JP7227685B2 - 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.

Japanese Patent Application Laid-Open No. 2000-118280

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 and a back pad covering the front of the back frame,
The back pad has a weakened portion in at least a part of the portion where the back frame is located,
The fragile portion breaks when a load greater than or equal to a predetermined value is applied rearward to the back pad to allow rearward movement of the back pad relative to the back frame.

According to the vehicle seat structure described above, whiplash injury can be reduced with a simple configuration in which the back pad of the seat back is provided with the fragile portion. In the event of a rear-end collision of the vehicle, the back of the occupant is pushed by the seat back, and the reaction causes a rearward load to act on the back pad. In the above-described vehicle seat structure, the back pad has a fragile portion, and when a load greater than or equal to a predetermined value is applied rearward to the back pad, the fragile portion breaks, causing the back pad to move rearward with respect to the back frame. allow. Therefore, when the occupant's back is pushed by the seat back due to the impact of a rear-end collision, the position of the back pad relative to the back frame does not have a weakened portion if the rearward load input to the back pad exceeds a predetermined value. Displaced backwards than the case. 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. As the position of the back pad is displaced rearward, the occupant's torso moves rearward, 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.

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. 1 is a cross-sectional view of a main part showing an outline of a vehicle seat structure according to Embodiment 1; FIG. FIG. 4 is a cross-sectional view of a main part for explaining the operation of the vehicle seat structure according to Embodiment 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. The point is that it has a fragile portion 35 . 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 has a fragile portion 35 (see FIG. 3), which will be described later.

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 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 in the width direction of the seat back 3 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.

(weak part)
As shown in FIG. 3, the back pad 32 is provided with a weakened portion 35 in at least a portion of the portion where the back frame 31 is positioned. FIG. 3 is a top view of a cross section along line III-III shown in FIG. The fragile portion 35 is a portion of the back pad 32 that has a locally low mechanical strength and is configured such that the back pad 32 is partially broken when pressed against the back frame 31 . The fragile portion 35 breaks when a load greater than or equal to a predetermined value is applied rearward to the back pad 32 , allowing the back pad 32 to move rearward with respect to the back frame 31 . The fragile portion 35 is preferably set in a portion of the back pad 32 where the side frame 311 is located. In this example, fragile portions 35 are provided on both side edges of the back pad 32 where both side frames 311 are located. The fragile portion 35 shown in FIG. 3 is constituted by slits 35s and holes 35h formed along the side edge of the back pad 32. As shown in FIG. The fragile portion 35 is provided on the rear surface side of the back pad 32 with which the side frame 311 is in contact. In this example, a slit 35s having a V-shaped cross section is formed by cutting from the rear surface of both side edges of the back pad 32, and a hole 35h having a circular cross section is formed in front of the slit 35s. . Three holes 35h are formed side by side in the front-rear direction, and holes 35h positioned further forward have smaller hole diameters.

The fragile portion 35 may be provided over the entire length of both side edges of the back pad 32, but it is particularly preferable that the fragile portion 35 is provided so as to be positioned above the waist of the occupant D (see FIG. 2). . In the case of this example, fragile portions 35 are provided on both upper side edges of the back pad 32 . In this example, since the upper portion of the back pad 32 is formed thick, it is easy to form the fragile portion 35 (hole 35h).

(Acute angle part)
In addition, when the side frames 311 are viewed from above, it is preferable that at least a portion of the front side of the side frames 311 contacting the rear surface of the back pad 32 is formed to have an acute angle toward the front. Since the front side of the side frame 311 is formed to have an acute angle, the back pad 32 is easily broken when a load greater than or equal to a predetermined amount is input to the back pad 32 rearward. In this example, as shown in FIG. 3, the side upper portion 311b of the side frame 311 has a substantially triangular cross-sectional shape on the front side, and an acute angle portion 36 is provided on the front side of the side upper portion 311b. Also, the acute-angled portion 36 is inserted into the slit 35s. The acute angle portion 36 is formed by press-molding both end portions of the upper frame 312 (see FIG. 1) that constitutes the side upper portion 311b. The acute-angled portion 36 may be formed by joining, for example, by welding, a member formed to have an acute-angled shape facing forward when viewed from above, on the front side of the side upper portion 311b. In this example, the acute-angled portion 36 is provided only on the side upper portion 311b, but the side main body portion 311a (see FIGS. 1 and 2) may also be provided with the acute-angled portion 36, or only the side main body portion 311a may be provided with the acute-angled portion 36. A section 36 can also be provided. When the acute angle portion 36 is provided on the front side of the side frame 311, it is preferably provided on the upper portion of both side frames 311 that support the upper side edges of the back pad 32 formed thickly. It is preferable to provide so as to face the fragile portion 35 .

(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 . 2 and 3 show the normal state. At the time of a rear collision, the back of the occupant D is pushed forward by the seat back 3 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 back pad 32. - 特許庁At that time, when a load greater than or equal to a predetermined amount is input backward to the back pad 32, the back pad 32 is pressed against the back frame 31 (side frame 311), and the fragile portion 35 provided in the back pad 32 (see FIG. 3). breaks. By breaking the fragile portion 35, as shown in FIG. 4, both side frames 311 are embedded in both side edges of the back pad 32, and the back pad 32 moves relatively rearward (in the figure, the back pad 32 is normal). state is indicated by a two-dot chain line). Therefore, the position of the back pad 32 relative to the back frame 31 (see FIG. 2) is displaced further rearward than when the weakened portion 35 is not present. As a result, the torso b of the occupant D (see FIG. 2) moves rearward at the beginning of the rear collision, and the head h can be brought closer to the headrest 4 accordingly. As shown in FIG. 4, since the torso b of the occupant D moves backward by the amount of the rearward displacement of the back pad 32, the timing of the forward movement of the torso b pushed by the seat back 3 should be delayed. can be done. Therefore, at the beginning of the rear collision, the timing difference between 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 the whiplash injury can be reduced.

