JP7223483B2 - vehicle seat structure - Google Patents

Description

The present invention relates to a vehicle seat structure.

A vehicle such as an automobile is provided with a vehicle seat for a passenger to sit on. This vehicle seat generally includes a seat cushion that supports the buttocks of an occupant, a seat back that supports the back of the occupant, and a headrest that supports the head of the occupant.

Patent Literature 1 discloses an invention relating to an automobile seat that reduces whiplash injury in the event of a rear-end collision. This automobile seat has a structure in which a headrest support frame on which a headrest is mounted is attached to a seatback frame so as to be rotatable back and forth, and a pressure receiving member is provided under the headrest support frame to receive a load applied from the front surface of the seatback.

JP 2018-39483 A

Development of vehicle seats capable of reducing whiplash injuries is underway. One of the causes of whiplash injuries is that in the early stages of a vehicle being rear-ended (hereinafter sometimes simply referred to as "rear-end collision"), the upper body of the occupant is pushed by the seat and the torso and head are injured. There is a timing lag between the movement of the torso and the head when the body moves forward. Specifically, the entire seat moves forward due to the impact of a rear collision, the occupant's back is pushed by the seat back, and the torso moves forward. At this time, if the head is separated from the headrest, after the body moves forward, the head follows the body and moves forward. In other words, at the beginning of the rear impact, the timing at which the trunk moves forward may not match the timing at which the head moves forward. Since the torso moves forward before the head, a shear load acts on the neck, resulting in a whiplash injury.

In the automobile seat disclosed in Patent Literature 1, the pressure receiving member is pushed rearward by a rearward load acting on the front surface of the seatback due to the reaction of the occupant's back being pushed by the seatback in the event of a rear-end collision. When a load exceeding a certain level acts on the pressure receiving member, the pressure receiving member rotates rearward, and the headrest moves forward accordingly. By moving the headrest forward, the headrest approaches the occupant's head and receives the head on the headrest. As a result, the torso and head are simultaneously supported by the seat back and headrest, and by minimizing the difference in timing when the torso and head move forward, the load in the shear direction acting on the neck is reduced, resulting in whiplash. We are trying to reduce injuries. However, this automobile seat requires a complicated mechanism for interlocking the headrest with the rotating pressure receiving member.

One of the objects of the present invention is to provide a vehicle seat structure that can reduce whiplash injuries with a simple configuration.

A vehicle seat structure according to an aspect of the present invention includes:
A vehicle seat structure including a seat back and a headrest,
The seat back has a back frame,
The back frame is
a pair of side frames spaced apart in the width direction of the seat back;
a pressure receiving portion that spans between the side frames and receives a rearward load acting on the seat back;
The pressure-receiving portion deforms the side frames in a direction to widen the space between the side frames when a load greater than or equal to a predetermined value is input rearward.

As one aspect of the above vehicle seat structure,
The pressure-receiving portion may have a bent portion that protrudes forward.

As one aspect of the above vehicle seat structure,
Mounting portions provided on the both side frames to which both ends of the pressure receiving portion are mounted,
The mounting portion may have a guide portion that guides the end portion of the pressure receiving portion inward and rearward in the width direction of the seat back.

According to the vehicle seat structure described above, whiplash injury can be reduced with a simple configuration in which the pressure receiving portion is provided between the side frames of the back frame of the seat back. In the event of a rear-end collision of a vehicle, the back of the occupant is pushed by the seat back, and a rearward load acts on the seat back as a reaction. The vehicle seat structure described above has a pressure receiving portion between the side frames of the back frame, and a rearward load acting on the seat back is input to the pressure receiving portion. Then, when a load greater than or equal to a predetermined amount is input to the rearward pressure receiving portion, the pressure receiving portion deforms the side frames in the direction of widening the space between the side frames. Therefore, when the occupant's back is pushed by the seatback due to the impact of a rear-end collision, the rearward load acting on the seatback and inputting the rearward load to the pressure receiving portion exceeds a predetermined value. increases the space between the side frames. By widening the space between the two side frames, the occupant's torso can easily sink into the seat back. As a result, at the initial stage of the rear collision, the torso of the occupant moves rearward, and the head can be brought closer to the headrest accordingly. In addition, as the amount of the occupant's torso sinking into the seat back increases, the occupant's torso moves backward, and the timing of the forward movement of the occupant's torso pushed by the seat back can be delayed. Therefore, in the vehicle seat structure described above, at the initial stage of a rear-end collision, it is possible to minimize the difference in the timing of forward movement of the torso and the head, thereby reducing the load in the shearing direction acting on the neck. Whiplash injury can be reduced.

