JP7498552B2 - Vehicle seat - Google Patents

Description

The present invention relates to a vehicle seat, and in particular to a vehicle seat that is designed to absorb the impact force generated during a vehicle collision.

In order to reduce the impact on the occupants during a vehicle collision, some vehicle seats are equipped with a shock absorbing device. For example, there is a vehicle seat in which a shock absorbing member made of a locking member that plastically deforms in response to the impact load acting on the occupants during a vehicle collision is provided on the underside of the seat cushion that constitutes the seat, and the seat cushion is supported on the vehicle body via this shock absorbing member, and the shock absorbing member is plastically deformed to absorb the impact energy during the impact (Patent Document 1).

On the other hand, in recent years, vehicles have been equipped with airbags to cushion the impact. These airbags cushion the impact during a frontal collision. However, the pressure of the airbag can push the upper body backward again, and the impact of this push back on the head and back against the vehicle seat can cause damage to the cervical and thoracic vertebrae.

The inventor has confirmed that it is effective to use the seat back to absorb the impact, rather than the entire seat, in order to achieve this. However, the invention described in Patent Document 1 does not change the shape of the vehicle seat, but absorbs the impact by moving the entire vehicle seat, making it difficult to effectively absorb the impact of being pushed back backwards by the compressive force of the airbag.

Japanese Patent Application Laid-Open No. 4-356240

Therefore, the present invention was made in consideration of these problems, and aims to provide a vehicle seat that can effectively cushion the impact on the head and back caused by the pushback from the airbag.

To achieve the above-mentioned objectives, the present invention adopts the following means.

The vehicle seat according to the present invention comprises:
A vehicle seat having a seat cushion and a seat back,
The seat back includes an upper frame and a lower frame that are divided into upper and lower portions.
The upper frame is fixed to the lower frame by a single support shaft,
The support shaft is characterized in that it deforms before the upper frame when an impact load is applied to the upper frame.

By forming the seat back as a separate upper and lower frame, and fixing the upper frame to the lower frame with a single support shaft, when the impact of the airbag pushing back during a collision is applied to the seat back, the pressure applied to the upper frame is concentrated on the support shaft. This makes the support shaft a weak point, and as the support shaft deforms, the upper frame falls backward, mitigating the impact force on the occupant's head and back. This reduces damage to the cervical and thoracic vertebrae.

In addition, in the vehicle seat according to the present invention,
The support shaft may be formed to have a bending rigidity lower than a bending rigidity of the upper frame.

By adopting this configuration, the support shaft can be reliably deformed before the upper frame bends. This causes the upper frame to fall backward, mitigating the impact force on the occupant's head and back. This reduces damage to the cervical and thoracic vertebrae.

Furthermore, in the vehicle seat according to the present invention,
The support shaft may be characterized in that, when an impact load is applied to the headrest, it deforms before the headrest stay.

By adopting this configuration, the support shaft is reliably deformed before the headrest stay bends, reducing the possibility of damage to the cervical or thoracic vertebrae.

FIG. 1 is a perspective view of a vehicle seat 100 according to an embodiment. FIG. 2 is a perspective view showing the internal structure of the vehicle seat 100 according to the embodiment. FIG. 3 is a perspective view showing a state in which the support shaft 60 of the seat back frame 30 of the vehicle seat 100 according to the embodiment is bent and the upper frame 50 is laid down.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the embodiments and drawings described below are intended to illustrate a portion of the embodiment of the present invention, and are not intended to be used to limit the present invention to these configurations. In addition, corresponding components in each drawing are denoted by the same or similar reference numerals.

The vehicle seat 100 according to this embodiment is a seat that is attached to a vehicle, and includes a seat cushion 1 and a seat back 2, as shown in FIG. 1. FIG. 2 shows a perspective view of the internal structure excluding the cushion. As shown in FIG. 2, the internal structure of the vehicle seat 100 according to this embodiment mainly includes a seat cushion frame 20 that is disposed inside the seat cushion 1, and a seat back frame 30 that is attached to the seat cushion frame 20 in a reclining manner and disposed inside the seat back 2.

The seatback frame 30 includes a lower frame 40 that is attached to the seat cushion frame 20 via a reclining mechanism 13, and an upper frame 50 that is attached above the lower frame 40 via a support shaft 60.

As shown in FIG. 3, the lower frame 40 is formed in a generally inverted U-shape, and a support shaft 60 to which the upper frame 50 can be fixed is attached in the center.

