U.S. patent application number 14/827825 was filed with the patent office on 2015-12-10 for vehicle seat.
The applicant listed for this patent is TS TECH CO., LTD.. Invention is credited to Takaya Kurisu, Kenichi Niitsuma, Yuichiro Seki.
Application Number | 20150352985 14/827825 |
Document ID | / |
Family ID | 46207247 |
Filed Date | 2015-12-10 |
United States Patent
Application |
20150352985 |
Kind Code |
A1 |
Seki; Yuichiro ; et
al. |
December 10, 2015 |
VEHICLE SEAT
Abstract
Provided is a vehicle seat having a high absorbing efficiency of
impact energy upon rear end collision. The vehicle seat includes a
pair of side frames that are arranged on the side, and lower frames
and that connect lower portions of the pair of side frames to each
other, in which a narrow portion including: a horizontal portion
formed inside the pair of side frames along a longitudinal
direction with a flexibility against a load equal to or more than a
predetermined impact load, and an inclined portion extending from
the horizontal portion via a bent portion inside the pair of side
frames is formed on the lower frames.
Inventors: |
Seki; Yuichiro; (Tochigi,
JP) ; Kurisu; Takaya; (Tochigi, JP) ;
Niitsuma; Kenichi; (Tochigi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TS TECH CO., LTD. |
Asaka-shi |
|
JP |
|
|
Family ID: |
46207247 |
Appl. No.: |
14/827825 |
Filed: |
August 17, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13991572 |
Jun 4, 2013 |
9108546 |
|
|
PCT/JP2011/078478 |
Dec 8, 2011 |
|
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14827825 |
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Current U.S.
Class: |
297/216.1 |
Current CPC
Class: |
B60N 2/42709 20130101;
B60N 2/4228 20130101; B60N 2/42745 20130101; B60N 2/806 20180201;
B60N 2/688 20130101; B60N 2/682 20130101; B60N 2/888 20180201; B60N
2/68 20130101; B60N 2/7094 20130101 |
International
Class: |
B60N 2/42 20060101
B60N002/42; B60N 2/427 20060101 B60N002/427; B60N 2/68 20060101
B60N002/68 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2010 |
JP |
2010-273867 |
Claims
1. A vehicle seat comprising: a pair of side frames that are
arranged on the side; and a lower frame that connect lower portions
of the pair of side frames to each other, wherein a narrow portion
including: a horizontal portion formed inside the pair of side
frames along a longitudinal direction with a flexibility against a
load equal to or more than a predetermined impact load, and an
inclined portion extending from the horizontal portion via a bent
portion inside the pair of side frames is formed on the lower
frame.
2. The vehicle seat according to claim 1, wherein: the lower frame
includes a pair of lower frame side portions arranged below the
pair of side frames, and a lower frame center portion that connects
the pair of lower frame side portions to each other; the lower
frame side portion includes a side plate joined to a side plate of
the side frame, and an intermediate plate formed by being bent from
an end portion of the side plate; and the narrow portion is formed
on the intermediate plate.
3. The vehicle seat according to claim 1, wherein a harness
attachment portion bulging toward a side opposite to a bulging
direction of the narrow portion is formed below the bent
portion.
4. The vehicle seat according to claim 2, wherein the narrow
portion is formed above the lower frame center portion.
5. The vehicle seat according to claim 1, wherein a reinforcement
portion that reinforces the lower frame is provided at a position
displaced from the narrow portion in an up and down direction.
6. The vehicle seat according to claim 5, wherein the reinforcement
portion is provided below the narrow portion.
7. The vehicle seat according to claim 5, wherein the reinforcement
portion is provided at a position overlapping at least partially
the narrow portion in a front to back direction.
8. The vehicle seat according to claim 1, further comprising: a
pressure receiving member that is connected to the pair of side
frames via a connection member to support an occupant; and an
impact reducing member that is arranged at least on one of the side
frames and is connected to the connection member, to move the
pressure receiving member rearward by a predetermined impact load
applied to the pressure receiving member.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 13/991,572, filed Jun. 4, 2013, which is a
National Stage Entry application of PCT Application No.
PCT/JP2011/078478, filed Dec. 8, 2011, which claims the priority
benefit of Japanese Patent Application No. 2010-273867, filed Dec.
8, 2010, the contents of all being incorporated herein by
reference.
BACKGROUND
[0002] Disclosed herein is a vehicle seat, and more particularly a
vehicle seat with an improved impact energy absorption efficiency
upon rear end collision.
[0003] An occupant on a seat is rapidly moved rearward, and the
upper body of the occupant inclines rearward during a so-called
rear end collision where a rear portion of a vehicle such as a
motor vehicle is in a collision from behind, or collides hard
during a rearward travel.
[0004] Therefore, the upper body of the occupant rapidly approaches
a seatback of a vehicle seat due to the inertial force, and an
impact is applied to the body of the occupant. The seatback is
mainly constructed by placing a cushion material on a metal
seatback frame and covering the cushion material with a skin
material, which does not provide sufficient deformation amount for
the rapid rearward movement of the occupant upon rear end collision
or the like and may not efficiently reduce a load applied to the
body of the occupant. Moreover, the large load is applied to the
seatback and thus some damage may be caused to the seatback.
[0005] In order to solve the problems, Japanese Patent Document No.
4200580 ("the '580 document") proposes a technique configuring side
frames (described as side members in this document) to bend when a
rearward load is applied to an upper portion of a seatback frame,
thereby mitigating the load applied to an occupant during the
rearward movement.
[0006] Moreover, Japanese Patent Document Nos. 2000-118279 A ("the
'279 document") and 2006-213201 A ("the '201 document") propose a
seatback frame configured to have concavo-convex portions extending
in a seat width direction, formed on a lower frame (cross frame in
the '279 document) and lower frame portion in the '201 document)
constructed in the seat width direction (right and left direction)
below a seatback frame. With the recesses and protrusion provided
to extend in the seat width direction on the lower frame, when a
large load is applied rearward to the seatback frame, the
concavo-convex portions can deform, thereby absorbing impact
energy.
[0007] When a load is applied rearward as a result of a rearward
movement of the occupant upon rear end collision or the like, the
side frames bend, and the impact energy of the rearward movement is
absorbed by the seatback frame disclosed in the '580 document.
However, a position to be deformed (bent portion) cannot be limited
for deformation in the seatback in this document, and bends occur
at any points in the up and down direction on the side frames. As a
result, the bending point cannot be limited, and the impact energy
is thus transmitted to the entire seatback frame, resulting in a
decreased absorption efficiency of the impact energy.
[0008] When a large load is applied rearward to the seatback frames
disclosed in the '279 and '201 documents, the concavo-convex
portions provided in the seat width direction on the lower frame
are deformed, thereby absorbing the impact energy while the
deformed position of the seatback frame is limited to the portion
below the seatback frame.
