JP4067740B2 - Airbag device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle airbag device attached to a vehicle such as an automobile.
[0002]
[Prior art]
Some vehicles such as automobiles have an airbag device as a safety means in an emergency. In the airbag device, when an impact force of a predetermined value or more is applied to the vehicle body, the airbag main body folded and housed in a housing disposed inside an instrument panel or the like has a pressure gas from the inflator. It bulges out toward the passenger in the passenger compartment due to the pressure, receives the head of an occupant seated at a fixed position, and protects the head from being in contact with the instrument panel or the like.
[0003]
The airbag body presses the airbag grid portion formed on the instrument panel at the time of inflation, and forms an inflation opening by cleaving a tear line formed on the airbag grid portion. It is designed to bulge from the opening toward the passenger in the passenger compartment.
[0004]
In the airbag device, as in JP-A-9-156443, a core material is welded to the back surface of a multilayer laminate sheet having a skin layer, an intermediate layer, and a barrier layer to constitute an airbag grid portion, There is one in which a groove-shaped cleavage line is formed at a depth beyond the barrier layer from the back side of the airbag grid portion.
[0005]
[Problems to be solved by the invention]
However, in the airbag device of the above publication, the cleavage line has a depth exceeding the barrier layer in order to ensure breakability, but the linear expansion coefficient is different between the core material and the barrier layer of the multilayer laminate sheet, so that the thermal deformation Sometimes stress concentrates on the cleavage line processed part where the barrier layer is cut, and the surface appearance performance of the air bag grid part is impaired.
[0006]
For this reason, a character line is formed at a position on the surface side corresponding to the cleavage line of the airbag grid portion so that the thermal deformation of the airbag grid portion is less noticeable.
[0007]
Accordingly, an object of the present invention is to provide a vehicle airbag device that can solve the above-described problems and prevent deterioration in appearance quality due to thermal deformation of an airbag grid portion using a multilayer laminate sheet. .
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the invention described in claim 1, the linear thermal expansion coefficient differs from that of the barrier layer on the back surface of the multilayer laminate sheet including at least the skin layer, the foam layer, and the barrier layer. In a vehicle airbag apparatus in which a core material is welded to form an air bag grid portion, and a grooved tear line is formed from the back side of the welded airbag grid portion, the tear line is the multilayer laminate sheet There is no character line on the surface of the core material, and there is no thin wall portion on the back surface of the core material, and a uniform thickness portion is formed from the back surface side of the airbag grid portion, and the tear line is a tear line at the time of thermal deformation In order to prevent stress concentration on the processed portion, the core is continuously formed to a depth that penetrates the core material and a part of the barrier layer remains, and the air bag grid portion corresponds to the cleavage line. There is no character line in the position of the surface, it is characterized in that it is a smooth surface shape with flat.
[0009]
According to the invention according to claim 1 configured as described above, a core material having a linear thermal expansion coefficient different from that of the barrier layer on the back surface of the multilayer laminate sheet including at least a skin layer, a foam layer, and a barrier layer. In the vehicle airbag apparatus in which a groove-shaped tear line is formed from the back side of the welded airbag grid part, wherein the tear line is a surface of the multilayer laminate sheet There is no character line, and there is no thin wall portion on the back surface of the core material, whereas the uniform wall thickness portion is formed from the back surface side of the airbag grid portion, and the cleavage line is a cleavage line processed portion during thermal deformation. In order to prevent stress concentration on the surface, the air bag grid portion is formed on the surface corresponding to the cleavage line. There is no character line in the position of, by which is a gentle surface shape flat, such as the following, effects can be obtained. That is, since the barrier layer remains without being cut, stress is prevented from concentrating on the cleavage line processed part during thermal deformation, and the surface appearance performance of the air bag grid part is degraded (wrinkles and sagging in the cleavage line processed part). And the occurrence of a surface appearance performance degradation portion such as distortion is prevented. Therefore, the air bag grid part can be formed into a substantially flat and gentle surface shape without a character line or the like for making the thermal deformation of the air bag grid part inconspicuous at the position on the surface side corresponding to the cleavage line. Become.
