JP4391273B2 - Airbag device - Google Patents

Description

  The present invention relates to an improvement of an airbag device mounted on a vehicle in order to reduce impact.

  Conventionally, when a traveling vehicle collides with a pedestrian or the like, the pedestrian or the like is flipped up by an impact at the time of the collision, and there is a risk of secondary collision with a hood, a windshield, a front pillar, or the like at the front of the vehicle.

  Accordingly, various so-called pedestrian airbag devices have been proposed to alleviate the impact caused by such secondary collisions.

  For example, if an airbag device is placed on the side of the vehicle body chassis located slightly forward under the windshield and collides with a pedestrian, the rear part of the hood is moved upward using the inflating and deploying force of the airbag. In addition, there is a structure that is deployed in front of a windshield or a front pillar to relieve an impact caused by a pedestrian's secondary collision (see, for example, Patent Document 1).

  However, since the pedestrian airbag disclosed in Patent Document 1 has a large protection area and is difficult to inflate evenly, for example, as shown in FIG. 11, a part of the airbag body 1 is sewn. There is a configuration in which the expansion region 3 is divided by being sewn by the portion 2 or the like and developed into a flat shape. In this case, there is a problem that the shock absorption characteristics for the collision object 4 such as the head are greatly different because a thickness difference for shock reduction occurs between the position of the inflation region 3 of the airbag body 1 and the position of the sewing portion 2. .

  Further, as a method for bringing the difference in shock absorption characteristics at the time of a collision close to a constant level, as shown in FIG. 12, a tether belt 6 is sewn and arranged inside the airbag body 1 to divide the inflating region 5. Some are configured to develop into a flat shape. In this case, since the difference in thickness for shock relaxation is equalized, there is an advantage that the difference in shock absorption characteristics at the time of collision can be made close to a constant value, but it takes time to sew the tether belt 6 and is difficult to manufacture. There is a problem that productivity is low.

  Therefore, in order to solve these problems, as shown in FIG. 13, a bag skin 8 is disposed along the outer surface of the airbag body 1 having the sewing portion 2 from the viewpoint of shock absorption characteristics and productivity. An airbag is proposed in which a recess 9 is formed on the outer surface of the airbag body 1 in the inflated state of the airbag body 1 and the bag skin 8 is tensioned across the recess 9 (for example, , See Patent Document 2).

JP 2000-264146 A JP 2004-17776 A

  However, according to the airbag device disclosed in Patent Document 2, the bag outer skin 8 portion that is in tension across the inflated region 3 inflated with the gas generated by the inflator and the recess 9 formed between the inflated regions 3. However, since there is a pressure difference in the internal space, there is still a drawback that a difference occurs in the shock absorption characteristics.

  Therefore, the problem to be solved by the present invention is to provide an airbag device that achieves even more uniform shock absorption characteristics.

The technical means for solving the above-described problem includes an airbag that is inflated and deployed by a gas generated by an inflator, and the airbag includes an airbag main body in which a concave portion is generated on the outer surface in a single inflated state. In the airbag device comprising a surface protection sheet that covers a part or all of the portion corresponding to the recess in the circumferential direction and is tensioned by the inflation of the airbag body, the fully inflated state in the airbag body than said widthwise length across the recess, the formed it is short of a length corresponding to the width direction of tension state Rutotomoni of the surface protective sheet, inner opening of the cross section of the tensioning state of the surface protective sheet The area is in the fully inflated state in each inflated region of the portion covered with the surface protection sheet in the airbag body. Is less than the total area occupied by the Mel section, occurrence of the concave portion during inflation of the air bag body by the surface protection sheet is in that it is suppressed.

  Moreover, the said recessed part is good also as a structure formed by the partial sewing or adhesion | attachment of the said airbag main body.

  Further, at least a part of the airbag main body may be provided with a bag weaving structure in which hollow bag portions are woven in parallel, and the recess may be formed on the outer surface by expansion of the bag weaving portion.

  Further, the airbag device is mounted on the inside of the hood of the vehicle, and the rear portion of the hood is moved upward by the deployment operation of the airbag device so that the airbag is deployed in front of the windshield. It is good also as a structure made into the shape covered.

  Furthermore, it is good also as a structure where the said surface protection sheet is arrange | positioned in the part which covers the said both front pillars in the said airbag main body.

