JP4460503B2 - Collision protection device - Google Patents

Description

  The present invention relates to a collision object protection apparatus that absorbs an impact and protects the collision object when the vehicle collides with a collision object, and more particularly to a collision object protection apparatus that can extend the internal pressure holding time of an airbag.

A collision object protection device that absorbs and reduces the impact force applied to a collision object by inflating and deploying an air bag on the upper surface of the vehicle when a collision with the vehicle is detected or predicted. The air is composed of a cylindrical bag body in which a main body portion that inflates and expands along the two sides and a pair of pillar portions that are bent from both ends of the main body portion and expands and expands along the vicinity of the lower portion of the front pillar of the vehicle. There is a collision object protection device including a bag (see, for example, Patent Document 1).
JP 2000-264146 A

By the way, in general, in the collision object protection device around the front windshield and the front pillar of the vehicle, there is a time difference from the collision of the front surface of the vehicle to the collision object until the collision object secondarily contacts the airbag. Therefore, it is necessary to maintain the internal pressure of the airbag for a long time as compared with the passenger protection device in the passenger compartment.
On the other hand, a vent hole is provided to discharge the gas from the airbag so as to absorb the impact at the time of contact so that the impacted object will not be bounced back when it comes into contact with the airbag and cause a secondary failure. It is also known to adjust the internal pressure.
However, if a vent hole is provided, a certain amount of gas will always be discharged. Therefore, if the airbag is inflated as soon as possible and the internal pressure of the airbag is maintained in that state, an inflator (gas) The capacity of the generator) must be increased, and there are problems such as securing a space for mounting a large inflator, increasing the weight, and increasing costs.

  Therefore, the present invention provides a collision object protection device that solves the above-described problems, secures the internal pressure holding time of the airbag, and can absorb the shock at the time of contact with the collision object while reducing the size of the inflator. This is the issue.

In order to solve the above-mentioned problems, the present invention provides a collision object protection apparatus including an airbag that generates a high-pressure gas to inflate and deploy on the upper surface of the vehicle when a collision with a vehicle is detected or predicted. The airbag is a cylindrical bag body, inflated and deployed along a lower portion of the front windshield of the vehicle, and bent from both ends of the body portion to the front pillar of the vehicle. A pair of pillar portions that inflate and expand along the pillar portion, and the pillar portion includes a vent hole provided at an upper end of the pillar portion, and the flow of the gas toward the vent hole is restricted. A restricting portion that reduces a cross-sectional area of the bag body, and the restricting portion is a sewing portion that is formed by sewing the bag body so that the restriction is released by the pressure of the gas , Bentho The gas discharge path toward the pipe is a non-sewn part that penetrates the sewing part, and extends in a straight line from the main body side toward the vent hole at the center of the pillar part. And a tether that adjusts the shape of the airbag when the airbag is inflated. The tether has a central portion of the pillar portion along the discharge passage from the main body portion side to the vent hole side. It is comprised as a belt | belt-shaped belt which couple | bonds a front side base fabric and a back side base fabric toward this .

According to the collision object protection device of the present invention, a vent hole is provided at the upper end of the pillar portion, gas is discharged from the vent hole, and the internal pressure of the airbag is adjusted, whereby the collision object is applied to the inflated airbag. It is possible to protect the impacted object from secondary damage due to the impact at the time of contact by absorbing the impact when the contact is made.
In addition, by providing a restricting section that reduces the cross-sectional area of the bag body so as to restrict the flow of gas toward the vent hole, it is possible to suppress gas discharge and reduce the volume of the airbag for a short time. Can be inflated and deployed. And, by configuring so that the regulation is released by the gas pressure, the internal pressure of the airbag is maintained for a long time, and the gas is discharged from the vent hole to ensure the shock absorbing function at the time of contact. ing.
In this way, by restricting the discharge of gas when the airbag is inflated, the airbag is inflated and deployed in a short time, and the restriction is released by the pressure of the gas, thereby increasing the capacity of the inflator. Therefore, the internal pressure of the airbag can be maintained for a long time.
Therefore, it is easy to secure a space for mounting the inflator, and while maintaining the internal pressure of the airbag for a long time while avoiding an increase in weight due to the increase in size of the inflator, it is possible to sufficiently absorb the impact when a collision object comes into contact.