In the form in which the pressure receiving portion has the bent portion, when a rearward load is input to the pressure receiving portion, the bent portion deforms linearly so as to extend in the width direction of the seatback. Both side frames are pushed outward in the width direction by the force that causes the pressure receiving portion to straighten, and the side frames can be deformed in the direction of widening the space between the side frames.

In the configuration having the mounting portions in which both ends of the pressure receiving portion are attached to both side frames, the pressure receiving portion moves rearward when a rearward load is input to the pressure receiving portion. At this time, the end portion of the pressure receiving portion is guided inward and rearward in the width direction of the seat back by the guide portion provided in the mounting portion. Therefore, the pressure receiving portion pushes the side frames outward in the width direction, and the side frames can be deformed in the direction of widening the space between the side frames.

1 is a schematic perspective view of a vehicle seat structure according to Embodiment 1. FIG. 1 is a side view showing an outline of a vehicle seat structure according to Embodiment 1; FIG. FIG. 2 is a perspective view of essential parts showing an outline of a back frame provided in the vehicle seat structure according to the first embodiment; FIG. 4 is a schematic diagram illustrating the operation of the vehicle seat structure according to Embodiment 1 at the time of a rear-end collision; FIG. 7 is a schematic diagram illustrating the operation of the vehicle seat structure according to Modification 1 at the time of a rear-end collision;

A specific example of a vehicle seat structure according to an embodiment of the present invention will be described with reference to the drawings. The same reference numerals in the drawings indicate the same names. In the drawings, "FR" refers to the front, "RR" to the rear, "LH" to the left, "RH" to the right, "UP" to the top, and "LWR" to the bottom.

[Embodiment 1]
A vehicle seat structure 1 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. A vehicle seat structure 1 according to Embodiment 1 includes a seat cushion 2, a seat back 3, and a headrest 4, as shown in FIGS. The seat cushion 2 has a cushion frame 21 and a cushion pad 22 . The seatback 3 has a back frame 31 and a back pad 32 . In FIG. 1, for convenience, the left halves of the cushion pad 22 and the back pad 32 are partially cut away. FIG. 2 shows a state in which the passenger D is seated. One of the features of the vehicle seat structure 1 according to Embodiment 1 is that, as shown in FIG. Therefore, the pressure receiving portion 5 widening the space between the side frames 311 is provided. The vehicle seat structure 1 will be described in detail below.

(Overview of vehicle seat structure)
This embodiment shows an example in which the vehicle seat structure 1 is applied to a seat installed in an automobile. The type of vehicle seat to which the vehicle seat structure 1 is applied is not particularly limited. For example, it may be a front seat or a rear seat. Also, a separate seat as shown in FIG. 1 or a bench seat may be used. Furthermore, it may be a sliding seat that can be slid in the front-rear direction, or a fixed seat that is fixed to the floor panel.

(seat cushion)
The seat cushion 2 has a cushion frame 21 and a cushion pad 22 covering the upper part of the cushion frame 21, as shown in FIG. The cushion frame 21 constitutes the skeleton of the seat cushion 2 . The cushion pad 22 is installed on the cushion frame 21 and forms a seat surface for supporting the buttocks of the occupant D (see FIG. 2). In this example, a cushion frame 21 is formed in a rectangular frame shape along the periphery of the seat cushion 2 . Examples of materials for the cushion frame 21 include metals such as steel and aluminum alloys. The cushion pad 22 is made of an elastic material such as polyurethane foam, and its surface is covered with a skin material (trim cover). Examples of the material of the skin material include cloth, leather, synthetic resin, and the like.

