JP7505418B2 - Vehicle occupant restraint device - Google Patents

Description

The present invention relates to a vehicle occupant restraint device.

Patent Document 1 describes a device that protects an occupant by inflating and deploying an airbag stored in the seat cushion or footrest (ottoman) of a vehicle seat during a frontal collision, thereby catching the lower body (lower back and lower legs) of the occupant attempting to move forward. In other words, it describes how the device protects the seated occupant by preventing the so-called submarine phenomenon, in which the lower body of a seated occupant wearing a seat belt moves forward during a frontal collision, even if the vehicle seat is in a comfortable position.

Patent document 2 also describes a vehicle occupant protection device that restrains the toes of an occupant seated in a vehicle seat by deploying an airbag stored in an ottoman of the vehicle seat.

JP 2020-1681 A JP 2020-69816 A

In the device described in Patent Document 1 and the vehicle occupant protection device described in Patent Document 2, in order to protect an occupant seated in a comfortable position in a vehicle seat during a frontal collision of the vehicle, it is necessary to increase the internal pressure of the airbag and/or increase the strength and rigidity of the fixing member (such as an ottoman) that supports the airbag.

In addition, because airbags use explosives to inflate and deploy, it is difficult to return them to their pre-deployment state in the event of a malfunction.

In consideration of the above, the present invention aims to provide a vehicle occupant restraint device that stably protects occupants and can return to its pre-activation state after activation.

The vehicle occupant restraint device according to claim 1 includes a seat cushion that supports the lumbar region of an occupant, a seat back that is supported by a reclining shaft that is provided on the rear side of the seat cushion and extends in the seat width direction and is configured to be tiltable about the reclining shaft and supports the back of the occupant, an ottoman that is provided on the front side of the seat cushion and supports the lower legs of the occupant, a seat adjustment device that can change the position of the vehicle seat including the seat cushion, the seat back, the ottoman, etc., and a restraint member that is provided along the outer periphery of the ottoman and is supported by a reclining shaft that is provided on the rear side of the ottoman and extends in the seat width direction. The lower leg restraint device is supported at both ends by a rotation shaft, is rotatable around the rotation shaft, and is displaceable between a storage position parallel to the ottoman in a side view of the seat, a rotation position rotated around the rotation shaft in a direction substantially perpendicular to the ottoman, and a restraint position approaching the ottoman from the rotation position and at a predetermined distance from the occupant's lower legs. When the seat back is tilted back at least at a predetermined angle to a comfortable position or a lying position, the restraint member is displaced from the storage position to the restraint position via the rotation position, and the vehicle seat is changed to the comfortable position or the lying position by the seat adjustment device.

In this vehicle occupant restraint device, when the vehicle seat is placed in at least the comfortable or reclining position, the restraint member of the restraint device rotates about a rotation axis from a storage position parallel to the ottoman in a side view of the vehicle to a rotation position substantially perpendicular to the ottoman. As a result, the occupant's lower legs are positioned between the restraint member of the restraint device and the ottoman.

In this state, the restraint member is moved closer to the ottoman and displaced to the restraining position, setting the restraint member at an appropriate distance from the lower legs of the seated occupant and restraining the occupant's lower legs.

This vehicle occupant restraint device restrains the occupant's lower limbs as described above, and the vehicle seat can be adjusted to a comfortable or reclining position using the seat adjustment device.

Therefore, even if the vehicle crashes head-on when the vehicle seat is in a comfortable or reclining position, the lower limbs of the occupant seated in the vehicle seat are restrained by the restraining member, so a reaction force is input from the lower limbs to the pelvis of the seated occupant, preventing or suppressing the so-called "submarine phenomenon" in which the pelvis of the seated occupant moves downward toward the front of the vehicle during a frontal collision.

In addition, unlike restraint devices that use explosives or airbags, this restraint device only displaces the restraint member, so it can return to its initial (storage) position. In other words, it can be used repeatedly.

As described above, the vehicle occupant restraint device of the present invention provides stable protection for the occupant and can return to its pre-activation state after activation.

