JP2013047087A - Airbag cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airbag cover that can prevent the scattering of splinters of a foaming layer at rupture while suppressing the deterioration of production efficiency and an increase in cost.SOLUTION: An airbag cover 110 which covers the surface of the vehicular side of the folded airbag (PAB 120) and is ruptured when the airbag expands and develops includes: a base layer 112; and a foam layer 114 formed on the base layer where the base layer has: a tearing-line 130 at which the airbag is ruptured when expanding and developing and which is provided on the surface at a side facing the airbag; and projecting portion 132 which is provided on a surface at a side abutting the foaming layer and protrudes toward the foaming layer.

Description

  The present invention relates to an airbag cover that covers a compartment side surface of a folded airbag and is cleaved when the airbag is inflated and deployed.

  In order to protect passengers in the event of a collision, airbags are arranged in various places on the vehicle. The airbag is normally covered and accommodated by an airbag cover in a folded state. The airbag cover is mainly composed of a base material layer made of a hard resin and a foamed layer made of a foamed resin formed thereon, and is disposed in a place that is exposed to the passenger compartment and visible to the passenger In some cases, a skin layer may be formed on the foam layer.

  When a vehicle collision accident occurs, the airbag is inflated by the inflation gas supplied from the inflator, and the airbag cover is cleaved along with it, so that the airbag is inflated and deployed to protect the occupant. A groove called a tear line (breaking groove) is formed on the back surface of the airbag cover (the surface of the base material layer of the airbag cover that is not in contact with the foamed layer) so that the tearing at the time of inflation and deployment is performed quickly and efficiently. Is formed. Since the portion of the airbag cover where the tear line is formed becomes weaker than its surroundings, when the force from the airbag that is inflated and deployed is received, the airbag cover is easily cleaved from the tear line as a starting point.

  Specifically, when the airbag cover is torn, the tear line starts from the tear line, and the foam layer is torn near the tear line. At this time, the base material layer is regularly cleaved along the tear line that is the planned cleavage portion. However, the foamed layer is cleaved in a state in which the foamed layer is irregularly broken because no tear-scheduled portion like the tear line is formed. For this reason, there is a possibility that fragments of the foam layer broken at the time of tearing the airbag cover will be scattered.

  As a method for solving the above-described problem, it is conceivable to form a groove or notch that also becomes a tear line in the foam layer. For example, in patent document 1, the tear line which penetrates a core material (base material layer) and a foaming layer and reaches a surface material (skin layer) is formed by laser processing. As another method, it is conceivable to form a cut in the foamed layer with a cutter.

JP 2004-175121 A

  It seems that by forming a tear line in the foamed layer as in Patent Document 1 or by forming notches in the foamed layer, the foamed layer is regularly cleaved, and scattering of fragments at the time of cleavage can be suppressed. . However, when laser processing or cutting with a cutter is performed, it is necessary to install such expensive equipment or increase the number of processes when manufacturing the airbag cover. For this reason, the method described above has problems in terms of cost and manufacturing efficiency.

  In view of such problems, the present invention has an object to provide an airbag cover capable of preventing the scattering of the fragments of the foam layer at the time of tearing while suppressing an increase in cost and a decrease in manufacturing efficiency. Yes.

  In order to solve the above problems, a typical structure of an airbag cover according to the present invention is an airbag cover that covers a surface of a folded airbag on the passenger compartment side and is cleaved when the airbag is inflated and deployed. A base material layer and a foam layer formed on the base material layer, and the base material layer has a tear line on the surface facing the air bag that becomes a tearing position when the air bag is inflated and deployed. It is characterized by having the convex part which is arrange | positioned on the surface of the side contact | abutted with a foaming layer, and protruded toward the foaming layer.

  According to the said structure, the foaming layer formed on the base material layer will be depressed in the shape corresponding to a convex part by the convex part formed in the base material layer. Since this dent becomes a fragile portion in the foamed layer, the foamed layer is cleaved starting from the dent when the airbag is inflated and deployed. Therefore, irregular breakage of the foamed layer when the airbag cover is opened can be prevented, and scattering of fragments of the foamed layer can be prevented.

  Said convex part is arrange | positioned in the vicinity of a tear line, and it is good to have a locus | trajectory along a tear line. With such a configuration, the base material layer and the foamed layer are located at substantially the same location, so that it is possible to promote efficient air bag cover tearing and thus rapid inflation and deployment of the air bag. It becomes.

  The above foam layer has a concave portion formed by foaming along the shape of the convex portion on the base material layer when the foam layer is formed on the base material layer on the surface in contact with the base material layer. It is good to have. Thereby, in the process of forming a foam layer on a base material layer at the time of manufacture of the airbag cover, a recess along the shape of the protrusion, that is, the above-described recess can be formed.

  In the longitudinal section in the direction substantially orthogonal to the tear line, the tear line and the convex portion may be arranged at a position where they do not overlap in the longitudinal direction. The longitudinal section means a section cut in the thickness direction of the base material layer, and the longitudinal direction means the thickness direction in the section. In a longitudinal section in a direction substantially perpendicular to the tear line, if the tear line and the convex portion overlap in the vertical direction, that is, if the tear line and the convex portion are arranged in the same straight line in the vertical direction, the tear line portion in the base material layer Since the thickness of the substrate increases, it may affect the cleavage of the base material layer. Therefore, by arranging the tear line and the convex part at a position where they do not overlap in the vertical direction, that is, by shifting them in the lateral direction (plane direction of the base material layer), it is possible to ensure reliable and rapid cleavage of the base material layer. It becomes possible.