  According to the airbag device of the present invention, the length corresponding to the width direction in the tension state of the surface protection sheet is formed shorter than the width direction length across the recessed portion in the fully inflated state in the airbag body, and the surface Since the protective sheet prevents the formation of a recess when the airbag body is inflated, when the airbag body is inflated, the outer surface of the airbag body is the surface with the generation of the recess on the outer surface thereof being suppressed. Because the surface protection sheet is in tight contact with the inner surface of the protection sheet, it develops into a flat shape with almost no difference in thickness, and there is almost no pressure difference in its internal space. There is an advantage that the shock absorbing characteristics can be made even more uniform.

  Further, if the recess is formed by partial sewing or bonding of the airbag body, it can be easily formed by sewing or bonding, and the productivity is excellent.

  Further, at least a part of the airbag body is provided with a bag weaving structure in which hollow bag portions are woven side by side, and a recess is formed on the outer surface by the expansion of the bag weaving portion. Post-processing such as sewing for forming is unnecessary and can be provided more easily.

  The airbag device is mounted inside the hood of the vehicle, and the airbag device is deployed to move the rear part of the hood upward so that the airbag is deployed in front of the windshield and covers at least a part of both front pillars. If it is set as the structure made into it, the impact by secondary collisions, such as a pedestrian with respect to a bonnet, a windshield, and a front pillar, can be relieve | moderated effectively.

  Furthermore, if the surface protection sheet is arranged on the portion of the airbag body that covers both front pillars, the impact caused by the secondary collision of a pedestrian or the like on the front pillar, which is a strength member of the vehicle in particular, is further increased. Can be effectively mitigated.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, a structure in which a pedestrian airbag device 13 is mounted on an inner surface of a rear portion of a bonnet 12 in a vehicle 11. It is said that.

  The bonnet 12 is configured such that its rear part can move up and down, and is normally held at a lowered position closed by a suitably provided holding mechanism or the like. For example, it is held at the lowered position by a structure as disclosed in Patent Document 1.

  The airbag device 13 is an inflator 14 that generates gas, and is inflated by the gas. As shown in FIGS. 4 and 5, left and right front pillars in front of the windshield 15 of the vehicle 11 and on both sides of the windshield 15. 16 It is set as the structure provided with the airbag 17 expand | deployed ahead.

  That is, the airbag 17 is inflated by the gas of the inflator 14 and extends over the entire length in the left and right width direction in the lower half portion of the windshield 15, and the airbag base portion 18 a and the airbag base portion 18 a over the lower half portion of the left and right front pillars 16. The airbag body 18 having a shape that is long in the vehicle width direction and includes an airbag pillar portion 18b that protrudes upward along the left and right front pillars 16 on both sides of the airbag, and an outer surface of the airbag body 18 It is comprised from the surface protection sheet 19 with which the circumferential direction was covered and mounted | worn.

  And in this embodiment, it is set as the structure where the surface protection sheet 19 of the appropriate length was partially attached to the vehicle width direction intermediate part of the airbag base part 18a, and both the airbag pillar parts 18b, respectively. Yes.

  At this time, as shown in FIG. 6 and FIG. 7, the airbag body 18 has an upper fabric 18c and a lower fabric 18d, which are superposed on each other, sewn together in a bag shape by a sewing portion 20a along the periphery. The airbag base portion 18a and the airbag pillar portions 18b of the airbag body 18 are developed in a flat shape, and a plurality of sewing portions are formed along the length direction so as to form a plurality of inflatable regions 21 when inflated. It is set as the structure sewn suitably length by 20b. Therefore, when the airbag main body 18 is in a fully inflated state alone, as shown in FIG. 7, a groove-like recess 22 along the sewing portion 20b is generated on the outer surface thereof.

  Further, the surface protection sheet 19 attached to the airbag body 18 is also composed of a pair of a belt-like upper fabric 19a and a lower fabric 19b having an appropriate width, and traverses the recessed portion 22 of the airbag body 18 in the fully inflated state. The length corresponding to the width direction of the surface protection sheet 19 in the tension state when the airbag 17 is deployed is shorter than the length (the length in the left-right direction in FIG. 7).

  In the present embodiment, as shown in FIG. 7, the internal opening area S of the cross section when the airbag 17 is deployed formed by the upper fabric 19 a and the lower fabric 19 b is the surface of the airbag body 18. The portion covered with the protective sheet 19 is formed to be smaller than the total exclusive area P of the cross section occupied in the fully expanded state in each expanded region 21.

