JP4924161B2 - Hood airbag device for pedestrian protection - Google Patents

Description

  The present invention relates to a hood airbag device for protecting pedestrians.

  Conventionally, a pedestrian protection hood airbag device for protecting a pedestrian that has collided with the front side of a vehicle has been known (see, for example, Patent Documents 1 to 4). In the hood airbag device described in Patent Literature 1, a plurality of airbags in the right half and the left half that are deployed on the upper surface of the hood can be selectively deployed according to the collision position of the pedestrian. It has the function of protecting the body, shoulders, and head that come into contact with the vehicle body.

  However, when the vehicle speed is high or a tall person collides, the head moves to the window shield side, so the head may collide with the vehicle body, and the head is reliably protected There was a problem that could not be done. In addition, since the airbag does not have a function of holding the body, the body may fall on the road surface after contacting the airbag and cause a secondary collision.

  Further, the hood airbag device described in Patent Document 2 is an outer surface deployment type airbag device that deploys an airbag from a rear portion of a hood to a target location along a window shield. By lifting the hood on the side of the window shield by turning up and down, the deployment direction of the airbag is regulated, and the head is protected when a pedestrian collides. However, in this case, since the function of absorbing the impact is not provided on the hood surface, before the head contacts the vehicle body, it is impossible to protect the shoulder part and the body part contacting the vehicle body, and as a result There is a problem that the acceleration of the head cannot be reduced.

  In addition, the hood airbag device described in Patent Document 3 is provided with an adhesive layer on the outer surface of the deployed airbag. Before the airbag is deployed, it does not have an adhesion function and is attached to a bumper. Detects contact with a pedestrian, and after the airbag is deployed, the adhesive is soaked into the adhesive layer. However, in this case, since the airbag is deployed after detecting contact with a pedestrian, it is considered difficult to soak the adhesive in a collision event with a short phenomenon time (within 100 ms), and the human body holding function is small. it is conceivable that.

Moreover, in the hood airbag device described in Patent Document 4, the shape of the airbag is devised in order to prevent a pedestrian riding on the hood from dropping onto the road surface. However, with such a configuration, there is a problem that when the collision position deviates from the front, the fall cannot be prevented. Also, it is difficult to protect the head when the vehicle speed is high or when a tall person collides.
Japanese Patent Laid-Open No. 9-30368 JP 2003-95044 A JP-A-8-183423 JP 2004-136814 A

  Then, an object of this invention is to obtain the hood airbag apparatus for pedestrian protection which can protect a pedestrian reliably.

In order to achieve the above object, a hood airbag device for protecting a pedestrian according to claim 1 according to the present invention is divided into two at a substantially central portion in the longitudinal direction of the vehicle body, and the hood front portion on the vehicle body front side is the vehicle rear side. A hood configured to be rotatable with respect to the rear portion of the hood, a back surface on one end side is fixed to the inner surface of the front portion of the hood, and a rear surface on the other end side is fixed to the vehicle body side and folded and stored, An airbag that is deployed with the rotation of the front portion of the hood, suction holding means that is provided on the folded stomach side of the airbag and that attracts and holds pedestrians when the airbag is deployed, and folding the airbag provided the ventral side, have a, and adhesion prevention means for preventing the said suction holding means during storage of the air bag are bonded together, the hood front portion, upward as viewed from the longitudinal direction of the vehicle body It is curved toward Accordingly, even when rotated upon deployment of the airbag, it is characterized in that no bottoming in the hood rear.

  According to the first aspect of the present invention, since the airbag appears on the front side of the hood that comes into contact with the pedestrian and the suction holding means is provided on the abdominal surface side thereof, at least the pedestrian's buttocks, The shoulder is shock-absorbed by the airbag and is sucked and held by the suction-holding means. Therefore, the injury reduction effect in those parts can be obtained, and secondary collisions such as a pedestrian in contact with the airbag falling on the road surface can be prevented.

  Further, the impact is absorbed by the buttocks, the trunk, and the shoulders, and further, these parts are attracted and held, whereby the acceleration of the head is reduced and the movement range of the head is further limited. Therefore, the protection performance of the head can be enhanced, and the head injury reduction effect can be enhanced. Further, when the airbag is stored, the adhesion holding means can be prevented from adhering to each other by the adhesion preventing means, so that the adsorption holding means can be configured to function simultaneously with the deployment of the airbag.