In the present invention described above, by providing the discharge passage of the gas to the regulation unit, the internal pressure of the airbag, separating force applied for a minimum of the regulating portion from the discharge path side acts, because the restricting portion is easily released more reliably The gas flow path can be opened.
In addition, by restricting the gas flow path with the restricting portion to reduce the volume of the airbag and securing the gas discharge passage, the pillar portion can be reliably inflated and expanded upward by the gas passing through the discharge passage. In addition, by enabling the gas to be discharged from the vent hole, the shock absorbing function can be exhibited even when it comes into contact with an obstacle from a relatively early stage.

Wherein the by the present invention lever, by a tether connecting the front base fabric and back base fabric, it can be stabilized adjust the shape at the time of inflation of the airbag. Further, by providing the tether in the discharge path, it is not necessary to consider the interference between the tether and the regulating portion, so that the degree of freedom in designing the regulating portion and the tether increases.

In the present invention described above, in Rukoto configure the restricting portion and sutured bag, it is possible to reduce the cross-sectional area of the bag that is inflated with a simple configuration. In the case of sewing, the strength of sewing can be easily adjusted by changing the strength of the sewing thread and the sewing method. Therefore, by adjusting so that the sewing thread can be cut off with a predetermined gas pressure, it becomes possible to release the regulation at an appropriate expansion and deployment time.

In the above-described present invention, the sewing portion can be sewn with a thread that is easier to cut in the portion closer to the vent hole than in the far portion.
As the airbag is inflated and deployed, the portion closer to the vent hole has a larger volume of the airbag and a lower internal pressure, which makes it difficult to cut the sewing thread. Therefore, by sewing with the thread that is easily cut off, the restriction by the sewing portion is surely released and the gas flow path is opened. If the gas flow path is opened, a sufficient amount of gas can be discharged from the vent hole, and the impact at the time of contact with the collision object can be more reliably absorbed.
In addition, the configuration in which the restriction is reliably released provides a wide range of sewing parts, and the restriction is released sequentially from the main body side where the pressure of the airbag is high. Can be extended.

In the above-described present invention, the sewing part can make the pitch of the seam coarser in the portion closer to the vent hole than in the far portion, and can increase the interval between the adjacent sewing lines.
As the airbag is inflated and deployed, the portion closer to the vent hole has a larger volume of the airbag and a lower internal pressure, which makes it difficult to cut the sewing thread. Therefore, by making the pitch of the seam coarser or increasing the interval between adjacent sewing lines to make the sewing thread easy to break, the gas flow path is surely opened and the gas is discharged from the vent hole. The impact can be absorbed more reliably when it comes into contact with the impacting object by allowing it to be discharged sufficiently.

In the above-described present invention, the restriction portion can be configured such that the portion closer to the vent hole is more easily released from the restriction than the portion farther away.
According to such a configuration, as the airbag is inflated and deployed, the portion closer to the vent hole becomes larger in the volume of the airbag and the internal pressure becomes lower. By configuring, the restriction can be reliably released. Then, by releasing the restriction, the gas flow path is opened, and a sufficient gas discharge amount from the vent hole can be ensured to more reliably absorb the impact at the time of contact with the collision object.
In addition, by reliably releasing the restriction, the restriction portion is provided in a wide range, and the restriction is sequentially released from the main body portion side where the pressure of the airbag is high, so that the internal pressure holding time of the airbag can be extended. .

  According to the collision object protection device of the present invention, it is possible to provide a collision object protection device capable of securing the internal pressure holding time of the airbag and absorbing the shock at the time of contact with the collision object while reducing the size of the inflator. it can.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
1A and 1B are diagrams illustrating a collision object protection device according to the present embodiment, in which FIG. 1A is a plan view of a state before the airbag is inflated and deployed, and FIG. It is a top view. 2A and 2B are diagrams showing the collision object protection apparatus of the present embodiment, in which FIG. 2A is a cross-sectional view taken along the line AA in FIG. 1A, and FIG. is there. FIG. 3 is an exploded perspective view showing the airbag in the collision object protection apparatus of the present embodiment.

