JPH06127331A - Airbag device - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object to obtain an airbag device capable of coping with a bounce phenomenon of an occupant during sudden deceleration of a vehicle. The airbag device 54 is in a non-actuated state when the occupant inertially moves when the vehicle is suddenly decelerated. But,
After the inertial movement of the occupant, the airbag device 54 is configured to be actuated when the occupant is rebounded toward the seat back 64 by its reaction force. Therefore, it is possible to effectively deal with the bounce phenomenon of the occupant during the rapid vehicle deceleration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for inflating a bag toward an occupant when the vehicle suddenly decelerates.

[0002]

2. Description of the Related Art Recently, an air bag device has become widespread as an auxiliary device for a seat belt device for restraining an occupant during sudden deceleration of a vehicle. There are various types of the airbag device depending on the location of the airbag device. Among them, there is one in which the airbag device is disposed in the headrest of a vehicle seat (for example, see Japanese Utility Model Laid-Open No. 4-65644).

According to the structure disclosed in this publication, when a predetermined load is applied to the vehicle (mainly when a predetermined load is applied to the rear bumper or the like), the air bag device disposed in the headrest of the vehicle seat. Is configured to operate immediately.

[0004]

However, according to the structure disclosed in this publication, it is controlled so that the airbag device in the headrest is instantaneously activated when a predetermined load acts on the vehicle. A predetermined load acts on the front bumper, and when the occupant starts inertial movement toward the front side of the vehicle, the swelling operation of the bag body is already completed.
Therefore, there is a problem in that the so-called bounce phenomenon in which the occupant is inertially moved to the front of the vehicle and then pushed toward the seat back by the reaction force cannot be dealt with. That is, when the occupant bounces back to the seat back side, the internal pressure of the bag body has already dropped, so that a sufficient energy absorbing effect cannot be obtained.

In view of the above facts, an object of the present invention is to obtain an airbag device capable of coping with the bounce phenomenon of an occupant during sudden vehicle deceleration.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a headrest and a neck of an occupant that is bulged when the vehicle is suddenly decelerated and is seated on a headrest or a seatback of a vehicle seat and at least a seat cushion of the vehicle seat. It is characterized in that it has a bag body interposed between the member and a section, and a control means for inflating the bag body after a predetermined time has elapsed from the time of the sudden deceleration of the vehicle.

[0007]

According to the above construction, the control means causes the bag body to bulge after a predetermined time has elapsed from the time of sudden deceleration of the vehicle, and the bulged bag body is at least the headrest or seatback of the vehicle seat and at least the vehicle seat. It is interposed between the head and neck of the occupant sitting on the seat cushion of the seat. Therefore, for example, when the vehicle is rapidly decelerating such that a predetermined load acts on the front bumper of the vehicle, the occupant first inertially moves toward the front side of the vehicle, and then the occupant bounces back to the seat back side with a reaction force. At this time, the bag body is interposed between the headrest or the seat back and at least the head and neck of the occupant. Therefore, the bag body having the optimum internal pressure can be interposed between the headrest or the seatback and at least the head and neck of the occupant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air bag device 54 according to an embodiment of the present invention will be described below with reference to FIGS.

3 and 4 show a webbing take-up device 12 of a type that holds the webbing 10 at the time of sudden deceleration of the vehicle. First, the structure of the webbing take-up device 12 will be described.

The webbing retractor 12 is provided with a frame 14 having a U-shaped cross section. The frame 14 is attached to the lower compartment side of the vehicle side wall (not shown) by attachment bolts.

The webbing take-up device 12 is also provided with a take-up shaft 18 having a shaft 16 penetratingly arranged in its shaft core. A pair of ratchet wheels 20 and a disc-shaped flange 22 are coaxially fixed to both ends of the winding shaft 18 in the axial direction. Therefore, when the winding shaft 18 rotates, the ratchet wheel 20 and the flange 22 also rotate. Further, the webbing 10 for restraining an occupant is wound in layers between the pair of ratchet wheels 20 on the circumferential surface of the winding shaft 18. A spiral spring (not shown) is arranged outside one of the leg plates 14A (or the leg plate 14B), and the winding shaft 1
8 is urged in the webbing winding rotation direction (direction of arrow C in FIG. 3).

Further, plate-like arms 24 are arranged on the outer sides of both ends of the winding shaft 18 in the axial direction (between the flange 22 and the leg plates 14A and 14B). A support shaft 26 pivotally supported by the leg plates 14A and 14B penetrates through the base ends of the pair of arms 24. In addition, the pair of arms 24
Both ends of the shaft 16 of the winding shaft 18 are passed through the intermediate part of the. The penetrating end of the shaft 16 is inserted into a curved bearing hole 28 formed near the center of the pair of leg plates 14A and 14B of the frame 14. Therefore, when the arm 24 swings around the support shaft 26, the winding shaft 18 moves along the curved shape of the bearing hole 28 in FIG.
Can be swung in the direction of arrow B.