1 is a side view showing a state in a normal mode of a vehicle occupant restraint device according to an embodiment; 1A and 1B are diagrams showing a restraint device according to one embodiment in a stored state, in which FIG. 1 is a block diagram showing a hardware configuration of a vehicle occupant restraint device according to an embodiment; 2 is a block diagram showing a hardware configuration of a restraint ECU according to an embodiment; 2 is a block diagram showing a functional configuration of a restraint ECU according to an embodiment; 1 is a side view showing a use position of an ottoman and a storage position of a restraint device in a vehicle occupant restraint device according to an embodiment of the present invention. 2 is a side view showing a use position of an ottoman and an extended position of a restraining member of a vehicle occupant restraint device according to an embodiment of the present invention; FIG. 4 is a side view showing a use position of an ottoman and a rotation position of a restraint member of a vehicle occupant restraint device according to one embodiment. FIG. 1A and 1B are side views of a lower limb restraint device according to one embodiment, in which FIG. 1A shows a rotated position of a restraint member, and FIG. 1 is a side view showing a use position of an ottoman of a vehicle occupant restraint device according to one embodiment, and a restraining (sliding) state of a restraining member; 11 is an enlarged cross-sectional view of line AA in FIG. 10. 1 is a side view showing a comfortable position of a vehicle seat according to an embodiment; 1A is a diagram showing the behavior of the pelvis of a seated occupant during a frontal collision in a comparative example, and FIG. 1B is a diagram showing the pelvis of a seated occupant during a frontal collision in this embodiment.

A vehicle occupant restraint device according to one embodiment will be described with reference to Figures 1 to 13. In each figure, the front of the seat is the front of the vehicle, the sides of the seat are the same as the vehicle width direction, and the top of the seat is the same as the vehicle top, so these will be uniformly described as the front of the vehicle, the vehicle width direction, and the vehicle top, respectively. In each figure, the front of the vehicle is indicated by the arrow FR, the vehicle width direction is indicated by the arrow W, and the top of the vehicle is indicated by the arrow UP.

First, the vehicle seat 12 to which the vehicle occupant restraint device 10 is applied will be described with reference to FIG. 1.

As described above, the vehicle seat 12 is positioned within the vehicle cabin so that the front of the seat is aligned with the front of the vehicle, the sides of the seat are aligned with the vehicle width direction, and the top of the seat is aligned with the top of the vehicle.

As shown in FIG. 1, the vehicle seat 12 has a base 18 disposed on a seat rail 16 disposed on the floor 14 of the vehicle compartment, and a seat cushion 20 provided on the base 18.

A reclining shaft 22 extending in the vehicle width direction is provided on the rear side of the seat cushion 20. The seat back 24 is supported by the reclining shaft 22 and can tilt relative to the seat cushion 20 around the reclining shaft 22.

A headrest 26 is provided above the seat back 24 to support the head of the seated occupant P.

An ottoman shaft 28 extending in the vehicle width direction is provided on the front side of the seat cushion 20. An ottoman 30 is supported by the ottoman shaft 28 and is rotatable relative to the seat cushion 20 around the ottoman shaft 28. This allows the ottoman 30 to rotate (switch) between a storage position (see FIG. 1) and a use position (see FIG. 6), which will be described later.

As shown in Fig. 1, Fig. 2(A) and Fig. 2(B), a lower leg restraint device 32 is provided on the ottoman 30. The configuration of the lower leg restraint device 32 will be described later.

The vehicle seat 12 is an electrically operated so-called "power seat," and has a seat slide motor 40, a reclining motor 42, and an ottoman motor 44 (not shown in FIG. 1, etc.) as shown in FIG. 3.

In other words, when the seat slide motor 40 is driven, the base 18 moves on the seat rails 16 in the fore-and-aft direction of the vehicle.

When the reclining motor 42 is driven, the seat back 24 tilts around the reclining shaft 22 relative to the seat cushion 20 (changing the rearward tilt angle of the seat back 24).