(seat back)
The seat back 3 has a back frame 31 and a back pad 32 covering the front of the back frame 31, as shown in FIG. The back frame 31 constitutes the skeleton of the seat back 3 . The back pad 32 is installed on the back frame 31 and forms a back portion that supports the back of the occupant D (see FIG. 2). In this example, a back frame 31 is formed in a rectangular frame shape along the periphery of the seat back 3 . Examples of the material of the back frame 31 include metals such as steel and aluminum alloys. The back pad 32 is made of an elastic material such as polyurethane foam, and its surface is covered with a skin material (trim cover). Examples of the material of the skin material include cloth, leather, synthetic resin, and the like.

The back pad 32 of this example is formed thick on the upper side, and the thickness of the upper portion is increased. The thickness here is the dimension in the front-rear direction from the front surface of the back pad 32 to the rear surface with which the back frame 31 contacts.

The back frame 31 of this example has a pair of left and right side frames 311 arranged on both left and right sides and extending in the vertical direction, an upper frame 312 arranged on the upper side, and a lower frame 313 arranged on the lower side. Of the pair of side frames 311, only the left side frame 311 is shown in FIG. The side frames 311 are spaced apart in the width direction (horizontal direction) of the seatback 3 and support both side edges of the back pad 32 . Upper frame 312 supports the upper edge of back pad 32 . Lower frame 313 supports the lower edge of back pad 32 . The back frame 31 further has a pressure receiving portion 5, which will be described later (see also FIG. 3).

The side frame 311 of this example is composed of a side body portion 311a and a side upper portion 311b. The side body portion 311a is made of a plate-like material. A cross-sectional shape of the side main body portion 311a cut in a direction orthogonal to the longitudinal direction (up-down direction) is a shape in which the inner side of the seat back 3 in the width direction is concave. A lower end portion of the side body portion 311a is coupled to a rear end portion of the cushion frame 21 by a hinge (not shown) or the like. The upper frame 312 of this example is made of a pipe material and has an inverted U shape with both ends bent downward. Each end of the upper frame 312 is joined to the upper end of the side body portion 311a by welding or the like. In this example, the bent end portion of the upper frame 312 becomes the side upper portion 311b. In other words, the side frame 311 is configured by the side main body portion 311a and the end portion of the upper frame 312 serving as the side upper portion 311b. The lower frame 313 of this example is formed of a plate-like material, and both ends thereof are joined to the lower portions of the side body portions 311a on both sides by welding or the like. In this example, the seat back 3 is configured to be reclinable with respect to the seat cushion 2, but the seat back 3 may be fixed to the seat cushion 2 so as not to move. Also, the side main body portion 311a and the lower frame 313 may be formed of a pipe material or a rod-shaped material. The upper frame 312 may be made of a plate-shaped material or a rod-shaped material. The side frame 311 and the upper frame 312 may be integrally formed.

(headrest)
The headrest 4 is arranged above the seat back 3, as shown in FIG. 1, and supports the head h of the occupant D (see FIG. 2). The headrest 4 has a stay 41 projecting downward from its lower portion. A headrest attachment portion 34 to which the headrest 4 is attached is provided in the central portion of the upper frame 312 . The headrest mounting portion 34 is formed in a tubular shape into which the stay 41 is inserted. The headrest 4 is attached to the seat back 3 by inserting the stay 41 into the headrest attachment portion 34 . The height of the headrest 4 can be adjusted by adjusting the amount of insertion of the stay 41 into the headrest mounting portion 34 . In this example, the seat back 3 and the headrest 4 are configured to be separable, but the seat back 3 and the headrest 4 may be integrated.

(Pressure receiver)
As shown in FIG. 1, the pressure receiving portion 5 is located between the upper frame 312 and the lower frame 313, and spans between the side frames 311 (in this example, between the side body portions 311a) (see FIG. 3). see also). A rearward load acting on the seat back 3 is input to the pressure receiving portion 5 . In the case of this example, the pressure receiving portion 5 is provided so as to be in contact with the rear surface of the back pad 32 , and a rearward load acting on the back pad 32 is input. The pressure receiving portion 5 has a rigidity capable of receiving a rearward load acting on the seat back 3 (back pad 32). The pressure-receiving portion 5 is made of a plate-shaped metal such as steel or aluminum alloy. The front surface of the pressure receiving portion 5 facing the rear surface of the back pad 32 serves as a pressure receiving surface pressed against the back pad 32 .

