Land vehicles: bodies and tops – Bodies – Seats with body modifications
Reexamination Certificate
2003-05-14
2004-12-14
Patel, Kiran (Department: 3612)
Land vehicles: bodies and tops
Bodies
Seats with body modifications
C297S216120, C297S216130, C701S045000
Reexamination Certificate
active
06830278
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a vehicle occupant protection apparatus for protecting the neck of an occupant seated in a vehicle seat.
BACKGROUND OF THE INVENTION
Normally, between the headrest at the top of a vehicle seat and the neck of an occupant seated in the seat, there is a so-called behind-the-neck gap. When a vehicle is impacted from behind by an impacting body (hereinafter called a “rear-end collision”), as a reaction to this the upper body of the occupant falls backward. And the larger is the behind-the-neck gap, the greater is the load which acts on the neck of the occupant.
As technology for lightening the load on the neck, there has been that in which the cushioning capacity of the seat back is raised. When the upper body of the occupant falls backward, because a seat back with a large cushioning effect compresses greatly, the behind-the-neck gap decreases and the load on the neck is lightened. However, when the cushioning effect of the seat back is too large, ride comfort may decrease. To avoid this, technology aiming to achieve both ride comfort and protection has been developed, as shown in FIG.
13
and
FIG. 14A through 14C
.
An occupant protection apparatus shown in
FIG. 13
has a headrest
103
mounted swingably front/rearward by way of a swinging mechanism
102
to the top of a seat back
101
of a seat
100
.
When as a reaction to the vehicle suffering a rear-end collision the upper body of an occupant
104
falls rearward, an external force W
1
acts on the seat back
101
from the upper body. The swinging mechanism
102
swings under this external force W
1
, and the headrest
103
consequently advances from a normal position shown with broken lines to the position shown with solid lines. And by a behind-the-neck gap
105
between the neck of the occupant and the headrest
103
becoming small in this way, the load on the neck is lightened.
A seat
200
provided with an occupant protection apparatus shown in
FIG. 14A
has a seat cushion
201
, a hinge mechanism
202
, a seat back
203
attached swingably front/rearward to the seat cushion
201
by way of this hinge mechanism
202
, and a headrest
204
attached to the top of the seat back
203
.
The hinge mechanism
202
is made up of a fixed plate
211
attached to the rear end of the seat cushion
201
, a first swing arm
214
attached swingably up/downward to the fixed plate
211
by way of a first link
212
and a second link
213
, and a second swing arm
215
attached swingably front/rearward to the first swing arm
214
. The seat back
203
is attached to the distal end of the second swing arm
215
. The swing angles of the first swing arm
214
and the second swing arm
215
correspond to size of an external force.
From the state shown in
FIG. 14A
, the first swing arm
214
and the second swing arm
215
will swing counter-clockwise in the figure under the impact force of a rear-end collision. As a result, because the seat back
203
temporarily moves toward the upright, as shown in
FIG. 14B
, a behind-the-neck gap
221
decreases. After that, due to the upper body of an occupant
222
falling rearward as a reaction to the rear-end collision, an external force acts on the seat back
203
from the upper body. And under this external force, as shown in
FIG. 14C
, the seat back
203
and the second swing arm
215
fall rearward. As a result, the impact acting on the occupant
222
is absorbed by the seat back
203
, and the behind-the-neck gap
221
decreases further. In this way it is possible to make the behind-the-neck gap
221
small and moderate the impact which acts on the neck.
However, the two related art technologies described above, as shown in FIG.
13
and
FIGS. 14A through 14C
, are passive vehicle occupant protection apparatus, which commence operation when an external force acting at the time of rear-end collision reaches a preset fixed reference value.
Consequently, when the reference value for operation commencement is too large, in the case of a light collision with a small impact energy, the vehicle occupant protection apparatus cannot operate. And, when the upper body of an occupant falls rearward as a reaction to a rear-end collision, the external force which acts on the seat back from the upper body varies depending on the weight of the occupant. When the occupant of the seat is light, the reference value for actuation commencement may not be reached.
When on the other hand the reference value for operation commencement is too small, there is a risk that the vehicle occupant protection apparatus may operate even in the normal state, when there has been no rear-end collision. Thus, there is room for improvement in the protection apparatus of related art described above. That is, there is a need to more certainly lighten the load on the neck of an occupant seated in a vehicle seat when the vehicle is collided with by an impacting body from behind (suffers a rear-end collision).
SUMMARY OF THE INVENTION
The present invention provides a vehicle occupant protection apparatus including a headrest mounted movably front/rearward to the top of a vehicle seat, a headrest actuating mechanism for moving the headrest forward, and a headrest control unit for drive-controlling the headrest actuating mechanism, wherein the headrest control unit includes impact predicting means for predicting the impact of an impacting body on the vehicle from behind and drive-controls the headrest actuating mechanism on the basis of a prediction signal from this impact predicting means.
That is, an active vehicle occupant protection apparatus can be constructed which controls the operation of a headrest actuating mechanism to commence on the basis of predicting itself that an impacting body is about to impact the vehicle from behind. Accordingly, when a rear-end collision is predicted by the impact predicting means, in correspondence with a prediction signal outputted from the impact predicting means, a control signal is issued to the headrest actuating mechanism from the headrest control unit, and the headrest is moved forward by the headrest actuating mechanism. Consequently, at the rear-end collision prediction stage, the gap between the headrest at the top of the seat and the neck of the occupant seated in the seat is forcibly reduced in advance. And by the behind-the-neck gap being reduced like this immediately before the rear-end collision, the load acting on the neck of the occupant when the upper body of the occupant falls rearward as a reaction to the rear-end collision can be more certainly lightened.
Preferably, the impact predicting means includes relative speed detecting means for detecting the relative speed of the impacting body with respect to the vehicle and the headrest control unit controls the headrest actuating mechanism to increase the amount of forward movement of the headrest in correspondence with a detection signal from the relative speed detecting means. In this case, when an impact is predicted by the impact predicting means, in correspondence with the relative speed of the impacting body with respect to the vehicle, the amount of forward movement of the headrest can be varied more suitably. When there has been a rear-end collision, as a reaction to this the upper body of the occupant tends to fall rearward. The amount of this falling is larger the larger is the relative speed. In this invention, the larger is the relative speed, the more the amount of forward movement of the headrest is increased. Consequently it is possible to make the behind-the-neck gap smaller immediately before the impact, and the load acting on the neck of the occupant when as a reaction to the rear-end collision the upper body of the occupant falls rearward can be rapidly and certainly lightened.
Preferably the seat in this invention has a seat back deformation detector for detecting deformation of a seat back deforming in accordance with the size of a rearward external force acting on the seat back, and the headrest control unit controls the headrest actuating mechanism to increa
Nakanishi Isamu
Yoshizawa Ryozo
Honda Giken Kogyo Kabushiki Kaisha
Patel Kiran
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