Furthermore, when the ottoman motor 44 (see FIG. 2B) is driven, the ottoman 30 rotates about the ottoman shaft 28, and the tip of the ottoman 30 is configured to be rotatable from a storage position (see FIG. 1) in which the tip faces downwards of the vehicle to a use position (see FIG. 6) in which the tip faces substantially forwards of the vehicle.

Note that Figure 2(A) and Figure 2(B) show the ottoman 30 when viewed from the side of the vehicle in the state shown in Figure 6, and Figure 2(B) shows the ottoman 30 when viewed from a direction perpendicular to the extension direction.

The seat slide motor 40, reclining motor 42, and ottoman motor 44 correspond to the "seat adjustment device."

As shown in Figures 2(A) and 2(B), the above-mentioned lower leg restraint device 32 has a restraint member 50 that restrains the lower legs of a seated occupant, a pair of sliders 52 that support the restraint member 50 and slide the restraint member 50 toward and away from the ottoman 30, and a pair of guide members 54 that guide the restraint member 50 when sliding.

As shown in FIG. 2B, the restraining member 50 has an arc portion 56 that extends in the vehicle width direction on the vehicle front side of the ottoman 30 in a plan view, and a pair of support portions 58 that extend from both ends of the arc portion 56 along the ottoman 30 on the vehicle width outer side of the ottoman 30.

The pair of support parts 58 are supported by slide members 62 of the slider 52, which will be described later.

The pair of sliders 52 are provided on the vehicle rear side of the ottoman 30 on the vehicle width outer side and below the vehicle, and are supported on both ends of a slider shaft 60 that is provided below the ottoman 30 and extends in the vehicle width direction.

The slider shaft 60 corresponds to the "rotation shaft."

As shown in Figures 2(A) and 2(B), each slider 52 is generally rectangular and is arranged so that its longitudinal direction is aligned with the vehicle width direction side (extension direction) of the ottoman 30 when the lower leg restraint device 32 is in the stored position. Inside the slider 52, a slide member 62 is arranged so as to be movable in the longitudinal direction, for example, by a rack and pinion. The slide member 62 slides longitudinally inside the slider 52 when driven by a slide motor 64 provided at the end of the slider 52. This allows the restraint member 50 supported by the slide member 62 to be displaced longitudinally.

The slide motor 64 is equipped with a load sensor 72 that can detect when the restraint member 50 comes into contact with the lower legs of the seated occupant P.

As shown in Figures 2(A) and 2(B), the guide member 54 is a plate that is fixed to the slider 52 and has a pair of parallel elongated holes 66 that extend in the longitudinal direction of the slider 52.

A pair of pins 68 provided on the support portion 58 of the restraining member 50 are inserted into the pair of long holes 66, respectively. Therefore, when the restraining member 50 supported by the sliding member 62 slides, the pins 68 move within the long holes 66, thereby guiding the restraining member 50.

In addition, the lower leg restraint device 32 has a rotary motor 70 disposed on the slider shaft 60. Therefore, when the rotary motor 70 is driven, the lower leg restraint device 32 (the slider 52 and the restraint member 50 and guide member 54 supported by the slider 52) rotates around the slider shaft 60 relative to the ottoman 30.

Furthermore, as shown in FIG. 1, there is an interior camera 80 on the upper side of the vehicle on the front side of the vehicle cabin that captures images of the interior of the cabin.

Also provided within the vehicle cabin are a speaker 82 that issues warnings and the like, which will be described later, a display unit 84 that displays warnings and the like, and a mode selection switch 86 that selects a mode, which will be described later (see FIG. 3, respectively; not shown in FIG. 1, etc.).

The "mode" refers to a mode for selecting the posture of the vehicle seat 12. The "comfortable mode" is a mode for putting the vehicle seat 12 into a comfortable posture, in which the rearward tilt angle of the seat back 24 is at least greater than a predetermined angle, for example, 40 degrees. The "sleep mode" is a mode for putting the vehicle seat 12 into a lying position, in which the rearward tilt angle of the seat back 24 is at least greater than the comfortable posture.

