Vehicle seat and headrest rotating method

Abstract

To relax an occupant on a seat 1 with a seat back 3 tilted backward.SOLUTION: A seat 1 includes a seat cushion 2 that supports buttocks of an occupant, a seat back 3 that is provided so as to be tiltable on the seat cushion 2 and supports an upper body of the occupant, a headrest 4 that is rotatably provided on the seat back 3 and supports a head portion of the occupant, and a third rotating device 7 that rotates the headrest 4 in conjunction with tilting operation of the seat back 3. The third rotation device 7 is configured to be able to adjust an angle of the headrest 4 with respect to the seat back 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle seat having a headrest and a method for rotating the headrest.

Background Art

[0002] Conventionally, a vehicle seat configured to be able to change the position of a headrest has been known (see, for example, Patent Document 1). The vehicle seat described in Patent Document 1 expands the forward field of view of an occupant sitting in the rear seat by rotating the headrest forward.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the vehicle seat described in Patent Document 1 has a configuration in which the headrest is only rotated forward from the seating position. Further, from the viewpoint of protecting the head of the occupant, the headrest is attached to the seat back in a state where the upper part is bent forward along the seating posture of the occupant. Therefore, when the seat back is tilted backward and the occupant rests on the headrest on the vehicle seat, the occupant may feel discomfort in the head and may not be able to relax.

Means for Solving the Problems

[0005] One aspect of the present invention is a vehicle seat mounted on a vehicle, comprising a seat cushion that supports the occupant's buttocks, a seat back that is tiltably provided on the seat cushion and supports the occupant's upper body, a headrest that is rotatably provided on the seat back and supports the occupant's head, and a rotation device that rotates the headrest in conjunction with the tilting operation of the seat back. The rotation device is configured to be able to adjust the angle of the headrest with respect to the seat back.

[0006] Another aspect of the present invention is a method for rotating a headrest of a vehicle seat, the vehicle seat comprising a seat cushion that supports the occupant's buttocks, a seat back that is tiltably provided on the seat cushion and supports the occupant's upper body, and a headrest that is rotatably provided on the seat back and supports the occupant's head. The method for rotating the headrest includes an interlocking step of interlocking with the tilting operation of the seat back and an adjustment step of adjusting the angle of the headrest with respect to the seat back.

Advantages of the Invention

[0007] According to the present invention, even on a vehicle seat with the seat back tilted backward, the occupant can relax and take a break or the like.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 7. The vehicle seat according to the embodiment of the present invention is a seat provided with a headrest, and can be used for seats mounted on various vehicles such as airplanes, railways, and automobiles. Hereinafter, as an example of the vehicle seat, a seat mounted on an automobile, particularly a front seat (hereinafter simply referred to as seat 1) used for the front seat of the automobile will be used for explanation. Further, hereinafter, the front-rear direction, the left-right direction (width direction), and the up-down direction (height direction) are defined based on the occupant seated on seat 1, and the configuration of each part will be described according to this definition.

[0010] First, the main part configuration of seat 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view showing the main part configuration of seat 1 according to the present embodiment.

[0011] As shown in FIG. 1, seat 1 includes a seat cushion 2 that supports the occupant's buttocks, a seat back 3 that supports the occupant's upper body (waist and back), and a headrest 4 that supports the occupant's head. Seat cushion 2 is supported slidably in the front-rear direction by a slide mechanism (not shown) provided on the vehicle floor. Seat back 3 is provided at the rear end of seat cushion 2 and is rotatably supported by seat cushion 2. Headrest 4 is provided at the upper end of seat back 3 and is rotatably supported by seat back 3.

[0012] The seat 1 further includes a first rotating device 5 configured to rotatably support the seat cushion 2, a second rotating device 6 configured to rotatably support the seat back 3, a third rotating device 7 (rotating device) configured to rotatably support the headrest 4, and a controller 8 (control unit) for controlling these components.