In particular, the pressure receiving portion 5 is preferably provided so as to be positioned above the waist of the occupant D (see FIG. 2). In the case of this example, the pressure receiving portion 5 is provided above an intermediate position in the vertical direction of the back frame 31 .

The pressure-receiving portion 5 deforms the side frames 311 in a direction to widen the space between the side frames 311 when a load greater than or equal to a predetermined value is input rearward. Examples of the pressure receiving portion 5 include a bending type in which the pressure receiving portion 5 is deformed (see FIGS. 3 and 4) and a sliding type in which the pressure receiving portion 5 moves backward (see FIG. 5 described later). In this embodiment, a bent type is shown as an example of the pressure receiving portion 5 .

As shown in FIG. 3, the pressure receiving portion 5 of this example has a bent portion 51 that protrudes toward the back pad 32 (see FIG. 1) side, that is, toward the front. FIG. 3 is a perspective view of the main part of the back frame 31 as seen from the rear. In the case of this example, when the pressure receiving portion 5 is viewed from above, a curved portion 51 is formed so as to protrude forward at the center portion of the back frame 31 in the width direction (horizontal direction) (Fig. 4 (A )). In this example, the bent portion 51 is formed by bending the pressure receiving portion 5 in an arc shape, but the bent portion 51 may be formed by bending the pressure receiving portion 5 in a V shape. Both ends of the pressure receiving portion 5 are joined to the inner surfaces of the side body portions 311a by welding, bolts, or the like. The bent portion 51 can deform linearly so as to extend in the width direction of the back frame 31 when a rearward load is input to the pressure receiving portion 5 . In this example, the pressure receiving portion 5 is provided only between the side main body portions 311a, but the pressure receiving portion 5 may be provided also between the side upper portions 311b, or may be provided only between the side upper portions 311b. It is possible.

Furthermore, in this example, the upper frame 312 is configured to be separable in the width direction (horizontal direction) of the back frame 31 . Specifically, the upper frame 312 is connected so as to be freely split in the width direction, and includes a connecting portion that releases the connection when the pressure receiving portion 5 deforms the side frames 311 in a width-enlarging direction. The upper frame 312 of this example is divided into left and right parts in the width direction of the back frame 31 at its central portion, and has a left upper frame 312L and a right upper frame 312R, as shown in FIG. One of the left and right upper frames 312L and 312R is thick and the other is thinner than the other. The connecting portion between the left upper frame 312L and the right upper frame 312R has an insertion structure and is formed so as to overlap each other. Also, the connecting portion between the left upper frame 312L and the right upper frame 312R is connected via a connecting tool that releases the connection when a force exceeding a certain level acts. In this example, a pin 312p is used as the connector. A through hole (not shown) communicating with each other is formed in a connecting portion between the left upper frame 312L and the right upper frame 312R. By inserting a pin 312p into this through hole, the left upper frame 312L and the right upper frame 312L are connected to each other. The frame 312R is connected via a pin 312p. When the pressure-receiving portion 5 deforms the side frames 311 in the width-expanding direction, the upper frame 312 is pulled in the width direction of the back frame 31, and a shearing force perpendicular to the axial direction acts on the pins 312p. The pin 312p is configured to break when a force above a certain level acts in the shear direction. By breaking the pin 312p, the connection between the left upper frame 312L and the right upper frame 312R is released.