Further, the front portion of the hood that is flipped up (turned) to the window shield side by the deployment of the airbag does not bottom out at the rear portion of the hood after the deployment of the airbag .

Therefore, having a hood front cushion function, the head is moved to the window shield side, it can be further prevented from colliding with the vehicle body. That is, as a result, the head can be reliably protected, and the head injury reduction effect can be further enhanced.

The pedestrian protection hood airbag device according to claim 2 is the pedestrian protection hood airbag device according to claim 1 , wherein the adsorption holding means is a pressure-sensitive adhesive. Yes.

According to invention of Claim 2 , the pedestrian who collided with the airbag can be suitably adsorbed and held by using the pressure sensitive adhesive. Therefore, it is possible to reliably prevent a pedestrian who has collided with the airbag from dropping onto the road surface. In addition, since the adhesive force can be increased by increasing the thickness of the pressure-sensitive adhesive, the effect of fixing the pedestrian (human body) to the airbag can be easily enhanced.

  As described above, according to the present invention, it is possible to provide a pedestrian protection hood airbag device that can reliably protect a pedestrian.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a schematic perspective view showing a state of a vehicle 12 equipped with a pedestrian protection hood airbag device 10 according to the present embodiment before the airbag 30 is deployed, and FIG. 2 is a schematic sectional side view. 3 is a schematic perspective view showing a state after the airbag 30 of the vehicle 12 equipped with the pedestrian protection hood airbag device 10 according to this embodiment is deployed, and FIG. 4 is a schematic sectional side view. is there. 1 to 4, the arrow UP is the vehicle body upward direction, and the arrow FR is the vehicle body front direction.

  As shown in FIGS. 1 to 4, the hood 14 of the vehicle 12 has a front side (hereinafter referred to as “hood front part”) 16 from a substantially central part in the longitudinal direction of the vehicle body to a rear side (hereinafter referred to as “hood rear part”) 18. And can be rotated. That is, the vehicle body rear side of the hood front portion 16 is hinged 20 so as to be pivotable to the vehicle body front side of the hood rear portion 18, and the hood front portion 16 rotates toward the window shield 22 side when an airbag 30 described later is deployed. Thus, the airbag 30 is allowed to be deployed.

  During normal times (when the airbag 30 is not deployed), the hood front portion 16 is fixed so as not to rotate by a stopper or the like (not shown). That is, when the hood 14 is opened and closed during normal times (when the airbag 30 is not deployed), the rear side of the vehicle body of the hood rear portion 18 is hinged and opened as in the conventional case. Further, when the hood front portion 16 rotates toward the window shield 22, the hood front portion 16 does not bottom the hood rear portion 18.

  That is, when the hood front portion 16 is rotated toward the window shield 22, the surface (outer surface) of the hood front portion 16 is not in contact with the surface (outer surface) of the hood rear portion 18. This is because the vehicle width direction of the hood front portion 16 (hood 14) is curved outward, but a stopper or the like (not shown) is provided on the hinge 20 so that the hood front portion 16 is opposed to the hood rear portion 18. It may be configured not to bottom out. Thereby, the hood front part 16 has a configuration having a cushion function in the rotation direction around the hinge 20.

  Further, a support plate 24 is provided on the back surface side of the hood front portion 16 with a predetermined gap from the back surface, and at least the hood front portion 16 has a double structure. An airbag 30 is provided between the upper surface of the support plate 24 and the back surface of the hood front portion 16. That is, the back surface on one end side of the airbag 30 is fixed to the back surface of the hood front portion 16, and the back surface on the other end side of the airbag 30 is fixed to the upper surface of the support plate 24. At the time of deployment, the airbag 30 is stored in a folded state. An inflator 26 that ejects gas to the airbag 30 is provided on the lower surface side of the support plate 24.

  As shown in FIGS. 3 to 5, a pressure-sensitive adhesive 32 as an adsorbing / holding means is applied to the entire surface of the abdomen (surface) side of the airbag 30 that is deployed at the time of collision and contacts the pedestrian. On the pressure-sensitive adhesive 32, a mesh member (hereinafter referred to as “net”) 28 is provided as an adhesion preventing means. Even if the airbag 30 is stored in a folded state by the net 28, the pressure sensitive adhesives 32 on the surface (abdominal surface) are not bonded to each other.

