 has a seat cushion frame 12F (see FIG. 3) covered with a seat cushion pad 12P. The seat back 14 has a seat back frame 14F (see FIG. 2) covered with a seat back pad 14P.

[0016] Fig. 2 shows a perspective view of the skeletal structure of the seatback 14. As shown in Fig. 2, the seatback frame 14F includes a pair of left and right side frames 14S extending in the up-down direction of the seatback on both sides thereof, and an upper frame 14U that is in an inverted U shape when viewed from the front of the seatback and connects the upper ends of the left and right side frames 14S. Furthermore, the seatback frame 14F includes a seatback upper panel 14A that connects the pair of left and right vertically extending portions of the upper frame 14U in the seat width direction, and a seatback lower panel 14B (see Fig. 5) that connects the lower parts of the left and right side frames 14S in the seat width direction.

[0017] FIG. 3 is a perspective view of the skeletal structure of the seat cushion 12. As shown in FIG. 3, the seat cushion frame 12F includes a pair of left and right side frame portions 12S extending in the front-rear direction of the seat on both sides of the seat cushion frame 12F, a seat pan portion 12A suspended between the front ends of the pair of left and right side frame portions 12S, and a rod 12B connecting the rear ends of the pair of left and right side frame portions 12S. A seat cushion spring 12C is suspended between the seat pan portion 12A and the rod 12B. This seat cushion spring 12C is composed of multiple (four in this example) S-springs arranged side by side in the seat width direction. The rear portion of the seat cushion spring 12C, forward of the rod 12B, is inclined upward and toward the rear of the seat in a side view. A rear panel 12R extending in the seat width direction is attached to the rear portion of the seat cushion spring 12C.

[0018] As shown in FIG. 4A, the seat main body 10H is provided with a pelvis support 18 (shown simply and schematically in FIG. 4) as a pressing mechanism. The pelvis support 18 is configured to be switchable between a pressing state in which it presses the pelvis Pp of the seated occupant P as shown in FIG. 4B and a non-pressing state in which it does not press the pelvis Pp of the seated occupant P as shown in FIG. 4A. In this embodiment, the pelvis support 18 is in the pressing state when it is in the ON state, and in the non-pressing state when it is in the OFF state. An example of the configuration of the pelvis support 18 will be described below.

[0019] The pelvis support 18 includes a lower back support 20 provided on the seat back frame 14F shown in FIG. 2, and a cushion support 40 provided on the seat cushion frame 12F shown in FIG.

[0020] Fig. 5 shows an exploded perspective view of the skeletal structure of the seat back 14 (see Fig. 1) disassembled into a seat back frame 14F and a back lower support 20. Fig. 6 shows an exploded perspective view of the back lower support 20 disassembled.

[0021] As shown in these figures, the back lower support 20 includes a resin plate 22 for pressing the lower portion of the seat back pad 14P (see FIG. 1) toward the front of the seat. A pair of left and right locking portions 22A are formed on the upper back surface of the plate 22. The locking portions 22A are locked to locked portions 24A of a wire 24 for attaching the seat. The wire 24 is generally U-shaped in front view, and the locked portion 24A is formed on the lower side of a middle portion in the up-down direction. The locked portion 24A is formed in a portion of the wire 24 that is bent so as to jut outward in the seat width direction in a generally U-shape. An upper portion 24B of the wire 24 is locked to the seat back upper panel 14A of the seat back frame 14F (see FIG. 2).

[0022] The lower portion of the wire 24 is inclined toward the seat back as it extends downward. A lower side portion 24C constituting the lower end of the wire 24 is sandwiched in the seat front-rear direction between a left-right intermediate portion 26M of a resin fixing member 26 and a pair of left and right bushings 28, and in this state, the bushings 28 are screwed to the fixing member 26. The fixing member 26 is formed in a horizontally elongated, approximately U-shape when viewed from the front, and is screwed at the top, bottom, left, and right to the seatback lower panel 14B of the seatback frame 14F when the vehicle seat 10 is completed.

[0023] An axially intermediate portion 30M of the drive wire 30 is provided between the left and right side portions 26S of the fixing member 26. The axially intermediate portions 30S of the drive wire 30 are arranged with their axial direction aligned with the seat width direction and are sandwiched between the left and right side portions 26S of the fixing member 26 and fixing parts 32 (see FIG. 6), respectively. In this state, the fixing parts 32 are screwed to the fixing member 26. The axially intermediate portion 30M of the drive wire 30 is bent downward in a U-shape and is arranged on the seat front side relative to the left-right intermediate portion 26M (see FIG. 6) of the fixing member 26. In addition, a gear 34 (see FIG. 6) with its axial direction aligned with the seat width direction is integrated with one axial end of the drive wire 30.