[0010]
In order to solve the above-mentioned problem, the invention described in claim 2 is characterized in that, in addition to claim 1, the cleavage line is formed by laser processing.
[0011]
According to the invention according to claim 2 configured as described above, since the cleavage line is formed by laser processing, the cleavage line can be surely formed even if the core material is somewhat hard.
[0012]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Hereinafter, a specific first exemplary embodiment of the present invention will be described together with illustrated examples.
[0013]
1 to 5 show a first embodiment of the present invention.
[0014]
First, the configuration will be described. An instrument panel 2 as shown in FIGS. 1 and 2 is provided at the front of a passenger compartment in a vehicle such as an automobile and at the lower part of the front window glass 1. An air bag inflation opening 3 is formed in the instrument panel 2. And the airbag apparatus 6 which consists of the airbag grid part 4 and the airbag module 5 which block | close the opening 3 for airbag expansion | swelling with respect to this instrument panel 2 is attached.
[0015]
The instrument panel 2 is obtained by, for example, attaching a skin 8 to the surface of the core material 7.
[0016]
For example, the airbag grid part 4 is formed by previously forming a multilayer laminate sheet 13 having a skin layer 10, a foam layer 11 serving as an intermediate layer, and a barrier layer 12 into the shape of the airbag grid part 4. It is provided with a configuration in which a core material 14 having a different linear thermal expansion coefficient from that of the barrier layer 12 is welded by injection molding on the back surface in an injection mold. A groove-shaped cleavage line 15 is formed on the back surface of the airbag grid part 4 in an H shape or U shape in a plan view.
[0017]
The skin layer 10 has a thickness of 0.05 mm to 1.5 mm, preferably 0.1 mm to 1.0 mm. The foam layer as the intermediate layer 11 has a thickness of 1.0 mm to 5.0 mm. The barrier layer 12 has a thickness of 0.1 mm to 2.0 mm.
[0018]
The skin layer 10 has a tensile strength at −40 ° C. of 250 × 9.8 N / cm ² (250 Kgf / cm ² ) to 500 × 9.8 N / cm ² (500 Kgf / cm ² ) and an elongation of 50%. The tear strength is 10 × 9.8 N / cm ² (10 Kgf / cm ² ) or more, and the tensile strength at 23 ° C. is 50 × 9.8 N / cm ² (50 Kgf / cm ² ) to 100 × 9. 0.8 N / cm ² (100 Kgf / cm ² ), elongation of 100% or more, tear strength of 10 × 9.8 N / cm ² (10 Kgf / cm ² ) or more, and tensile strength at 85 ° C. 10 × 9.8 N / cm ² (10 Kgf / cm ² ) to 100 × 9.8 N / cm ² (100 Kgf / cm ² ), elongation is 150% to 500%, and tear strength is 5 × 9.8 N / Cm ² (5 kgf / cm ² ) or more of material is used.
[0019]
The barrier layer 12 has a tensile strength at −40 ° C. of 130 × 9.8 N / cm ² (130 kgf / cm ² ) to 400 × 9.8 N / cm ² (400 kgf / cm ² ) (preferably 250 kgf / cm ² ). cm ^{2 to} 310 Kgf / cm ² ), the elongation is 65% to 350% (preferably 100% to 230%), and the tear strength is 65 × 9.8 N / cm ² (65 Kgf / cm ² ) to 350 ×. 9.8 N / cm ² (350 Kgf / cm ² ) (preferably 150 Kgf / cm ^{2 to} 280 Kgf / cm ² ) and a tensile strength at 23 ° C. of 70 × 9.8 N / cm ² (70 Kgf / cm ² ) to 250 × 9.8 N / cm ² (250 kgf / cm ² ) (preferably 130 kgf / cm ² to 200 kgf / cm ² ), elongation of 200% to 800% (preferably 450% to 580%), tear strength The In ^{40 × 9.8N / cm 2 (40Kgf} / cm 2) ~150 × 9.8N / cm 2 (150Kgf / cm 2) ( preferably ^{40Kgf / cm 2 ~120Kgf / cm 2} ), tensile strength at 85 ° C. 10 × 9.8 N / cm ² (10 Kgf / cm ² ) to 150 × 9.8 N / cm ² (150 Kgf / cm ² ) (preferably 250 Kgf / cm ^{2 to} 350 Kgf / cm ² ), and the elongation is 150. % To 450% (preferably 250% to 350%), and a tear strength of 10 × 9.8 N / cm ² (10 Kgf / cm ² ) to 100 × 9.8 N / cm ² (100 Kgf / cm ² ) (preferably Is 10 kgf / cm ^{2 to} 50 kgf / cm ² ).
