Curtain airbag system

Abstract

A curtain airbag device is provided that can prevent a front pillar garnish from being damaged during operation. The curtain airbag device (100) includes: a curtain airbag cushion (120) in a long, retractable form and covered by a front pillar garnish (118) and a roof garnish (116); and an inflator (122) fixed to a roof rail (114). The curtain airbag cushion (120) includes: an inflation portion (130) extending from the inflator (122) toward the front pillar (108); and a temporary sewing portion (138) formed on a portion of the inflation portion (130) located near an upper end portion (140) of the front pillar garnish (118), which ruptures when a predetermined force is applied. The temporary sewn portion (138) is formed to extend obliquely downward along the front side of the vehicle from the upper edge (142) of the inflation portion (130) when the curtain airbag cushion (120) is deployed on a plane.

Description

Technical Field

[0001] The present invention relates to a curtain type safety airbag device for protecting passengers when a vehicle has a side collision or rollover. Background Art

[0002] A curtain airbag system includes a bag-shaped curtain airbag cushion that expands and deploys in an emergency to catch and protect the occupant. To protect the occupant's head and upper body from any potential collision, even in the event of a side collision and rollover, the curtain airbag cushion deploys along the side of the vehicle.

[0003] The curtain airbag cushion is stored in the upper side of the vehicle interior along the front-to-back direction. It is housed not only in the roof rails but also between the front pillar located on the vehicle front side of the roof rails and the front pillar garnish that covers the front pillar from the vehicle interior. To accommodate such limited storage space, the curtain airbag cushion is typically installed in the upper side of the vehicle interior in a rolled or folded state.

[0004] The curtain airbag cushion inflates and deploys by pushing aside the roof trim covering the roof rails and the pillar trims. For example, in the technology of Patent Document 1, a curtain airbag KB is provided with a patch portion P3 on the upper portion of the pillar trim 6 of the B-pillar 3 as an inflation suppressor. According to Patent Document 1, the provision of the patch portion P3 suppresses inflation, preventing the application of significant inflation pressure to the pillar trim 6 and, consequently, preventing damage to the pillar trim 6.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-199067 Summary of the Invention

[0007] As mentioned above, the front side of the vehicle's curtain airbag cushion is covered by a front pillar garnish. When the front pillar garnish is pushed open, the cushion inflates and deploys. At this point, the inflation pressure of the curtain airbag cushion tends to concentrate on the upper end of the front pillar garnish, potentially damaging it. If the front pillar garnish detaches or scatters, it could compromise occupant safety, so adequate precautions are essential.

[0008] Problems to be solved by the invention

[0009] In view of the above problems, an object of the present invention is to provide a curtain airbag device that can prevent damage to a front pillar garnish during operation.

[0010] Solutions to the Problem

[0011] To solve the above-mentioned problems, a curtain airbag device according to the present invention is typically configured to include: a curtain airbag cushion mounted in a long, stowed configuration in the vehicle's front-to-rear direction, extending from a front pillar inside the vehicle along a roof rail, and covered by a front pillar garnish and a roof garnish; and an inflator secured to the roof rail with a portion thereof inserted into the curtain airbag cushion for supplying gas in an emergency. The curtain airbag cushion is characterized in that it includes: an inflation portion disposed on the vehicle's front side and inflated and deployed by receiving gas from the inflator; and a temporary sewn portion formed by sewing the inflation portion to a portion of the inflation portion located near an upper end of the front pillar garnish during inflation and deployment, the temporary sewn portion being ruptured when a predetermined force is applied, the temporary sewn portion being formed to extend obliquely downwardly from an upper edge of the inflation portion along the front side of the vehicle when the curtain airbag cushion is deployed on a flat surface.

[0012] With this structure, the gas supplied from the inflator to the inflation unit is blocked by the temporary seam before reaching the upper end of the front pillar garnish at the front of the vehicle. Consequently, the inflation unit first expands and deploys downward, pushing open the roof garnish. Then, the inflation pressure dissipates the temporary seam and expands toward the front pillar garnish. In other words, this structure provides a curtain airbag device with enhanced safety considerations. By protecting the upper end of the front pillar garnish from the force of gas directed toward the upper end of the front pillar garnish at the temporary seam, the upper end of the front pillar garnish is prevented from being damaged.

