Vehicle seat

Abstract

This vehicle seat comprises: a seat cushion that supports the buttocks of an occupant; and a lifting device that changes the inclination angle of a seating surface of the seat cushion. A change device is configured to be able to change the inclination angle so that the attitude of the seat surface of the seat cushion is switched between a first attitude in which the attitude of the seat surface of the seat cushion is substantially horizontal or inclined downward toward the rear and a second attitude in which the attitude is inclined upward toward the rear.

Description

Vehicle seats

[0001] The present invention relates to a vehicle seat to be installed in various types of vehicles.

[0002] A vehicle seat that supports a seat cushion via a pair of front and rear links is known (see, for example, Patent Document 1). The vehicle seat described in Patent Document 1 is configured to be positionally changeable between a relax mode in which the front portion of the seat cushion is moved higher than the rear portion, and a work mode in which both the front and rear portions of the seat cushion are moved higher than the position of the seat cushion in the drive mode.

[0003] Japanese Patent Application Laid-Open No. 2023-075051

[0004] However, when the seat back is tilted forward, the occupant's posture becomes cramped, making it difficult to achieve a desirable working posture.

[0005] A vehicle seat according to one aspect of the present invention includes a seat cushion that supports the buttocks of an occupant and a tilt angle changer that changes the tilt angle of the seat cushion's seat surface. The tilt angle changer is configured to change the seat surface's position between a first position in which the seat surface is substantially horizontal or slopes downward toward the rear, and a second position in which the seat surface slopes upward toward the rear.

[0006] According to the present invention, it is possible for an occupant to work in a forward-leaning position without placing the occupant in an uncomfortable position.

[0007] 1 is a perspective view of a vehicle seat according to an embodiment of the present invention. FIG. 1 is a perspective view showing the structure of a seat cushion frame. FIG. 2 is a perspective view showing the structure of a seat cushion frame. FIG. 3 is a side view showing the lifting mechanism of a right side frame from the inside. FIG. 4 is a side view showing the lifting mechanism of a left side frame from the inside. FIG. 5 is a plan view of a seat cushion frame. FIG. 6 is a rear view of a seat cushion frame. FIG. 7 is a cross-sectional view of an end cap. FIG. 8 is a side view of a cushion side frame viewed from the inside in the width direction. FIG. 9 is a side view of a cushion side frame viewed from the inside in the width direction. FIG. 10 is a perspective view of a cover member attached to a front pipe. FIG. 11 is a plan view of a cover member attached to a front pipe.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A vehicle seat according to an embodiment of the present invention can be applied to various vehicles, but the following describes an example in which the vehicle seat is applied to a vehicle, particularly a vehicle with an automatic driving function, i.e., an automatic driving vehicle. A vehicle to which the vehicle seat according to this embodiment is applied can travel not only in an automatic driving mode in which no driver operation is required, but also in a manual driving mode in which the driver operates the vehicle. Note that the vehicle to which the vehicle seat according to this embodiment is applied may be an engine vehicle having an internal combustion engine (engine) as a driving source, an electric vehicle having a driving motor as a driving source, or a hybrid vehicle having an engine and a driving motor as driving sources.

[0009] Fig. 1 is a perspective view (viewed diagonally from the front) of a vehicle seat (hereinafter simply referred to as "seat") 100 according to an embodiment of the present invention. The front-to-rear direction in Fig. 1 corresponds to the length of the vehicle, the up-to-down direction corresponds to the height of the vehicle, and the left-to-right direction corresponds to the width of the vehicle. In other words, the front of the front-to-rear direction in Fig. 1 is the direction in which an occupant in a riding position faces, the left-to-right direction is the seat width direction, and the up-to-down direction is the seat height direction.

[0010] As shown in FIG. 1 , the seat 100 is a vehicle seat used as a driver's seat or passenger seat in a vehicle, and includes a seat cushion 1 that supports the buttocks of an occupant, a seat back 2 that supports the back of the occupant, and a headrest 3 that is provided on the upper part of the seat back 2 and supports the head of the occupant. The seat cushion 1 extends in the front-rear and left-right directions and has a generally rectangular shape. The seat back 2 extends in the top-down and left-right directions and has a generally rectangular shape. The lower end of the seat back 2 is supported on the rear end of the seat cushion 1 via a pair of left and right reclining mechanisms 4 so that it can tilt in the front-rear direction around a shaft 4a that extends left-right. The reclining mechanisms 4 include a reclining actuator 4b, which will be described later. A controller 60, which will be described later, is provided under the cover of the seat cushion 1.