A fan-shaped opening 30 is formed at the lower ends of the pair of arms 24. Into the opening 30, both longitudinal ends of a lock bar 32 arranged so as to face the ratchet wheel 20 are fitted. In addition, lock bar 3
A pendulum 34 that swings by receiving an inertial force when the vehicle is suddenly decelerated is disposed below the intermediate portion in the longitudinal direction of 2. Therefore, when the vehicle suddenly decelerates, the pendulum 34 oscillates due to the inertial force and pushes up the lock bar 32 in the opening 30 to engage the lock bar 32 and the ratchet wheel 20. When the lock bar 32 and the ratchet wheel 20 are engaged, rotation of the winding shaft 18 in the webbing pull-out direction (direction of arrow A in FIG. 3) is prevented.

Further, one ends of tension coil springs 36 are locked to the arms 24, respectively. Tension coil spring 3
The other end of 6 is locked to the leg plates 14A and 14B, respectively. Therefore, the tension coil spring 36 urges the arm 24 in the direction opposite to the arrow B direction in FIG. For this reason,
Normally, both ends of the shaft 16 of the winding shaft 18 are held at the lower end of the bearing hole 28.

On the other hand, on the upper side of the pair of flanges 22,
A lock lever 38 having a substantially rectangular parallelepiped shape is arranged. A shaft 40 extends through one end of the lock lever 38, and the shaft 40 is pivotally supported by the pair of leg plates 14A and 14B. The lock lever 38 is integrally formed with projections 42 projecting downward on the lower end surfaces of both sides thereof. The pair of protrusions 42 are in contact with the peripheral surface of the flange 22.

On both sides of the lock lever 38, one ends of return springs 44, which are tension coil springs, are locked. The other end of the return spring 44 has the leg plate 14
It is locked to each of A and 14B. Therefore, the return spring 44 urges the lock lever 38 toward the winding shaft 18 side.

A holding plate 46 having a substantially semicircular cross section in the longitudinal direction is loosely fitted to the tip of the lock lever 38 through a pin 47. A corrugated tooth portion 46A is formed on the plane portion of the holding plate 46. A plate-like lock plate 48 is arranged at a position facing the sandwiching plate 46. A lock tooth 48A that meshes with a tooth portion 46A of the holding plate 46 is integrally formed on a surface of the lock plate 48 facing the holding plate 46. The lock plate 48 has a predetermined load acting on the lock plate 48 so that the teeth 46A of the holding plate 46 and the lock teeth 48A mesh with each other, whereby the height direction of the frame 14 (direction of arrow D in FIGS. 4 and 5). ) To slide. Further, an intermediate portion of the webbing 10 pulled out from the winding shaft 18 is arranged so as to be inserted between the lock plate 48 and the sandwiching plate 46. However, at the time of sudden deceleration of the vehicle, the intermediate portion of the webbing 10 and the tooth portion 46A of the holding plate 46 and the lock plate 4 are
It is configured to be sandwiched between the eight lock teeth 48A.

As shown in FIGS. 4 and 5, the switch 5 is provided at three upper and lower positions near the swing-side end of the lock lever 38 (the end where the holding plate 46 is loosely fitted).
0, 51, 52 are arranged.

More specifically, as shown in FIG. 5, the first switch 50 is located at a position when the lock lever 38, which is at the position (normal position) shown by the solid line, is raised when the vehicle is rapidly decelerating at a relatively low degree ( Position indicated by broken line; hereinafter, "load increase low position"
It is located in). In addition, the second switch 51
Is arranged at a position when the lock lever 38, which was at the position shown by the solid line when the vehicle is moderately decelerated suddenly, moves up (the position shown by the chain line; hereinafter referred to as “load increase intermediate position”). Therefore, the position shown by the one-dot chain line is above the position shown by the broken line. Further, the third switch 52 is located at a position when the lock lever 38, which was at the position shown by the solid line during the sudden deceleration of the vehicle at a relatively high altitude, is raised (the position shown by the chain double-dashed line;
Hereinafter, it is arranged in a "load increase high position").
Therefore, the position shown by the two-dot chain line is above the position shown by the one-dot chain line. Note that in FIG. 5, the types of lines are made different and the outer shape of the lock lever 38 is gradually made smaller so that the lines do not overlap.