[0013] The temporary seam can be formed from the upper edge of the expansion portion to just above the lower edge of the expansion portion. With this temporary seam, gas is initially directed below the expansion portion. As the expansion portion continues to inflate, the temporary seam is removed, effectively suppressing the force of gas directed toward the front pillar garnish.

[0014] The temporary stitching portion can be formed in a range from the upper edge of the inflation portion to the vicinity of the vertical center of the inflation portion. With such a temporary stitching portion, the force of gas directed toward the front pillar garnish when the inflation portion inflates can also be effectively suppressed.

[0015] The upper end of the temporary stitching portion may be formed on a portion of the upper edge of the inflation portion that is located rearward of the vehicle relative to the upper end of the front pillar garnish. This temporary stitching portion effectively suppresses the force of gas directed toward the front pillar garnish during inflation of the inflation portion.

[0016] The lower end of the temporary stitching portion may be formed on a portion of the inflation portion that is located rearward of the vehicle relative to the upper end of the front pillar garnish. This temporary stitching portion can also effectively suppress the force of gas directed toward the front pillar garnish during inflation of the inflation portion.

[0017] The lower end of the temporary stitching portion may be formed on a portion of the inflation portion that is located forward of the vehicle relative to the upper end of the front pillar garnish. This temporary stitching portion can also effectively suppress the force of gas directed toward the front pillar garnish during inflation of the inflation portion.

[0018] Effects of the Invention

[0019] According to the present invention, a curtain airbag device capable of preventing a front pillar garnish from being damaged during operation can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing an outline of a curtain airbag device according to an embodiment of the present invention.

[0021] Figure 2 It shows Figure 1 (b) is a diagram showing a state where the curtain airbag cushion is deployed on a flat surface.

[0022] Figure 3 yes Figure 2 An enlarged view of the curtain airbag cushion on the front side of the vehicle.

[0023] Figure 4 It shows Figure 3 Diagram showing the deployment action of the curtain airbag cushion.

[0024] Figure 5 It shows Figure 3 Figures showing various variations of the temporary suture portion. DETAILED DESCRIPTION

[0025] The following describes in detail preferred embodiments of the present invention with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples to facilitate understanding of the invention and, unless otherwise specified, do not limit the invention. Furthermore, in this specification and the accompanying drawings, elements having substantially the same function or structure will be assigned the same reference numerals to avoid duplicate descriptions, and elements not directly related to the present invention will be omitted from illustration.

[0026] Figure 1 1 is a diagram schematically showing a curtain airbag device 100 according to an embodiment of the present invention. Figure 1 (a) is a diagram showing a state before the curtain airbag device 100 is activated. The curtain airbag device 100 shown in the figure is for the right side of the vehicle, but the curtain airbag device 100 for the left side (not shown) also has the same symmetrical structure.

[0027] Below, in Figure 1In (a) and other figures, arrows F (Forward) and B (Back) indicate the vehicle's front-to-back direction, arrows L (Left) and R (Right) indicate the vehicle's left and right widthwise directions, and arrows U (Up) and D (Down) indicate the vehicle's up-down direction. Specifically, "up" refers to the direction of a passenger's head when properly seated, and "down" refers to the direction of the passenger's lower limbs.

[0028] Assume that vehicle 102 is a double-row vehicle, with front seats 104 and rear seats 106 arranged from the front. Side windows 105 and 107 are provided on the sides of the vehicle from the front. Multiple pillars supporting the roof are provided in the longitudinal direction of each side window. These pillars are referred to as front pillar 108, center pillar 110, and rear pillar 112, in order from the front of the vehicle.