[0020]
The tensile strength at −20 ° C. of the skin 10 is 200 × 9.8 N / cm ² (200 Kgf / cm ² ) to 450 × 9.8 N / cm ² (450 Kgf / cm ² ) (preferably 300 Kgf / cm ² ) with an elongation of 70% or more (preferably 500%) and a tear strength of 10 × 9.8 N / cm ² (10 Kgf / cm ² ) or more (preferably 10 Kgf / cm ² ) at 23 ° C. The tensile strength is 50 × 9.8 N / cm ² (50 kgf / cm ² ) to 100 × 9.8 N / cm ² (100 kgf / cm ² ), the elongation is 100% or more, and the tear strength is 10 ×. in ^{9.8N / cm 2 (10Kgf / cm} 2) or more, the tensile strength at ^{85 ℃ 10 × 9.8N / cm 2} (10Kgf / cm 2) ~100 × 9.8N / cm 2 (100Kgf / cm ² ) with an elongation of 150% to 500% and tear strength A material having a thickness of 5 × 9.8 N / cm ² (5 kgf / cm ² ) or more is used.
[0021]
Further, the barrier layer 12 has a tensile strength at −20 ° C. of 200 × 9.8 N / cm ² (200 Kgf / cm ² ) to 450 × 9.8 N / cm ² (450 Kgf / cm ² ) (preferably 340 Kgf / cm ^{2 to} 310 Kgf / cm ² ), an elongation of 200% to 800% (preferably 500%), and a tear strength of 50 × 9.8 N / cm ² (50 Kgf / cm ² ) or more (preferably 50 Kgf / cm ² ). cm ² ) and a tensile strength at 23 ° C. of 70 × 9.8 N / cm ² (70 Kgf / cm ² ) to 250 × 9.8 N / cm ² (250 Kgf / cm ² ) (preferably 130 Kgf / cm ² to 200 Kgf / cm ² ), elongation is 200% to 800% (preferably 450% to 580%), and tear strength is 40 × 9.8 N / cm ² (40 Kgf / cm ² ) to 150 × 9.8 N. / cm ² (15 Kgf / cm ²⁾ (preferably 40Kgf / cm ² ~120Kgf / in cm ^2), tensile strength at ^{85 ℃ 10 × 9.8N / cm 2} (10Kgf / cm 2) ~150 × 9.8N / cm ² (150 kgf / cm ² ) (preferably 250 kgf / cm ^{2 to} 350 kgf / cm ² ), an elongation of 150% to 450% (preferably 250% to 350%), and a tear strength of 10 × 9.8 N / Cm ² (10 Kgf / cm ² ) to 100 × 9.8 N / cm ² (100 Kgf / cm ² ) (preferably 10 Kgf / cm ^{2 to} 50 Kgf / cm ² ) may be used.
[0022]
Therefore, as the barrier layer 12, materials such as PPC, olefin (TEO) TPO elastomer, styrene (TES) TPS, polyester / styrene TPE are used.