[0011] 2A is a perspective view showing a part of the seat frame inside the seat 100, more specifically, the structure of a frame (hereinafter referred to as a seat cushion frame) 10 corresponding to the seat cushion 1. The seat cushion frame 10 is formed to fit the outer shape of the seat cushion 1. As shown in FIG. 1, the seat cushion 1 is constructed by attaching a seat cushion pad made of a cushioning material such as urethane foam to the seat cushion frame 10 and further covering the outside of the seat cushion with a covering material made of synthetic leather, fabric, or the like. The seat cushion pad is supported by the seat cushion frame 10 and functions as a pressure-receiving portion that receives the load from the buttocks of the occupant.

[0012] The seat cushion 1 includes a lifting / lowering device (hereinafter also referred to as a changing device) 20 that changes the tilt angle of the seat cushion frame 10 so that the posture of the seat surface of the seat cushion 1 can be switched among three posture modes (drive mode, work mode, and relax mode) described below, and a slide device 30 that serves as a base member that supports the seat cushion frame 10 so that it can move in the front-rear direction. Details of the lifting / lowering device 20 and the slide device 30 will be described later.

[0013] 2A, the slide device 30 is provided on the floor (body floor) below the seat 100, extending in the front-rear direction. The seat cushion frame 10 is slidably engaged with the slide device 30, thereby allowing the seat cushion 1 to move in the front-rear direction along the slide device 30 relative to the vehicle body.

[0014] The seat cushion frame 10 includes a pair of cushion side frames (hereinafter simply referred to as side frames) 11 (11L, 11R) aligned on the left and right, a cushion pan frame 12 connecting the front ends of the side frames 11L, 11R and covering the front of the side frames 11L, 11R, a metal front pipe 13 connecting the front ends of the side frames 11L, 11R rearward of the front ends of the cushion pan frame 12, more preferably rearward of the front end of the cushion pan frame 12 and forward of the rear end of the cushion pan frame 12, a metal rear pipe 14 connecting the rear ends of the side frames 11L, 11R, and a pressure-receiving member 15 spanning the front pipe 13 and the rear pipe 14 and receiving a load from above due to the weight of an occupant (seat occupant) or the like. End caps 13a are attached to the right and left ends of the front pipe 13.

[0015] The slide device 30 has a pair of slide rails (hereinafter referred to as upper rails) 31 (31L, 31R) arranged side by side on the left and right, and a pair of slide rails (hereinafter referred to as lower rails) 32 (32L, 32R) that are connected to the floor (vehicle body floor) via feet 19L, 19R and support the upper rails 31L, 31R so that they can move in the fore-and-aft direction. The slide device 30 also has a pair of upper rail brackets 28 (28L, 28R) that are provided on the upper surfaces of the upper rails 31L, 31R and connect the upper rails 31L, 31R to the side frames 11L, 11R. Furthermore, the slide device 30 has a rail connecting member 33 that connects the front ends of the lower rails 32L, 32R, a slide actuator (hereinafter also referred to as the rail actuator) 34 that is supported by the rail connecting member 33, a screw shaft 35 that rotates by the driving force of the slide actuator 34, and a set of shaft support members 36 (36L, 36R) that are provided at the outer end of the screw shaft 35 in the seat width direction and support the screw shaft 35.

[0016] The slide actuator 34 has a built-in electric motor and generates a driving force via the electric motor to rotate the screw shaft 35. The shaft support member 36 has a gearbox and transmits the rotational power of the screw shaft 35 via the gearbox to a screw shaft (not shown) that is provided inside the upper rail 31 and extends along the front-rear direction. The screw shaft of the upper rail 31 is provided so as to pass through a ball screw (not shown) provided in the lower rail 32, and rotation of the screw shaft of the upper rail 31 moves the upper rail 31 relative to the lower rail 32 in the front-rear direction. With this configuration, the slide device 30 functions as a slide mechanism.

[0017] 2B is a perspective view showing the structure of the seat cushion frame 10 with the cushion pan frame 12 removed. As shown in Fig. 2B, the seat cushion frame 10 further includes, below the cushion pan frame 12, a gear cover portion 16 that covers a part of the lifting device 20 (sector link 22R) in the seat width direction, and an air conditioning unit 40 that sends air to the seating surface of the seat cushion frame 10 or draws air into the seating surface side.