[0009] As described above, according to the techniques of the '279
and '201 documents, the portion that tends to be bent by the large
rearward load is provided at a specific position, thereby deforming
the portion that tends to be bent, and mitigating the impact upon
rear end collision. However, a technique for increasing rigidity of
portions other than the portion that tends to bend (deformation
portion) to facilitate the restriction of the bent portion, thereby
further restricting the bent position, and efficiently absorbing
the impact energy is needed.
[0010] Moreover, a technique of sufficiently sinking the body of
the occupant into the pressure receiving member provided for the
seatback frame, thereby efficiently absorbing the impact energy, is
needed. In other words, not a technique for facilitating
deformation when a large rearward load is applied, but a technique
for providing a proper rigidity against the load and sufficiently
sinking the body of the occupant into the seatback frame, thereby
efficiently absorbing the impact energy, is needed.
SUMMARY
[0011] An object according to various embodiments of the present
invention is to provide a vehicle seat capable of providing an
improved rigidity of portions other than portions which deform to
absorb impact energy upon rear end collision, thereby efficiently
absorbing the impact energy. Moreover, another object is to provide
a vehicle seat with an improved rigidity of portions other than
portions that tend to bend (deformation portion) to facilitate
restriction of the deformation portions, thereby facilitating
guidance of the seatback frame deformation. Further, still another
object is to provide a vehicle seat capable of sufficiently sinking
the body of an occupant, thereby efficiently absorbing the impact
energy.
[0012] The problems are solved by a vehicle seat according to
various embodiments of the present invention including a pair of
side frames that are arranged on the side, and lower frames that
connect lower portions of the pair of side frames to each other; in
which a narrow portion including: a horizontal portion formed
inside the pair of side frames along a longitudinal direction with
a flexibility against a load equal to or more than a predetermined
impact load, and an inclined portion extending from the horizontal
portion via a bent portion inside the pair of side frames is formed
on the lower frame.
[0013] As described above, the vehicle seat includes the narrow
portions on the lower frame. Then, the narrow portion includes the
horizontal portion provided to extend approximately horizontally in
the longitudinal direction of the lower frame, namely in the right
and left direction of the seat, and the inclined portion extending
while bending from the horizontal portion. The horizontal portion
formed inside the side frames is configured to have the
flexibility, and, when a predetermined impact load is applied to
the vehicle seat upon rear end collision or the like, can deform to
absorb the impact energy.
[0014] The impact load applied to the seatback frame constructing
the vehicle seat upon rear end collision is a load applied mainly
rearward, in more detail, in a direction that the seatback frame
inclines rearward. Thus, when the rearward impact load is applied
to the seatback frame by the rear end collision or the like, the
horizontal portions having the narrow portions can deform (bend),
and the entire seatback frame thus deforms to incline rearward,
thereby absorbing the impact energy.
[0015] Then, the inclined portions bent and extended from the
horizontal portions are provided to extend in directions other than
the horizontal direction. Thus, when the rearward inclination load
is applied to the seatback frame upon rear end collision or the
like, the horizontal portions deform to absorb the impact energy,
while the inclined portions are hard to deform, thereby increasing
rigidity of portions other than portions where the horizontal
portions are provided. As a result, only the horizontal portions
are caused to efficiently absorb the impact energy.
[0016] Further, if the horizontal portions are provided, a lateral
load (load in a direction parallel to the extending direction of
the horizontal portions) can be received at ridge portions of the
horizontal portions, and the rigidity of the lower frame against
the lateral load can thus be increased. Further, the inclined
portions can also receive the lateral load, and the rigidity
against the lateral load is further increased.
[0017] In an embodiment, preferably, the lower frame includes a
pair of lower frame side portions arranged below the pair of side
frames, and a lower frame center portion that connects the pair of
lower frame side portions to each other; the lower frame side
portion includes a side plate joined to a side plate of the side
frame, and an intermediate plate formed by being bent from an end
portion of the side plate; and the narrow portion is formed on the
intermediate plate.
[0018] There may be provided such a configuration that lower frame
side portions and the lower frame center portion are provided as a
lower frame, and the lower frame side portions include the narrow
portions. On the lower frame side portion including the side plate
and the intermediate plate, the horizontal portion formed on the
lower frame side portion can be made thin to more easily be bent by
forming the intermediate plates in the longitudinal direction of
the lower frame, and by forming the narrow potions by machining the
intermediate plates to form a part of each of the intermediate
plates into a recessed shape. Further, this configuration can
simplify the configuration of the lower frame side portions.
Moreover, each of the lower frame side portions is constructed by
the side plate and the intermediate plate, namely plate members,
and the weight can be extremely reduced compared to a case where
the lower frame side portion is formed into a box shape or the
like.
[0019] Moreover, in this embodiment, preferably, a harness
attachment portion bulging toward a side opposite to a bulging
direction of the narrow portion is formed below the bent
portion.
[0020] In this way, the rigidity of the lower frame against the
load can be increased by forming the harness attachment portions
around the narrow portions, thereby forming multiple concavo-convex
portions including the narrow portions. Then, the load applied to
the inclined portion and the bent portion can be received by the
harness attachment portion by providing the harness attachment
portion below the bent portion of the narrow portion, resulting in
an increased rigidity of portions other than the narrow portions in
the lower frame.
[0021] Moreover, the necessity of independently forming a member
for attaching a harness is eliminated by providing the multiple
concavo-convex portions and attaching the harness to the part
thereof, resulting in space saving. Further, the necessity of
independent assembly of a member for attaching the harness is
eliminated, resulting in a reduced manufacturing process.
[0022] Further, preferably, the narrow portion is formed above the
lower frame center portion.
[0023] Preferably, the narrow portions formed on the lower frame
side portions are arranged at positions which do not overlap the
lower frame center portion (in more detail, above the lower frame
center portion). If the narrow portions are arranged at positions
which do not overlap the lower frame center portion, the rearward
load applied to the seatback frame deforms the narrow portions more
than the lower frame center portion. Thus, the impact energy is
efficiently transmitted to the narrow portions. As a result, when a
load in the rearward direction is applied to the seatback frame by
rear end collision or the like, deformation of the narrow portions
is not prevented by the lower frame center portion, resulting in
efficient absorption of the impact energy.
[0024] In an embodiment, preferably, a reinforcement portion that
reinforces the lower frame is provided at a position displaced from
the narrow portion in an up and down direction.
[0025] If the vehicle seat includes the reinforcement portion that
reinforces the lower frame at a position displaced from the narrow
portions in the up and down direction as described above, portions
other than the narrow portions of the lower frame are reinforced by
the reinforcement portion. Thus, when an impact load is applied,
the seatback frame can be restrained from deforming starting from
portions other than the narrow portions, and position restriction
on the deformation portions and guidance of deformation can be
facilitated on the seatback frame.
[0026] Moreover, preferably, the reinforcement portion is provided
below the narrow portion.