[0013] Figure 2 is a side view showing a main part configuration of a seat frame 10 that forms the skeleton of the seat 1 in Figure 1. The seat frame 10 shown in Figure 2 is in a state where a cushion pad 11 made of a cushion material such as urethane foam and a skin material 12 made of synthetic leather or fabric have been removed from the seat 1 shown in Figure 1. As shown in Figure 2, the seat frame 10 includes a seat cushion frame 20 that forms the skeleton of the seat cushion 2, a seat back frame 30 that forms the skeleton of the seat back 3, and a headrest frame 40 that forms the skeleton of the headrest 4.

[0014] The seat cushion frame 20 has a pair of left and right cushion side frames 21, 21 extending in the front-rear direction, a cushion pan frame 22 provided to cover the front end portions of the pair of left and right cushion side frames 21, 21, a front pipe 23 extending in the left-right direction and connecting the pair of left and right cushion side frames 21, 21 slightly in front of the rear end portion of the cushion pan frame 22, and a rear pipe 24 extending in the left-right direction and connecting the rear end portions of the pair of left and right cushion side frames 21, 21.

[0015] The cushion side frame 21 is formed in a substantially plate shape facing in the left - right direction, and is formed to be wider in the up - down direction as it extends rearward. Further, a flange portion extending inward or outward is provided at the outer edge of the cushion side frame 21, and the frame is reinforced. The cushion pan frame 22 is formed in a substantially plate shape facing in the up - down direction, and its tip is provided so as to be slightly forward of the front end portions of the pair of left - right cushion side frames 21, 21 respectively. The seat cushion frame 20 having such a configuration is formed in a substantially rectangular frame shape in plan view. Inside it, a cushion panel (not shown) that receives a load from above by a seated occupant is arranged to be spanned between the front pipe 23 and the rear pipe 24.

[0016] The seat back frame 30 has a pair of left - right back side frames 31, 31 extending in the up - down direction, an upper end connection frame 32 extending in the left - right direction and connecting the upper end portions of the pair of left - right back side frames 31, 31, and a lower end connection frame 33 connecting the lower end portions of the pair of left - right back side frames 31, 31.

[0017] The back side frame 31 is formed in a substantially plate shape facing in the left - right direction, and is formed to be wider in the front - rear direction as it extends downward. Also, a flange portion extending inward or outward is provided at the outer edge of the back side frame 31, and the frame is reinforced. The seat back frame 30 having such a configuration is formed in a substantially rectangular frame shape when viewed from the front. Inside it, a back panel (not shown) that receives a load from the upper body (waist and back) of a seated occupant is arranged to be spanned between the upper end connection frame 32 and the lower end connection frame 33.

[0018] The headrest frame 40 includes a pair of left and right head side frames 41, 41 extending in the vertical direction, an upper end connecting pipe 42 extending in the left - right direction and connecting the upper ends of the pair of left and right head side frames 41, 41, and a lower end connecting pipe 43 connecting the lower ends of the pair of left and right head side frames 41, 41. The headrest frame 40 having such a configuration is formed in a substantially rectangular frame shape when viewed from the front, and is attached to the seat back frame 30 in a state where the upper part is bent forward along the seating posture of the occupant from the viewpoint of protecting the occupant's head.

[0019] The first rotation device 5 is interposed between a slide mechanism (not shown) provided on the vehicle floor and the seat cushion 2, and is configured to be rotatable in the vertical direction in front of the seat cushion 2 with the rear end of the seat cushion 2 as the center. Specifically, the first rotation device 5 includes a first rotation support portion 51 that rotatably supports the seat cushion 2, a first actuator 52 that rotates the seat cushion 2, and a first sensor 53 that detects the rotation angle of the seat cushion 2. The first rotation support portion 51 extends in the left - right direction and includes a first rotation shaft 51a provided by connecting the rear ends of a pair of left and right cushion side frames 21, 21, and a pair of left and right first upper brackets 51b, 51b attached to each of a pair of left and right upper rails constituting the slide mechanism (not shown) and rotatably supporting the first rotation shaft 51a. The first actuator 52 is attached to the first upper bracket 51b and is connected to the first rotation shaft 51a via a gear train to rotate the first rotation shaft 51a. The first sensor 53 detects the angle of the support surface 2a of the seat cushion 2 with respect to the horizontal line (hereinafter referred to as the first rotation angle θ1).