  In the present embodiment, when a vehicle, which is an automobile, collides with a colliding object while traveling, and the colliding object has a secondary collision with the upper surface of the front part of the vehicle, in order to absorb and relax the impact force applied to the colliding object. The collision object protection device mounted on the front part of the vehicle will be described as an example.

  As shown in FIG. 1, the collision object protection device 1 includes a collision determination device (not shown) that detects or predicts a collision between the vehicle 2 and the collision object, and the collision determination device detects or predicts a collision with the vehicle 2. The airbag 10 is inflated and deployed on the upper surface of the vehicle 2.

  The collision determination device is configured by an ECU (Electronic Control Unit) that detects or predicts a collision between the vehicle 2 and a collision object based on a signal from a sensor mounted on the vehicle 2 or a radar (not shown). When the collision with the vehicle 2 is detected or predicted, the inflators 20 and 20 that generate gas for inflating and deploying the airbag 10 are operated. In addition, the collision determination apparatus is configured using an existing apparatus, and the configuration is not limited.

As shown in FIG. 1 (b), the airbag 10 is a cylindrical bag body, and a body portion 11 that inflates and deploys along the lower portion of the front window glass 2 a of the vehicle 2, and both end portions of the body portion 11. And a pair of pillar portions 12 and 12 that are inflated and deployed along the front pillars 2 b and 2 b of the vehicle 2.
Further, the airbag 10 is provided with tethers 11a and 15 in the main body 11 and the pillar 12 in order to adjust the shape when inflated and deployed to cover the lower part of the front windshield 2a and the front pillar 2b. (See FIG. 2B and FIG. 3). The pillar portion tether 15 will be described later.

  The airbag 10 before being inflated and deployed is stored in a folded state inside a retainer 2e disposed below the hood 2c of the vehicle 2 as shown in FIG. The retainer 2e opens at the front portion of the cowl top 2d, and the opening is closed by a lid (lid) 2f that forms the same surface as the cowl top 2d.

In the present embodiment, as shown in FIG. 1A, two inflators 20, 20 are attached to the main body 11, and the airbag 10 is inflated by the gas generated in each inflator 20, 20. Configured to deploy.
In this way, by inflating and deploying the entire airbag 10 by the gas generated in each inflator 20 and 20 attached to the main body part 11 without attaching the inflator 20 to the main body part 11 and each pillar part 12 and 12, respectively. Therefore, the collision object protection device 1 can have a simple configuration.
When the airbag 10 is inflated and deployed, as shown in FIG. 2B, the lid 2f (see FIG. 2A) is opened forward from the opening of the retainer 2e by the inflating force, and the vehicle 2 It expands and develops on the upper surface.

The pillar portions 12 and 12 of the airbag 10 are inflated and deployed in the vertical direction along the front pillars 2b and 2b of the vehicle 2 (see FIG. 1B). As shown in FIG. 10a and the back side base fabric 10b are the cylindrical bag bodies sewn by the peripheral part 10c.
In addition, since each pillar part 12 and 12 is the same structure, the following pillar part 12 is demonstrated about the front side of the vehicle 2, and description about the left pillar part 12 is abbreviate | omitted in the following description.

Here, the structure of the upper part of the pillar part 12 is demonstrated in detail, referring FIG.
4A is a partially enlarged plan view showing the structure of the upper portion of the pillar portion, FIG. 4B is a cross-sectional view taken along the line CC of FIG. 4A, and FIG. It is sectional drawing which shows a mode that a bag expand | swells.
In each drawing, the thickness of the base fabric, the sewing method, etc. may be exaggerated for convenience of explanation.

  As shown in FIG. 4A, the pillar portion 12 includes a vent hole 13 for discharging gas provided at the upper end, a gas discharge path 14 formed from the main body portion toward the vent hole 13, and a discharge. A tether 15 that adjusts the shape of the airbag provided in the passage 14 when inflated, and a sewing portion 16 as a restricting portion that is sewn in a direction orthogonal to the discharge passage 14 while avoiding the discharge passage 14 are provided. .

  As shown in FIG. 4A, the vent hole 13 is a gas discharge hole in the airbag 10, and is formed to project like a nozzle upward from the upper end of the pillar portion 12. The gas generated in the inflator 20 (see FIG. 3) reaches the pillar portion 12 from the main body side, so that the gas that has been filled and becomes high pressure can be discharged from the vent hole 13 through the discharge passage 14 that is not sewn. It is configured. This is because when the collision object contacts the airbag 10, the gas is discharged from the vent hole 13 to absorb the impact at the time of contact.