[0024] A motor 36 is disposed adjacent to the gear 34. The motor 36 is screwed to one side portion 26S (26S1) of the fixed member 26. The output side of the motor 36 is connected to the gear 34. The motor 36 is capable of being driven in both forward and reverse directions, and is disposed so that rotating the gear 34 causes the drive wire 30 to rotate about an axis in the seat width direction.

[0025] FIG. 7A shows a perspective view of the back lower support 20 before it is activated, and FIG. 7B shows a side view of the back lower support 20 before it is activated. FIG. 8A shows a perspective view of the back lower support 20 after it is activated, and FIG. 8B shows a side view of the back lower support 20 after it is activated. As shown in these figures, the drive wire 30 rotates about an axis in the seat width direction, causing a large portion of the plate 22 (a portion other than the upper end) to rotate between the non-pressing position shown in FIGS. 7A and 7B and the pressing position shown in FIGS. 8A and 8B. The non-pressing position shown in FIGS. 7A and 7B is a position where the plate 22 does not press the lower portion of the seatback pad 14P (see FIG. 1) toward the front of the seat, and the pressing position shown in FIGS. 8A and 8B is a position where the plate 22 presses the lower portion of the seatback pad 14P (see FIG. 1) toward the front of the seat.

[0026] 9 shows an exploded perspective view of the seat cushion 12 (see FIG. 1) with a portion of the skeletal structure disassembled. FIG. 10 shows a perspective view of the cushion support 40 after it has been activated, as seen from diagonally above. As shown in FIGS. 9 and 10, the cushion support 40 includes a cushion pan 42 above the rear portion of the seat cushion spring 12C and the rear panel 12R. The cushion pan 42 is provided on the seat cushion 12C. cushion pad 12P (See Figure 1) is a panel-shaped member for pressing the rear portion of the seat upward.

[0027] A single wire 43 is attached to the cushion pan 42 and is bent so as to pass through its rear end and side end. The wire 43 is formed in a generally U-shape with an open front end in a plan view, and in a generally L-shape with an upright rear end in a side view. A pair of mounting shafts 43A are formed at the front end of the wire 43, extending short distances toward each other in a plan view. The pair of mounting shafts 43A are supported rotatably about an axis in the seat width direction by shaft support portions 44A of support pieces 44 fixed to both sides of the seat front-rear direction middle portion of the seat cushion spring 12C. As a result, the cushion pan 42 is rotatable about an axis in the seat width direction between a non-pressed position shown in FIG. 3 and a pressed position shown in FIG. 10. The non-pressed position of the cushion pan 42 shown in FIG. 3 is a position where the seat is pressed against the seat. cushion pad 12P The pressing position shown in Figure 10 is a position where the rear of the seat (see Figure 1) is not pressed upward. cushion pad 12P (See Figure 1) is in a position where it presses the rear of the seat upward.

[0028] One end of a tension spring 46 is engaged with both side portions of the rear end portion 43B of the wire 43 shown in Figures 3 and 9. In this embodiment, the tension spring 46 is a tension coil spring arranged along the seat up-down direction. The other end of the tension spring 46 is engaged with engaging members 48 provided on both sides of the rear panel 12R. The engaging members 48 are fixed to the rear panel 12R with screws and protrude outward in the seat width direction relative to the rear panel 12R. As a result, as shown in Figure 3, the tension spring 46 biases the cushion pan 42 toward the non-pressed position.

[0029] As shown in Figure 9, a support panel 56 is attached to a seat width direction intermediate portion of the seat cushion spring 12C at a position in the seat front-rear direction that is further forward of the rear panel 12R and further rearward of the support piece 44. Both side portions 56S of the support panel 56 are attached to the seat cushion spring 12C. Furthermore, a recess 56M is formed in the seat width direction intermediate portion of the support panel 56, recessed one step lower than the both side portions 56S of the support panel 56. The bottom surface of the recess 56M is gently curved so that it slopes upward toward the seat rear and has the downward and diagonally rearward side of the seat radially outward.

[0030] 10, an attachment member 57 is disposed above the recess 56M of the support panel 56. Both side portions of the attachment member 57 are attached to both sides of the recess 56M of the support panel 56. A part of the movable member 58 is disposed between the attachment member 57 and the recess 56M of the support panel 56.