[0020] The first rotation device 5 configured as described above can adjust the rotation angle of the seat cushion 2. For example, it rotatably supports the seat cushion 2 between a driving position where the support surface 2a of the seat cushion 2 supporting the occupant's buttocks is substantially horizontal and a relaxation position where the front of the seat cushion 2 is rotated upward to relax the occupant on the seat 1.

[0021] The second rotation device 6 is interposed between the seat cushion 2 and the seat back 3, and is configured to be able to rotate the seat back 3 in the front-rear direction about the lower end of the seat back 3. Specifically, the second rotation device 6 includes a second rotation support portion 61 that rotatably supports the seat back 3, a second actuator 62 that rotates the seat back 3, and a second sensor 63 (second detection portion) that detects the rotation angle of the seat back 3. The second rotation support portion 61 extends in the left-right direction, and includes a second rotation shaft 61a that is provided by connecting the lower ends of the pair of left and right back side frames 31, 31, and a pair of left and right side brackets 61b, 61b that are attached to the rear end portions of the pair of left and right cushion side frames 21, 21 respectively and rotatably support the second rotation shaft 61a. The second actuator 62 is attached to the cushion side frame 21 and is connected to the second rotation shaft 61a via a gear train, and rotates the second rotation shaft 61a. The second sensor 63 detects the angle of the support surface 3a of the seat back 3 with respect to the horizontal line (hereinafter referred to as the second rotation angle θ2).

[0022] The second rotation device 6 configured as described above can adjust the rotation angle of the seat back 3. For example, the support surface 3a of the seat back 3 that supports the upper body of the occupant faces forward at the driving position where the occupant assumes a driving posture, and the seat back 3 is rotatably supported between the driving position and the relaxation position where the seat back 3 is tilted so that the support surface 3a of the seat back 3 faces upward to relax the occupant on the seat 1.

[0023] The third rotating device 7 is interposed between the seat back 3 and the headrest 4, and is configured to be rotatable in the front-rear direction about the lower end of the headrest 4. Specifically, the third rotating device 7 includes a third rotation support portion 71 that rotatably supports the headrest 4, a third actuator 72 that rotates the headrest 4, and a third sensor 73 (first detection portion) that detects the rotation angle of the headrest 4. The third rotation support portion 71 extends in the left-right direction and includes a third rotation shaft 71a provided by connecting the lower ends of a pair of left and right head side frames 41, 41, and a pair of left and right second upper brackets 71b, 71b attached to the upper end connecting frame 32 of the seat back 3 and rotatably supporting the third rotation shaft 71a. The third actuator 72 is attached to the upper end connecting frame 32 of the seat back 3 and is connected to the third rotation shaft 71a via a gear train to rotate the third rotation shaft 71a. The third sensor 73 detects the angle of the support surface 4a of the headrest 4 with respect to the horizontal line (hereinafter referred to as the third rotation angle θ3).

[0024] The third rotating device 7 configured as described above can adjust the rotation angle of the headrest 4. For example, it rotatably supports the headrest 4 between a driving position where the upper part is bent forward along the seating posture of the occupant and a relaxation position where the headrest 4 is rotated so that the support surface 3a of the seat back 3 facing upward and the support surface 4a of the headrest 4 are substantially parallel. The angle of the headrest 4 with respect to the seat back 3 is calculated based on the second rotation angle θ2 detected by the second sensor 63 and the third rotation angle θ3 detected by the third sensor 73.

[0025] Next, the main configuration of the controller 8 that drives the seat 1 configured as described above will be described with reference to FIGS. 3 to 6. FIG. 3 is a block diagram of the controller 8 that controls the driving of the seat 1. As shown in FIG. 3, the controller 8 includes a computer having an arithmetic unit 81 such as a CPU, a storage unit 82 such as a ROM, a RAM, and a hard disk, and other peripheral circuits (not shown).