The speaker 82 and the display unit 84 correspond to the "alert unit."

Next, the control configuration of the vehicle occupant restraint device 10 will be described with reference to Figures 3 to 5.

As shown in FIG. 3, the vehicle occupant restraint device 10 has a seat ECU 100, a restraint ECU 110, and a control ECU 120, and the seat ECU 100, the restraint ECU 110, and the control ECU 120 are interconnected by a bus 130.

The seat ECU 100 corresponds to the "seat adjustment device."

The seat ECU 100 is connected to the seat slide motor 40, the reclining motor 42, and the ottoman motor 44, and controls the drive of each motor based on control signals input from the control ECU 120 to control the vehicle seat 12 to a specified position.

The restraint ECU 110 is connected to a rotary motor 70, a slide motor 64, a load sensor 72, an in-vehicle camera 80, a speaker 82, and a display unit 84, and controls the operation of the lower leg restraint device 32 based on a control signal input from the control ECU 120 to restrain the lower legs of an occupant seated in the vehicle seat 12.

The control ECU 120 is connected to a mode selection switch 86, and outputs control signals to the seat ECU 100 and the restraint ECU 110 based on a mode selection signal from the mode selection switch 86, thereby controlling the posture of the vehicle seat 12 and the lower limb restraint device 32.

As shown in FIG. 4, the restraint ECU 110 includes a CPU (Central Processing Unit) 110A, a ROM (Read only Memory) 110B, a RAM (Random Access Memory) 110C, a storage 110D, and an input/output I/F 110F. The CPU 110A, the ROM 110B, the RAM 110C, the storage 110D, and the input/output I/F 110F are connected to each other so as to be able to communicate with each other via a bus 110G.

The CPU 110A is a central processing unit that executes various programs and controls each part. That is, the CPU 110A reads the programs from the ROM 110B and executes the programs using the RAM 110C as a working area. In this embodiment, the execution programs are stored in the ROM 110B.

ROM 110B stores various programs and data. RAM 110C temporarily stores programs or data as a working area.

The input/output I/F 110F is an interface for communicating with the seat ECU 100, the control ECU 120, etc. via the bus 130. The restraint ECU 110 is connected to the seat ECU 100, the control ECU 120, etc. from the input/output I/F 110F via the bus 130.

The seat ECU 100 and the control ECU 120 have substantially the same configuration as the restraint ECU 110, so detailed explanations will be omitted. When explaining the CPUs of the seat ECU 100 and the control ECU 120, the same reference characters "A" to "F" will be added to the reference numbers "100" and "120" respectively (see FIG. 4).

Figure 5 is a block diagram showing an example of the functional configuration of the restraint ECU 110. The restraint ECU 110 has a mode signal acquisition unit 200, a rotation end signal acquisition unit 202, a rotation control unit 204, a slide control unit 206, an image acquisition unit 208, a restraint determination unit 210, an permission signal generation unit 212, and a warning signal generation unit 214. Each functional configuration is realized by the CPU 110A reading out and executing an execution program stored in the ROM 110B or storage 110D.

The mode signal acquisition unit 200 acquires the mode (selection) signal output from the control ECU 120.

The rotation end signal acquisition unit 202 acquires a rotation end signal from the seat ECU 100, which indicates that the ottoman 30 has been rotated from the storage position to the use position.

When the mode acquired by the mode signal acquisition unit 200 is the comfort mode or the sleep mode, the rotation control unit 204 detects that the restraint member 50 has been extended and outputs a drive signal to the rotation motor 70 to move the restraint member 50 from the stored position to the rotation position.

When the slide control unit 206 detects the rotation end signal, it outputs a drive signal to the slide motor 64 to displace the restraint member 50 to an extended position, which will be described later. In addition, after the restraint member 50 moves to the rotation position, the slide control unit 206 outputs a drive signal to the slide motor 64 to displace the restraint member 50 to a restraint position on the ottoman side to restrain the lower limbs of the seated occupant P.