[0029] The roof rail 114 is a member forming the upper side of the vehicle interior. The roof rail 114 is covered by a roof garnish 116 that covers the roof of the vehicle interior. Figure 4 (a) The vehicle interior side of the front pillar 108 is covered with a resin front pillar garnish 118 .

[0030] Before the curtain airbag device 100 is activated, the curtain airbag cushion 120 is rolled or folded into a long strip in the vehicle front-to-rear direction. The curtain airbag cushion 120 is installed along the roof rail 114 from the front pillar 108. Before the curtain airbag cushion 120 is activated, it is covered by the front pillar garnish 118 (see Figure 4 (a)) and the roof trim 116 are covered and hidden so as not to be seen by the occupants.

[0031] The curtain airbag device 100 includes an inflator 122 as a gas generating device. The inflator 122 is a cylindrical cylinder type and is fixed to the roof rail 114 with a portion thereof inserted into the curtain airbag cushion 120 .

[0032] Figure 1 (a) is a diagram showing a state in which the curtain airbag device 100 is operated. In an emergency such as a side collision, the curtain airbag cushion 120 pushes the roof trim 116 (see FIG. 1 ) outward by the gas pressure supplied from the inflator 122. Figure 4 (a)) and the front pillar garnish 118 and deploy to restrain the occupant.

[0033] The curtain airbag cushion 120 inflates and deploys over a wide area in the vehicle front-to-rear direction outside the front and rear seats 104 and 106. Each portion of the inflatable portion of the curtain airbag cushion 120 is divided into small cells called chambers based on the flow of gas and the interaction with structures such as occupants and seats.

[0034] The curtain airbag cushion 120 further includes a strap 124. The strap 124 is a strip-shaped component having a front end mounted on the front pillar 108 and a rear end mounted on the front end of the curtain airbag cushion 120. Before operation, the strap 124 is stored between the front pillar 108 and the front pillar trim 118. Figure 4 (a).

[0035] Figure 2 It shows that Figure 1 (b) shows the curtain airbag cushion 120 deployed on a flat surface. When the curtain airbag cushion 120 is placed on a flat surface, the side where the inflator 122 is mounted is the "up" side, and the opposite side is the "down" side. When the curtain airbag cushion 120 is mounted on a vehicle, this up-down direction corresponds to the up-down direction of the vehicle body.

[0036] The curtain airbag cushion 120 is formed into a strip shape by, for example, sewing the front and back sides of a base fabric constituting the surface of the curtain airbag cushion 120, or by sewing using an OPW (One Piece W oven). The curtain airbag cushion 120 is fixed to the roof rail 114 via a plurality of tabs 126 provided on the upper edge. The upper edge is also provided with a slot for inserting the inflator 122 (see FIG. 1 ). Figure 1 (b)) The inflator insertion portion 128.

[0037] The inflatable portion 130 of the curtain airbag cushion 120 is broadly divided into a duct portion 132 and a plurality of protection chambers, namely, protection chambers 134 a. The duct portion 132 is a gas connection passage extending from the inflator insertion portion 128 in the vehicle longitudinal direction and forms the upper portion of the inflatable portion 130 .

[0038] The protection chamber is divided into protection chambers 134a to 134c for mainly restraining the occupants of the front seats 104 and a protection chamber 136 for mainly restraining the occupants of the rear seats 106. Gas is supplied to each protection chamber from the duct portion 132 above.

[0039] Figure 3 yes Figure 2 An enlarged view of the vehicle front side of the curtain airbag cushion 120 . Figure 3 Shown with dotted lines Figure 1 (b) The front pillar garnish 118 . The curtain airbag cushion 120 of this embodiment is provided with a temporary sewn portion 138 to prevent excessive inflation pressure from being applied to the front pillar garnish 118 .

[0040] The temporary stitching portion 138 is a stitching line that can be eliminated by the force of the curtain airbag cushion 120 when it is inflated and deployed, and is provided in the protection chamber 134 a near the upper end portion 140 of the front pillar garnish 118 when the curtain airbag cushion 120 is inflated and deployed.