The discharge path 14 is an unsewn portion that is penetrated by a sewing portion 16 that will be described later, and is formed by linearly extending the center of the pillar portion 12 from the main body portion toward the vent hole 13.
Here, the amount of gas discharged from the vent hole 13 is such that the discharge is limited as much as possible at the initial stage of inflation and deployment, the airbag is inflated at an early stage, and the internal pressure of the airbag 10 is increased as the sewing portion 16 is opened. While holding, after the sewing part 16 is opened, a predetermined discharge amount required from the vent hole 13 is secured, and the impact when the collision object contacts the airbag 10 can be sufficiently absorbed. Is set.

In the present embodiment, the discharge passage 14 is configured to penetrate the sewing portion 16 so as to reach the vent hole 13 from the main body portion side, but is not limited to this, and for example, a tether 15 is provided. The discharge thread 14 is shielded by connecting the left and right sewing threads L7 on the vent hole 13 side that are not, and the sewing thread L7 is cut by a predetermined gas pressure so that the discharge path 14 penetrates to the vent hole 13. You can also
Thus, by initially shielding the discharge passage 14, the airbag 10 can be inflated and deployed in a shorter time.

  Moreover, in this embodiment, although the discharge path 14 was formed in linear form, it is not limited to this, You may make it meander. Further, a plurality of discharge paths 14 may be formed.

As shown in FIG. 4, the tether 15 is provided inside the discharge path 14 which is an unsewn portion, and the central portion of the pillar portion 12 is directed from the main body side toward the vent hole 13 along the discharge path 14. The belt is configured as a belt-like belt that joins the front base fabric 10a and the back base fabric 10b.
With such a configuration, when the airbag 10 is inflated, as shown in FIG. 4C, two substantially circular bag bodies 10d and 10d are formed side by side across the tether 15 in cross section, and the front pillar 2b (See FIG. 1A) can be covered widely.
In the present embodiment, the tether 15 is provided at the central portion, but the tether 15 is not limited to this and may be provided at a plurality of locations.

As shown in FIG. 4A, the sewing portion 16 is formed by stitching the front base fabric 10a and the back base fabric 10b (L1, L2, L3..., L7) as a cylindrical bag body. The vent hole 13 is controlled so that the flow of the gas generated from the inflators 20 and 20 (see FIG. 3) toward the vent hole 13 of the pillar part 12 from the main body part side is regulated by reducing the cross-sectional area of the pillar part 12 of It is provided in front of.
Specifically, as shown in FIG. 4A, the sewing parts 16 are disposed on the left and right sides of the discharge path 14 so as to avoid the discharge path 14 and to be orthogonal to the discharge path 14. From the left peripheral edge 10 c to the left side of the discharge path 14 and from the right side of the discharge path 14 to the right peripheral edge 10 c of the pillar part 12.
Therefore, a part of gas which goes to the vent hole 13 through the discharge path 14 from the main body side passes between adjacent sewing threads (L1, L2, L3..., L7) and passes through the pillar portion 12. It is supplied up to the peripheral portion 10c.

In addition, as an example, the sewing thread (L1, L2, L3,..., L7) for sewing the front side base fabric 10a and the back side base fabric 10b in the sewing unit 16 goes from the main body side to the vent hole 13 side. The sewing thread (L1, L2, L3,..., L7) is made thin and easy to cut.
That is, when the airbag 10 is inflated and deployed, the volume of the airbag 10 is small and the internal pressure is high in the portion of the sewing thread L1 on the main body side, but the volume of the airbag 10 becomes closer to the vent hole 13 (L7 side). Since the inner pressure decreases and the internal pressure decreases, the sewing thread (L1, L2, L3,..., L7) can be surely cut by making the thickness of the sewing thread thinner on the L7 side than on the L1 side. Is.

The collision object protection apparatus 1 configured as described above operates as follows to achieve the effects of the present invention.
As shown in FIG. 1A, a collision determination device (not shown) detects or predicts a collision with the vehicle 2 based on a signal from a sensor mounted on the vehicle 2 or a radar (not shown). When this occurs, the collision determination device activates the inflators 20 and 20, and the airbag 10 is inflated on the upper surface of the vehicle 2 by the gas generated in the inflators 20 and 20, as shown in FIG. Will be deployed.