[0018] The gear cover portion 16 and the sector link 22R have insertion holes formed therein for inserting the front pipe 13. The front portion of the gear cover portion 16 is attached to the right side frame 11R via the front pipe 13, and the rear end portion is joined to the inner wall surface of the side frame 11R. The sector link 22R is rotatably supported on the side frame 11R via the front pipe 13. The gear cover portion 16 is arranged so that the sector link 22R is disposed in a gap formed between the side frame 11R and the gear cover portion 16 in the seat width direction, i.e., so that the gear cover portion 16 is located widthwise inward of the sector link 22R.

[0019] The air conditioning unit 40 includes a blower 41, a blower bracket 42 that attaches the blower 41 to the cushion pan frame 12, and a duct 43 that extends from the blower 41 toward the seating surface and forms an airway that guides air from the blower 41 to the seating surface or from the seating surface to the blower 41. An end portion (supply / exhaust portion) 43S of the duct 43 on the seating surface side is attached to a mounting port formed in the pressure-receiving member 15.

[0020] The configuration of the lifting device 20 will now be described. Fig. 3 is a side view showing the lifting mechanism of the right side frame 11R from the inside. Fig. 4 is a side view showing the lifting mechanism of the left side frame 11L from the inside. As shown in Fig. 3, the lifting device 20 includes a front link 21R having one end rotatably connected to the upper rail bracket 28R by a front support shaft 28Rf, a sector link 22R connected to the other end of the front link 21R by a link connecting shaft 22Rc and connected to the front portion of the side frame 11R via a front pipe (frame connecting shaft) 13, a pinion gear 24 engageable with a sector gear 22Rg formed on the rear surface of the sector link 22R, and a rear link 23R having one end rotatably connected to the upper rail bracket 28R by a rear support shaft 28Rr and the other end connected to the rear portion of the side frame 11R via a rear pipe (rear connecting shaft) 14. In Figure 3, the gear cover portion 16 is indicated by a dashed line for ease of viewing. A stopper pin 22Rs is inserted into an opening provided in the sector link 22R, and when the end of the opening abuts against the stopper pin 22Rs, the rotation of the sector link 22R is restricted. In this way, the rotation range of the sector link 22R is restricted by inserting the stopper pin 22Rs into the opening. The front link 21R is connected so that its front end is located rearward of the front end of the side frame 11R regardless of the position mode of the seat cushion 1. The front link 21L is connected so that its front end is located rearward of the front end of the side frame 11L regardless of the position mode of the seat cushion 1. In addition, the front link 21R and the sector link 22R are connected so that the link connecting shaft 22Rc is positioned above the front pipe 13 regardless of the posture mode of the seat cushion 1, that is, so that the link connecting shaft 22Rc moves above the front pipe 13 in a side view.

[0021] As shown in FIG. 4, the lifting device 20 also includes a front link 21L having one end rotatably connected to the upper rail bracket 28L by a front support shaft 28Lf, a support link 29 connected to the other end of the front link 21L by a link connecting shaft 29c and connected to the front portion of the side frame 11L via a front pipe (frame connecting shaft) 13, a rear link (sector link) 22L having one end rotatably connected to the upper rail bracket 28L by a rear support shaft 28Lr and the other end connected to the rear portion of the side frame 11R via a rear pipe (rear connecting shaft) 14, and a pinion gear 27 engageable with a sector gear 22Rg formed on the front surface of the sector link 22L.

[0022] FIG. 5 is a plan view of the seat cushion frame 10 with the cushion pan frame 12 removed. FIG. 6 is a rear view of the seat cushion frame 10 with the cushion pan frame 12 removed. As shown in FIGS. 5 and 6 , the lifting device 20 further includes a front lifting actuator (hereinafter also simply referred to as the lifting actuator) 25 attached to the outer surface of the front portion of the side frame 11R in the seat width direction, and a rear lifting actuator 26 (hereinafter also simply referred to as the lifting actuator) attached to the outer surface of the rear portion of the side frame 11L in the seat width direction. The lifting actuator 25 incorporates an electric motor and generates a driving force for rotating the pinion gear 24 via the electric motor. Similarly, the lifting actuator 26 incorporates an electric motor and generates a driving force for rotating the pinion gear 27 via the electric motor.