(Operation during rear collision)
Next, the operation of the above-described vehicle seat structure 1 at the time of a rear collision will be described using FIG. 4 while appropriately referring to FIGS. 2 and 3 . 4A and 4B are diagrams of the pressure receiving portion 5 viewed from above. FIG. 4A shows the state of the pressure receiving portion 5 during normal operation, and FIG. ing. In FIGS. 4A and 4B, illustration of the back pad 32 is omitted. At the time of a rear collision, the back of the occupant D (see FIG. 2) is pushed forward by the seat back 3 (see FIG. 2) due to the impact. As a reaction, the back of the occupant D is pressed against the seat back 3 , and a rearward load acts on the seat back 3 . At this time, the pressure receiving portion 5 (see FIGS. 3 and 4A) bridged between the side frames 311 is pressed against the back pad 32 (see FIG. 2), and a rearward load is input to the pressure receiving portion 5. be. When a predetermined load or more is applied to the pressure receiving portion 5, the bending portion 51 is linearly deformed so as to extend in the width direction (horizontal direction) of the back frame 31, as shown in FIG. 4B. Both side main body portions 311a are pushed outward in the width direction by the force that causes the pressure receiving portion 5 to straighten. Therefore, the side frames 311 are deformed in the direction in which the space between the side frames 311 widens, and the space between the side frames 311 widens. By widening the space between the two side frames 311, the torso b of the occupant D (see FIG. 2) can easily sink into the seat back 3 (back pad 32). As a result, at the beginning of the rear collision, the torso b of the occupant D moves rearward, and along with this, the head h can be brought closer to the headrest 4 (see FIG. 2). Further, since the body b of the occupant D moves backward by the amount of sinking of the body b of the occupant D into the seat back 3, the timing of the forward movement of the body b pushed by the seat back 3 can be delayed. Therefore, at the initial stage of rear impact, the difference in the timing of the forward movement of the torso b and the head h of the occupant D can be minimized, thereby reducing the load acting on the neck in the shear direction and reducing whiplash injury.

In this example, as described above, the upper frame 312 is configured to be separable in the width direction (horizontal direction) of the back frame 31 . Specifically, as shown in FIG. 3, the upper frame 312 includes a connecting portion in which a left upper frame 312L and a right upper frame 312R are connected via pins 312p. Both side body portions 311 a are pushed outward in the width direction by the pressure receiving portion 5 , and when the side frames 311 are deformed in the direction in which the space between the side frames 311 is widened, the upper frame 312 is pulled in the width direction of the back frame 31 . A force acts in a direction. At that time, a shearing force acts on the pin 312p that connects the left upper frame 312L and the right upper frame 312R. In the event of a rear-end collision, the pins 312p are broken due to the action of a force above a certain level in the shearing direction of the pins 312p, thereby releasing the connection between the left upper frame 312L and the right upper frame 312R. Therefore, as indicated by the two-dot chain line in FIG. 3, the upper portions of both side frames 311 are easily pushed outward in the width direction. Therefore, it is easy to deform the side frames 311 in the direction of widening the space between the side frames 311 . Further, during normal times other than rear-end collision, the pin 312p prevents the width between the side frames 311 from widening even if the occupant D (see FIG. 2) leans against the seat back 3 (see FIG. 2).

[Modification 1]
In the first embodiment, the pressure receiving portion 5 is of a bending type in which the side frame 311 is deformed by deformation of the pressure receiving portion 5 with reference to FIGS. 3 and 4 . In Modification 1, referring to FIG. 5, a sliding type that deforms the side frame 311 by moving the pressure receiving portion 5 rearward will be described. In the following description, differences from the first embodiment will be mainly described, and descriptions of similar items will be omitted.

5A and 5B are diagrams of the pressure receiving portion 5 viewed from above. FIG. 5A shows the pressure receiving portion 5 in a normal state, and FIG. ing. In FIGS. 5A and 5B, illustration of the back pad 32 is omitted. In Modification 1, as shown in FIG. 5A, both side frames 311 have attachment portions 52 to which both ends of the pressure receiving portion 5 are attached. In this example, mounting portions 52 are provided on the inner surfaces of both side body portions 311a. The mounting portion 52 also has a guide portion 53 that guides the end portion of the pressure receiving portion 5 inwardly and rearwardly in the width direction (horizontal direction) of the back frame 31 . In this example, the guide portion 53 is configured by a long hole 53h. The long hole 53h forming the guide portion 53 is formed so as to obliquely extend inward in the width direction from the front to the rear when the mounting portion 52 is viewed from above.

Both ends of the pressure receiving portion 5 of this example are provided with projections 5p to be inserted into the long holes 53h. ing. The projection 5p is movably engaged with the elongated hole 53h and guided along the elongated hole 53h. Therefore, both ends of the pressure receiving portion 5 are attached to the attachment portion 52 so as to be slidable in the front-rear direction.