[0041] In this embodiment, the temporary sewing portion 138 is provided on the inflator 122 (see Figure 2 ) is provided on the vehicle front side of a duct portion 132 extending toward the front pillar 108 and is provided in the upper portion of a frontmost protection chamber 134a in the curtain airbag cushion 120. The temporary sewn portion 138 is formed by sewing the upper portion of the protection chamber 134a in the vehicle width direction using a sewing thread that breaks when subjected to a predetermined force.

[0042] When the curtain airbag cushion 120 is deployed on a flat surface, the upper end 138a of the temporary stitching portion 138 is formed within the upper edge 142 of the protection chamber 134a, located rearward of the vehicle relative to the vertical straight line L1 behind the upper end portion 140 of the front pillar garnish 118. Furthermore, the temporary stitching portion 138 is formed so as to extend obliquely downward toward the front of the vehicle from the upper edge 142 of the duct portion 132. At this time, the lower end 138b of the temporary stitching portion 138 is also formed within the protection chamber 134a, located rearward of the vehicle relative to the upper end portion 140 of the front pillar garnish 118.

[0043] According to the above structure, the temporary sewn portion 138 is inclined toward the vehicle front and lower side, so that the gas flowing into the front pillar garnish 118 in front of the vehicle through the duct portion 132 is first guided toward the vehicle front and lower side along the temporary sewn portion 138 .

[0044] Figure 4 It shows Figure 3 FIG. 1 is a diagram illustrating a deployment operation of the curtain airbag cushion 120 . Figure 4 (a) shows the state before the curtain airbag cushion 120 is activated. The upper end portion 140 of the front pillar garnish 118 is positioned adjacent to the roof garnish 116. From the front pillar garnish 118 to the front portion of the roof garnish 116, the curtain airbag cushion 120's strap 124 accommodates the duct portion 132 and the vicinity of the protection chamber 134a.

[0045] Figure 4 (b) shows the Figure 4 (a) The state of the curtain airbag cushion 120. In this embodiment, when the gas is discharged from the inflator 122 (see Figure 2 ) is supplied to the protection chamber 134a through the duct portion 132, the gas is blocked by the temporary sewn portion 138 before reaching the upper end portion 140 of the front pillar garnish 118. Therefore, the protection chamber 134a does not expand and deploy toward the front of the vehicle, but instead expands and deploys while first pushing the roof garnish 116 downward.

[0046] Figure 4 (c) shows that the gas is further supplied to Figure 4(b) The state of the protective chamber 134a. When the protective chamber 134a is unwound and deployed downward, the temporary suture 138 is also fully deployed. Then, the expansion pressure from below is concentrated at the lower end 138b of the temporary suture 138, causing the protective chamber 134a to expand and deploy toward the front pillar garnish 118 while breaking the temporary suture 138.

[0047] As described above, in this embodiment, the force of gas directed toward the upper end portion 140 of the front pillar garnish 118 is received at the temporary stitching portion 138, thereby preventing damage to the upper end portion 140 of the front pillar garnish 118. In particular, by preventing the front pillar garnish 118 from falling off or fragments from being scattered, a curtain airbag device 100 that is more safety-conscious can be provided.

[0048] The following describes various parameters of the temporary sewing portion 138. First, the force applied to the temporary sewing portion 138 when the curtain airbag cushion 120 is inflated and deployed is discussed. The temporary sewing portion 138 is provided within the protection chamber 134a (see FIG. Figure 3 16025 mm above 2 Range E1 is defined as the area extending from the vertical straight line L1 behind the upper end 140 of the front pillar garnish 118 to the vertical straight line L2 approximately 140 mm rearward. Since the coiling in range E1 was observed to be eliminated within 12 milliseconds after the inflator 122 began operating, the time required to maintain the temporarily stitched portion 138 was set to 12 milliseconds. Measurements revealed that the internal pressure of the protection chamber 134a at 12 milliseconds was 72.7 kPa.

[0049] Based on the above values, the force applied to the temporary suture portion 138 at the time of 12 ms is 1165 [N] according to the following calculation formula.