The image acquisition unit 208 acquires image data captured by the in-vehicle camera 80 after the restraint member 50 reaches the restraint position.

The restraint determination unit 210 determines whether the restraint member 50 is restraining the lower limbs of the seated occupant from the acquired captured image.

The permission signal generating unit 212 generates a permission signal and outputs it to the seat ECU 100 when the restraint determining unit 210 determines that the restraint member 50 is restraining the lower limbs of the seated occupant. This permission signal causes the seat ECU 100 to output a drive signal to the reclining motor 42, causing the seat back 24 to tilt backward to an angle corresponding to a comfortable position or a lying position.

The warning signal generating unit 214 generates a warning signal and outputs it to the speaker 82 and the display unit 84 when the restraint determining unit 210 determines that the restraint member 50 is not restraining the lower limbs of the seated occupant. This warning signal causes a warning message or a warning sound to be played from the speaker 82 in the vehicle cabin, and also causes a warning message to be displayed on the display unit 84.

(Action)
The vehicle occupant restraint device 10 configured as above is initially in a stored state with the tip of the ottoman 30 facing downward toward the vehicle, as shown in Fig. 1. The restraint member 50 of the lower leg restraint device 32 is also in a stored state parallel to the ottoman 30.

In this state, when the occupant operates the mode selection switch 86 provided on a dash panel or the like (not shown) to select the comfort mode, the control ECU 120 outputs a comfort mode signal to the seat ECU 100 and the restraint ECU 110.

When the comfort mode signal is input, the seat ECU 100 controls the posture of the vehicle seat 12 so that it is in a comfortable position. However, the rearward tilting movement of the seat back 24 is suspended until restraint confirmation, which will be described later, is performed.

Specifically, as shown in FIG. 3, the CPU 100A of the seat ECU 100 outputs a drive signal to the seat slide motor 40 to move the base 18, i.e., the vehicle seat 12, toward the rear of the vehicle on the seat rails 16.

This ensures space for rotating the ottoman 30 to its in-use position, and also ensures space for the seated occupant P to stretch his/her legs.

The CPU 100A of the seat ECU 100 outputs a drive signal to the ottoman motor 44 as shown in FIG. 3, whereby the ottoman 30 rotates about the ottoman shaft 28 and displaces to the use position as shown in FIG. 6, supporting the lower legs of the seated occupant P. At this time, the lower leg restraint device 32 supported by the ottoman 30 also rotates toward the front of the vehicle together with the ottoman 30.

When the ottoman 30 reaches the use position and the drive of the ottoman motor 44 is stopped, a rotation end signal is output from the seat ECU 100 to the restraint ECU 110.

Meanwhile, the CPU 110A of the restraint ECU 110 acquires the comfort mode signal input from the control ECU 120 at the mode signal acquisition unit 200, and acquires the rotation end signal input from the seat ECU 100 at the rotation end signal acquisition unit 202. That is, the CPU 110A of the restraint ECU 110 determines that a lower limb restraint operation of the seated occupant P is necessary upon acquisition of the comfort mode signal, and determines acquisition of the rotation end signal as the timing for starting the lower limb restraint operation.

As a result, the CPU 110A of the restraint ECU 110 outputs a drive signal to the slide motor 64 via the slide control unit 206.

As a result, as shown in FIG. 7, the slider 52 is driven and the restraining member 50 moves in a direction away from the ottoman 30. At this time, the pin 68 attached to the restraining member 50 moves within the long hole 66 of the guide member 54, thereby guiding the restraining member 50 in a predetermined direction.

When the pin 68 reaches the end (top left end in FIG. 7) of the long hole 66 of the guide member 54, i.e., when the restraint member 50 is in an extended state in which it is farthest from the ottoman 30, the CPU 110A of the restraint ECU 110 outputs a drive signal to the rotation motor 70 via the rotation control unit 204.