[0031] As shown in Fig. 9, the movable member 58 includes a load receiving portion 58A that forms the front end side of the movable member 58, and a pair of left and right arm portions 58B that extend from the load receiving portion 58A toward the rear upper side of the seat. Rear end portions 58R of the pair of left and right arm portions 58B extend in directions that separate them from each other. As shown in Fig. 10, portions of the pair of left and right arm portions 58B are disposed between the recessed portion 56M of the support panel 56 and the mounting member 57.

[0032] Fig. 11A is a perspective view of the cushion support 40 before it is activated, as viewed from diagonally below, and Fig. 11B is a perspective view of the cushion support 40 after it is activated, as viewed from diagonally below. Note that Figs. 11A and 11B show a cutaway portion including the recess 56M (see Fig. 9) of the support panel 56 in order to illustrate the position of the arm portion 58B of the movable member 58. The movable member 58 is movable between the position shown in Figs. 3 and 11A (a position where it does not press against the cushion pan 42) and the position shown in Figs. 10 and 11B (a position where it presses against the cushion pan 42).

[0033] 11A and 11B, a portion of the inner cable 54B extending in the seat width direction is engaged with the load receiving portion 58A of the movable member 58. An attachment pin 54P attached to the tip of the inner cable 54B is attached to a support panel 56 (see FIG. 10), and the other end of the inner cable 54B is fixed to the take-up portion of the take-up device 52. The inner cable 54B is movably inserted through the outer cable 54A, with the tip side portion exposed from the outer cable 54A, and constitutes the cable 54 together with the outer cable 54A.

[0034] The base end side of the outer cable 54A is attached to a winding device 52. The winding device 52 is provided with a motor 50, and when the motor 50 is operated, the winding portion of the winding device 52 rotates.

[0035] As described above, when the winding portion of the winding device 52 rotates in conjunction with the operation of the motor 50 and the inner cable 54B is wound, the inner cable 54B displaces the load receiving portion 58A, which is in the state shown in Fig. 11A, toward the rear and upper side of the seat as shown in Fig. 11B. That is, the operation of the motor 50 displaces the movable member 58 toward the rear and upper side of the seat, moving the cushion pan 42 from the non-pressing position to the pressing position. Furthermore, when the motor 50 stops, the urging force of the tension spring 46 (see Fig. 3) moves the cushion pan 42 from the pressing position to the non-pressing position.

[0036] As shown in Fig. 4A, the motor 36 and the motor 50 are electrically connected to an ECU 60 (shown as a block in the figure). The ECU 60 has a CPU, a ROM, a RAM, a storage, and a communication interface, and these components are connected to each other via a bus so that they can communicate with each other. The ECU 60 also has a control unit 62 as a functional component. The functional component of the control unit 62 is realized by the CPU reading and executing a program stored in the ROM or storage.

[0037] As an example, a buckle switch 64 (shown as a block in the figure with a two-dot chain line) is electrically connected to the ECU 60 (the connection state is not shown). The buckle switch 64 is configured to output a signal indicating whether or not a tongue plate of a seat belt device (not shown) is fastened to a buckle to the ECU 60. Also, as an example, a seat occupancy sensor 66 (shown as a block in the figure with a two-dot chain line) is electrically connected to the ECU 60 (the connection state is not shown). The seat occupancy sensor 66 is provided in the seat cushion 12 and is configured to output a signal indicating whether or not an occupant is seated in the seat main body 10H to the ECU 60.

[0038] The control unit 62 of the ECU 60 controls the pelvis support 18 so that the pressed state shown in Fig. 4B and the non-pressed state shown in Fig. 4A are alternately repeated when an occupant is seated in the seat main body 10H. The control unit 62 determines whether or not an occupant is seated in the seat main body 10H based on a signal from a seating sensor 66 to the ECU 60, for example. Note that the control unit 62 controls the pelvis support 18 so that the pelvis support 18 is in the pressed state shown in Fig. 4B after a signal indicating that a tongue plate has been fastened to a buckle is input from a buckle switch 64 to the ECU 60 in a seat belt device (not shown). Furthermore, the control unit 62 ends control of the pelvis support 18 when a signal indicating that the tongue plate has been released from the buckle is input from the buckle switch 64 to the ECU 60, for example. As a variant, the control unit 62 may start or end control of the pelvic support 18 based on the ON / OFF signal of an operating switch (not shown) that can be operated by a seated occupant, instead of the signal from the buckle switch 64.