[0050] Pressure [N / m 2] = force [N] / force-bearing area [mm 2]: 72700 [N / m 2] × 16025 [mm 2] = 1165 [N].

[0051] Next, the strength [N] of temporary suture 138 was investigated. The tensile strength of the suture thread used to form temporary suture 138 was 33 ± 5 [N]. Furthermore, the length of temporary suture 138 was 150 mm. The seam spacing, or suture pitch, was 2.5 ± 0.3 mm. The number of sutures, or suture count, was calculated as: length / pitch: 150 / 2.5 = 60 [counts].

[0052] Based on the above values, the strength of the temporary stitching [N] is 33 [N] x 60 [counts] = 1980 [N]. However, due to the tolerances of the tensile strength and stitch spacing of the suture thread, the lower tolerance limit of the strength of the temporary stitching [N], or the lower limit of the stitching endurance, is 28 [N] x 54 [counts] = 1512 [N]. Furthermore, the air permeability, or thread tension, of the temporary stitching 138 is controlled within the range of 500 ± 100 [mm / s] for the upper thread and 220 ± 50 [mm / s] for the lower thread.

[0053] It is known that the temporary suture portion 138 (1512 [N]) set above can withstand the force (1165 [N]) received from the rear at 12 ms. Figure 4 As shown in (c), until the 12 ms point when the protection chamber 134a is unwound, if the temporary stitching portion 138 has the above-mentioned parameters, the stitching can be better maintained and the unfolding force of the protection chamber 134a can be prevented from being applied to the upper end portion 140 of the front pillar decoration 118.

[0054] When the winding of the protective chamber 134a was unwound, that is, 12 ms later, the portion of the protective chamber 134a below the lower end 138b of the temporary suture 138 also expanded. As a result, an expansion force was applied from below to the lower end 138b of the temporary suture 138. Consequently, the load from below concentrated on the suture thread (33 [N]) at the lower end 138b of the temporary suture 138, causing it to begin to rupture.

[0055] In summary, it is understood that the temporary seam 138 maintains its seal effectively from the time the inflator 122 begins operating until 12 milliseconds, and is released after 12 milliseconds, allowing the entire protective chamber 134a to inflate and deploy securely. This temporary seam 138 prevents the force of the gas from the duct portion 132 from directly impacting the front pillar garnish 118, thereby preventing the front pillar garnish 118 from falling off or scattering.

[0056] (Variation)

[0057] Hereinafter, variations of the above-mentioned components will be described. Figure 5 Hereinafter, the same reference numerals will be used for the same components as those already described, and the description of the components already described will be omitted. In addition, in the following description, even if components having the same names as those already described are given different reference numerals, they have the same functions unless otherwise specified.

[0058] Figure 5 It shows Figure 3 Figures showing various variations of the temporary suture portion. Figure 5(a) is a diagram showing a temporary suture portion 200 according to a first modification. The temporary suture portion 200 is provided Figure 3 Temporary stitching 138 is long, for example, extending from upper edge 142 of protection chamber 134a to approximately the vertical center C1 of protection chamber 134a. By varying the length of temporary stitching 200, the force of gas flowing toward front pillar garnish 118 can be effectively suppressed according to the timing of expansion and deployment of protection chamber 134a.

[0059] Figure 5 (b) is a diagram showing a temporary suture portion 220 according to a second modification. Figure 3 The temporary stitching portion 138 is angled further toward the vehicle front. For example, the lower end 220b of the temporary stitching portion 220 forms the portion of the vehicle front of the vertical straight line L1 extending from the rear side of the upper end portion 140 of the front pillar garnish within the protection chamber 134a. By varying the angle of the temporary stitching portion 220, the airflow within the protection chamber 134a can be adjusted according to the shape and size of the protection chamber 134a and the front pillar garnish 118, thereby effectively suppressing the force of the air flowing toward the front pillar garnish 118.