[0026] The calculation unit 81 includes, as a functional configuration, an information reception unit 811 and an information output unit 812.

[0027] The information reception unit 811 receives various types of information and various commands. For example, the information reception unit 811 receives information such as the first rotation angle θ1 detected by the first sensor 53, the second rotation angle θ2 detected by the second sensor 63, and the third rotation angle θ3 detected by the third sensor 73. The information reception unit 811 also receives commands such as a tilt signal output when a passenger presses a tilt switch SW1 to tilt the seat back 3, a drive mode signal output when a passenger presses a drive mode switch SW2 to set the state of the seat 1 to the drive mode, and a relaxation mode signal output when a passenger presses a relaxation mode switch SW3 to set the state of the seat 1 to the relaxation mode.

[0028] Based on the various types of information and various commands received by the information reception unit 811, the information output unit 812 outputs a control signal to various devices. For example, when the information reception unit 811 receives a tilt signal, the information output unit 812 outputs a control signal to the second rotation device 6 to drive the second actuator 62. The information output unit 812 continues to output a control signal to the second rotation device 6 while the information reception unit 811 is receiving the tilt signal. That is, while the passenger is pressing the tilt switch SW1, the seat back 3 continues to tilt.

[0029] When the information reception unit 811 receives a drive mode signal, the information output unit 812 also outputs a control signal to the first to third rotation devices 5, 6, and 7 so that the seat 1 assumes the drive mode form stored in the storage unit 82, and drives the first to third actuators 52, 62, and 72 based on the first to third rotation angles θ1, θ2, and θ3. That is, when the passenger presses the drive mode switch SW2, the form of the seat 1 is changed to the drive mode.

[0030] Similarly, when the information receiving unit 811 receives the relaxation mode signal, the information output unit 812 outputs a control signal to the first to third rotating devices 5, 6, and 7 so that the seat 1 assumes the relaxation mode stored in the storage unit 82, and drives the first to third actuators based on the first to third rotation angles θ1, θ2, and θ3. That is, when the occupant presses the relaxation mode switch SW3, the mode of the seat 1 is changed to the relaxation mode.

[0031] The storage unit 82 stores various programs and various data executed by the calculation unit 81. The storage unit 82 has a mode storage unit 821 that stores the modes of the seat 1 in various modes. The mode storage unit 821 stores the mode of the seat 1 in the drive mode, the mode of the seat 1 in the relaxation mode, and the like.

[0032] FIG. 4A is a side view of the seat 1 set in the drive mode, and FIG. 4B is a side view of the seat 1 set in the relaxation mode. For example, as shown in FIG. 4A, in the mode storage unit 821, as the mode of the seat 1 in the drive mode, the first rotation angle θ1 input by the first sensor 53 is 0°, the second rotation angle θ2 input by the second sensor 63 is 100°, and the third rotation angle θ3 input by the third sensor 73 is 70° are stored. That is, in the mode storage unit 821, as the drive mode, the support surface 2a of the seat cushion 2 is substantially horizontal, the seat back 3 is slightly tilted backward, and the upper part of the headrest 4 is slightly bent forward along the seating posture of the occupant.

[0033] Similarly, as shown in FIG. 4B, in the mode memory unit 821, as the aspect of the relaxation mode of the seat 1, the first rotation angle θ1 input by the first sensor 53 is 30°, the second rotation angle θ2 input by the second sensor 63 is 170°, and the third rotation angle θ3 input by the third sensor 73 is 170° are stored. That is, in the mode memory unit 821, as the relaxation mode, an aspect is stored in which the front of the seat cushion 2 slightly rises, the seat back 3 largely tilts backward, and the support surface 4a of the headrest 4 becomes substantially parallel to the support surface 3a of the seat back 3.