  Here, the operation | movement at the time of inflation expansion | deployment of an airbag is demonstrated in detail, referring FIG. FIG. 5 is a graph showing a change in the internal pressure of the airbag. A line A shows a collision object protecting apparatus according to this embodiment having a sewing part, and a line B shows a thing without a sewing part.

When the collision object protection apparatus 1 according to the present embodiment detects or predicts a collision as shown in a diagram A of FIG. 5, the inflator 20 or 20 (see FIG. 3) is operated to generate high-pressure gas. , And supplied to the folded airbag 10. At this time, the lid 2f (see FIG. 2A) is opened at a pressure at which the airbag 10 is to be inflated. However, since the airbag 10 is not yet inflated and deployed, the internal pressure of the airbag 10 is It rises instantaneously (t1). Immediately thereafter, the airbag 10 starts to inflate and deploy, so that the internal pressure of the airbag 10 again decreases instantaneously (t2).
In this state, the airbag 10 is not sufficiently inflated and deployed. After that, the airbag 10 is filled with gas, and the internal pressure of the airbag 10 starts to rise rapidly and soon reaches a peak (t3). This peak means that the volume when the airbag 10 is inflated is filled with gas and becomes saturated. In the present embodiment, the pillar portion 12 is provided with a sewing portion 16 (see FIG. 4A), and since the volume of the airbag 10 is narrowed by the range of the sewing portion 16, the time to reach the peak is reached. It has been shortened.

However, a part of the gas is discharged from the vent hole 13 through the discharge path 14 (see FIG. 4A). However, since the sewing part 16 is provided, the discharge path 14 has a narrow flow path and a fluid resistance. Therefore, when the sewing portion 16 is provided, the gas discharged from the discharge path 14 is regulated by the sewing portion 16 as compared with the case where the sewing portion 16 is not provided. It can be increased with time (difference between t4 and t3).
Further, by providing the discharge path 14, the gas flowing through the discharge path 14 even before the sewing thread (L1, L2, L3,..., L7) of the sewing portion 16 is cut and the flow path is opened. Since the gas is supplied from the discharge path through the sewing threads (L1, L2, L3,..., L7) to the peripheral edge portion 10c of the pillar portion 12 (see FIG. 3A), the pillar portion 12 Can be deployed.
Furthermore, by discharging the gas from the vent hole 13, even when a collision object comes into contact with the airbag 10 from the early stage of inflation and deployment, the impact can be absorbed.

In the state (t3) when the peak of the internal pressure of the airbag 10 is reached, the strength is set so that the sewing threads (L1, L2, L3,..., L7) of the sewing portion 16 are cut (see FIG. 4). .
Specifically, the sewing thread (L2, L3,..., L7) is sequentially cut from the sewing thread (L1) in the portion of the sewing portion 16 far from the vent hole 13 where the internal pressure of the airbag 10 directly acts. It is configured. For this reason, as the sewing thread (L2, L3,..., L7) is cut and the volume of the airbag 10 is increased, the internal pressure gradually decreases, and the ejection of gas from the inflators 20, 20 is completed (t4). .

Here, the manner in which the sewing thread of the sewing portion is cut will be further described with reference to FIG.
As described above, the sewing portion 16 is sewn along a direction orthogonal to the discharge path 14 while avoiding the discharge path 14 toward the vent hole 13 (see FIG. 4A). With this configuration, the internal pressure of the airbag 10 acts on the sewing portion 16, and the airbag 10 is inflated also from the discharge path 14 side, so that the front base fabric 10a and the back base fabric 10b (see FIG. 4B). ) Acts on the sewing thread (L1). Since this tensile force acts in the direction of the seam from the discharge path 14 side toward the peripheral edge 10c, the sewing threads (L1, L2, L3,..., L7) are easily cut off, as shown in FIG. As shown, when the sewing thread L1 in one row is viewed, the sewing thread L1 is gradually cut from the discharge path 14 side toward the peripheral edge portion 10c, and the pillar portion 12 is inflated and deployed.