[0023] The lifting / lowering actuators 25, 26 of the lifting device 20 and the slide actuator 34 of the slide device 30 are connected to a controller 60 via a wire harness (not shown) (hereinafter simply referred to as the harness), and the built-in motors are stopped or activated based on control signals from the controller 60 received via the harness. On the other hand, when the controller 60 is provided on the left side of the seat cushion 1 as shown in FIG. 1 , the harness must be routed from the controller 60 to the lifting / lowering actuator 25 provided on the right side of the seat cushion 1, using the space below the seat cushion frame 10. However, routing the harness in this manner may cause the harness to be pulled or bent if the distance between the controller 60 and the lifting / lowering actuator 25 changes due to, for example, the sliding movement of the seat cushion frame 10. Furthermore, the bent harness may interfere with a part of the seat cushion frame 10. One possible way to avoid such an effect on the harness is to route the harness by inserting the front pipe 13 from the controller 60 to the lifting / lowering actuator 25. However, the end of the front pipe 13 may have unwanted protrusions, or burrs, generated during processes such as cutting. Therefore, when a harness is inserted through the front pipe 13, the burrs on the end of the front pipe 13 may cause wear on the surface of the harness or, in some cases, cause the harness to be severed. To address this issue, end caps 13a are attached to the ends (right and left ends) of the front pipe 13, as shown in FIGS. 2A and 2B , to allow the harness to be routed through the front pipe 13. FIG. 7 is a cross-sectional view of the end caps 13a. Attaching the end caps 13a shown in FIG. 7 to the ends of the front pipe 13 prevents the burrs on the end of the front pipe 13 from coming into contact with the harness. This allows the harness to be routed through the front pipe 13 from one side to the other in the seat width direction of the seat cushion frame 10.

[0024] Next, changing the position of the seat cushion 1 by the lifting device 20 will be described with reference to Figures 8A to 8C. Figures 8A to 8C are side views of the side frame 11R as viewed from the inside in the width direction. Note that, for simplicity of explanation, Figures 8A to 8C omit illustration of the cushion pan frame 12 and the gear cover portion 16. The seat 100 can be changed to a number of positions, including a drive mode that places the occupant in a position suitable for driving during normal vehicle operation, a work mode that places the occupant in a position that makes it easy to work during parking or autonomous driving, and a relax mode that tilts the seat back 2 to place the occupant in a position that makes it easy to lie down.

[0025] The lifting device 20 rotates the pinion gears 24, 27 via lifting actuators 25, 26 to change the posture of the seat cushion 1 (hereinafter, sometimes simply referred to as the posture of the seat cushion 1) to correspond to each mode. More specifically, it changes the inclination angle of the seat cushion 1. When the pinion gear 24 rotates, the meshing position between the pinion gear 24 and the sector gear 22Rg changes. This causes the sector link 22R to swing, and in conjunction with this, the front link 21R connected to the sector link 22R rotates about the front support shaft 28Rf. Furthermore, the front link 21L connected to the support link 29, which is journaled via the front pipe (frame connecting shaft) 13 at a position opposite the sector link 22R in the seat width direction, rotates. Furthermore, when the pinion gear 27 rotates, the meshing position between the pinion gear 27 and the sector gear 22Lg changes. This causes the sector link 22L to swing, which in turn causes the rear link 23R, which is rotatably supported via the rear pipe (rear connecting shaft) 14 at a position opposite the sector link 22L in the seat width direction, to rotate. The tilt angle of the sitting surface of the seat cushion 1 is adjusted by the above-mentioned movements of the links 21R, 21L, 22R, 22L, 23R, and 29.

[0026] 8A is a side view of the seat cushion 1 in the drive mode. In the drive mode, the lifting device 20 adjusts the meshing position between the pinion gear 24 and the sector gear 22Rg and the meshing position between the pinion gear 27 and the sector gear 22Lg so that the posture of the seat cushion 1 is approximately horizontal or slopes downward toward the rear as shown in FIG. 8A , more specifically, so that the side frame 11 is approximately parallel to the upper rail 31 of the slide device 30 in a side view. In the drive mode, the upper rail 31 is moved in the front-rear direction relative to the lower rail 32 via the slide actuator 34 to adjust the position (front-rear direction position) of the seat cushion 1 so that the seat occupant can assume a driving posture that makes it easy to operate the steering wheel, accelerator pedal, brake pedal, etc.

[0027] 8B is a side view of the seat cushion 1 in the work mode. In the work mode, the lifting device 20 adjusts the meshing position between the pinion gear 24 and the sector gear 22Rg and the meshing position between the pinion gear 27 and the sector gear 22Lg so that the posture of the seat cushion 1 slopes upward toward the rear as shown in FIG. 8B . More specifically, the height of the front portions of the side frames 11 relative to the upper rails 31 is lower than in the drive mode, and the height of the rear portions of the side frames 11 relative to the upper rails 31 is higher than in the drive mode. In the work mode, the upper rails 31 are moved rearward via the slide actuator 34 relative to the drive mode, thereby adjusting the position (front-rear direction) of the seat cushion 1 so that sufficient space is secured for the feet of the seated occupant. More specifically, when the posture of the seat cushion 1 is in the state shown in FIG. 8B , sufficient space is secured between the legs (thighs) of the seated occupant and the bottom of the vehicle dashboard.