[0034] In addition to the drive mode and the relaxation mode, the controller 8 also performs cooperative control of the seat back 3 and the headrest 4, and cooperative control of the seat cushion 2, the seat back 3, and the headrest 4. FIGS. 5A to 5C are explanatory diagrams for explaining the cooperative control of the seat cushion 2, the seat back 3, the headrest 4, etc. by the controller 8. In FIGS. 5A to 5C, the solid line indicates the operation of the seat back 3, the broken line indicates the operation of the headrest 4, and in FIG. 5C, the one-dot chain line indicates the operation of the seat cushion 2.

[0035] When the information receiving unit 811 receives a tilt signal, the information output unit 812 outputs a control signal to the second rotation device 6 to drive the second actuator 62, which has been described above. At this time, as shown in FIG. 5A, the information output unit 812 also outputs a control signal to the third rotation device 7 to drive the third actuator 72 (interlocking step). The information output unit 812 outputs a control signal to the third rotation device 7 so that the headrest 4 also displaces to the relaxation mode state at the timing t2 when the seat back 3 displaces to the relaxation mode state. At this time, the information output unit 812 outputs a control signal to the third rotation device 7 based on the second rotation angle θ2 of the seat back 3 detected by the second sensor 63 and the third rotation angle θ3 of the headrest 4 detected by the third sensor 73 so that the third rotation angle θ3 of the headrest 4 with respect to the second rotation angle θ2 of the seat back 3 becomes an optimal angle (adjustment step). Therefore, the seat back 3 and the headrest 4 can be tilted without giving discomfort to the occupant pressing the tilt switch SW1 while sitting on the seat 1.

[0036] Also, for example, as shown in FIG. 5B, when the occupant stops pressing the tilt switch SW1 at the timing t1, the information output unit 812 stops outputting the control signal to the second rotation device 6 and the third rotation device 7 at the timing t1 (interlocking step). As described above, since the information output unit 812 outputs a control signal to the third rotation device 7 so that the third rotation angle θ3 of the headrest 4 becomes an optimal angle based on the second rotation angle θ2 of the seat back 3, even when the occupant wants to tilt the seat back 3 halfway (for example, 150°), the headrest 4 becomes an optimal angle with respect to the seat back (adjustment step). Therefore, for example, even when the seat back 3 is tilted to the rotation angle desired by the occupant, the angle of the headrest 4 with respect to the seat back 3 becomes optimal.

[0037] Furthermore, for example, as shown in FIG. 5C, when the seat back 3 that has started to tilt exceeds a predetermined angle (e.g., 130°), a configuration may be adopted in which the rotation of the headrest 4 is started (interlocking step). When the second rotation angle θ2 of the seat back 3 detected by the second sensor 63 exceeds a predetermined angle, the information output unit 812 outputs a control signal to the third rotation device 7 to rotate the headrest 4. Also in this case, the controller 8 outputs control signals to the second rotation device 6 and the third rotation device 7 so that the angle of the headrest 4 with respect to the seat back 3 becomes an optimal angle (adjustment step).

[0038] Furthermore, when the seat back 3 that has started to tilt exceeds a predetermined angle (e.g., 130°), a configuration may be adopted in which the seat cushion 2 is also rotated. When the second rotation angle θ2 of the seat back 3 detected by the second sensor 63 exceeds a predetermined angle, the information output unit 812 outputs a control signal to the first rotation device 5 to rotate the seat cushion 2 and outputs a control signal to the third rotation device 7 to rotate the headrest 4. Based on the second rotation angle θ2 of the seat back 3 detected by the second sensor 63, the information output unit 812 outputs control signals to the first rotation device 5 and the third rotation device 7 so that the first rotation angle θ1 of the seat cushion 2 with respect to the second rotation angle θ2 and the third rotation angle θ3 of the headrest 4 with respect to the second rotation angle θ2 become optimal angles.

[0039] FIG. 6 is a flowchart of the cooperative control shown in FIG. 5C executed by the arithmetic unit 81 of the controller 8. The process shown in this flowchart is started, for example, when the information receiving unit 811 receives a tilt signal for tilting the seat back 3.