[0027] If the reinforcement portions are provided below the narrow
portions, rigidity of the portions below the narrow portions are
increased in the lower frame, and deformations below the narrow
portions are restrained when a rearward impact load is applied,
resulting in efficient transmission of the impact energy to the
narrow portions. As a result, the position restriction on the
deformation portions and the guidance of deformation are further
facilitated on the seatback frame.
[0028] Further, preferably, the reinforcement portion is provided
at a position overlapping at least partially the narrow portion in
a front to back direction.
[0029] As described above, if the reinforcement portion is provided
at a position overlapping at least partially the narrow portion in
the front to back direction, the deformations of the narrow
portions by an impact load are not prevented, and the directions of
the deformations of the narrow portions can be regulated for an
input load in a complex direction. This configuration can further
facilitate the guidance of deformation, can efficiently absorb the
impact energy, and can properly deform the seatback frame.
[0030] In an embodiment, preferably the vehicle seat further
includes a pressure receiving member that is connected to the pair
of side frames via a connection member to support an occupant; and
an impact reducing member that is arranged at least on one of the
side frames and is connected to the connection member, to move the
pressure receiving member rearward by a predetermined impact load
applied to the pressure receiving member.
[0031] As described above, rearward inclination (rearward movement)
of an occupant can be facilitated by receiving the body of the
occupant moving rearward on the pressure receiving member upon rear
end collision or the like, and configuring the pressure receiving
member to be able to move rearward. Then, the impact energy can be
more efficiently transmitted to the lower frame side portions
constructing the seatback frame by facilitating the rearward
inclination of the occupant. As a result, the impact energy due to
a rear end collision or the like can be more efficiently
absorbed.
[0032] Accordingly, in an embodiment, there can be provided a
vehicle seat which includes the narrow portions each provided with
the horizontal portion and the inclined portion, in which only the
horizontal portions are bent, thereby efficiently absorbing an
impact energy when an impact load is applied by a rear end
collision or the like.
[0033] Accordingly, in an embodiment, the narrow portions formed on
the lower frame side portions can be bent by a large amount, and
the impact energy can be more efficiently absorbed by the narrow
portions.
[0034] Accordingly, in an embodiment, the number of components can
be reduced, and a vehicle seat high in absorption efficiency of the
impact energy by increasing the rigidity of portions other than the
narrow portions can be provided.
[0035] Accordingly, in an embodiment, a vehicle seat which can more
efficiently absorb impact energy without degradation of absorption
efficiency of the impact energy by way of the lower frame center
portion upon rear end collision can be provided.
[0036] Accordingly, in an embodiment, when an impact load is
applied, the seatback frame can be prevented from deforming
starting from portions other than the narrow portions, and the
position restriction of the deformation portions, and the guidance
of deformation can be facilitated on the seatback frame.
[0037] Accordingly, in an embodiment, the deformations are
restrained below the narrow portions, and the position restriction
of the deformation portions, and the guidance of deformation can be
further facilitated.
[0038] Accordingly, in an embodiment, deformations of the narrow
portions by an impact load are not prevented, and the direction of
the deformations of the narrow portions can be regulated for an
input load in a complex direction.
[0039] Accordingly, in an embodiment, the vehicle seat does not
prevent the rearward inclination of the occupant, secures a
sufficient sinking amount, and efficiently absorbs the impact
energy caused by the rearward inclination load.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a schematic perspective view of a seat according
to a first embodiment of the present invention.
[0041] FIG. 2 is a schematic perspective view of a seat frame
according to the first embodiment of the present invention.
[0042] FIG. 3 is a front view of the seat frame according to the
first embodiment of the present invention.
[0043] FIG. 4 is a rear view of the seat frame according to the
first embodiment of the present invention.
[0044] FIG. 5 is a schematic perspective view of lower frame side
portions according to the first embodiment of the present
invention.
[0045] FIG. 6 is a cross sectional view taken along the A-A line in
FIG. 5.
[0046] FIG. 7 is an explanatory diagram showing a state of the
lower frame side portion after a rear end collision according to
the first embodiment of the present invention.
[0047] FIG. 8 is a schematic perspective view of the seat according
to a second embodiment of the present invention.
[0048] FIG. 9 is a partially enlarged explanatory diagram of a
lower frame center portion and a frame side portion according to
the second embodiment of the present invention.
[0049] FIG. 10 is a partial cross sectional view of a lower frame
according to the second embodiment of the present invention.
[0050] FIG. 11 is a rear view of the seat frame according to the
second embodiment of the present invention.
DETAILED DESCRIPTION
[0051] A description will now be given of an embodiment of the
present invention referring to drawings. It should be noted that
members, arrangements, and the like described below do not limit
the present invention, and can be modified in various ways within
the purport of the present invention. Moreover, a vehicle herein
refers to a vehicle for travel on which a seat can be installed
such as a ground traveling vehicle having wheels such as a motor
vehicle and a railroad vehicle, and air planes and ships which do
not travel on the ground. Moreover, a normal seating load includes
a seating impact generated during seating, and a load during
acceleration generated when the vehicle starts rapidly. Moreover,
impact energy upon rear end collision is energy by a large load
generated upon rear end collision, is caused by a large collision
of a vehicle from behind or a serious collision during a rearward
travel, and does not include energy by a load in a load range
similar to a load generated during normal seating.
[0052] FIGS. 1 to 7 relate to a first embodiment of the present
invention. A description will now be given of a vehicle seat S
according to a first embodiment referring to FIGS. 1 to 7.
[0053] The vehicle seat S is constructed by a seatback S1 (back
portion), seat base portion S2, and a headrest S3 as shown in FIG.
1, the seatback S1 (back portion) and the seat base portion S2 are
respectively formed by placing cushion pads 1a and 2a on the seat
frame F, and covering them with skin materials 1b and 2b. The
headrest S3 is formed by placing a pad material 3a on a core
material (not shown) for a head portion, and covering them with a
skin material 3b. Moreover, reference numeral 19 denotes headrest
pillars for supporting the headrest S3.
[0054] The seat frame F for the vehicle seat S is constructed by a
seatback frame 1 for constructing the seatback S1, and a seat base
frame 2 for constructing the seat base portion S2 as shown in FIG.
2.
[0055] The seat base frame 2 is formed by placing the cushion pad
2a, and covering the cushion pad 2a with the skin material 2b as
described above, and is configured to support an occupant from the
underside. The seat base frame 2 is supported by a leg portion (not
shown), inner rails, which are not shown, are attached to the leg
portion, and are assembled to outer rails installed on a floor of a
vehicle body to slide for adjusting the position in a front to back
direction.
[0056] Moreover, a back end portion of the seat base frame 2 is
connected to the seatback frame 1 via a reclining mechanism 11.
[0057] The reclining mechanism 11 includes at least a reclining
shaft 11a along a rotation axis of the reclining mechanism 11, and
the reclining shaft 11a is arranged thorough shaft insertion holes
17c (refer to FIG. 6) formed on the pair of lower frame side
portions 17 (member sides) provided below the seatback frame 1 (in
more detail, a pair of side frames 15) to protrude therefrom on
side portions of the seat frame F.