  That is, the airbag main body 18 is disposed in the surface protection sheet 19 in a non-inflated state in each inflated region 21, and in the present embodiment, the upper fabric 19a and the lower fabric 19b in the surface protection sheet 19 are aired by the sewing portion 20a. The bag main body 18 is sewn together and integrated.

  When the airbag main body 18 is inflated and deployed, a concave portion 22 as shown in FIG. 7 is generated on the outer surface of the airbag base 18a or both airbag pillars 18b covered with the surface protection sheet 19. Before entering the fully expanded state, as shown in FIG. 6, the outer surface is in close contact with the inner surface of the surface protective sheet 19 so that the surface protective sheet 19 is in a tensioned state. Accordingly, the subsequent inflation of the airbag main body 18 is restricted by the surface protection sheet 19, and the structure is suppressed to an incompletely inflated state in which the concave portion 22 hardly occurs.

  The airbag device 13 configured in such a unit shape has a substantially central portion at the rear portion of the bonnet 12 as shown by a dotted line in FIG. The structure is mounted along the left-right direction.

  The inflator 14 is structured to operate upon receiving an operation signal from a pedestrian collision detection sensor. The pedestrian collision detection sensor is mounted on a front bumper or the like at the front of the vehicle body and collides with a pedestrian when the vehicle travels. Is configured to detect.

  Between the bonnet 12 positioned on the lower front side of the windshield 15, as shown in FIGS. 1, 3 and 4, a bowl-shaped cowl panel 25 constituting a vehicle body chassis is formed along the vehicle width direction. A wiper unit 26 is mounted on the lower side of the cowl panel 25 to drive the wiper located above the cowl panel 25. Reference numeral 27 denotes a dash panel that partitions the engine room and the vehicle interior.

  The airbag device 13 is attached to the inner surface side of the bonnet 12 at a position immediately in front of the cowl panel 25. At this time, the airbag 17 is held by a holding member such as an adhesive tape as appropriate at a plurality of positions separated in the vehicle width direction in the folded state (when the airbag 17 is inflated and deployed, it is easily cut by the pressure at the time of deployment). In this folded and held state, the inflator 14 is attached to the screwing portion 12a provided on the lower surface side of the bonnet 12 via the support bracket 28.

  Further, the airbag device 13 includes a cover body 30 as a covering member that covers the inflator 14 and the airbag 17 from the lower side of the bonnet 12. In the present embodiment, the cover body 30 is an appropriate resin material having flexibility. As shown in FIG. 3, the resin is made of resin and has a structure having a cross-sectional shape and an appropriate length in the vehicle width direction.

  Then, one end of the cover body 30, that is, the front end mounting portion 30 b extending forward from the front upper end portion of the groove-shaped flange portion 30 a is attached to the lower surface of the bonnet 12 by the fixing bolt 31 together with the mounting piece portion 28 a of the support bracket 28. The screw fixing portion 12a on the side is fixed by screwing. The front end mounting portion 30b may be fixed by the fixing bolt 31 at a plurality of positions separated in the vehicle width direction, or may be at one place as long as it can be sufficiently fixed and held. Further, when the mounting piece 28 a of the support bracket 28 is not in the fixed position, only the front end mounting portion 30 b of the cover body 30 may be fixed with the fixing bolt 31.

  Further, a locking piece 30c extends rearward from the other end portion of the cover body 30, that is, the rear upper end portion of the flange portion 30a, and is mounted on a locking receiving portion 12b provided on the inner surface side of the bonnet 12. The cover body 30 is locked in a stationary manner and is configured to be detachably held when the cover body 30 is bent and deformed by the pressure when the airbag 17 is expanded due to inflation. At this time, the position of the locking piece portion 30c held by the locking receiving portion 12b is configured to be disposed immediately above the protruding portion 25a protruding upward on the front side of the cowl panel 25. Note that a plurality of the locking piece portions 30c may be arranged separately in the vehicle width direction, or may be a single structure having an appropriate length in the vehicle width direction. What is necessary is just to determine suitably. Further, the protrusion 25a on the vehicle body chassis side may have a structure that continues in the vehicle width direction, or may have a structure in which a plurality of protrusions 25a are provided in the vehicle width direction.