[0028] In the work mode, if the height of the front portion of the side frame 11 relative to the upper rail 31 is lowered, there is a risk of interference between the front end of the blower bracket 42 and the rail connecting member 33 or the screw shaft 35, depending on the positions of the rail connecting member 33 and the screw shaft 35. To avoid such interference, the blower bracket 42 is attached to the cushion pan frame 12 so that, in the work mode, its front end is positioned rearward of the rear end of the rail connecting member 33 in the longitudinal direction, more specifically, in the extension direction of the upper rail 31 (or the lower rail 32). On the other hand, if the blower bracket 42 is positioned rearward to avoid interference between the front end of the blower bracket 42 and the rear end of the rail connecting member 33, there is a risk of interference between the duct 43 and the front pipe 13. Therefore, as shown in FIG. 8B and other figures, the blower bracket 42 has a lower surface (more specifically, a support surface that supports the blower 41) that slopes downward toward the rear. By making the support surface sloped in this manner, a sufficient gap can be provided between the duct 43 and the front pipe 13 in the vertical direction. As a result, it is possible to position the blower bracket 42 rearward of the rear end of the rail connecting member 33 while avoiding interference between the duct 43 and the front pipe 13. Furthermore, as shown in FIG. 8B , in the work mode, the lower end of the duct 43 is positioned lower than the upper ends of the slide rails 31 and 32, so that a portion of the air conditioning unit 40 overlaps the slide rails 31 and 32 in the vertical direction in a side view. However, as shown in FIGS. 5 and 6 , the air conditioning unit 40 is positioned more inward in the width direction than the slide rails 31 and 32, so that the front portion of the side frame 11 can be lowered to the height shown in FIG. 8B without interfering with the air conditioning unit 40 and the slide rails 31 and 32. Note that, as shown in FIG. 8B , it is preferable that the blower bracket 42 be attached to the cushion pan frame 12 so that the link connecting shaft 22Rc is positioned higher than the blower bracket 42 in the work mode.

[0029] 8C is a side view of the seat cushion 1 in the relaxation mode. In the relaxation mode, as shown in FIG. 8C , the posture of the seat cushion 1 is tilted downward at a greater angle toward the rear than in the drive mode. More specifically, the lifting device 20 adjusts the meshing position between the pinion gear 24 and the sector gear 22Rg and the meshing position between the pinion gear 27 and the sector gear 22Lg so that the height of the front portions of the side frames 11 relative to the upper rails 31 is higher than in the drive mode and the height of the rear portions of the side frames 11 relative to the upper rails 31 is lower than in the drive mode. In the relaxation mode, the upper rails 31 are moved rearward via the slide actuator 34 relative to the drive mode to adjust the position (fore-aft direction) of the seat cushion 1 so that sufficient foot space is secured. More specifically, the position (fore-aft direction) of the seat cushion 1 is adjusted so that the knees and feet of the seat occupant do not come into contact with the steering wheel or the lower part of the dashboard when the seat occupant reclines the seat back 2 and lies down.

[0030] As shown in FIGS. 3 and 5 , the sector link 22R is covered by the gear cover 16 in the seat width direction but is not completely covered in the vertical direction. Specifically, a portion of the sector link 22R is exposed above the gear cover 16. This exposed portion may come into contact with the seat cushion pad attached to the seat cushion frame 10. In particular, in the drive mode ( FIG. 8A ) and the relax mode ( FIG. 8C ), the sector gear 22Rg is positioned above the sector link 22R, so a portion of the sector gear 22Rg is exposed. If the sector link 22R oscillates in this state, the sector gear 22Rg may catch on the seat cushion pad. Therefore, a cover member 50 that covers the sector link 22R in the vertical direction is attached to the right portion of the front pipe 13. FIG. 9A is a perspective view of the cover member 50 attached to the front pipe 13. FIG. 9B is a plan view of the cover member 50 attached to the front pipe 13. 9A and 9B , a bearing 51 that engages with the front pipe 13 is formed on the left side of the front part of the cover member 50. When attaching the cover member 50 to the front pipe 13, the bearing 51 is pushed in from above the front pipe 13 so that the bearing 51 engages with the front pipe 13.