[0058] The seatback S1 is formed by placing the cushion pad 1a on
the seatback frame 1, and covering the cushion pad 1a with the skin
material 1b, and supports the back of the occupant from behind.
According to this embodiment, the seatback frame 1 is a frame body
in approximately a rectangular shape as shown in FIG. 2, and
includes the side frames 15, an upper frame 16, and the lower frame
side portions 17.
[0059] The two (the pair of) side frames 15 define a seatback
width, and are arranged to be separated in the right and left
direction, and to extend in the up and down direction. Then, the
upper frame 16 for connecting the upper end portion sides of the
pair of the side frames 15 to each other extends upward from the
side frames 15. The upper frame 16 extends upward from one of the
side frames 15, bends, and extends to the other side frame 15.
[0060] A lower frame of the seatback frame 1 is constructed by the
lower frame side portions 17 and a lower frame center portion 18.
The lower frame center portion 18 (member center) is formed to
connect the pair of the lower frame side portions 17 arranged to be
separated in the right and left direction to each other, and is
arranged to be in contact with the lower frame side portions 17.
The lower frame side portions 17 are connected to bottom sides of
the side plates 15a of the side frames 15. Then, the lower frame
side portions 17 are formed to extend below the side plates 15a,
and extend within a range which does not cause a problem with the
seat base frame 2.
[0061] Although, in the seatback frame 1 according to this
embodiment, the side frames 15 and the lower frame side portions 17
are formed by independent members, the side frames 15 and the lower
frame side portions 17 may be an integral plate frame or the
like.
Lower Frame Side Portion 17
[0062] The side frames 15, the lower frame side portions 17, and
the lower frame center portion 18 are formed as independent
members, and can be easily assembled.
[0063] The lower frame side portion 17 includes a side plate 17a
joined to the side plate 15a of the side frame 15, and an
intermediate plate 17b formed to be folded from a rear end portion
of the side plate 17a at approximately the right angle as shown in
FIG. 5. The shaft insertion hole 17c for inserting the reclining
shaft 11a is formed at a bottom of the side plate 17a.
[0064] Moreover, multiple attachment holes 17d for attaching the
lower frame side portion 17 to the side frame 15 are formed above
the shaft insertion hole 17c on the side plate 17a. Holes are
formed in lower portions of the side frames 15 at positions
corresponding to the attachment holes 17d when the side plates 17a
overlap, and joining elements such as bolts run through the holes
formed on the side frames 15 and the attachment holes 17d of the
lower frame side portions 17, thereby joining the side frames 15
and the lower frame side portions 17 to each other.
[0065] Then, a flexible narrow portion 17e as a weak portion for
efficiently absorbing impact energy upon rear end collision is
formed on each of the intermediate plate 17b as shown in FIG. 6.
The narrow portion 17e serving as the weak portion is a recessed
portion formed to be approximately semicircular in cross section to
bulge forward, and is formed inside the side frame 15 in the right
and left direction, namely along the widthwise direction of the
seat. In this way, a horizontal portion (horizontal potion 17f) in
the narrow portion 17e formed to be approximately semicircular in
cross section on the lower frame side portion 17 can bend, and
deforms to collapse in the up and down direction (refer to FIG. 7)
when a predetermined impact load (impact load larger than that
during normal seating) is applied to the seatback frame 1 upon rear
end collision or the like. As a result, the rearward inclination
load can be efficiently absorbed. Moreover, the horizontal portion
17f is provided to extend along the seat width direction, namely
the longitudinal direction of the lower frame center portion 18,
and even when a load in the right and left direction is applied, a
ridge portion can receive the load, resulting in an extreme
increase in rigidity of the lower frame side portion 17.
[0066] The horizontal portion 17f extends to a border portion
between the intermediate plate 17b and the side plate 17a as shown
in FIG. 5, and thus tends to deform when a load is applied, thereby
efficiently absorbing the energy of the rearward inclination
load.
[0067] Then, the narrow portion 17e bends upward as the narrow
portion 17e approaches the inside of the seat, and extends to an
upper end portion of the intermediate plate 17b. In other words,
the narrow portion 17e includes the horizontal portion 17f and an
inclined portion 17h provided to extend from the horizontal portion
17f via a bent portion 17g.
[0068] As described above, the narrow portion 17e is not configured
to have only the horizontal portion 17f extending straight in the
horizontal direction, but to include the bent portion 17g, and the
portion (inclined portion 17h) which is provided to extend in a
direction other than the approximately horizontal direction, namely
an oblique direction, can thus absorb energy when a load which
deforms the seatback frame 1 to incline the seatback frame 1
rearward is applied by the rear end collision or the like, for
example, and increases in rigidity against the load.
[0069] Although the inclined portion 17h may be formed to be
approximately vertical with respect to the horizontal portion 17f,
the inclined portion 17h is preferably formed to be inclined with
respect to the horizontal portion 17f. In other words, the inclined
portion 17h is preferably configured to form an acute angle or an
obtuse angle with respect to the horizontal portion 17f. If the
inclined portion 17h is formed to be approximately vertical with
respect to the horizontal portion 17f, the inclined portion 17h
increases the rigidity of the intermediate plate 17b when a load to
incline the seatback frame 1 rearward is applied, and the
horizontal portion 17f is harder to be deformed by the rearward
inclination load. The inclined portion 17h is configured to form an
acute angle or an obtuse angle with respect to the horizontal
portion 17f, the intermediate plate 17b appropriately deforms,
thereby bending the horizontal portion 17f.
[0070] Moreover, a harness attachment portion 17i bulging toward a
side opposite to the bulging direction of the narrow portion 17e is
formed below the bent portion 17g. In other words, the harness
attachment portion 17i is formed to bulge rearward below the bent
portion 17g. In this way, the multiple concavo-convex shapes are
formed on the intermediate plates 17b by forming the harness
attachment portions 17i on the side opposite to the bending
direction of the bent portions 17g of the narrow portions 17e
(namely, on an obtuse angle side formed between the horizontal
portion 17f and the inclined portion 17h) on the intermediate
plates 17b, resulting in an increase in rigidity of the lower frame
side portions 17 (particularly rigidity in a neighborhood of the
bent portions 17g) against the load. As a result, when an impact
load is applied upon rear end collision or the like, the horizontal
portion 17f, the bent portion 17g, and the inclined portion 17h of
each narrow portion 17e deform without bending portions other than
the narrow portions 17e to absorb impact energy.
[0071] As described above, the harness attachment portion 17i is
formed to bulge rearward at the position below the narrow portion
17e on each of the intermediate plates 17b, and functions as a
reinforcement portion which prevents portions other than the narrow
portion 17e from bending when an impact load is applied upon rear
end collision. The increased rigidity resulting from the
concavo-convex shapes restricts the rearward deformations of the
harness attachment portions 17i, the seatback frame 1 can be
prevented from deforming from portions other than the narrow
portions 17e, and the position restriction on the deformation
portions and the guidance of deformation are facilitated on the
seatback frame 1.