  When the locking piece 30c is detached from the locking receiving portion 12b due to the pressure when the airbag 17 is deployed, the locking piece 30c interferes with the protrusion 25a, and the pressure when the airbag 17 is further deployed. Thereby, the space part between the bonnet 12 and the cover body 30 is expanded. In this case, since the front-side front end mounting portion 30b is screwed by the fixing bolt 31, the rear-side locking piece 30c side in the free end state has a fixed portion by the fixing bolt 31 as a so-called rotation center. Although it is pushed downward, since the locking piece 30c interferes with the protrusion 25a, the rear part of the bonnet 12 is relatively lifted as the airbag 17 is deployed, as shown in FIG. The rear part of the bonnet 12 moves upward, and the airbag 17 is deployed toward the windshield 15 from the gap between the bonnet 12 and the cover body 30 in the upward movement state.

  In addition, a drainage hole 30d is provided in an appropriate number in the vehicle width direction at the bottom of the flange portion 30a in the cover body 30.

  The present embodiment is configured as described above. When the vehicle 11 collides with a pedestrian during traveling, a collision with a pedestrian is detected by a pedestrian collision detection sensor, and a collision load greater than a predetermined value is detected. When detected, an operation signal is output to the inflator 14 of the airbag device 13.

  Then, the operation of the inflator 14 generates gas and the airbag 17 is inflated. As the airbag 17 is inflated, the cover body 30 is pressed from the inner surface side to be bent and deformed, and the non-fixed locking piece 30c is detached from the locking receiving portion 12b and interferes with the protrusion 25a. As the airbag 17 is inflated, the rear part of the bonnet 12 is relatively pushed up, and in the pushed-up state, the airbag is directed toward the windshield 15 from the gap between the bonnet 12 and the cover body 30. 17 expands.

  Therefore, even when a pedestrian that has collided with the vehicle 11 jumps up and collides with the hood 12, the windshield 15, and the front pillar 16, the rear part of the hood 12 is pushed up, Since the front of the front pillar 16 is covered with the inflated and deployed airbag 17, the bonnet 12 and the airbag 17 pushed up by the airbag 17 can effectively mitigate the impact in the secondary collision.

  At this time, since the airbag base portion 18a and the airbag pillar portion 18b of the airbag body 18 are flattened by the sewing portion 20b, the airbag body 18 is more effectively inflated and deployed by the gas of the inflator 14 even in a wide protection region. Can be made.

  In particular, in the present embodiment, the surface protection sheet 19 is attached to each of the airbag base portion 18a and each airbag pillar portion 18b, and each expansion region 21 of the airbag body 18 is completely inflated. Before the recess 22 is formed on the outer surface of the airbag body 18, the outer surface of the airbag body 18 is brought into close contact with the inner surface of the surface protection sheet 19 as shown in FIG. Because it is in a tight state, it develops into a flat shape with almost no thickness difference, and there is almost no pressure difference in its internal space, and even more uniform shock absorption characteristics compared to the conventional structure This is advantageous in that it can be firmly received regardless of the collision position of the pedestrian's head or the like and can exhibit sufficient shock absorption characteristics.

  At this time, the surface protection sheet 19 is also attached to the airbag pillar portion 18b that covers both the front pillars 16 and is caused by a secondary collision such as a pedestrian against the front pillar 16 that is a strength member of the vehicle 11. Impact can be mitigated more effectively.

  Furthermore, in the present embodiment, the recessed portion 22 is formed by the sewing portion 20b of the upper fabric 18c and the lower fabric 18d when the airbag body 18 is inflated and deployed, and simple flat stitching may be performed and sewing can be easily performed. It has the advantage of being suitable for productivity.

  In the present embodiment, since the cover body 30 is formed of a flexible resin material, the force to lift and hold the rear part of the bonnet 12 upward is not strong, and a secondary collision of the pedestrian with the bonnet 12 is not caused. Impact can also be mitigated more effectively. At this time, if the rigidity of the cover body 30 is configured so as to be bent and deformed by the dead weight of the bonnet 12 and the bonnet 12 is closed, the bonnet 12 is automatically closed after the airbag 17 is deployed. It becomes possible to secure it well.

  Further, the rear portion of the bonnet 12 is moved upward by using the pressure generated by the deployment of the airbag 17, and the airbag 17 is deployed with the rear portion of the bonnet 12 moved upward. The air bag 17 can be deployed while avoiding interference such as a wiper disposed at the lower portion of the air bag 15, and the air bag 17 can be smoothly deployed.

  Further, when the airbag 17 is deployed, the locking piece 30c of the cover body 30 interferes with the protrusion 25a on the vehicle body chassis side, and the bonnet 12 with the protrusion 25a as a fulcrum with the fixing position by the fixing bolt 31 as the rotation center. The rear part of the hood 12 is moved upward as the airbag 17 is deployed, so that a space is opened in the deployment direction of the airbag 17 and the airbag 17 is deployed. The function of guiding the deployment direction of the airbag 17 is effectively exhibited.