In this example, the acute angle portion 36 is provided on the front side of the side frame 311 facing the fragile portion 35, specifically, on the front side of the side upper portion 311b. Therefore, in the event of a rear-end collision, the fragile portion 35 is pressed against the acute-angled portion 36 by the rearward load on the back pad 32 , thereby easily breaking the fragile portion 35 . Furthermore, since the fragile portion 35 has the slit 35s, the fragile portion 35 is easily broken.

The amount of rearward displacement of the back pad 32 with respect to the back frame 31 at the time of a rear collision is determined by the amount of embedment of the side frame 311 into the back pad 32 due to the breakage of the fragile portion 35 . The amount of embedment of the side frame 311 can be adjusted by the amount of breakage of the fragile portion 35 , specifically, the depth of the forward cut from the back surface of the back pad 32 . In this example, since the breaking amount of the fragile portion 35 is smaller than the thickness of the back pad 32 , it does not reach the front surface of the back pad 32 . Therefore, even if the fragile portion 35 provided in the back pad 32 is broken in the event of a rear-end collision, as shown in FIG. . In this example, as shown in FIG. 3, the fragile portion 35 is provided only on the rear surface side of the back pad 32, and the upper side edges of the back pad 32 on which the fragile portion 35 is provided are formed thick. Therefore, it is easy to leave the front portion of the back pad 32 . By leaving the front portion of the back pad 32, the side frame 311 does not directly collide with the occupant D.

As in this example, when the fragile portion 35 is formed by the holes 35h, the breaking amount of the fragile portion 35 can be set according to the cross-sectional shape, number, hole diameter, formation position, and the like of the holes 35h. For example, when the number of holes 35h is increased or the hole diameter of the holes 35h is increased, the fragile portion 35 is easily broken, and the breaking amount of the fragile portion 35 can be set large. In the case of this example, the holes 35h are formed only on the rear side of both side edges of the back pad 32, and the holes 35h do not reach near the front surface of the back pad 32. less than That is, the breaking amount of the fragile portion 35 is set so that the front portion of the back pad 32 remains. The cross-sectional shape, number, hole diameter, formation position, and the like of the holes 35h may be appropriately determined according to the breaking amount of the fragile portion 35 to be set. The configuration of the fragile portion 35 is not limited to that described in this example, and can be changed as appropriate. In this example, the slit 35s is provided in the fragile portion 35, but the slit 35s may be omitted, and the fragile portion 35 may be configured only by the hole 35h.

<Action and effect>
The vehicle seat structure 1 according to Embodiment 1 can reduce whiplash injuries with a simple configuration in which the back pad 32 of the seat back 3 is provided with the fragile portion 35 . In the vehicle seat structure 1 , when a rearward load greater than or equal to a predetermined amount is applied to the back pad 32 during a rear collision, the fragile portion 35 breaks and the back pad 32 is displaced rearward with respect to the back frame 31 . 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. Further, the torso b of the occupant D moves rearward by the amount of the position of the back pad 32 being displaced rearward, and the timing of the forward movement of the torso 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, so that the load acting on the neck in the shear direction can be reduced, and whiplash injury can be reduced.

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, the vehicle seat structure 1 of this embodiment can be applied to the vehicle seat described in Patent Document 1. In the vehicle seat structure 1, the rearward displacement amount of the back pad 32 with respect to the back frame 31 is large at the time of a rear-end collision. Therefore, when applied to the automobile seat described in Patent Document 1, the pressure receiving member can be largely rotated rearward, so that the headrest 4 can be rotated forward more effectively. Also, the vehicle seat structure 1 may be applied to a seat with a side airbag. In this case, the side airbag is accommodated in the side portion of the back pad 32 at the center in the vertical direction, and a fragile portion that breaks when the side airbag is deployed is set. Further, fragile portions 35 that break at the time of a rear-end collision may be provided on both side edges above the central portion of the back pad 32 in which the side airbag is accommodated.

In the first embodiment described above, the case where the fragile portions 35 are provided on both side edges of the back pad 32 where both side frames 311 are located has been described as an example. may be provided. In this case, the upper frame 312 arranged on the upper side of the back frame 31 may be provided with an acute-angled portion 36 formed in an acute-angled shape when viewed from the side.

The vehicle seat structure of the present invention can be suitably used for automobile seats.

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 313 lower frame 32 back pad 34 headrest mounting portion 35 fragile portion 35s slit 35h hole 36 acute angle portion 4 headrest 41 stay D occupant b torso h head

Claims (1)

A vehicle seat structure including a seat back and a headrest,
The seat back has a back frame and a back pad covering the front of the back frame,
The back pad has a weakened portion in at least a part of the portion where the back frame is located,
The fragile portion includes a plurality of holes that break when a predetermined or more load is applied rearward to the back pad to allow the back pad to move rearward with respect to the back frame,
The plurality of holes are arranged forward from the rear surface of the back pad with which the back frame is in contact, and the hole diameter is smaller toward the front of the back pad.
Vehicle seat structure.

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