[0023]
As an example of the material, the skin layer 10 is (TEO) TPO, TPS, PVC, PVC / S / E / B / S (composite), and the foam layer 11 is PPF, PE / PPF, PVCF (vinyl chloride foam) ), And the barrier layer 12 is a combination of (TEO) TPO, TPS, PPC (composite material), and the core material 14 is PPC, PPG.
[0024]
As another example of the material, the skin layer 10 is (TEO) TPO, TPS, PVCPVC / S · E · B · S (styrene), and the foam layer 11 is EP / PPF, EP / PPF / S · Combination of E / B / S (styrene), barrier layer 12 as PVC / ABS, PPO / S / E / B / S (styrene), and core 14 as PPOG, PC / ABS, ABS, PC And
[0025]
A metal reinforcing member 16 and a door member 17 that closes the airbag inflation opening 3 are fixed to the portion of the airbag inflation opening 3 in the core member 14 of the instrument panel 2 with bolts 18. The airbag module 5 is connected to the reinforcing member 16 with a bolt 20. The lower part of the airbag module 5 is fixed to a vehicle body side member such as a steering support member (not shown).
[0026]
The airbag module 5 includes an inflator accommodating portion 25 that accommodates an inflator that ejects pressure gas, and an airbag main body accommodating portion 26 that accommodates an airbag main body that is deployed by the pressure gas from the inflator.
[0027]
In the first embodiment, the cleavage line 15 has an air bag against a substantially uniform wall portion where there is no character line or the like on the surface of the multilayer laminate sheet 13 and there is no thin portion or the like on the back surface of the core material 14. It is formed from the back side of the grid part 4 . In addition, the cleavage line 15 is continuously penetrated to a depth that penetrates the core material 14 and a part of the barrier layer 12 remains so as to prevent stress concentration on the processed portion of the cleavage line 15 during thermal deformation. It is formed (remaining part 30). The thickness of the remaining portion 30 is, for example, about 10% to 90% of the set thickness of the barrier layer 12. For example, when the set thickness of the barrier layer 12 is 1.2 mm, the thickness of the remaining portion 30 is 0.6 ± 0.5 mm, more preferably 0.6 ± 0.3 mm. The air bag grid 4 has a substantially flat and smooth surface shape without a character line or the like at a position on the surface side corresponding to the cleavage line 15.
[0028]
The tear line 15 is formed by turning the air bag grid portion 4 upside down, a laser processing machine 35 as shown in FIG. 4, a hot blade 36 or an ultrasonic processing machine as shown in FIG. 5, a rotary cutter blade, a high-frequency welder, etc. Is used. At this time, as shown in FIG. 5, a vacuum path 38 may be formed in a cradle 37 on which the air bag grid portion 4 is placed, and vacuum suction may be performed by a vacuum suction device 39. Moreover, you may use a rotary tool (a router, an end mill, etc.) as a cleavage line processing machine. In this case as well, a cleavage line can be reliably formed even if the core material is somewhat hard, as in laser processing.
[0029]
Next, the operation of the first embodiment will be described.
[0030]
When the inflator is activated, the pressure gas is ejected from the inflator, and the pressure gas is introduced into the airbag body.
[0031]
The airbag body is inflated with the introduction of the pressure gas, and at the same time, the door member 17 and the airbag grid part 4 are first cleaved along the cleavage line 15 by the inflation pressure to form an inflated opening. The airbag body bulges from the bulging opening toward the rear of the vehicle body (in the passenger compartment). As a result, the airbag body receives the passenger's head on the passenger seat seated at a fixed position and protects the head from being in contact with the instrument panel 2 or the like.