The upper frame 50 is a frame for maintaining the shape of the seat back, and has an upper frame 51 that supports the upper side of the seat back, side frames 52 that support both sides, and a lower frame 53 located below. The lower frame 53 is formed horizontally near the center, and is connected to the side frame 52 at an angle upward from the middle. The upper frame 50 is formed in a tapered shape so that the width narrows from the middle toward the bottom, and has a shape that combines a rectangle and an inverted trapezoid as a whole. The upper frame 50 is fixed to the support shaft 60 described above near the center of the lower frame 53. In addition, since the lower sides of the upper frame 50 are formed in a tapered shape, a larger space α is formed between the upper frame 50 and the lower frame 40 compared to the center. By forming such a space α, the upper frame 50 can deform the support shaft 60 so that it can fall not only rearward but also diagonally and laterally.

The upper frame 50 is provided with a headrest guide bracket 91, into which the headrest stay 10 is inserted to secure the headrest (not shown).

The cross-sectional shape of the support shaft 60 is not particularly limited to a square, a circle, an ellipse, or the like. If it is formed into a circle, it can be deformed in the same direction by the same impact force regardless of the direction. If it is formed into an ellipse, it can be easily deformed when a force is applied to the short axis side, and it can be made difficult to bend when a force is applied to the long axis side. In this way, by selecting the cross-sectional shape of the support shaft 60, it is possible to adjust the ease of bending in a predetermined direction or the difficulty of bending. In addition, the support shaft 60 has a rigidity lower than that of the upper frame 50, and is formed so that it deforms before the upper frame 50 deforms, or the deformation rate is large. In addition, the support shaft 60 is formed so that it deforms before the headrest stay 10 when an impact load is applied to the headrest. The support shaft 60 is formed to a length such that a width is provided so that the upper frame 50 and the lower frame 40 do not interfere with each other when deformed. Furthermore, the support shaft 60 is formed so that it can deform in a torsional direction around the support shaft 60, and can also change while twisting, as shown in Figure 3.

As shown in FIG. 1, the vehicle seat 100 manufactured as described above is constructed by attaching the seat cushion 3 to the seat cushion frame 20, and attaching the upper cushion 4 and the lower cushion 5 to the upper frame 50 and the lower frame 40, respectively, to form the vehicle seat 100. In the vehicle seat 100 manufactured in this manner, the upper cushion 4 bends rearward due to the impact of the occupant's back or head when pushed back by the airbag after a vehicle collision, thereby mitigating the impact on the head and back. In addition, since the upper frame 50 and the lower frame 40 of the vehicle seat 100 according to this embodiment are formed by a single support shaft 60, even if a large force is applied in a rearward diagonal direction or a lateral direction other than the rearward direction in the case of a side collision with the vehicle, the upper frame 50 can deform in a rearward diagonal direction or a lateral direction, and can bend in an appropriate direction according to the direction of the impact to mitigate the impact on the head and back. In addition, for example, if a strong impact is applied to the right side of the body and the left side is weak, the right side of the upper frame 50 that received the strong impact can be deformed in a twisted manner, thereby greatly mitigating the impact on the right side of the body that received the strong impact.

As shown in the above-mentioned embodiment, it can be used industrially as a vehicle seat for an automobile.

Reference Signs List 1: seat cushion 1, 2: seat back, 3: seat cushion, 4: upper cushion, 5: lower cushion, 10: headrest stay, 13: reclining mechanism, 20: seat cushion frame, 30: seat back frame, 40: lower frame, 50: upper frame, 51: upper frame, 52: side frame, 53: lower frame, 60: support shaft, 91: headrest guide bracket, 100: vehicle seat

Claims (2)

A vehicle seat having a seat cushion and a seat back,
The seat back includes an upper frame and a lower frame that are divided into upper and lower portions.
the upper frame is fixed to the lower frame by a single support shaft, and the upper frame is formed in a tapered shape in which an overall width thereof narrows downward from a middle portion, and a larger space is formed between the upper frame and the lower frame on both lateral sides in the lower portion compared to a space near a center,
The vehicle seat, wherein the support shaft deforms rearward, obliquely, laterally and torsionally before the upper frame when an impact load is applied to the upper frame. The vehicle seat according to claim 1, characterized in that the support shaft is made to have a bending rigidity lower than the bending rigidity of the upper frame.

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