The above-mentioned first switch 50, second switch 51, and third switch 52 are normally OF
It is set to F, and the lock lever 38 is turned on when the lock lever 38 swings to reach each position.

As shown in FIG. 7, each switch 50,
Each of 51 and 52 is connected to the control device 62, and is turned on to output an electric signal to the control device 62. A first inflator 56, a second inflator 58, and a third inflator 60 are connected to the control device 62, respectively. When the first switch 50 is turned on, the first inflator 56 is operated by receiving an operation signal from the control device 62. Second inflator 58
When the second switch 51 is turned on, and when the third inflator 60 is turned on, the third inflator 60 is actuated by receiving the actuation signal from the controller 62. There is.

On the other hand, in FIG. 6, the load is plotted on the vertical axis and the time is plotted on the horizontal axis, and the operation timings of the first inflator 56, the second inflator 58, and the third inflator 60 of the airbag device 54 are shown. Is shown. Here, the acting load at the point A is the lock lever 38.
Is a load that acts at a relatively low vehicle speed deceleration that raises the lock lever 38 to the load increasing low position, and the acting load at point B acts when the vehicle is rapidly decelerating to a middle level to raise the lock lever 38 to the load increasing intermediate position. The load at point C is the load that acts when the vehicle is suddenly decelerated at a relatively high altitude to raise the lock lever 38 to the load-raising high position. Therefore, the first inflator 56 operates when the point A is reached (a predetermined time has elapsed from the time when the vehicle suddenly decelerates), and the second inflator 58 operates when the point B is reached, and C When the point is reached, the third inflator 60 will be activated. Therefore, as shown in FIG. 1 (A), when the vehicle suddenly decelerates, the occupant only inertially moves in the direction of the arrow Q and the airbag device 54 is still inactive, but after the occupant inertially moves, When the occupant bounces back toward the seat back 64 due to the reaction force, as shown in FIG.
As shown in FIG. 5, the airbag device 54 is actuated so that a bag body 66, which will be described later, is bulged toward the head of the occupant.

As shown in FIGS. 2 (A) and 2 (B), the airbag device 54 (shown by a chain double-dashed line) including the above-described first to third inflators 56, 58 and 60 is a seat back. It is built in near the upper end of 64. On the vehicle front side of these inflators 56, 58, 60, the bag 6
6 is arranged in a folded state.

As shown in FIGS. 8 and 9, a plurality of (here, two) elongated straps 68 and 70 are disposed inside the bag 66. A pair of slacks 68 is provided at the middle of the straps 68, 70 in the longitudinal direction.
A and 70A (enlarged and illustrated in FIG. 9A) are formed respectively. Then, the slack portions 68A and 70A
When the internal pressure of the bag body 66 reaches a predetermined value or more, the suture thread is cut and is in an extended state (see FIG. 9 (B)), and the bag body 66 is inflated correspondingly. Although various settings can be made as the predetermined value of the internal pressure, as an example, the slack portion 68A of the first strap 68 is activated by the operation of the second inflator 58 at point B in the graph shown in FIG. It is conceivable to set the strength of each suture thread such that the suture thread is cut and the third inflator 60 is operated at the point C so that the suture thread of the slack portion 70A of the second strap 70 is cut.

The operation of this embodiment will be described below with reference to the graph shown in FIG. In a normal vehicle running state, the pendulum 34 of the webbing retractor 12 does not swing due to inertial force, so the lock lever 38 maintains the non-swing state.

When the vehicle suddenly decelerates from this state, an inertial force acts on the pendulum 34 and the lock bar 32 is pushed up in the opening 30. Therefore, the lock bar 32 is engaged with the ratchet wheel 20. This prevents the winding shaft 18 from rotating in the webbing pull-out direction. Since the point A in the graph is not reached at the time when the winding device 18 is prevented from rotating in the webbing pull-out direction (when the vehicle suddenly decelerates), each inflator 56 of the airbag device 54,
58 and 60 still remain inactive.

Next, when the occupant inertially moves in the direction of arrow Q in FIG. 1A, tension is applied to the webbing 10 in the pull-out direction. Therefore, the shaft 1 of the winding shaft 18
6 is swung along the bearing hole 28 by a predetermined amount. As a result, the lock lever 38 swings and the sandwiching plate 46 is pressed against the lock plate 48. As a result, the intermediate portion of the webbing 10 is held between the holding plate 46 and the lock plate 48.

After the holding plate 46 of the lock lever 38 holds the intermediate portion of the webbing 10 between the holding plate 46 and the lock plate 48, the holding plate 46 and the lock plate 48 of the lock lever 38 rise together. The amount of increase at this time varies depending on the magnitude of the acting load during the rapid deceleration of the vehicle.