[0032]
And in this Embodiment 1, the cleavage line 15 has no character line or the like on the surface of the multilayer laminate sheet 13, and there is no thin portion or the like on the back surface of the core material 14 , Formed from the back surface side of the air grid portion 4 , the cleavage line 15 penetrates the core material 14 and a part of the barrier layer 12 remains so that stress concentration on the cleavage line processed portion at the time of thermal deformation is prevented. depth continuously formed to the airbag lid portion 4, tear lines 15 is no character line or the like at a position of a corresponding surface side, by which a smooth surface shape with substantially flat, such as the following, effects An effect can be obtained. That is, since the barrier layer 12 remains without being cut, stress is prevented from concentrating on the processing portion of the cleavage line 15 during thermal deformation, and the surface appearance performance of the air bag grid portion 4 is deteriorated (processing portion of the cleavage line 15). In other words, it is possible to prevent surface appearance performance degradation such as wrinkles, sagging and distortion) . Therefore, the airbag grid part 4 is made to have a substantially flat and gentle surface shape without a character line or the like for making the thermal deformation of the airbag grid part 4 inconspicuous at the position on the surface side corresponding to the cleavage line 15. become able to.
[0033]
Further, since the cleavage line 15 is formed by laser processing, the cleavage line 15 can be reliably formed even if the core material is somewhat hard.
[0034]
【The invention's effect】
As described above, according to the invention of claim 1, the core material having a linear thermal expansion coefficient different from that of the barrier layer on the back surface of the multilayer laminate sheet having at least the skin layer, the foam layer, and the barrier layer. In the vehicle airbag apparatus in which a groove-shaped tear line is formed from the back side of the welded airbag grid part, wherein the tear line is a surface of the multilayer laminate sheet There is no character line, and there is no thin wall portion on the back surface of the core material, whereas the uniform wall thickness portion is formed from the back surface side of the airbag grid portion, and the cleavage line is a cleavage line processed portion during thermal deformation. The air bag grid portion is formed on the surface side corresponding to the cleavage line so as to prevent stress concentration on the core material. Position is not the character line, by which is a gentle surface shape flat, such as the following, effects can be obtained. That is, since the barrier layer remains without being cut, stress is prevented from concentrating on the cleavage line processed part during thermal deformation, and the surface appearance performance of the air bag grid part is degraded (wrinkles and sagging in the cleavage line processed part). And the occurrence of a surface appearance performance degradation portion such as distortion is prevented. Therefore, the air bag grid part can be formed into a substantially flat and gentle surface shape without a character line or the like for making the thermal deformation of the air bag grid part inconspicuous at the position on the surface side corresponding to the cleavage line. Become. In addition, according to the invention of claim 2, since it is cleavage line forming by laser processing, it is possible to exhibit a practically beneficial effect that a cleavage line can be reliably formed even if the core material is somewhat hard.
[Brief description of the drawings]
FIG. 1 is a perspective view of an instrument panel according to a first embodiment of the present invention.
2 is a side sectional view of the airbag device of FIG. 1. FIG.
FIG. 3 is a partially enlarged view of FIG. 2;
FIG. 4 is a diagram showing a processing state of a cleavage line.
FIG. 5 is another view showing a processing state of a cleavage line.
[Explanation of symbols]
4 air bag grid part 10 skin layer 11 intermediate layer 12 barrier layer 13 multilayer laminate sheet 14 core material 15 cleavage line 30 remaining part

Claims (2)

At least the core layer having a linear thermal expansion coefficient different from that of the barrier layer is welded to the back surface of the multilayer laminate sheet having at least a skin layer, a foam layer, and a barrier layer to form an air bag grid portion, In the vehicle airbag device in which a groove-shaped tear line is formed from the back side of the airbag grid part,
The cleavage line has no character line on the surface of the multilayer laminate sheet, and there is no thin portion on the back surface of the core material, and is formed from the back side of the air bag grid portion for a uniform thickness portion,
The cleavage line is continuously formed to a depth that penetrates the core material and a part of the barrier layer remains so as to prevent stress concentration on the cleavage line processed part during thermal deformation,
The airbag apparatus according to claim 1, wherein the airbag grid portion has a flat and gentle surface shape without a character line at a position on the surface side corresponding to the cleavage line .   The vehicle airbag device according to claim 1, wherein the tear line is formed by laser processing.

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