[0060] Each of the temporary stitching sections 138, 200, and 220 has an upper end 138a, 200a, and 220b formed at the upper edge 142 of the protection chamber 134a, which serves as the expansion portion, and a lower end 138b, 200b, and 220b formed within a range extending from the upper edge 142 to above the lower edge 144 of the protection chamber 134a. In other words, a gas flow path is ensured below the temporary stitching sections 138, 200, and 220, concentrating the deployment force from below on the lower ends 138b, 200b, and 220b. Consequently, the temporary stitching sections 138, 200, and 220 suppress the force of gas directed toward the front pillar garnish 118 and release as the protection chamber 134a expands, resulting in a structure that does not affect the restraint force on the occupant.

[0061] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. The aforementioned embodiments are preferred examples of the present invention, and other embodiments can be implemented or carried out in various ways. Unless otherwise specified in this specification, the present invention is not limited by the shape, size, and structural configuration of the detailed components shown in the accompanying drawings. In addition, the expressions and terms used in this specification are for illustrative purposes only and are not limited to these unless otherwise specified.

[0062] Therefore, those skilled in the art can conceive of various changes and modifications within the scope of the claims, and it is obvious that these should also fall within the technical scope of the present invention.

[0063] Industrial applicability

[0064] The present invention can be used in a curtain airbag device for protecting passengers when a vehicle is involved in a side collision or rollover.

[0065] Explanation of symbols

[0066] 100…curtain airbag device, 102…vehicle, 104…front seat, 105, 107…side windows, 106…rear seat, 108…front pillar, 110…center pillar, 112…rear pillar, 114…roof rail, 116…roof garnish, 118…front pillar garnish, 120…curtain airbag cushion, 122…inflator, 124…strap, 126…tab, 128…inflator insertion portion, 130…inflation portion, 132…duct portion, 134a…protection chamber, 136…protection chamber, 138…temporary suture portion, 138a…upper end, 138b…lower end, 140…upper end portion, 142…upper edge, 144…lower edge, C1…protection chamber center, E 1...range, 200...temporary suture portion of the first modified example, 200a...upper end, 200b...lower end, 220...temporary suture portion, 220a...upper end, 220b...lower end.

Claims

1. A curtain airbag device comprising: a curtain airbag cushion in a stowed, elongated configuration extending in the front-to-rear direction of the vehicle, mounted along a roof rail from a front pillar inside the vehicle and covered by a front pillar garnish and a roof garnish; and an inflator fixed to the roof rail with a portion of the cushion inserted into the curtain airbag cushion, for supplying gas in an emergency, wherein: The curtain airbag cushion comprises: an inflation portion that is provided on a vehicle front side of the curtain airbag cushion and receives gas from the inflator to inflate and deploy; and a temporary sewn portion formed by sewing the inflation portion at a portion of the inflation portion located near the upper end portion of the front pillar garnish when the curtain airbag cushion is inflated and deployed, and ruptured when a predetermined force is applied; The temporary sewn portion is formed to extend obliquely downward along the front side of the vehicle from an upper edge of the inflation portion in a state in which the curtain airbag cushion is deployed on a flat surface.

2. The curtain airbag device according to claim 1, wherein: The temporary sewn portion is formed in a range from an upper edge of the expansion portion to an upper portion of a lower edge of the expansion portion.

3. The curtain airbag device according to claim 1 or 2, wherein: The temporary sewn portion is formed in a range from an upper edge of the inflation portion to near a vertical center of the inflation portion.

4. The curtain airbag device according to any one of claims 1 to 3, wherein: An upper end of the temporary sewn portion is formed on a portion of an upper edge of the inflation portion that is located rearward of the vehicle relative to an upper end portion of the front pillar garnish.

5. The curtain airbag device according to any one of claims 1 to 4, characterized in that: A lower end of the temporary sewn portion is formed on a portion of the inflation portion that is located rearward of the vehicle relative to an upper end portion of the front pillar garnish.

6. The curtain airbag device according to any one of claims 1 to 4, characterized in that: A lower end of the temporary sewn portion is formed on a portion of the inflation portion that is located forward of the vehicle relative to an upper end portion of the front pillar garnish.

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