[0072] Multiple attachment holes 17j are also formed on the
intermediate plate 17b. Joining elements such as bolts pass through
the attachment holes 17j when other member (such as an actuator) is
attached to the seat frame F.
[0073] There are provided such effects that a space is saved for
attaching other member and the number of components is further
reduced by providing the harness attachment portion 17i and the
attachment holes 17j on the intermediate plate 17b in this way.
Moreover, the harness attachment portion 17i has the function as
the reinforcement portion provided rearward of each of the narrow
portions 17e, can provide both the function of attaching components
and the function as the deformation guide for restricting the
deformation portions of the seatback frame, and contributes to the
deformations of the seatback frame while reducing the number of
components.
[0074] The lower frame center portion 18 is joined to the side
plates 17a or the intermediate plates 17b of the pair of lower
frame side portions 17. If the lower frame center portion 18 is
joined to both the side plates 17a and the intermediate plates 17b,
attachment rigidity is increased. Further, if side end portions of
the lower frame center portion 18 are formed to come in contact
with the side plates 17a, rigidity against a lateral load is
increased. Although the lower frame center portion 18 is arranged
forward of the intermediate plates 17b in this embodiment, the
lower frame center portion 18 may be arranged behind the
intermediate plates 17b.
[0075] The narrow portions 17e are preferably formed at positions
which do not overlap the lower frame center portion 18, and are
above the lower frame center portion 18. If there is provided such
a configuration that the narrow portions 17e are provided at
positions which do not overlap the lower frame center portion 18 as
described above, when a load in the direction of rearward
inclination is applied to the seatback frame 1, the deformations of
the narrow portions 17e are not prevented by the lower frame center
portion 18.
[0076] In other words, the lower frame center portion 18 is at a
position displaced in the up and down direction from the narrow
portions 17e, and is provided below the narrow portions 17e. As a
result of this arrangement, the lower frame center portion 18
functions as a reinforcement portion for increasing rigidity of
portions below the narrow portions 17e when a load in the direction
of rearward inclination is applied to the seatback frame 1 upon
rear end collision. Thus, the lower frame side portions 17 can be
prevented from bending from portions other than the narrow portions
17e, and the position restriction on the deformation portions of
the seatback frame 1 and the guidance of deformation are
facilitated.
[0077] The upper frame 16 formed by a member having a closed
sectional shape (such as a circular or rectangular sectional shape)
is bent in a substantially U shape as shown in FIG. 2. Then, the
side surface portions 16a of the upper frame 16 are arranged to
partially overlap the side plates 15a of the side frames 15 in the
up and down direction, and are anchored to the side frames 15 at
the overlapped portions. Although the upper frame 16 is constructed
by the tubular member having the circular cross section in the
first embodiment, the upper frame 16 may be constructed by a
tubular member having a rectangular cross section.
[0078] Moreover, the headrest S3 is arranged above the upper frame
16. The headrest S3 is constructed by providing the pad member 3a
on an outer peripheral portion of the core material (not shown),
and covering the pad material 3a with the skin material 3b as
described before. Pillar support portions 19a are arranged on the
upper frame 16. Headrest pillars 19 (refer to FIG. 1) for
supporting the headrest S3 are attached via guide locks (not shown)
to the pillar support portions 19a to attach the headrest S3.
Although an example where the seatback S1 and the headrest S3 are
formed independently of each other is described in the first
embodiment, the seatback S1 and the headrest S3 may be integrated,
which is a configuration of the bucket type seat.
[0079] The side frames 15 partially constructing the seatback frame
1 are extending members for constructing side surfaces of the
seatback frame 1 as shown in FIG. 2, and include the side plates
15a in a flat plate shape, front edge portions 15b each bent inward
and folded back in a U shape from a front edge portion (end portion
located on the vehicle front side) of the side plates 15a, and rear
edge portions 15c each bent inward in an L shape from rear end
portions.
[0080] A protruded portion 15d protruding toward the rear edge
portion 15c side is formed on the front edge portion 15b according
to this embodiment, and a lock hole serving as a lock portion for
locking an extension coil spring 35 is formed on the protruded
portion 15d.
[0081] Then, moving members 30, described later, are locked to the
side frames 15 according to this embodiment. A configuration and an
action of the moving members 30 are described later.
Pressure Receiving Member 20
[0082] The pressure receiving member 20 as a pressure receiving
member for supporting the cushion pad 1a from behind is arranged on
an inside area of the seatback frame 1 inside the seatback frame 1
(between the side frames 15).
[0083] The pressure receiving member 20 according to this
embodiment is a member obtained by forming a resin into a plate in
approximately a rectangular shape, and smooth concavo-convex
portions are formed on a surface in contact with the cushion pad
1a. Pawl portions for locking a wire 21 serving as a top connection
member, and a wire 22 serving as a bottom connection member are
formed on a top side and a bottom side of the pressure receiving
member 20 as shown in FIG. 2.
[0084] The pressure receiving member 20 according to this
embodiment is supported by the connection members. In other words,
the two wires 21 and 22 serving as the connection members are
provided between the side frames 15 on the both sides, and engage
with the pressure receiving member 20 by the pawl portions formed
at predetermined positions on the top side and the bottom side on
the rear side of the pressure receiving member 20 to support the
pressure receiving member 20 on a rear surface of the cushion pad
1a. The wires 21 and 22 are formed by a springy steel wire
material, and have concavo-convex portions, which are bent
portions, formed thereon.
[0085] Particularly, the wire 21 positioned above in the two wires
21 and 22 locked to the pressure receiving member 20 according to
this embodiment is constructed by a wire thinner than the wire 22
positioned below. As a result, the pressure receiving member 20
tends to move rearward more at the upper portion than at the lower
portion.
[0086] Moreover, the wire 22 is constructed by a thicker wire
material, is thus high in rigidity, and is hard to deform during
normal seating. Thus, the upper portion of the pressure receiving
member 20 supported by the wire 21 constructed by the thinner wire
material tends to move rearward, and the lower portion of the
pressure receiving member 20 supported by the wire 22 constructed
by the thicker wire material does not move rearward greatly during
normal seating. As a result, the upper portion of the pressure
receiving member 20 properly sinks rearward, and the lower portion
supports the body of the occupant during normal seating, thereby
preventing sense of seating from degrading.
[0087] Further, there is provided such a configuration that the
wires 21 and 22 have the concavo and convex portions formed
thereon, and are thus deformed greatly by a load more than a
predetermined load (load larger than a load for moving or pivoting
impact reducing members described later) to move rearward the
pressure receiving member 20 by a larger movement quantity.