  The sewing part 16 is provided in a wide range from the sewing thread L1 on the main body side of the pillar part 12 to the sewing thread L7 on the vent hole side. For this reason, by reducing the volume of the airbag 10 depending on the range where the sewing portion 16 is provided, the airbag 10 is connected from the main body portion 11 (see FIG. 3) where the sewing portion 16 is not provided to the sewing portion 16. Can be expanded in a short time.

In this manner, the sewing portion 16 is provided with a time lag, and the sewing strength is increased so that the sewing threads (L1, L2, L3,..., L7) are sequentially cut from the sewing thread L1 to the sewing thread L7. By setting, as shown in the diagram A of FIG. 5, it is possible to extend the time until all the sewing parts 16 are opened (t4 to t5), and to maintain the internal pressure necessary for the airbag 10 for a long time. it can. In this regard, in the diagram B where the sewing portion 16 described later is not provided, an internal pressure insufficient region is generated (t4 to t5).
After all the sewing parts 16 are opened, the internal pressure rapidly decreases. As described above, a time lag is provided until all the sewing parts 16 are opened. It is possible to ensure the internal pressure of the bag 10 (t5 to t6).

  It should be noted that the position and range in which the sewing portion 16 is provided, the time until the sewing portion 16 is completely cut and opened, and the like should be secured depending on the shape of the front portion of the vehicle on which the collision object protection device 1 is mounted. It should be appropriately determined in consideration of the internal pressure holding time of 10.

On the other hand, in the collision object protection apparatus 1 in which the sewing part 16 is not provided, as shown in a diagram B of FIG. 5, the airbag 10 is slightly moderate until gas is completely ejected from the inflators 20 and 20 (see FIG. 3). The internal pressure increases and reaches a peak (t2 to t4). This is because the pressure loss is large because a certain amount of gas more than necessary is always discharged from the vent hole 13 in the state at t2.
Therefore, after the gas blow-out from the inflators 20 and 20 is completed (t4), the internal pressure rapidly decreases (t4 to t6), so it is necessary to increase the capacity of the inflator (internal pressure shortage region).

  On the other hand, in the collision object protection device 1 according to the present embodiment having the sewing portion 16, the sewing thread L1 starts to be cut as described above (t3), and the time lag is maintained until all the sewing portions 16 are released (t5). Therefore, the flow of gas is regulated by the sewing unit 16 to suppress pressure loss, and even after the internal pressure is rapidly increased to the required pressure, the decrease in the internal pressure is suppressed until the regulation is released. Can do.

  Next, a modification of the present invention will be described with reference to FIG. FIG. 6 is a partial plan view showing an upper portion of a pillar portion according to a modification of the present invention. Since the configuration other than the pillar portion is the same as that of the collision object protection apparatus according to the above-described embodiment, the description thereof is omitted.

In the first modified example of the present invention, as shown in FIG. 6A, the sewing portion 16 is provided to avoid the discharge path 14, but is not in a direction perpendicular to the discharge path 14, but the pillar portion 12. It is provided to be curved upward from the peripheral edge portion 10 c toward the vent hole 13.
With this configuration, the internal pressure increased in the airbag 10 is converged toward the vent hole 13 to generate a fluid resistance, restrict the gas flow path, and the sewing threads L1 and L2 enter the vent hole 13 from below. It works to cut sequentially.

As shown in FIG. 6 (b), the first reference example of the present invention is adjusted by the strength of the sewing thread L as in the above-described embodiment in order to adjust the strength of the sewing portion 16 in the sewing portion 16. Instead, the stitch pitch or the interval between adjacent sewing lines is adjusted.
Specifically, a portion (16a) close to the vent hole 13 while the sewing thread L meanders in the width direction in the sewing portion 16 has a coarse seam pitch and a large interval between adjacent sewing lines (sewing line). Sew) and sew. On the other hand, the portion (16b) far from the vent hole 13 is sewn with a fine stitch pitch and a narrow interval between adjacent sewing lines (a larger number of sewing lines).