[0040] First, in step S1, the arithmetic unit 81 causes the information output unit 812 to output a control signal for the second rotating device 6, and drives the second actuator 62. Next, in step S2, the arithmetic unit 81 determines whether or not the second rotation angle θ2 input by the second sensor 63 has reached a first predetermined angle (for example, 130°). If it is negated in step S2, this is repeated until it is affirmed. On the other hand, if it is affirmed in step S2, in step S3, the information output unit 812 is caused to output control signals for the first rotating device 5 and the third rotating device 7, and the first actuator 52 and the third actuator 72 are driven (interlocking step).

[0041] Next, in step S4, the arithmetic unit 81 determines whether or not the second rotation angle θ2 input by the second sensor 63 has reached a second predetermined angle (for example, 170°). If it is negated in step S4, this is repeated until it is affirmed. On the other hand, if it is affirmed in step S4, in step S5, the arithmetic unit 81 stops the output of the control signal for the second rotating device 6 by the information output unit 812, and stops the driving of the second actuator 62.

[0042] Next, in step S6, it is determined whether or not the third rotation angle θ3 input by the third sensor 73 has reached the second predetermined angle. If it is negated in step S6, this is repeated until it is affirmed. On the other hand, if it is affirmed in step S6, in step S7, the arithmetic unit 81 stops the output of the control signal for the third rotating device 7 by the information output unit 812, and stops the driving of the third actuator 72 (adjustment step).

[0043] Next, in step S8, it is determined whether or not the first rotation angle θ1 input by the first sensor 53 has reached the second predetermined angle. If it is negated in step S8, this is repeated until it is affirmed. On the other hand, if it is affirmed in step S8, in step S9, the arithmetic unit 81 stops the output of the control signal for the first rotating device 5 by the information output unit 812, stops the driving of the first actuator 52, and ends the process.

[0044] In this embodiment, steps S1 to S9 are executed in the above procedure. However, for example, steps S6 and S8 may be executed simultaneously, or steps S4, S6, and S8 may be executed simultaneously.

[0045] According to this embodiment, the following operational effects can be achieved. (1) The seat 1 according to this embodiment is a front seat mounted on an automobile. The seat 1 includes a seat cushion 2 that supports the occupant's buttocks, a seat back 3 that is tiltably provided on the seat cushion 2 and supports the occupant's upper body, a headrest 4 that is rotatably provided on the seat back 3 and supports the occupant's head, and a third rotation device 7 (rotation device) that rotates the headrest 4 in conjunction with the tilting operation of the seat back 3. The third rotation device 7 is configured to be able to adjust the angle of the headrest 4 with respect to the seat back 3.

[0046] With this configuration, the angle of the headrest 4 with respect to the seat back 3 can be set to an optimal angle. Therefore, when the occupant rests or takes a short nap on the seat 1 with their head on the headrest 4, the occupant can rest or take a short nap in a relaxed state. For example, from the perspective of protecting the occupant's head, the headrest 4 may be attached to the seat back 3 in a state where the upper part is bent forward along the seating posture of the occupant during driving. Therefore, when the seat back 3 is tilted in this state, the occupant may feel discomfort in the head and may not be able to relax. However, by adjusting the angle of the headrest 4 with respect to the seat back 3 to an optimal angle, the discomfort in the head when the seat back 3 is tilted is eliminated, and the occupant can relax sufficiently on the seat 1.

[0047] (2) In the seat 1 described in (1), the third rotating device 7 is configured to be able to adjust the angle of the headrest 4 with respect to the seat back 3 when the seat back 3 is tilted backward. With this configuration, for example, by adjusting the angle of the headrest 4 so that the support surface 3a of the seat back 3 and the support surface 4a of the headrest 4 are substantially parallel when the seat back 3 is tilted backward, when taking a nap or the like on the seat 1 with the head placed on the headrest 4, the occupant can take a nap or the like in a relaxed state.

[0048] (3) In the seat 1 described in (1), the third rotating device 7 (rotating device) is interposed between the seat back 3 and the headrest 4, and includes a third rotation support portion 71 that supports the headrest 4 so as to be rotatable in the front-rear direction about a third rotation axis 71a extending in the width direction, a third actuator 72 that rotates the headrest 4, a third sensor 73 that detects the rotation angle of the headrest 4, and a controller 8 that controls the third actuator 72 so that the headrest 4 rotates based on the third rotation angle θ3 detected by the third sensor 73.