For example, when the vehicle is suddenly decelerated with a relatively low working load, that is, when the working load reaches a peak at point A on the graph shown in FIG. Is the low load rise position (the position shown in broken lines in Fig. 5)
Rise to. Therefore, since the first switch 50 is turned on, the first inflator 56 operates. As a result, the bag body 66 of the airbag device 54 bulges toward the head of the occupant. Then, at this time, the occupant receives a reaction force from the webbing 10 when inertially moved, and receives the seat back 6
4 (the direction of the arrow R in FIG. 1B) is bounced back. Therefore, the head and the neck of the occupant come into contact with the bag body 66 having the optimum internal pressure (F1) for the relatively low vehicle sudden deceleration state, so that the optimum energy absorption effect is obtained. can get.

Further, when the vehicle is suddenly decelerating when the acting load is medium, that is, when the acting load reaches a peak at point B on the graph shown in FIG. 6, the lock lever 38 applies the load. Ascending intermediate position (the position shown by the alternate long and short dash line in Figure 5)
Rise to. Therefore, since the second switch 51 is turned on, the second inflator 58 operates. At this point, the first inflator 56 is already in operation. As a result, the bag body 66 of the airbag device 54 has a higher internal pressure (approximately F1 + F2) than the above case. Therefore, the bag body 66 in which the suture thread of the slack portion 68A of the first strap 68 is cut and greatly expanded by that amount is
It will be bulged toward the head of the occupant. Therefore, the optimum energy absorption effect can be obtained even during this moderate vehicle sudden deceleration.

Further, when the vehicle is rapidly decelerating, where the applied load is relatively high, that is, when the applied load reaches a peak at point C on the graph shown in FIG. 6, the lock lever 38 operates. The load rises to the high position (the position shown by the chain double-dashed line in FIG. 5). Therefore, the third switch 52 is turned on.
As a result, the third inflator 60 operates. At this point, the first inflator 56 and the second inflator 58 are already in operation. As a result, the bag 66 of the airbag device 54 has a higher internal pressure (approximately F1 + F2 + F3) than in the above case. For this reason, not only the suture thread of the slack portion 68A of the first strap 68 is cut, but also the suture thread of the slack portion 70A of the second strap 70 is cut, and the bag body 66 that has expanded the most is It will be swollen to the head side. Therefore, the optimum energy absorption effect can be obtained even when the vehicle is suddenly decelerated at a relatively high altitude.

As described above, in this embodiment, the air bag device 54 is activated after a predetermined time has elapsed from the time when the vehicle suddenly decelerated, so that the occupant's bounce phenomenon can be dealt with. That is, the airbag device 54 can be operated when the occupant inertially moves and bounces back toward the seat back 64. Therefore, the head and neck of the occupant can be effectively protected.

Further, in this embodiment, the first inflator 56, the second inflator 58 and the third inflator 60 are selectively operated according to the acting load at the time of sudden deceleration of the vehicle, and the bag body is accordingly operated. Since the bulging shape of 66 is changed, the bag body 66 can have an optimum internal pressure and shape according to the magnitude of the acting load at the time of sudden deceleration of the vehicle.

Further, when a predetermined load is applied to the rear bumper or the like of the vehicle, after the occupant is first pressed to the seat back 64 side, when the reaction force causes inertial movement to the front side of the vehicle, the airbag device 66 is Further, the occupant receives the reaction force from the webbing 10 again, and the seat back 64 is activated.
When it is bounced back to the side, the bag 66
Also follows the bounce of the occupant, so there is also the advantage that a certain amount of energy absorption effect can be obtained.

Further, since the webbing retractor 12 of the type for clamping the webbing 10 is used and the action load at the time of sudden deceleration of the vehicle is detected by utilizing the movement of the lock lever 38, the structure is simple. Inflator 5
6, 58, 60 can be selectively activated appropriately. That is, when the lock lever 38 is in the low load increasing position, the load acting on the occupant from the webbing 10 is small, the result is small bounce, and the lock lever 3 is also small.
When 8 is in the high load rising position, the load acting on the occupant from the webbing 10 is large, and as a result, the bounce is also large. Therefore, by detecting the position of the lock lever 38, the inflators 56, 58, 60 are detected. It can be selectively activated appropriately.

In this embodiment, the air bag device 54
Although it is arranged near the upper end of the seat back 64, the present invention is not limited to this, and may be arranged inside the headrest 72 as shown by the alternate long and short dash line in FIG. Alternatively, the airbag device 54 may be arranged at a position above the headrest 72 in the roof.