[0031] On the other hand, when the cover member 50 is attached, as shown in FIG. 9B , the distance between the cover member 50 and the front wing portion 15Rf on the right side of the pressure-receiving member 15 in the seat width direction becomes shorter, and if the pressure-receiving member 15 is displaced in the seat width direction, there is a risk of interference between the cover member 50 and the front wing portion 15Rf. To avoid such interference, as shown in FIG. 9B , a step portion (cutout portion) CT is formed in the front portion of the front wing portion 15Rf. Note that the step portion CT is not limited to the shape shown in FIG. 9B and may have other shapes. For example, if another cover member having a different shape from the cover member 50 is attached instead of the cover member 50, the step portion CT may be formed to match the planar shape of the exterior portion of that cover member.

[0032] The above-described embodiment provides the following advantageous effects. (1) The seat 100 according to this embodiment includes a seat cushion 1 that supports the buttocks of an occupant and a lifting / lowering device 20 that changes the tilt angle of the seat cushion 1's seat surface. The lifting / lowering device 20 is configured to change the tilt angle so that the seat cushion 1's seat surface is switched between a first position (the position shown in FIG. 8A ) that is substantially horizontal or slopes downward toward the rear, and a second position (the position shown in FIG. 8B ) that slopes upward toward the rear. The seat cushion 1 includes a seat cushion frame 10 that moves together with the seat surface. The lifting / lowering device 20 includes a first support portion (front link 21L, front link 21R, and sector link 22R) that supports the front end of the seat cushion frame 10 so that it can be raised and lowered, and a second support portion (rear links 22L, 23R) that supports the rear end of the seat cushion frame 10 so that it can be raised and lowered. The first support portion supports the front end of the seat cushion frame 10 so that the height of the front end of the seat cushion frame 10 can be changed between a first front end height (the height of the front end of the side frame 11R in FIG. 8A ) corresponding to the first position and a second front end height (the height of the front end of the side frame 11R in FIG. 8B ) lower than the first front end height. The second support portion supports the rear end of the seat cushion frame 10 so that the height of the rear end of the seat cushion frame 10 can be changed between a first rear end height (the height of the rear end of the side frame 11R in FIG. 8A ) corresponding to the first position and a second rear end height (the height of the rear end of the side frame 11R in FIG. 8B ) higher than the first rear end height. This configuration allows the position of the seat cushion's sitting surface to be changed so that the occupant can work in a forward-leaning position without being cramped.

[0033] (2) The first support portion further supports the front end of the seat cushion frame 10 so that the height of the front end of the seat cushion frame 10 can be changed to a third front end height (the height of the front end of the side frame 11R in FIG. 8C ) that is higher than the first front end height. The second support portion further supports the rear end of the seat cushion frame 10 so that the height of the rear end of the seat cushion frame 10 can be changed to a third rear end height (the height of the rear end of the side frame 11R in FIG. 8C ) that is lower than the first rear end height. The lifting device 20 is configured to change the tilt angle so that the position of the seat cushion 1's seat surface can be switched between a first position, a second position, and a third position (the position in FIG. 8C ) that slopes downward toward the rear at a tilt angle greater than the tilt angle in the first position. This configuration allows the occupant to not only work but also take a nap or lie down to rest while the vehicle is parked or during autonomous driving.

[0034] (3) The seat 100 further includes upper rail brackets 28L, 28R as support members that support the seat cushion frame 10. The first support portion includes a front link 21R as a first link whose front end is connected to a front portion of the upper rail bracket 28R and which is rotatable in the vertical direction relative to the connection portion with the upper rail bracket 28R, and a sector link 22R as a second link which is connected to a rear end of the front link 21R and to the front portion of the seat cushion frame 10 and which is rotatable in the vertical direction about a connection portion with the seat cushion frame 10 (link connection shaft 22Rc in FIG. 3 ). When the front link 21R rotates relative to the connection portion with the upper rail bracket 28R, the front end of the front link 21R is positioned rearward of the front end of the seat cushion frame 10. The lifting device 20 further has a pinion gear 24 as a first pinion gear that rotates about a rotation axis along the seat width direction, and the sector link 22R has a sector gear 22Rg formed on a part of its outer circumferential surface that engages with the pinion gear 24 so as to be rotatable in conjunction with the rotation of the pinion gear 24. The front link 21R and the sector link 22R are arranged so that the connection between the front link 21R and the sector link 22R moves above the connection between the sector link 22R and the seat cushion frame 10 (front pipe (frame connection shaft) 13 in FIG. 3). This makes it possible to realize a seat cushion (seat cushion frame) with a compact configuration that allows the position of the seat cushion to be changed using the link.