[0088] As illustrated in FIG. 2, both end portions of the wire 21
locked to the top side out of the two wires 21 and 22 locked to the
pressure receiving member 20 according to this embodiment are
hooked on journal portions 21a provided on the side frames 15 on
the both sides. Both end portions of the wire 22 locked to the
bottom side are hooked on the moving members 30 installed on the
right and left side frames 15.
[0089] The wire 22 constructed by the thicker wire material than
the wire 21 is hard to deform as described above, and the lower
portion of the pressure reception portion 20 is thus hard to move
rearward during normal seating. Thus, the moving members 30 are
attached to the end portions of the wire 22 for securing a
sufficient sinking amount upon rear end collision.
Moving Member 30
[0090] The moving members 30 serving as impact reducing members are
moved rearward of the vehicle by an impact load transmitted via the
connection member (wire 22), and simultaneously move rearward the
pressure receiving member 20 to move rearward the occupant when an
impact load larger than the predetermined impact load is applied to
the pressure receiving member 20 upon rear end collision or the
like. The "movement" refers to motions such as horizontal
translation or pivoting. A description will now be given of the
moving members 30 that pivot about shaft portions 32 as pivot axes
according to this embodiment. The pressure receiving member 20 can
be moved greatly rearward of the vehicle by the movement of the
moving members 30 to consequently move rearward the occupant, and
the load applied to the occupant can be efficiently reduced.
[0091] The moving members 30 are pivotally journaled via the shaft
portions 32 serving as pivot axes to the insides of the side plates
15a of the side frames 15 on the both sides, lock the wire 22 at
the bottom position serving as the connection member, and are
connected to the springs (extension coil springs 35) serving as
biasing elements for biasing the wire 22 according to this
embodiment as shown in FIG. 2. In other words, the moving members
30 are connected to the biasing elements 35, and are configured to
bias the pressure receiving member 20 via the wire 22 serving as
the connection member forward of the seatback frame 1.
[0092] Then, the moving members 30 according to this embodiment are
journaled by the pivotable shaft portions 32 to the inside of the
side frames 15, in more detail, to convex portions 15e formed by
bulging parts of the side plates 15a toward the inside of the
seat.
[0093] The above-described moving members 30 are attached to the
side frames 15 on both sides, both ends of the wire 22 are hooked
to the moving members 30 respectively arranged on both sides, and
there is provided such a configuration that the respective moving
members 30 are individually activated.
[0094] According to this embodiment, the moving members 30 are
attached to the side frames 15 on both sides, and the moving
members 30 attached to both sides are configured to move (pivot)
independently of each other. As a result, if a generated load is
biased in the right and left direction, the moving members 30
attached to the side frames 15 on both sides move (pivot)
independently of each other according to the load, and the body of
the occupant can sink according to the magnitude of the impact
load.
[0095] A description will now be given of configurations and
actions of the pressure receiving member 20 and the moving members
30.
[0096] A tensile force of moving rearward (pivoting) the moving
members 30 via the cushion pad 1a, the pressure receiving member
20, and the wire 22 inside the seatback S1 is generated during
normal seating where the occupant is seated. The extension coil
springs 35 bias the moving members 30 to move (pivot) forward of
the seatback frame 1. On this occasion, the extension coil springs
35 connected to the moving members 30 have a load characteristic
which does not present an extension in a load range generated
during normal seating, and the moving members 30 are always held at
initial positions. In other words, there is provided such a
configuration that a force of returning the moving members 30 to
the initial state resisting the force of moving (pivoting) the
moving members 30 is maximized during normal seating.
[0097] Then, a movement preventing portion 39 provided for each of
the moving members 30 is an abutment portion for abutting against a
rear edge portion 15c of the side frame 15 to prevent the motion
(pivoting) after the moving member 30 moves (pivots).
[0098] The movement preventing portion 39 of the moving member 30
is integrally formed by extending the moving member 30 in an outer
peripheral direction, an abutment surface thereof abuts against the
side frame 15 (rear edge portion 15c in more detail) after the
movement (pivot), and the movement (pivot) of the moving member 30
can be stably and reliably stopped even if an impact load more than
the predetermined load is applied to the pressure receiving member
20 due to a rear end collision or the like.
[0099] The movement preventing portion 39 is formed at a position
which does not interfere with the biasing element (extension coil
spring 35) and the connection member (wire 22).
[0100] Although the movement preventing portions 39 of the moving
members 30 directly abut against the side frames 15 to prevent the
movement (pivoting) according to this embodiment, a sound reducing
member such as rubber having such a thickness as not to obstruct
stability of stopping the movement (pivoting) of the moving members
30 may be attached to each of gaps between the movement preventing
portion 39 and the side frame 15 in order to remove noise generated
upon the abutment, this configuration can stably prevent the
movement (pivoting), and a sound reduction effect is expected.
[0101] The moving members 30 abut against the side frames 15
(portions formed by partially cutting out the convex portions 15e
in more detail) in a normal state, which prevents a force applied
upward by the extension coil springs 35, and restricts a movement
(pivoting) range to prevent an excessive forward movement
(pivoting) of the moving members 30.
[0102] Then, when the occupant starts moving rearward by inertia
upon rear end collision, a load thereof generates a tension in the
direction to move (pivot) rearward the moving members 30 via the
pressure receiving member 20 and the wire 22 locked to the pressure
receiving member 20. The tensile force extends the extension coil
springs 35, which hold the moving members 30 at the initial
positions on this occasion, to form a load sufficient to move
(pivot) rearward the moving members 30.
[0103] A threshold for a force starting the movement (pivoting) of
the moving members 30 is set to a value larger than the normal
seating load.
[0104] In this situation, regarding the threshold for the force
starting the movement (pivoting) of the moving members 30, the load
applied to the seatback S1 is approximately 150 N in the normal
seating state (here, small impacts generated by a seating impact
and a rapid start of the vehicle are excluded), and the threshold
is thus preferably a value larger than 150 N.
[0105] Moreover, considering the seating impact generated during
normal seating, and the load caused by an acceleration generated by
the rapid start of the vehicle or the like, the threshold is
preferably set to a value larger than 250 N, if the threshold is
set in this way, the moving members 30 are not activated in cases
other than the rear end collision, and the stable state can be
maintained.
[0106] The wire 22 hooked on the moving members 30 can be moved
rearward by moving (pivoting) the moving members 30 rearward as
described above, and simultaneously, the pressure receiving member
20 locked to the wire 22 and the cushion pad 1a supported by the
pressure receiving member 20 can be moved rearward to sink the
occupant into the seatback S1.
[0107] The moving members 30 have the movement (pivoting)
characteristic for the tensile force generated via the wire 22 as
described above, and can thus reliably and efficiently sink the
occupant into the cushion pad 1a of the seatback S1 when a rear end
collision is generated.
[0108] The back of the occupant sinks into the seatback S1 and thus
moves rearward on this occasion, the position of the headrest S3
does not change with respect to the seatback S1, a gap between the
headrest S3 and the head of the occupant decreases, the head can
thus be supported by the headrest S3, and an impact applied to the
neck can be efficiently reduced.