[0039] Furthermore, it is preferable that the control unit 62 further controls the pelvis support 18 so that the duration of the first pressed state after the occupant sits down is longer than the duration of the second or subsequent pressed states after the occupant sits down, and is between 35 and 45 minutes. Fig. 13 shows the time cycle of the operation of the pelvis support 18. As shown in this figure, in this embodiment, the control unit 62 (see Fig. 4B) controls the pelvis support 18 so that the duration of the first pressed state after the occupant sits down is, for example, 40 minutes, and the duration of the second or subsequent pressed states after the occupant sits down is, for example, 15 minutes. The control unit 62 (see Fig. 4B) also controls the pelvis support 18 so that the duration of the non-pressed state after the occupant sits down is, for example, 15 minutes.

[0040] Here, the reason why the duration of the initial pressing state after the occupant sits down is set to 40 minutes in this embodiment will be explained. FIG. 14 shows the time cycles tested in a test to determine the duration of the initial pressing state. In the figure, "ON" means that the pelvic support 18 is in the ON state, and "OFF" means that the pelvic support 18 is in the OFF state. FIG. 15 shows, in a bar graph, the comfort evaluation corresponding to each time cycle shown in FIG. 14, which was performed one hour after the start. In FIG. 15, the level on the vertical axis indicates the level of the sensory evaluation of overall comfort, with a higher value indicating a higher level of comfort. Level 5 indicates a comfortable state, level 4 indicates a state of slight discomfort, level 3 indicates a state of discomfort but within an acceptable range, level 2 indicates a state of wanting to move, and level 1 indicates a state of wanting to stand up from the seat.

[0041] As shown in Figure 14, in this test, the device was switched between a pressed state ("ON" state) and a non-pressed state ("OFF" state) in six patterns: every 10 minutes, every 20 minutes, every 30 minutes, every 40 minutes, every 50 minutes, and every 60 minutes. Note that in all cases, the test started from the pressed state ("ON" state).

[0042] As shown in Fig. 15, this test shows that 40 minutes is the most comfortable among the six patterns. For this reason, in this embodiment, the duration of the initial pressing state after the occupant sits down is set to 40 minutes. Note that, from the bar graph in Fig. 15, it can be estimated that a certain level of comfort can be ensured if the duration of the initial pressing state after the occupant sits down is set to 35 to 45 minutes.

[0043] On the other hand, Fig. 16 shows, in a bar graph, the comfort evaluations corresponding to each time cycle shown in Fig. 14, which were made two hours after the start. The vertical axis in Fig. 16 indicates the same level as the vertical axis in Fig. 15. As shown in this figure, it can be seen that the evaluation two hours after the start was not best when switching every 40 minutes.

[0044] Next, the reason why the duration of the second and subsequent pressing states after the occupant sits down is set to 15 minutes in this embodiment will be explained. Fig. 17 shows the time cycles tested in a test to determine the duration of the second and subsequent pressing states. In the figure, "ON" means the ON state of the pelvic support 18, and "OFF" means the OFF state of the pelvic support 18. Fig. 18 also shows, in a bar graph, the comfort evaluations corresponding to each time cycle shown in Fig. 17, which were made two hours after the start. In Fig. 18, the vertical axis indicates the same level as the vertical axis in Fig. 15.

[0045] As shown in Figure 17, in this test, the initial pressed state ("ON" state) after the occupant sat down lasted for 40 minutes, and thereafter the seat was switched between the non-pressed state ("OFF" state) and the pressed state ("ON" state) in four patterns: every 10 minutes, every 15 minutes, every 20 minutes, and every 25 minutes.

[0046] As shown in Fig. 18, this test shows that 15 minutes is the most comfortable of the four patterns. For this reason, in this embodiment, the duration of the pressing state from the second time onwards after the occupant sits down is set to 15 minutes. Note that, from the bar graph in Fig. 18, it can be estimated that a certain level of comfort can be ensured if the duration of the pressing state from the second time onwards after the occupant sits down is set to 14 to 18 minutes.

[0047] (Actions and Effects) Next, the operation and effects of this embodiment will be described.

[0048] In this embodiment, pelvis support 18 shown in Fig. 4A etc. is switchable between a pressing state shown in Fig. 4B in which it presses against the pelvis Pp of the seated occupant P, and a non-pressing state shown in Fig. 4A in which it does not press against the pelvis Pp of the seated occupant P. Then, when an occupant is seated in seat main body 10H, control unit 62 shown in Fig. 4A controls pelvis support 18 so that the pressing state shown in Fig. 4B and the non-pressing state shown in Fig. 4A are alternately repeated.