[0049] With this configuration, since the headrest 4 can be rotated by controlling the third actuator 72 that rotates the headrest 4 based on the third rotation angle θ3 with the controller 8, the seat back 3 and the headrest 4 can be cooperatively controlled with a simple configuration.

[0050] (4) The seat 1 described in (3) further includes a second sensor 63 that detects the rotation angle of the seat back 3. When the second rotation angle θ2 detected by the second sensor 63 exceeds a first predetermined angle, the controller 8 controls the third actuator 72 so that the support surface 3a of the seat back 3 and the support surface 4a of the headrest 4 are substantially parallel.

[0051] With this configuration, the support surface 3a of the seat back 3 and the support surface 4a of the headrest 4 can be made substantially parallel only when the occupant wants to relax on the seat 1. For example, when taking a short break or a break that is not overly relaxing on the seat 1, the seat back 3 may be tilted slightly. However, in such a case, if the occupant is allowed to assume a fully relaxed posture, the occupant may oversleep. Therefore, in such cases, by not rotating the headrest 4, it is possible to prevent the occupant from oversleeping on the seat 1 and the like.

[0052] (5) In the seat 1 according to (4), the seat cushion 2 is provided so as to be rotatable in the vertical direction at the front part about a first rotation axis 51a provided at the rear end with respect to the floor of the vehicle on which the seat 1 is disposed. When the second rotation angle θ2 detected by the second sensor 63 exceeds a first predetermined angle, the controller 8 controls the first to third actuators 52, 62, 72 so that the front part of the seat cushion 2 rotates upward and the support surface 3a of the seat back 3 and the support surface 4a of the headrest 4 become substantially parallel. With this configuration, since the front part of the seat cushion 2 also rises in conjunction with the tilting of the seat back 3, the occupant can be made more relaxed on the seat 1.

[0053] (6) The headrest rotation method according to the present embodiment is a headrest rotation method for a seat 1 including a seat cushion 2 that supports the buttocks of the occupant, a seat back 3 that is tiltably provided on the seat cushion 2 and supports the upper body of the occupant, and a headrest 4 that is rotatably provided on the seat back 3 and supports the head of the occupant. The headrest rotation method includes an interlocking step of interlocking with the tilting operation of the seat back 3 and an adjustment step of adjusting the angle of the headrest 4 with respect to the seat back 3, and these are executed by the controller 8.

[0054] By this method, the angle of the headrest 4 with respect to the seat back 3 can be set to an optimal angle. Therefore, when a passenger takes a rest or a short nap on the seat 1 with their head on the headrest 4, the passenger can take a rest or a short nap in a relaxed state. For example, from the viewpoint of protecting the head of the passenger, the headrest 4 may be attached to the seat back 3 in a state where the upper part is bent forward along the seating posture of the passenger during driving. Therefore, when the seat back 3 is tilted in this state, the passenger may feel discomfort in the head and may not be able to relax. However, by adjusting the angle of the headrest 4 with respect to the seat back 3 to an optimal angle, the discomfort in the head when the seat back 3 is tilted is eliminated, and the passenger can relax sufficiently on the seat 1.

[0055] The above-described embodiment can be modified into various forms. Hereinafter, a modification example will be described with reference to FIG. 7. FIG. 7 is a side view for explaining a modification example of the seat 1 according to the present embodiment.