[0109] Although the example where the moving members 30 are
provided on the side frames 15 on both right and left sides is
described in the embodiment, there may be provided such a
configuration that the moving member 30 may be provided only on one
of the side frames 15. In this case, there may be provided such a
configuration that the wires 21 and 22 are directly locked to the
side frame 15 on which the moving member 30 is not provided.
[0110] As described above, in the vehicle seat S, the moving
members 30 serving as the impact reducing members are arranged on
the side frames 15 to rearward sink the body of occupant upon rear
end collision. Then, the narrow portions 17e are provided on the
lower frame side portions 17 to efficiently absorb energy of the
rearward inclination load applied to the seatback frame 1 by the
body of the occupant sinking rearward.
[0111] The narrow portion 17e including the horizontal portion 17f
and the inclined portion 17h is formed on each of the lower frame
side portions 17 as described above. The narrow portions 17e are
formed to bulge toward the seating side of the occupant, and each
of the lower frame side portions 17 deforms to bend about the
narrow portion 17e as a base point, thereby absorbing impact energy
upon rear end collision or the like when the occupant rapidly moves
rearward upon rear end collision. The protrusion may bulge rearward
if the lower frame side portion 17 can be sufficiently bent.
[0112] The lower frame side portion 17 includes the narrow portion
17e having the cross section in approximately the arc shape on the
intermediate plate 17b forming the lower frame side portion 17 as
shown in FIG. 6. Then, there is provided such configuration that,
when the occupant moves rearward, and a load of rearward
inclination is applied to the seatback frame 1 upon rear end
collision or the like, the narrow portions 17e deform as shown in
FIG. 7, and the intermediate plates 17b bend rearward about the
narrow portions 17e as the base points.
[0113] Thus, the plate thickness of portions constructing the
narrow portions 17e may be formed to be thin in order to facilitate
the deformations of the narrow portions 17e as long as the narrow
portions 17e have strength withstanding the normal load.
[0114] Then, the narrow portion 17e is constructed by the
horizontal portion 17f and the inclined portion 17h across the bent
portion 17g as a border.
[0115] In this way, the inclined portion 17h is provided in
addition to the horizontal portion 17f, which enables not only the
absorption of the load energy by deformation of the horizontal
portion 17f, but also the increase in strength against the load by
the inclined portion 17h. Thus, portions other than the horizontal
portion 17f are prevented from deforming, and the rigidity of the
lower frame side portion 17 can be increased, resulting in
efficient absorption of the impact energy upon rear end
collision.
[0116] Further, the vehicle seat S includes the pressure receiving
member 20 connected to the moving members 30, and can thus
sufficiently sink the occupant in the seatback S1 upon rear end
collision or the like. Then, the narrow portions 17e of the lower
frame (lower frame side portions 17 in more detail) include the
inclined portions 17h, and the intermediate plates 17b thus have
proper rigidity. The sinking of the pressure receiving member 20
and the moving members 30 with respect to the side frames 15 and
the upper frame 16 can thus be facilitated, resulting in efficient
absorption of the impact energy generated by a rear end collision
or the like.
[0117] A description will now be given of the vehicle seat
according to a second embodiment referring to FIGS. 8 to 11. In the
second embodiment, like members, arrangements, and the like are
denoted by the same numerals as of the first embodiment, and a
detailed description thereof is therefore omitted.
[0118] A lower frame center portion 58 of the vehicle seat S
according to this embodiment is formed by folding a single plate
body into approximately a hollow quadrangular prism form, and
includes a forward bulging portion 58a, a rear surface 58b opposed
to the forward bulging portion 58a, and a connection surface 58c
for connecting the forward bulging portion 58a and the rear surface
58b to each other as shown in FIGS. 8 to 10. Regarding the lower
frame center portion 58 according to this embodiment, the forward
bulging portion 58a is arranged to bulge forward of the reclining
shaft 11a, thereby covering the reclining shaft 11a from the front
side.
[0119] The lower frame center portion 58 according to this
embodiment is connected to the lower frame side portions 17 by
joining the rear surface 58b opposed to the forward bulging portion
58a and arranged on the rear side to the intermediate plates 17b of
the lower frame side portions 17. The rear surface 58b and the
lower frame side portions 17 may be joined by way of any method
such as welding or fastening by fasteners such as screws and
bolts.
[0120] The lower frame center portion 58 is arranged at a position
corresponding to the lower back of the occupant when the occupant
is seated, and is arranged forward of the narrow portions 17e as
shown in FIG. 10. Thus, the lower frame center portion 58 receives
an impact load applied by the back of the occupant via the cushion
pad 1a and the skin material 1b placed on the seatback frame 1 upon
rear end collision on a part forward of the intermediate plates 17b
of the lower frame side portions 17, and functions as a
reinforcement portion for increasing the rigidity of the lower
frame side portions 17 against the impact load.
[0121] If the reinforcement portion is arranged forward of the
narrow portions 17e, an input of the load from the front side to
portions of the seatback frame 1 overlapping the reinforcement
portion in the front to back direction is restricted, and
deformations are restrained from generating from portions other
than the narrow portions 17. Thus, when an impact load is applied
from the front side, the seatback frame 1 can be prevented from
deforming starting from portions other than the narrow portions
17e, and the position restriction on the deformation portions, and
the guidance of deformation can be facilitated on the seatback
frame 1.
[0122] The lower frame center portion 58 serving as the
reinforcement portion is at a position displaced from the narrow
portions 17e in the up and down direction, and is below the narrow
portions 17e, and a upper end 58d of the lower frame center portion
58 overlaps the narrow portions 17e in the front to back direction
as shown in FIGS. 9 and 10. Further, the rear surface 58b, which is
a joint surface to the intermediate plates 17b is attached to the
position which does not overlap the narrow portions 17e in the
front to back direction, and is below the narrow portions 17e.
Moreover, an upper end 58e of the rear surface 58b is arranged
below the horizontal portions 17f to align with the extension
direction of the horizontal portions 17f of the narrow portions
17e, namely the longitudinal direction (seat width direction) of
the lower frame center portion 58.
[0123] In this way, the lower frame center portion 58 is arranged
at the position displaced in the up and down direction from the
narrow portions 17e, namely at a different level, and the
deformations of the narrow portions 17e generated when an impact
load is applied to the rear side of the seatback frame 1 are not
prevented by the lower frame center portion 58. Moreover, the
seatback frame 1 can be restrained from deforming from portions
other than the narrow portions 17e, and the position restriction on
the portions where the seatback frame 1 deforms and the guidance of
deformation are facilitated. According to this embodiment, the
lower frame center portion 58 is arranged below the narrow portions
17e, more specifically, the rear surface 58b of the lower frame
center portion 58 is attached to the intermediate plates 17b below
the narrow portions 17e, rigidity below the narrow portions 17e
thus increases to restrain deformations, and the impact energy upon
rear end collision can be efficiently transmitted to the narrow
portions 17e.