[0049] Fig. 12A shows the body pressure distribution of the seated occupant P on the seat cushion 12 side in the state shown in Fig. 4A, and Fig. 12B shows the body pressure distribution of the seated occupant P on the seat cushion 12 side in the state shown in Fig. 4B. In Fig. 12A and Fig. 12B, the vertical axis indicates the front-to-rear direction of the seat, and the horizontal axis indicates the width direction of the seat. Also, darker colors in the figures indicate high pressure states.

[0050] As shown in these figures, the distribution of body pressure around the pelvis Pp of the seated occupant P differs between when the pelvic support 18 is in a pressed state and when the pelvic support 18 is in a non-pressed state. More specifically, when the pelvic support 18 is in a pressed state, the pelvis Pp of the seated occupant P is stably supported, and the body pressure of the seated occupant P is dispersed (see FIG. 12B). In contrast, when the pelvic support 18 is in a non-pressed state, the stable support of the pelvis Pp of the seated occupant P is released, and the body pressure of the seated occupant P is concentrated at specific parts on the left and right (see FIG. 12A).

[0051] In this way, when the state of pelvis support 18 is switched between the pressed state shown in Fig. 4A and the non-pressed state shown in Fig. 4B, the body pressure distribution around the pelvis Pp of seated occupant P changes (see Figs. 12A and 12B). Therefore, even if the seated occupant P spends a long time sitting, the fatigue reduction effect is prevented from decreasing.

[0052] In this embodiment, the control unit 62 further controls the pelvis support 18 so that the duration of the first pressed state after the occupant sits down is 40 minutes, which is longer than the duration of the second or subsequent pressed states after the occupant sits down. Here, the test results described above show that it is more comfortable to stabilize the pelvis Pp of the seated occupant P for a longer period in the initial seating stage than in subsequent stages, and that a high level of comfort is achieved when the initial pressed state after the occupant sits down lasts 40 minutes. Therefore, according to the configuration of this embodiment, fatigue can be reduced in the initial seating stage, and the state of the pelvis support 18 is switched from the pressed state shown in FIG. 4B to the non-pressed state shown in FIG. 4A just before the seated occupant P feels that the pressure on the pelvis Pp should be released, thereby preventing a decrease in the fatigue reduction effect.

[0053] As described above, according to the vehicle seat 10 of this embodiment, even if the seating time is long, the fatigue reduction effect can be suppressed.

[0054] [Second embodiment] Next, a vehicle seat according to a second embodiment of the present invention will be described with reference to Fig. 19. Fig. 19 shows a perspective view of a vehicle seat 70 according to this embodiment. This embodiment has substantially the same configuration as the first embodiment, except for the points described below. Therefore, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0055] As shown in FIG. 19, the seat main body 10H is provided with a body pressure sensor 72 in a portion corresponding to the area where the pelvis support 18 (shown in the figure with the back lower support 20 and the cushion support 40 schematically illustrated) presses against the pelvis of the seated occupant. The body pressure sensor 72 is electrically connected to an ECU 74 (shown in the figure as a block). The ECU 74 is also electrically connected to external devices (including the motors 36, 50) to which the ECU 60 of the first embodiment (see FIG. 4A) is electrically connected. The ECU 74 has a control unit 76 as a functional configuration. The functional configuration of the control unit 76 is realized by a CPU reading and executing a program stored in a ROM or storage.

[0056] Similar to the control unit 62 of the first embodiment (see FIG. 4A), the control unit 76 controls the pelvis support 18 so that a pressed state and a non-pressed state are alternately repeated when an occupant is seated in the seat main body 10H. The control unit 76 further controls the pelvis support 18 so that, based on the detection result of the body pressure sensor 72, the pelvis support 18 switches between a first state (including, for example, the state shown in FIG. 12B) in which the area of ​​the portion on which the body pressure of the seated occupant P acts within the detection range of the body pressure sensor 72 is equal to or greater than a predetermined reference value and the maximum value of the body pressure is equal to or less than a predetermined value, and a second state other than the first state (including, for example, the state shown in FIG. 12A).