  That is, the net 28 can adsorb and hold at least the buttock, torso and shoulders of the pedestrian when the airbag 30 is deployed, and the net 28 contacts each other when the airbag 30 is stored. The mesh is such that the adhesives 32 do not come into contact with each other (see FIG. 5, in FIG. 3, the mesh of the net 28 is roughened to make the drawing easy to see). At the time of storage, adhesion between the pressure sensitive adhesives 32 is prevented.

  As the pressure sensitive adhesive 32, for example, silicone PSA (manufactured by GE TOSHIBA SILICONES) or the like can be used. This pressure-sensitive adhesive 32 is also called a pressure-sensitive adhesive, and is used for manufacturing special tapes and label products because it can be quickly bonded even at room temperature and peeled off. The adhesive force of the pressure sensitive adhesive 32 can be adjusted by increasing or decreasing the amount (thickness) of the pressure sensitive adhesive 32. Furthermore, the suction holding means is not limited to the pressure-sensitive adhesive 32, and for example, an adhesive tape or a non-pressure-sensitive adhesive may be used.

  Next, the operation of the pedestrian protection hood airbag device 10 configured as described above will be described. When the vehicle 12 collides with a pedestrian (or when the vehicle 12 detects a collision with a pedestrian in advance), the inflator 26 injects gas into the airbag 30 and the folded airbag 30 is inflated and deployed. Then, the hood front part 16 is flipped upward.

  That is, the rear side of the vehicle body of the hood front portion 16 is hinged to the front side of the vehicle body of the hood rear portion 18 and is normally locked so as not to rotate by a stopper (not shown), but it collides with a pedestrian (or collision detection). Thus, when the airbag 30 is inflated / deployed, first, the stopper is broken by its deploying force and the lock is released, and only the front portion of the hood 16 is directed toward the window shield 22 with the hinge 20 as the center. Rotate. Thereby, the airbag 30 covering the whole vehicle width direction appears on the vehicle body front side, and a pedestrian contacts (collises) the surface (abdominal surface).

  Thus, when the airbag 30 is deployed on the entire front side of the vehicle 12 (hood 14), the impact applied to the pedestrian's buttocks, torso, shoulders, and head is mitigated by the airbag 30. -Since it is absorbed, the effect of reducing injury at those sites can be obtained. In particular, the impact of the pedestrian's buttocks, torso, and shoulders comes into contact with the airbag 30 before the head, so that those shocks are suitably mitigated and absorbed, thereby reducing the acceleration of the head. be able to. Accordingly, it is possible to enhance the effect of reducing the injury in the head as compared with the case of protecting only the head as in the prior art.

  Further, the outer surface (surface) of the hood front portion 16 that has been flipped up (turned) to the window shield 22 side by the deployment of the airbag 30 does not bottom out (contact) the outer surface (surface) of the hood rear portion 18. It has become. That is, the hood front portion 16 has a structure having a cushion function. Therefore, the head of a pedestrian who has collided with the airbag 30 (vehicle 12) can be reliably prevented from moving toward the window shield 22 and colliding with the vehicle body, and the head can be reliably protected. (The injury-reducing effect on the head can be further enhanced).

  In addition, since the pressure sensitive adhesive 32 is stuck on the entire surface (abdominal surface) of the deployed airbag 30, the pedestrian who has contacted (collised) the surface of the airbag 30 has almost the whole body (at least The hips, torso and shoulders are adsorbed and held by the pressure sensitive adhesive 32. Accordingly, it is possible to prevent a secondary collision such that a pedestrian who collides with the airbag 30 (vehicle 12) falls on the road surface (ground). In addition, since at least the buttocks, torso, and shoulders of the pedestrian are attracted and held, the movement range of the head can be further limited. Therefore, the protection performance of the head can be further enhanced.

  In addition, since the adsorption | suction force (adhesion force) holding a pedestrian can be increased by increasing the quantity (thickness) of the pressure sensitive adhesive 32, the adsorption | suction and retention effect of the airbag 30 with respect to a pedestrian is increased. Can be easily increased. In addition, since the pressure sensitive adhesive 32 is pasted on the airbag 30 in advance, it is possible to avoid the problem that the adhesive soaking time is required as in the prior art.