As a result, the lower-leg restraint device 32 rotates about the slider shaft 60 to a position (rotation position) that is approximately perpendicular to the ottoman 30, as shown in FIG. 8. At this time, because the restraint member 50 is extended as described above, the lower-leg restraint device 32 can rotate without interfering with the lower legs (toes, etc.) of the seated occupant P supported by the ottoman 30 (see the two-dot chain arrow in FIG. 7).

When the drive of the rotary motor 70 is stopped, the CPU 110A of the restraint ECU 110 outputs a drive signal to the slide motor 64 again in the slide control unit 206. This causes the restraint member 50 supported by the slider 52 to move toward the ottoman 30. That is, the pin 68 inserted into the long hole 66 of the guide member 54 moves from one end side of the long hole 66 (see FIG. 9(A)) to the other end side (see FIG. 9(B)).

As a result, as shown in FIG. 10, the restraint member 50 moves (descends) toward the ottoman 30, and the arc portion 56 of the restraint member 50 comes into contact with the lower leg PL of the seated occupant P, causing the load sensor 72 to detect the load. When the restraint ECU 110 acquires this detection signal, the CPU 110A of the restraint ECU 110 outputs a drive signal for reverse rotation to the slide motor 64 via the slide control unit 206.

As a result, as shown in FIG. 11, the slide motor 64 rotates in the reverse direction, and the restraint member 50 moves approximately 10 mm away from the lower legs PL of the seated occupant P.

Next, when the CPU 110A of the restraint ECU 110 detects that the slide motor 64 has stopped rotating in reverse, the CPU's image acquisition unit 208 acquires image data captured by the in-vehicle camera 80. The CPU 110A of the restraint ECU 110 then uses the restraint determination unit 210 to determine whether or not the restraint member 50 is restraining the lower limbs of the seated occupant P based on the acquired captured image.

When the restraint determination unit 210 of the CPU 110A of the restraint ECU 110 determines that the lower limbs of the seated occupant P are restrained, the permission signal generation unit 212 generates a permission signal and outputs it to the seat ECU 100.

In response to receiving the permission signal, the seat ECU 100 outputs a drive signal to the reclining motor 42, and the seat back 24 is tilted backward to a rearward angle corresponding to the comfort mode (comfortable position), as shown in FIG. 12.

On the other hand, when the restraint determination unit 210 determines that the lower limbs are not restrained, the CPU 110A of the restraint ECU 110 generates a warning signal in the warning signal generation unit 214 and outputs the warning signal to the speaker 82 and the display unit 84. As a result, a warning message or an alarm sound is played from the speaker 82. Also, a warning message is displayed on the display unit 84.

It is believed that when the seated occupant P receives this warning, the seated occupant P will move his/her lower legs toward the lower part of the vehicle below the restraint member 50 of the lower leg restraint device 32, thereby correcting the posture of the seated occupant P.

In this way, when the comfort mode is selected for the seated occupant P, the lower limbs of the seated occupant P are restrained by the lower limb restraint device 32, and the vehicle seat 12 is placed in a comfort position.

Note that while the above explanation is for the case where the comfort mode is selected, the same applies to the sleep mode (lying position in the vehicle seat 12).

If the vehicle experiences a frontal collision in this state, even if the seated occupant P seated in the vehicle seat 12 is wearing a seat belt 90 (see FIG. 12), the lumbar region (pelvis 92) of the seated occupant P may move along the seating surface of the seat cushion 20 toward the front of the vehicle (from pelvis 92A to pelvis 92B), a phenomenon known as submarine motion (see FIG. 13(A)).

However, in the vehicle occupant restraint device 10, the lower limb restraint device 32 (restraint member 50) restrains the lower limbs of the seated occupant P, so that a reaction force F1 acts on the pelvis 92 from the lower limbs, and a rotational moment M acts to tilt the pelvis 92 forward, preventing or suppressing the pelvis 92 from tilting backward (see FIG. 13(B)). In other words, the submarine phenomenon can be prevented or suppressed.