[0057] The timing for initially switching to the first state is, for example, the same as that in the first embodiment. Also, as a preset switching timing, for example, the first state is set for 40 minutes the first time, and 15 minutes from the second time onwards, and the second state is set for 15 minutes each time. As another example, an automatic adjustment mode may be provided in the operation menu of the pelvic support 18, and the pelvic support 18 may be turned on when the automatic adjustment mode is selected by the occupant. Thereafter, the pelvic support 18 may be turned off when the first state is reached, and turned on when it is determined that the area of ​​the portion on which the body pressure of the seated occupant P acts within the detection range of the body pressure sensor 72 has reached a minimum level. This configuration may be repeated.

[0058] In this embodiment, the body pressure distribution state around the pelvis Pp of the seated occupant P is prevented from remaining the same for an excessively long time, thereby suppressing a decrease in the fatigue reduction effect. Therefore, with the vehicle seat 70 of this embodiment, it is possible to suppress a decrease in the fatigue reduction effect even if the seating time is long.

[0059] [Supplementary explanation of the embodiment] In the first embodiment, the control unit 62 shown in Figures 4A and 4B controls the pelvis support 18 so that the duration of the initial pressure state after the occupant sits down is, for example, 40 minutes. However, as a variation, the control unit 62 may control the pelvis support 18 so that the duration of the initial pressure state after the occupant sits down is either 35 to 39 minutes or 41 to 45 minutes.

[0060] As a modification of the first and second embodiments, a (4-way) lumbar support that can be adjusted in the front, back, up and down directions may be provided in parallel.

[0061] Also, the amount of protrusion by which the pelvis support (pressing mechanism) presses against the pelvis of a seated occupant may be determined according to personal preference.

[0062] In the above embodiment, the pelvis support 18 as a pressing mechanism includes the lower back support 20 and the cushion support 40. As a reference example that is not an embodiment of the present invention, The pressing mechanism may be composed of only one of the back lower support (20) and the cushion support (40).

[0063] In addition, vehicle seats are In addition to having the configuration of the above embodiment, Only one of the back lower support (20) and the cushion support (40) The machine (in other words, the other is a machine The system may be configured so that the passenger can select whether or not the system is enabled.

[0064] The above-described embodiment and the above-described modified examples can be implemented in appropriate combinations.

[0065] The above describes one example of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0066] 10 Vehicle seats 10H seat body 12 seat cushions 12F seat cushion frame 12P seat cushion pad 14 Seat back 14F seat back frame 14P seat back pad 18 Pelvic support (pressure mechanism) 20 Back lower support 40 Cushion Support 62 Control Unit 70 Vehicle seats 72 Body pressure sensor 76 Control Unit P Seated occupant Pp Pelvis of seated occupant

Claims

1. a seat body for an occupant to sit on, the seat body including a seat cushion having a seat cushion pad placed on a seat cushion frame to support the buttocks and thighs of the seated occupant, and a seat back having a seat back pad placed on a seat back frame to support the back of the seated occupant; a pressing mechanism that is switchable between a pressing state in which the pelvis of a seated occupant is pressed and a non-pressing state in which the pelvis of a seated occupant is not pressed; the pressing mechanism comprising: a cushion support that is provided on the seat cushion frame and that is capable of pressing only a rear portion of the seat cushion pad toward an upper side of the seat without pressing a front portion of the seat cushion pad toward an upper side of the seat; and a back lower support that is provided on the seat back frame and that is capable of pressing only a lower portion of the seat back pad toward a front side of the seat without pressing an upper portion of the seat back pad toward a front side of the seat; a control unit that controls the pressing mechanism so that the cushion support and the back lower support are synchronized when an occupant is seated on the seat body, and the pressing state and the non-pressing state are alternately repeated; A vehicle seat having:

2. 2. The vehicle seat according to claim 1, wherein the control unit further controls the pressing mechanism so that a duration of the first pressing state after the occupant sits down is longer than a duration of a second or subsequent pressing state after the occupant sits down, and is between 35 minutes and 45 minutes.

3. a body pressure sensor is provided on the seat body at a position corresponding to the area where the pressing mechanism presses against the pelvis of the seated occupant; 2. The vehicle seat according to claim 1, wherein the control unit further controls the pressing mechanism so that, based on the detection result of the body pressure sensor, the pressing state is switched between a first state in which an area of ​​a portion within the detection range of the body pressure sensor on which the body pressure of the seated occupant acts is equal to or greater than a predetermined reference value and a maximum value of the body pressure is equal to or less than a predetermined value, and a second state in which the non-pressing state is not the first state, and the first state is alternately repeated at preset timing.

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