  Further, during normal times (when the airbag 30 is not deployed), the airbag 30 is stored in a folded state, but the net 28 is placed on the pressure-sensitive adhesive 32 of the folded airbag 30. Since it is provided, it is possible to prevent the pressure-sensitive adhesives 32 from being bonded to each other. That is, in the airbag 30 in which the pressure-sensitive adhesive 32 is provided on the surface (abdominal surface) with which the pedestrian comes into contact, the problem before the deployment (problem in which the pressure-sensitive adhesive 32 is adhered to each other) can be avoided. it can.

  Here, the calculation result using the human body model which becomes the foundation of the hood airbag apparatus 10 for pedestrian protection which concerns on this embodiment is shown in FIG. That is, in the graph shown in FIG. 6, the acceleration generated on the pedestrian's head at the moment of collision with the vehicle 12 is obtained with and without a cushion (corresponding to the airbag 30) on the surface (outer surface) of the hood 14. It is the graph compared by. As can be seen from this graph, when the cushion (the outer surface) of the hood 14 has a cushion, the acceleration generated in the head is reduced to about half compared to the case without the cushion. The magnitude of acceleration generated in the head is considered as a reference for the occurrence of head injury, and this graph shows that providing a cushion on the surface (outer surface) of the hood 14 is effective in reducing head injury. ing.

  The reason why the acceleration generated in the head is reduced when the cushion is on the surface of the hood 14 is that the cushion relaxes and absorbs the impact when the buttocks, trunk, and shoulder contact the hood 14. is there. Therefore, it is desirable to provide an impact absorbing mechanism such as the airbag 30 in the entire hood 14. Since the airbag 30 according to the present embodiment is configured to be deployed on the entire hood 14, it has the same or higher effect than the cushion used in this simulation, and the head injury reduction effect can be sufficiently obtained. Conceivable.

  As described above, the pedestrian protection hood airbag device 10 according to the present embodiment includes the technology for deploying the airbag 30 on the entire hood 14 and the pressure-sensitive adhesive 32 provided on the contact surface between the airbag 30 and the pedestrian. When the front of the hood 16 is flipped up to the window shield 22 side by deploying the airbag 30, it is not simply combined with a technique for preventing a pedestrian from falling onto the road surface (ground) (secondary collision). In addition, since the hood front portion 16 does not bottom the hood rear portion 18, the head of the pedestrian who collided with the airbag 30 (vehicle 12) moves to the window shield 22 side and the vehicle body. It is possible to reliably prevent the collision, and it is possible to reliably increase the head injury reduction effect. Therefore, it is possible to reduce the number of pedestrian accident deaths, the number of injured persons, particularly head injury.

Schematic perspective view showing a state before the airbag deployment of a vehicle equipped with a hood airbag device for protecting pedestrians Schematic sectional view showing a state before the airbag deployment of a vehicle equipped with a hood airbag device for protecting pedestrians Schematic perspective view showing a state after deployment of an airbag of a vehicle equipped with a hood airbag device for protecting pedestrians Schematic sectional view showing a state after deployment of an airbag of a vehicle equipped with a hood airbag device for protecting pedestrians (A) Schematic perspective view showing deployed airbag, (B) Schematic sectional view of deployed airbag A graph comparing the acceleration generated on the head of a pedestrian with and without a cushion in the hood

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hood airbag apparatus for pedestrian protection 12 Vehicle 14 Hood 16 Hood front part 18 Hood rear part 20 Hinge 22 Window shield 24 Support plate (vehicle body)
26 Inflator 28 Net (adhesion prevention means)
30 air bag 32 pressure sensitive adhesive (adsorption holding means)

Claims (2)

A hood that is divided into two at a substantially central portion in the longitudinal direction of the vehicle body, and the hood front portion on the vehicle body front side is rotatable with respect to the hood rear portion on the vehicle body rear side;
An airbag that has a rear surface on one end side fixed to the inner surface of the front portion of the hood, a rear surface on the other end side fixed to the vehicle body side, folded and stored, and deployed with the rotation of the front portion of the hood;
A suction holding means provided on the folded stomach side of the airbag, for sucking and holding a pedestrian when the airbag is deployed;
An adhesion preventing means that is provided on the folded stomach side of the airbag and prevents the suction holding means from being adhered to each other when the airbag is stored;
I have a,
The front portion of the hood is curved upward when viewed from the front-rear direction of the vehicle body, so that even if the airbag is rotated during deployment, the rear portion of the hood does not bottom out. Food airbag device. The hood airbag device for pedestrian protection according to claim 1, wherein the adsorption holding means is a pressure sensitive adhesive .

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