[0035] (4) The upper rail brackets 28L, 28R include a slide device 30 that moves the seat cushion frame 10 in the fore-and-aft direction. The seat cushion frame 10 has a pair of left and right side frames 11L, 11R extending in the fore-and-aft direction. The slide device 30 includes a pair of left and right upper rails 31L, 31R corresponding to the pair of left and right side frames 11L, 11R, and a pair of left and right lower rails 32L, 32R that support the pair of left and right upper rails 31L, 31R so that they can move in the fore-and-aft direction. The lifting device 20 includes a pair of left and right first support portions that support front ends of the pair of left and right side frames 11L, 11R, and a pair of left and right second support portions that support rear ends of the pair of left and right side frames. Each of the pair of left and right first support portions includes a pair of left and right first links (front link 21L and front link 21R) whose front ends are connected to the front portions of the pair of left and right upper rails 31L, 31R, and a pair of left and right second links (support link 29 and sector link 22R) that are connected to the rear ends of the pair of left and right first links and connect the pair of left and right first links to the front portions of the pair of left and right side frames 11L, 11R. A sector gear is formed on one of the pair of left and right second links (sector link 22R), and a pinion gear 24 is provided on the front portion of the side frame 11R of the pair of left and right side frames 11L, 11R that corresponds to the second link (sector link 22R) on which the sector gear is formed. Furthermore, the lifting device 20 further includes a pinion gear 27 as a second pinion gear that rotates about a rotation axis along the seat width direction, at a rear portion of the side frame 11L that is not provided with the pinion gear 24 out of the pair of left and right side frames 11L, 11R. Each of the pair of left and right second support portions has a pair of left and right third links (sector link 22L and rear link 23R) whose front ends are connected to rear portions of the pair of left and right upper rails 31L, 31R and whose rear ends are connected to rear portions of the pair of left and right side frames 11L, 11R.Of the pair of left and right third links, the third link (sector link 22L) connected to the side frame 11L on which the pinion gear 27 is provided has a sector gear formed on part of its outer surface that engages with the pinion gear 27 so that the third link rotates up and down relative to the connection portion (rear pipe (rear connecting shaft) 14) with the side frame 11L in conjunction with the rotation of the pinion gear 27. In this way, by arranging the sector links 22L, 22R diagonally on the seat cushion frame 10 that is generally rectangular in plan view, it is possible to prevent uneven load on the seat cushion frame 10 from being applied by the lifting actuators 25, 26 that drive the sector links 22L, 22R, and to suppress distortion of the seat cushion frame 10.

[0036] The above-described embodiment can be modified in various ways. Modifications will be described below. In the above-described embodiment, an example has been shown in which the front end of the seat cushion frame 10 has three height levels (first front end height ( FIG. 8A ), second front end height ( FIG. 8B ), and third front end height ( FIG. 8C )). Also, an example has been shown in which the rear end of the seat cushion frame 10 has three height levels (first rear end height ( FIG. 8A ), second rear end height ( FIG. 8B ), and third rear end height ( FIG. 8C )). However, the heights of the front and rear ends of the seat cushion frame 10 may be changed in a number of levels other than three, for example, more than three. That is, the sitting surface of the seat cushion 1 may be switchable to a posture mode other than the three posture modes shown in FIGS. 8A to 8C .

[0037] In the above embodiment, the driving force for rotating the pinion gears 24, 27 is generated by the electric motors of the lifting actuators 25, 26. However, the pinion gears 24, 27 may be rotated by manual operation using an operating lever or dial provided on the side of the seat 100. That is, the occupant (seat occupant) may operate the operating lever or dial to change the position of the seat cushion 1. In the above embodiment, the electric motor of the slide actuator 34 generates driving force for rotating the screw shaft 35 to slide the upper rail 31 relative to the lower rail 32. However, the upper rail 31 may be manually slidable relative to the lower rail 32. For example, the seat 100 may be configured to slide the upper rail 31 relative to the lower rail 32 by operating a slide operating lever (not shown) extending left and right provided below the front portion of the seat 100. Furthermore, in the above embodiment, the rail connecting member 33 connects the front ends of the lower rails 32L, 32R, but the rail connecting member may connect the rear ends of the lower rails 32L, 32R. That is, the rail connecting member, the slide actuator, the screw shaft, and the shaft support member may be disposed at the rear ends of the lower rails 32L, 32R.

[0038] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications, as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other.