[0124] Moreover, at least a part of the lower frame center portion
58, the upper end 58d according to this embodiment, is arranged at
the position overlapping the narrow portions 17e in the front to
back direction, the input direction can thus be regulated for an
input load in a complex direction, the direction of the
deformations of the narrow portions 17e can be regulated, and the
portions generating the deformations of the seatback frame 1 can be
more properly restricted.
[0125] Further, the upper end 58e of the rear surface 58b is
aligned with the extension direction of the horizontal portions 17f
of the narrow portions 17e, and the guidance of the direction of
the deformations and a deformation shape of the seatback frame 1
can be facilitated.
[0126] Side end portions 58f on both right and left sides of the
forward bulging portion 58a according to this embodiment are
separated from the side plates 17a of the lower frame side portions
17, and are not fixed to the side portions of the seatback frame 1.
Although FIG. 9 shows only the side end portion 58f on the left
side viewed from the front side of the vehicle seat S, the side end
portion on the right side has the same configuration. In this way,
the configuration where the forward bulging portion 58a is not
connected to the side plates 17a does not excessively increase the
rigidity of reinforcement portion, and does not influence the
deformations of the seatback frame 1 upon impact load.
[0127] Although the reinforcement portion is arranged below the
narrow portions 17e which are the portions where the deformations
(bends) of the seatback frame 1 are generated according to this
embodiment, there may be provided such a configuration that the
reinforcement portion may be provided above the portions where the
deformations are generated as the relationship between the portions
where the deformations are generated and the reinforcement portion.
If the reinforcement portion is arranged at the position which is
above and does not overlap, in the front to back direction, the
portions where the deformations are generated in this way, the
position restriction on the portions where the deformations are
generated is facilitated similarly.
[0128] A description will now be given of actions of the forward
bulging portion 58a and the moving members 30 upon rear end
collision.
[0129] The forward bulging portion 58a according to this embodiment
is arranged at the position corresponding to the back of the
occupant when the occupant is seated, and is configured to bulge
toward the back of the occupant. As a result, the forward bulging
portion 58a has a function of a back entrance preventing member for
pushing and stopping a rearward movement of the back of the
occupant upon rear end collision.
[0130] When the occupant receives an impact upon rear end
collision, the occupant is rapidly moved rearward, and the lower
back of the occupant comes in contact with the forward bulging
portion 58a, and the rearward movement is stopped. As a result, the
entire upper body of the occupant inclines (rotates) rearward, and
an upper portion of the upper body moves rearward more, and sinks
into the seatback S1. Then, the load caused by the rearward
movement of the occupant is applied to the pressure receiving
member 20, the tensile force is applied in the direction of moving
(pivoting) the moving members 30 rearward via the wire 22 locked to
the pressure receiving member 20, and the moving members 30 move
rearward. The movement of the moving members 30 greatly moves the
pressure receiving member 20 rearward, the sinking quantity of the
occupant increases, and the impact load is absorbed.
[0131] The moving members 30 are provided above the positions of
the narrow portions 17e on the side frames 15, the impact load is
applied above the narrow portions 17e, and the impact load can be
absorbed by the deformations of the seatback frame 1.
[0132] The impact load can be absorbed by the action of the moving
members 30, the impact load can be absorbed by the action of the
narrow portions 17e as described above, and the impact load can
thus be absorbed more efficiently.
[0133] Although the lower frame center portion 58 is arranged as
the reinforcement portion on the front side of the narrow portions
17e in the second embodiment, the arrangement of the reinforcement
portion is not limited to this example, and the reinforcement
portion may be arranged on the rear side of the narrow portions
17e.
[0134] FIG. 11 is a rear view of the seat frame showing another
example of the reinforcement portion according to the second
embodiment. A reinforcement member 59 in a plate shape is provided
as the reinforcement portion rearward of the lower frame (lower
frame side portions 17 and the lower frame center portion 58) in
this example as shown in FIG. 11. The reinforcement member 59 is
provided at a position displaced from the narrow portions 17e in
the up and down direction and below the narrow portions 17e, and a
upper end 59a is aligned with the extension direction of the
horizontal portions 17f, namely, in the longitudinal direction
(seat width direction) of the lower frame center portion 58.
[0135] If the reinforcement member 59 is arranged rearward of the
narrow portions 17e in this way, when an impact load is applied, a
rearward deformation of a portion of the seatback frame 1
overlapping the reinforcement member 59 in the front to back
direction is restricted, and deformations are restrained from
generating from portions other than the narrow portions 17e. As a
result, the position restriction on the deformation portions and
the guidance of deformation are facilitated on the seatback frame
1.
[0136] The vehicle seat according to the second embodiment can
stably deform the seatback frame at the specific portions for a
complex input load upon rear end collision, and can increase
rigidity of portions other than the specific portions which tend to
deform, thereby facilitating the position restriction on the
deformation portions, and facilitating the guidance of deformation
as described above. Thus, even if a complex input load is applied
upon rear end collision, impact energy can be efficiently and
stably absorbed. Further, the back entrance preventing member is
provided for stopping the rearward movement of the lower back of
the occupant upon rear end collision, the upper body of the
occupant can be greatly moved rearward, thereby increasing the
sinking quantity of the occupant, and the impact load can be more
efficiently absorbed.
[0137] Although the respective embodiments are described for the
seatback of the front seat of a motor vehicle as specific examples,
the seatback is not limited to the example, and it should be
understood that the same configuration can be applied to the
seatback of a rear seat.
TABLE-US-00001 TABLE OF REFERENCE CHARACTERS s vehicle seat s1
seatback s2 seat base s3 headrest f seat frame 1 seatback frame 2
seat base frame 1a, 2a, 3a cushion pad (pad material) 1b, 2b, 3b
skin material 11 reclining mechanism 11a reclining shaft 15 side
frame 15a side plate 15b front edge portion 15c rear edge portion
15d protruded portion 15e convex portion 16 upper frame 16a side
surface portion 17 lower frame side portion (lower frame) 17a side
plate 17b intermediate plate 17c shaft insertion hole 17d, 17j
attachment hole 17e narrow portion 17f horizontal portion 17g bent
portion 17h inclined portion 17i harness attachment portion
(reinforcement portion) 18 lower frame center portion (lower frame,
reinforcement portion) 19 headrest pillar 19a pillar support
portion 20 pressure receiving member 21 wire (connection member,
upper connection member) 21a journal portion 22 wire (connection
member, lower connection member) 30 moving member (impact reducing
member) 32 shaft portion 35 extension coil spring (biasing means)
39 movement preventing portion 58 lower frame center portion (lower
frame, reinforcement portion) 58a forward bulging portion 58b rear
surface 58c connection surface 58d, 58e upper end 58f side end
portion 59 reinforcement member 59a upper end
* * * * *