[0056] In the above-described embodiment, the second actuator 62 and the third actuator 72 are used to cooperatively control the seat back 3 and the headrest 4, respectively. However, the seat back 3 and the headrest 4 may be cooperatively controlled using only the second actuator 62. For example, as shown in FIG. 7, the headrest 4 is biased by a biasing spring 75 so that the upper portion of the headrest 4 is bent forward, and one end of a wire cable 76 is attached to the headrest 4 so as to rotate about a third rotation axis 71a against the biasing force of the biasing spring 75. The other end of the wire cable 76 is attached to a winding device 77 capable of winding the wire cable 76, and the winding device 77 is configured to be driven in conjunction with the driving of the second actuator 62. For example, when the second actuator 62 is driven in a direction to tilt the seat back 3, the winding device 77 is configured to wind the wire cable 76, and when the second actuator 62 is driven rearward to raise the seat back 3, the winding device 77 is configured to feed out the wire cable 76. Thus, the seat back 3 and the headrest 4 can be cooperatively controlled using only the second actuator 62.

[0057] In the above-described embodiment, the first rotating device 5 rotates the front of the seat cushion 2 upward about the rear end of the seat cushion 2 as the rotation center to position the seat cushion 2 in the relaxation position. However, a configuration may be adopted in which elevating means is provided in front of and behind the seat cushion 2, and the seat cushion 2 is positioned in the relaxation position by raising or lowering the front or rear of the seat cushion.

[0058] Also, in the above-described embodiment, the headrest 4 having a rotation mechanism using the third rotating device 7 has been described. However, the headrest 4 may have a configuration having a moving mechanism capable of moving in the front-rear direction in addition to the rotation mechanism. For example, after rotating the headrest 4 so as to be substantially parallel to the support surface 3a of the seat back 3, the headrest 4 may be further moved forward to match the height of the occupant's head.

[0059] The above description is merely an example, and the present invention is not limited to the above-described embodiments and modifications as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and it is also possible to combine the modifications with each other.

Explanation of Signs

[0060] 1 Seat (vehicle seat), 2 Seat cushion, 3 Seat back, 4 Headrest, 5 First rotating device, 6 Second rotating device, 7 Third rotating device (rotating device), 8 Controller (control unit), θ1 First rotation angle, θ2 Second rotation angle, θ3 Third rotation angle

Claims

1. A vehicle seat to be mounted on a vehicle, A seat cushion that supports the buttocks of an occupant; a seat back provided on the seat cushion in a tiltable manner and supporting an upper body of an occupant; a headrest rotatably provided on the seat back and configured to support a head of an occupant; a rotation device that rotates the headrest in conjunction with a tilting movement of the seat back, 13. A vehicle seat, comprising: a headrest rotation device configured to adjust an angle of the headrest relative to the seat back.

2. The vehicle seat according to claim 1, The vehicle seat, wherein the rotation device is configured to be able to adjust an angle of the headrest relative to the seat back when the seat back is tilted rearward.

3. The vehicle seat according to claim 1 or 2, The rotating device is a rotation support portion interposed between the seat back and the headrest and configured to support the headrest so as to be rotatable in a front-rear direction about a rotation axis extending in a width direction; An actuator that rotates the headrest; A first detection unit that detects a rotation angle of the headrest; a control unit that controls the actuator so that a rotation angle of the headrest is adjustable based on the rotation angle detected by the first detection unit.

4. The vehicle seat according to claim 3, A second detection unit that detects a rotation angle of the seat back is further provided. The control unit controls the actuator so that the support surface of the seat back and the support surface of the headrest become approximately parallel when the rotation angle detected by the second detection unit exceeds a predetermined angle.

5. The vehicle seat according to claim 4, The seat cushion is provided so that a front portion thereof can be turned up and down around a rear end portion thereof with respect to a floor on which the vehicle seat is placed, The control unit controls the actuator so that, when the rotation angle detected by the second detection unit exceeds the predetermined angle, the front portion of the seat cushion rotates upward and the support surface of the seat back and the support surface of the headrest become approximately parallel.

6. A headrest rotating method for a vehicle seat comprising a seat cushion supporting the buttocks of an occupant, a seat back tiltably mounted on the seat cushion and supporting the upper body of the occupant, and a headrest rotatably mounted on the seat back and supporting the head of the occupant, the headrest rotating method comprising the steps of: linking the headrest with the tilting movement of the seat back; and adjusting the angle of the headrest relative to the seat back.

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