[0039] 1 seat cushion, 2 seat back, 3 headrest, 4 reclining mechanism, 10 seat cushion frame, 11L, 11R side frame, 13 front pipe, 14 rear pipe, 21L, 21R front link, 22R sector link, 22L, 23R rear link, 28L, 28R upper rail bracket, 31R, 31L upper rail, 32R, 32L lower rail, 25, 26 lifting actuator, 34 slide actuator, 60 controller, 100 seat

Claims

1. A vehicle seat comprising: a seat cushion that supports the buttocks of an occupant; and a change device that changes the inclination angle of the seating surface of the seat cushion, wherein the change device is configured to change the inclination angle so that the position of the seating surface can be switched between a first position in which it is substantially horizontal or has a downward slope toward the rear, and a second position in which it has an upward slope toward the rear.

2. A vehicle seat as described in claim 1, wherein the seat cushion has a seat cushion frame that is movable together with the seat surface, and the changing device has a first support portion that supports a front end portion of the seat cushion frame so that it can be raised and lowered, and a second support portion that supports a rear end portion of the seat cushion frame so that it can be raised and lowered.

3. A vehicle seat as described in claim 2, wherein the first support portion supports a front end of the seat cushion frame so that the height of the front end of the seat cushion frame is changeable between a first front end height corresponding to the first position and a second front end height lower than the first front end height, and the second support portion supports the rear end of the seat cushion frame so that the height of the rear end of the seat cushion frame is changeable between a first rear end height corresponding to the first position and a second rear end height higher than the first rear end height.

4. A vehicle seat as claimed in claim 2 or 3, wherein the first support portion further supports a front end of the seat cushion frame so that the height of the front end of the seat cushion frame can be changed to a third front end height higher than the first front end height; the second support portion further supports a rear end of the seat cushion frame so that the height of the rear end of the seat cushion frame can be changed to a third rear end height lower than the first rear end height; the change device is configured to be able to change the inclination angle so that the posture of the seat surface can be switched between the first posture, the second posture, and a third posture which slopes downward towards the rear; and the inclination angle in the third posture is greater than the inclination angle in the first posture.

5. A vehicle seat as described in any one of claims 2 to 4, further comprising a support member supporting the seat cushion frame, wherein the first support portion has a first link whose front end is connected to a front portion of the support member and is rotatable in the vertical direction relative to the connection portion with the support member, and a second link which is connected to the rear end of the first link and to the front portion of the seat cushion frame and is rotatable in the vertical direction around the connection portion with the seat cushion frame, wherein the front end of the first link is positioned rearward of the front end of the seat cushion frame when the first link rotates relative to the connection portion with the support member.

6. A vehicle seat as described in claim 5, characterized in that the first link and the second link are arranged so that the connection between the first link and the second link moves above the connection between the second link and the seat cushion frame.

7. A vehicle seat as described in claim 5 or 6, wherein the change device further has a pinion gear that rotates around a rotation axis along the seat width direction, and the second link has a sector gear formed on part of its outer circumferential surface that engages with the pinion gear so as to be rotatable in conjunction with the rotation of the pinion gear.

8. A vehicle seat as claimed in claim 7, wherein the support member is provided with a slide mechanism for moving the seat cushion frame in the front-rear direction, the seat cushion frame has a pair of left and right side frames extending in the front-rear direction, the slide mechanism has a pair of left and right upper rails corresponding to the pair of left and right side frames, and a pair of left and right lower rails supporting the pair of left and right upper rails so as to be movable in the front-rear direction, the change device has a pair of left and right first support parts supporting front ends of the pair of left and right side frames, and a pair of left and right second support parts supporting rear ends of the pair of left and right side frames, each of the pair of left and right first support parts having a pair of left and right first links whose front ends are connected to front parts of the pair of left and right upper rails, and a pair of left and right second links which are connected to the rear ends of the pair of left and right first links and connect the pair of left and right first links to front parts of the pair of left and right side frames, the sector gear is formed on one of the second links of the pair of left and right second links, The vehicle seat, wherein the pinion gear is provided at a front portion of one of the pair of left and right side frames that corresponds to the second link on which the sector gear is formed.

9. A vehicle seat as claimed in claim 7 or 8, wherein the pinion gear is a first pinion gear, and the changing device further has a second pinion gear which rotates around a rotation axis along the seat width direction, at a rear portion of the one of the pair of left and right side frames on which the first pinion gear is not provided, and each of the pair of left and right second support parts has a pair of left and right third links whose front ends are connected to the rear portions of the pair of left and right upper rails and whose rear ends are connected to the rear portions of the pair of left and right side frames, and a sector gear which engages with the second pinion gear is formed on a portion of the outer circumferential surface of one of the pair of left and right third links which is connected to the side frame on which the second pinion gear is provided, so that the third link rotates up and down relative to the connection portion with the side frame in conjunction with the rotation of the second pinion gear.

Images