(Operation during rear collision)
The operation of the pressure receiving portion 5 shown in Modification 1 at the time of rear impact will be described with reference to FIG. Normally, as shown in FIG. 5A, the pressure receiving portion 5 is arranged on the front side of the mounting portion 52, and the projection 5p is positioned on the front side of the long hole 53h. As described in the first embodiment, when a rearward load acts on the back pad 32 (see FIG. 2) during a rear-end collision, the pressure receiving portion 5 is pressed by the back pad 32, and the rearward load is applied to the pressure receiving portion 5. is entered. When a predetermined load or more is input to the pressure receiving portion 5, the pressure receiving portion 5 moves rearward as shown in FIG. 5(B). When the pressure receiving portion 5 moves to the rear side of the mounting portion 52 , the projections 5 p on both ends of the pressure receiving portion 5 move toward the inside and rear of the back frame 31 in the width direction (horizontal direction) by the elongated holes 53 h serving as the guide portions 53 . be guided towards. Therefore, as shown in FIG. 5B, the pressure receiving portion 5 pushes and expands the side body portions 311a outward in the width direction. Therefore, the side frames 311 are deformed in the direction in which the space between the side frames 311 widens, and the space between the side frames 311 widens.

<Action and effect>
The vehicle seat structure 1 according to the embodiment of the present invention can reduce whiplash injury with a simple configuration in which the pressure receiving portion 5 is provided between the side frames 311 of the back frame 31 of the seat back 3 . In the vehicle seat structure 1, when a rearward load greater than or equal to a predetermined amount is input to the pressure receiving portion 5 provided in the back frame 31 at the time of a rear-end collision, the pressure receiving portion 5 deforms the side frames 311 in the direction of widening the space between the side frames 311. . By widening the space between both side frames 311 , the torso b of the occupant D can easily sink into the seat back 3 . As a result, the torso b of the occupant D can move rearward and the head h can approach the headrest 4 at the initial stage of the rear collision. In addition, as the amount of sinking of the torso b of the occupant D into the seat back 3 increases, the torso b moves backward, and the timing of the torso b moving forward by being pushed by the seat back 3 can be delayed. . Therefore, at the initial stage of rear impact, the difference in the timing of the forward movement of the torso b and the head h of the occupant D can be minimized, so that the load acting on the neck in the shear direction can be reduced, and whiplash injury can be reduced. In particular, the vehicle seat structure 1 of the present embodiment is useful for a seat of a compact vehicle in which the distance between both side frames 311 is narrow and the torso b of the occupant D is less likely to sink into the seat back 3 .

The present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents of the scope of the claims. For example, a plurality of pressure receiving portions 5 may be provided between the side frames 311 . Also, only the upper portions of both side frames 311 may be widened, or both side frames 311 may be widened as a whole. In the above-described embodiment, the case where the seat cushion 2 and the seat back 3 have the cushion pad 22 and the back pad 32 has been described as an example, but the configuration without the cushion pad 22 and the back pad 32 is also possible. can. In this case, for example, the seat cushion 2 and the seat back 3 may be configured by covering the cushion frame 21 and the back frame 31 with a skin material.

Reference Signs List 1 vehicle seat structure 2 seat cushion 21 cushion frame 22 cushion pad 3 seat back 31 back frame 311 side frame 311a side body portion 311b side upper portion 312 upper frame 312L left upper frame 312R right upper frame 312p pin 313 lower frame 32 back pad 34 Headrest mounting portion 4 Headrest 41 Stay 5 Pressure receiving portion 51 Bending portion 52 Mounting portion 53 Guide portion 53h Long hole 5p Projection D Occupant b Body h Head

Claims (1)

A vehicle seat structure including a seat back and a headrest,
The seat back has a back frame,
The back frame is
a pair of side frames spaced apart in the width direction of the seat back;
a pressure receiving portion that spans between the side frames and receives a rearward load acting on the seat back;
Both ends of the pressure receiving portion are attached inside the side frame,
The pressure-receiving portion pushes and widens the entire portion of the side frame to which the both end portions are attached in the width direction outward when a load greater than or equal to a predetermined value is input in the rearward direction, thereby widening the space between the side frames. A vehicle seat structure that deforms the side frame.

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