  With this configuration, a portion of the sewing portion 16 that is close to the vent hole 13 and has a low internal pressure (16a) easily breaks the sewing thread L, and a portion that is far from the vent hole 13 and that has a high internal pressure (16b) breaks the sewing thread L. By making it harder, all the sewing thread L is surely cut off, the gas flow path is opened, and the gas can be discharged from the vent hole 13 so as to more securely absorb the impact at the time of contact with the collision object. can do. Moreover, since the sewing part 16 can be provided in a wide range by making it the structure which can cut the sewing thread | yarn L reliably, the internal pressure holding time of the airbag 10 can be extended.

Further, in the first reference example of the present invention, since the discharge path 14 as in Modification 1 is not provided, the gas is not discharged from the vent hole 13 until the sewing thread L is completely cut. For this reason, the airbag 10 can be inflated in a shorter time, and the holding time of the internal pressure can be further extended.
Therefore, in the case where it takes a longer time until the collision object comes into contact after the airbag 10 starts to inflate and deploy, it is effective because the discharge of the gas from the vent hole 13 can be delayed.

In the second reference example of the present invention, as shown in FIG. 6C, the width of the upper portion of the pillar portion 12 is narrowed, and a sewing portion 16 is provided in the narrow width portion.
Thus, by providing the sewing part 16 in a narrow part, the gas flow path can be efficiently regulated. And since the area | region of the sewing part 16 becomes narrow, the man-hour required for manufacture of the sewing part 16 by the part can be reduced.

It is the figure which showed the collision object protection apparatus of this embodiment, (a) is a top view of the state before inflating and deploying an airbag, (b) is a top view of the state after inflating and deploying an airbag. . It is the figure which showed the collision object protection apparatus of this embodiment, (a) is AA sectional drawing of Fig.1 (a), (b) is BB sectional drawing of FIG.1 (b). It is the disassembled perspective view which showed the airbag in the collision object protection apparatus of this embodiment. It is a figure which shows the structure of the upper part of the pillar part in the collision object protection apparatus of this embodiment, (a) is the elements on larger scale of the upper part of a pillar part, (b) is sectional drawing of CC line of (a), (C) is sectional drawing which shows a mode that an airbag expand | swells. It is a graph which shows the change of the internal pressure of the airbag which concerns on the collision object protection apparatus of this embodiment. It is a fragmentary top view which shows the structure of the upper part of the pillar part which concerns on the modification and reference example of this invention, (a) shows a 1st modification, (b) shows a 1st reference example , (c) is A second reference example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collision protection device 2 Vehicle 2b Front pillar 2e Retainer 10 Air bag 10a Front side base fabric 10b Back side base fabric 10c Peripheral part 10d Bag body 11 Main body part 12 Pillar part 13 Vent hole 14 Discharge path 15 Tether 16 Sewing part 20 Inflator

Claims (4)

A collision object protection apparatus comprising an airbag that generates a high-pressure gas to inflate and deploy on the upper surface of the vehicle when a collision with a vehicle is detected or predicted,
The airbag is a tubular bag body, a main body portion that inflates and expands along a lower portion of the front windshield of the vehicle, and an air bag that is bent from both ends of the main body portion and expands along the front pillar of the vehicle. A pair of pillars to be deployed are formed,
The pillar part includes a vent hole provided at an upper end of the pillar part, and a regulation part that reduces a cross-sectional area of the bag body so as to regulate the flow of the gas toward the vent hole,
The restricting portion is a sewing portion formed by stitching the bag body so that the restriction is released by the pressure of the gas, and includes a discharge path for the gas toward the vent hole,
The discharge path is an unsewn portion that is penetrated by the sewing portion, and is formed by extending the center of the pillar portion linearly from the body portion side toward the vent hole,
In the discharge path, provided with a tether for adjusting the shape of the airbag when inflated,
The tether is configured as a belt-like belt that joins the front base fabric and the back base fabric from the main body side toward the vent hole side at the center of the pillar portion along the discharge path. Characteristic collision object protection device. 2. The collision object protection device according to claim 1 , wherein the sewn portion is sewn with a thread that is easier to cut at a portion closer to the vent hole than at a far portion. 2. The collision object according to claim 1 , wherein a portion of the sewing portion closer to the vent hole has a larger seam pitch than a portion farther away, or has a larger interval between adjacent sewing lines. Protective device.   The collision object protection device according to claim 1, wherein the restriction portion is configured such that a portion closer to the vent hole is more easily released from a restriction than a portion far from the vent hole.

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