Further, in this embodiment, the airbag device 54
Although the straps 68 and 70 are used as a structure for changing the bulging shape of the bag body 66 according to the magnitude of the acting load, the present invention is not limited to this, and the bag body 74 such as the bag body 74 shown in FIG. A plurality of slack portions 76 </ b> A may be provided on the base fabric 76 itself that constitutes the. This slack portion 76A is also a bag 74
If the internal pressure of the needle is less than the predetermined value, the suture will not break (Fig. 11).
In the state shown in FIG. 11A, the suture thread is cut when the internal pressure of the bag 74 exceeds a predetermined value (state shown in FIG. 11B). Therefore, the same effect can be obtained with this bag 74 as well.

Further, the webbing retractor 1 of this embodiment.
In 2, the pendulum 34 is used to detect the rapid vehicle deceleration state, but the present invention is not limited to this, and a ball or the like may be used to detect the vehicle rapid deceleration state.
In addition, in the present embodiment, the movement of the lock lever 38 is used as an example of the method of detecting the applied load during sudden deceleration of the vehicle. However, the present invention is not limited to this, and an acceleration sensor using a pendulum or a ball or a bag is used. A method of detecting the internal pressure of the body and further the load acting on the webbing on the shoulder side may be adopted.

Further, in the present embodiment, the movement of the lock lever 38 is utilized to make the first switch 50, the first switch 5
Although the first and third switches 52 are mechanically turned on and off and the first inflator 56, the second inflator 58, and the third inflator 60 are sequentially operated by this, the invention is not limited to this. , Lock lever 38
The position of is detected and calculated by the control device 62,
The operation of each inflator 56, 58, 60 may be controlled.

Further, in this embodiment, the number of inflators to be operated is changed according to the magnitude of the acting load at the time of sudden deceleration of the vehicle so that the optimum inner pressure and shape of the bag body can be obtained. Excluding the viewpoint, only one inflator may be provided and the inflator may be activated after a predetermined time has elapsed from the time of sudden deceleration of the vehicle.

[0041]

As described above, in the airbag device according to the present invention, the control means inflates the bag body after a lapse of a predetermined time from the sudden deceleration of the vehicle, and at least the headrest of the vehicle seat or the seat. Since this is interposed between the back and the head and neck of the occupant seated on the seat cushion of the vehicle seat, the excellent effect of being able to cope with the bounce phenomenon of the occupant during sudden vehicle deceleration is provided. Have.

[Brief description of drawings]

FIG. 1A is an explanatory view seen from a side of a vehicle, showing a state in which an occupant inertially moves at the time of sudden deceleration of the vehicle.
(B) is an explanatory view showing a state in which the occupant bounces back to the seat back side after inertial movement when the vehicle is suddenly decelerated, as viewed from the same direction.

2 (A) and 2 (B) are explanatory views seen from the side of the vehicle and the front of the vehicle for explaining the arrangement position of the airbag device shown in FIG. 1.

3 is a first for operating the airbag device of FIG.
FIG. 6 is a perspective view showing a webbing retractor including a third switch.

FIG. 4 is a side view of the webbing retractor shown in FIG.

5 is an explanatory view showing the arrangement positions of the first switch to the third switch shown in FIG. 4 in the relationship with the lock lever, as seen from the direction of arrow P in FIG.

FIG. 6 is a graph showing the timing of activating the first to third inflators of the airbag device as a relationship between load and time.

FIG. 7 is a block diagram centering on a control device that controls the operation of the airbag device.

FIG. 8 is a perspective view showing an internal structure of the bag body of FIG.

9 (A) is an enlarged view taken along the line 9 (A) of FIG. 8, and FIG. 9 (B) shows a state in which the suture thread in the slack portion of FIG. 9 (A) is broken and extended. FIG.

10 is a perspective view showing a modified example of the bag body shown in FIG. 9, as viewed from the same direction as FIG.

11 (A) is a cross-sectional view of FIG. 11 (A) -11.
FIG. 11A is a sectional view taken along the line A, and FIG. 11B is an enlarged view showing a state in which the suture thread in the slack portion of FIG.

[Explanation of symbols]

 54 Airbag device 62 Control device (control means) 64 Seat back 66 Bag body 72 Headrest 74 Bag body

Claims (1)

[Claims] 1. When the vehicle decelerates suddenly, it swells and is interposed between the headrest or seatback of the vehicle seat and at least the head and neck of an occupant seated on the seat cushion of the vehicle seat. An airbag device comprising: a bag body; and a control means for inflating the bag body after a lapse of a predetermined time from the vehicle sudden deceleration.