In this way, when at least the comfort mode or sleep mode is selected, the vehicle occupant restraint device 10 restrains the lower limbs of the seated occupant P with the lower limb restraint device 32, and then tilts the seat back 24 of the vehicle seat 12 backward to assume a position corresponding to each mode, thereby preventing or suppressing the submarine phenomenon from occurring to the seated occupant P in the vehicle seat 12 during a frontal collision.

In addition, in the vehicle occupant restraint device 10, when the comfort mode or sleep mode is selected, the CPU 110A of the restraint ECU 110 is configured not to input an authorization signal to the seat ECU 100 unless the restraint determination unit 210 confirms that the lower limbs of the seated occupant are restrained by the lower limb restraint device 32, i.e., the seat back 24 of the vehicle seat 12 is not tilted backward by a predetermined angle, for example, 40 degrees or more. Therefore, the seated occupant P in the vehicle seat 12 in the comfort or sleeping position with the lower limbs of the seated occupant P not restrained by the lower limb restraint device 32 is prevented or suppressed from experiencing the submarine phenomenon in a frontal collision of the vehicle.

Conversely, when the comfort mode or sleep mode is not selected, the lower limbs of the seated occupant P are not restrained by the restraining member 50 of the lower limb restraint device 32. In other words, when the seated occupant P is seated in the vehicle seat 12 in another mode, the seated occupant P is prevented from feeling uncomfortable due to the lower limbs of the seated occupant P being restrained by the lower limb restraint device 32.

In addition, the restraining member 50 of the lower leg restraint device 32 is arranged parallel to the ottoman 30 when viewed from the side of the vehicle when stored, so it is unlikely to get in the way when stored.

(others)
In the vehicle occupant restraint device 10 of this embodiment, all adjustments of the vehicle seat 12 are performed by motor drive, but the present invention can also be applied to a device in which the seat slide and the like are performed manually.

However, the operation of the lower leg restraint device 32 and the rearward tilting of the seat back 24 are performed by a motor. This is to make it possible to prevent the seat back 24 from tilting backward if restraint confirmation is not performed.

In addition, the restraint determination unit 210 determines whether the lower limbs of the seated occupant P are restrained based on the image captured by the vehicle interior camera 80, but it may also be possible to determine whether the lower limbs of the seated occupant P are restrained using other methods.

For example, a load sensor may be placed on the ottoman 30 to determine whether or not a load (on the lower legs) is detected below the lower leg restraint device 32 (restraint member 50).

Furthermore, the configuration of the lower limb restraint device 32 is not limited to the configuration of this embodiment. For example, the slider 52 has been described as having a rack and pinion configuration, but is not limited to this.

Furthermore, when the lower leg restraint device 32 rotates from the stored position to the rotated position, the slider 52 displaces (extends) the restraint member 50 in a direction away from the ottoman 30, but this may be omitted if there is no risk of interference with the legs of the seated occupant P.

In the vehicle occupant restraint device according to the first aspect, in the vehicle occupant restraint device according to the present embodiment, the restraint member is displaced from the stored position to the restraint position, and the vehicle seat is changed to the comfortable position or the reclining position by the seat adjustment device at least only when the seat back is in the comfortable position or the reclining position.

This vehicle occupant restraint device restrains the lower limbs of a seated occupant by rotating the restraining member of the lower limb restraint device from the stored position to the use position and then displacing it to the restraining position only when the vehicle seat is in the comfortable or reclining position.

In other words, when the vehicle seat is not in the comfortable or sleeping position, the restraining member of the lower leg restraint device does not restrain the lower legs of the seated occupant.

Therefore, when the vehicle seat is not in the comfortable or reclining position, the lower limbs of the seated occupant are not restrained by the restraining member, improving the freedom of movement of the lower limbs of the seated occupant.

The vehicle occupant restraint device according to the second alternative embodiment is a vehicle occupant restraint device according to the present embodiment or the first alternative embodiment, further comprising a restraint determination unit that determines whether or not the lower limbs of the occupant are between the ottoman and the restraint member when the restraint member is displaced to the restraint position, and if the restraint determination unit does not confirm that the lower limbs of the seated occupant are restrained, the seat adjustment device does not adjust the vehicle seat to a comfortable or reclining position.