  In the above-described embodiment, a structure in which the outer surface of the airbag body 18 is partially covered with the surface protection sheet 19 is shown. However, as shown in the second embodiment of FIG. 9 or a structure in which only the airbag pillar portions 18b on both sides are covered with the surface protection sheet 19, as shown in the third embodiment of FIG. Not.

  Moreover, although the structure where the recessed part 22 is formed in the outer surface of the airbag main body 18 by the sewing part 20b is shown, the adhesion | attachment by an adhesive agent, melt | fusion, etc. may be sufficient and the same effect as the above can be acquired.

  Furthermore, as shown in the fourth embodiment of FIG. 10, a so-called bag woven structure having high airtightness in which hollow bag portions 32 are woven in parallel in the longitudinal direction at least at a part of the airbag body 18. It is good also as a structure which comprises using the woven fabric 33 of this, and equips the outer surface of the part with the surface protection sheet 19 of the said structure. In this case, the concave portion 22 is formed on the outer surface by the expansion of the woven fabric 33 portion having the bag woven structure, and there is no need for a separate post-process for forming the concave portion 22 such as sewing or adhesion, and it is easier. Can be provided.

  The surface protective sheet 19 in each of the above embodiments may be a mesh. And if the surface protection sheet 19 is made into a mesh, there exists an advantage which can attain weight reduction.

  In the above-described embodiment, the inflator 14 has a single structure, but the airbag 17 may be deployed by a plurality of inflators 14.

  Further, when the airbag 17 is inflated and deployed, the bonnet 12 is pushed up. However, the airbag 17 may be projected to the outside from an appropriate position and deployed on the outer surface of the bonnet 12 or the front surface of the windshield 15. It is not limited to the pedestrian airbag device 13 as described above, and may be a structure employed in an airbag device in a vehicle, and is not limited to the shape and structure of each of the above embodiments.

1 is a front side view of a vehicle showing a first embodiment of the present invention. It is the same perspective view. It is the principal part sectional drawing. It is a front side view at the time of deployment of an airbag. It is the same perspective view. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is sectional explanatory drawing of a surface protection sheet part. It is a perspective view of the airbag in 2nd Embodiment. It is a perspective view of the airbag in a 3rd embodiment. It is principal part explanatory drawing in 4th Embodiment. It is explanatory drawing of a conventional structure. It is explanatory drawing of a conventional structure. It is explanatory drawing of a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Vehicle 12 Bonnet 13 Air bag apparatus 14 Inflator 15 Front glass 16 Front pillar 17 Air bag 18 Air bag main body 18a Air bag base 18b Air bag pillar part 19 Surface protection sheet 20a Sewing part 20b Sewing part 21 Inflated area 22 Concave part

Claims (5)

The airbag includes an airbag that is inflated and deployed by a gas generated by an inflator, and the airbag includes an airbag body in which a concave portion is generated on an outer surface in a single inflated state, and a part or all of a portion corresponding to the concave portion. In the airbag device comprising a surface protection sheet that covers the surface in the circumferential direction and is tensioned by the expansion of the airbag body,
Said than the widthwise length across the concave portion of the full inflated state of the airbag body, the surface protective sheet of the formed shorter in length corresponding to the width direction of tension state Rutotomoni, the surface protective sheet The internal opening area of the cross section in the tension state is formed less than the total exclusive area of the cross section occupied in the fully inflated state in each inflated region of the portion covered with the surface protection sheet in the airbag body ,
The airbag device is characterized in that the surface protection sheet suppresses the generation of the recess when the airbag body is inflated. In the airbag apparatus of Claim 1,
The airbag device according to claim 1, wherein the recess is formed by partial sewing or bonding of the airbag body. In the airbag apparatus of Claim 1,
At least a part of the airbag main body has a bag weaving structure in which hollow bag portions are woven in parallel, and the recess is formed on the outer surface by expansion of the bag weaving portion. apparatus. In the airbag apparatus in any one of Claims 1 thru | or 3,
The airbag device is mounted on the inside of a hood of a vehicle, and a rear portion of the hood is moved upward by the deployment operation of the airbag device, so that the airbag is deployed in front of the windshield and covers at least a part of both front pillars. An airbag device having a shape. In the airbag apparatus of Claim 4,
The airbag device, wherein the surface protection sheet is disposed in a portion of the airbag body covering the front pillars.

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