In this vehicle occupant restraint device, if the restraint determination unit does not confirm that the lower limbs of a seated occupant are restrained by the restraint member, the seat adjustment device will not adjust the vehicle seat to a comfortable or lying position. This is because even if the restraint member of the lower limb restraint device is displaced from the stored position to the restraint position, the lower limbs of the seated occupant will not be restrained unless the occupant's lower limbs are positioned between the ottoman and the restraint member. If the vehicle experiences a frontal collision in this state, the pelvis of a seated occupant whose lower limbs are not restrained may move forward in the vehicle, a phenomenon known as the "submarine phenomenon."

In other words, if the occupant's lower limbs are not restrained by the restraining member, the vehicle seat in which the occupant sits will not be allowed to assume a comfortable or reclining position, further preventing or suppressing the submarine phenomenon in the seated occupant during a frontal collision of the vehicle.

The vehicle occupant restraint device according to the third aspect is a vehicle occupant restraint device according to the second aspect, which has a notification unit that issues a warning to the occupant that the lower limbs are not restrained if the restraint determination unit does not confirm that the occupant's lower limbs are restrained when the vehicle seat is in the comfortable position or reclining position.

In this vehicle occupant restraint device, when the vehicle seat is placed in the comfortable or reclining position, if the restraint determination unit does not confirm that the lower limbs of the seated occupant are restrained by the restraint members, the notification means notifies the user that the lower limbs of the seated occupant are not restrained.

This is thought to cause the occupant's legs to be restrained by inserting them between the ottoman and the restraining member.

In other words, even if the restraining member of the lower-leg restraint device is displaced from the stored position to the restraining position, the lower legs of the seated occupant remain unrestrained, and the vehicle can be reliably prevented or suppressed from colliding head-on.

In particular, when the vehicle seat is in a comfortable or reclining position, it is possible to prevent or suppress the submarine phenomenon occurring to a seated occupant whose lower legs are not restrained in the event of a frontal collision of the vehicle.

The above describes an embodiment, but it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the invention.

10 Passenger restraint device 12 Vehicle seat 20 Seat cushion 22 Reclining shaft 24 Seat back 30 Ottoman 32 Lower leg restraint device 40 Seat slide motor (seat adjustment device)
42 Reclining motor (seat adjustment device)
44 Ottoman motor (seat adjustment device)
50 Restraint member 60 Slider shaft (rotation shaft)
82 Speaker (alarm unit)
84 Display unit (notification unit)
100 Seat ECU (seat adjustment device)
210 Restraint determination unit

Claims (1)

a seat cushion that supports the lumbar region of an occupant; a seat back that is supported by a reclining shaft that is provided on the rear side of the seat cushion and extends in the seat width direction and is configured to be tiltable about the reclining shaft, and that supports the back of the occupant;
an ottoman disposed on a seat front side of the seat cushion and supporting the lower legs of the occupant;
a seat adjustment device capable of changing the position of a vehicle seat including the seat cushion, the seat back, the ottoman, etc.;
a lower leg restraint device in which a restraint member arranged along an outer periphery of the ottoman is supported at both ends by a rotation shaft provided on the seat rear side of the ottoman and extending in the seat width direction, the restraint member being rotatable about the rotation shaft, and the restraint member being displaceable between a stored position parallel to the ottoman in a side view of the seat, a rotated position rotated about the rotation shaft in a direction substantially perpendicular to the ottoman, and a restraint position moved from the rotated position closer to the ottoman and at a predetermined distance from the lower legs of the occupant;
and when at least the seat back is tilted backward at a predetermined angle to be in a comfortable position or a lying position, the restraint member is displaced from the stored position via the rotated position to the restraint position, and the vehicle seat is changed to the comfortable position or the lying position by the seat adjustment device.