  The tear line includes a first tear line and a second tear line extending and intersecting in different directions, and the convex portion formed along the first tear line and the convex portion formed along the second tear line are mutually connected. It is good to arrange at the position which does not cross. According to such a configuration, interference between the two convex portions formed along each of the first tear line and the second tear line does not occur. For this reason, it is possible to suitably realize regular tearing of the foam layer even when a plurality of tear lines intersecting each other are formed without the other projection being cut off by one projection. It becomes.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide providing the airbag cover which can prevent scattering of the fragment of the foaming layer at the time of tearing, suppressing the increase in cost and the fall of manufacturing efficiency.

It is a figure which illustrates the vehicle interior of a vehicle provided with the airbag cover of this embodiment. It is a front view of the instrument panel of FIG. It is a figure which illustrates the detail of the airbag cover of FIG. It is a figure which illustrates other embodiment of the positional relationship of a tear line and a convex part.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating the interior of a vehicle 102 including an airbag cover according to this embodiment. FIG. 2 is a front view of the instrument panel of FIG. In the present embodiment, the airbag apparatus 100 installed on the front side of the passenger seat 108 in the instrument panel (hereinafter referred to as the instrument panel 104) of the vehicle 102 will be described as an example.

  The airbag apparatus 100 illustrated in FIG. 1 and FIG. 2A accommodates a passenger airbag (Passenger AirBag; hereinafter referred to as PAB 120) illustrated in FIG. 2B in a folded state. ing. A surface of the folded PAB 120 on the passenger compartment side, that is, a surface of the airbag device 100 on the passenger compartment side is covered with an airbag cover 110. When a collision accident of the vehicle 102 occurs, the airbag cover 110 is cleaved and the PAB 120 is inflated and deployed as illustrated in FIG. As a result, the head and upper body (not shown) of the passenger seated in the passenger seat 108 are protected.

  3 is a diagram illustrating details of the airbag cover 110 in FIG. 1, FIG. 3 (a) is a rear view of the airbag cover 110 in FIG. 1, and FIG. 3 (b) is a diagram in FIG. It is AA sectional drawing. As illustrated in FIG. 3B, the airbag cover 110 includes a skin layer 116, a foam layer 114, and a base material layer 112 in order from the vehicle compartment side.

  The base material layer 112 is a layer on the side facing the PAB 120 (airbag) in the airbag cover 110 and is made of a synthetic resin. For example, a polypropylene resin or the like can be suitably used. The foamed layer 114 is a layer formed on the base material layer 112 and is made of a foamed resin. For example, a urethane-based resin can be suitably used. The skin layer 116 is a layer formed on the foam layer 114. By providing the skin layer 116, high designability can be obtained even when the airbag cover 110 is visible in the instrument panel 104 as in the present embodiment.

  As described above, when a collision accident of the vehicle 102 occurs, the airbag cover 110 needs to be easily cleaved by the pressure of the PAB 120 during inflation and deployment in order to efficiently and quickly protect the occupant with the PAB 120. For this reason, as illustrated in FIG. 3A, on the back surface of the airbag cover 110, that is, the surface of the base material layer 112 facing the airbag (hereinafter referred to as the back surface of the base material layer 112), A tear line 130 is formed as a cleavage site when the PAB 120 is expanded and deployed.

  The tear line 130 of the present embodiment includes a first tear line 130a and two second tear lines 130b and 130c. Specifically, the first tear line 130a is extended in the vehicle width direction in the airbag cover 110, and the two second tear lines 130b and 130c are different from the first tear line 130a (the vehicle height in the present embodiment). Direction). The two second tear lines 130b and 130c intersect the first tear line 130a at intersections B and C, respectively. That is, the tear line 130 of the present embodiment has a substantially H shape including the first tear line 130a and the two second tear lines 130b and 130c.

  In addition, in this embodiment, although the substantially H-shaped tear line 130 was illustrated, it is not limited to this. The shape of the tear line 130 can be changed as appropriate. For example, the tear line 130 may have a substantially Japanese character shape or other shape.

  As illustrated in FIG. 3B, the above-described tear line 130 (the second tear line 130 b is illustrated in FIG. 3B) is a linear groove formed on the back surface of the base material layer 112. In FIG. 3B, the second tear line 130b (the tear line 130) has a triangular cross-sectional shape, but the present invention is not limited to this, and may have another shape such as a trapezoid. The tear line 130 is not necessarily a linear groove, and may penetrate the base material layer 112 like a perforation.

  By providing the tear line 130 as described above, the base material layer 112 can be regularly cleaved when the PAB 120 is expanded and deployed. However, since the tear line 130 has an effect only on the tearing of the base material layer 112, the tear line 130 alone does not escape the irregular rupture of the foam layer 114, and the fragments of the foam layer 114 generated by the rupture scatter. There is a fear.

  Therefore, in the present embodiment, in the base material layer 112, the surface that is in contact with the foam layer 114, that is, the surface opposite to the surface (back surface) on which the tear line 130 is provided (hereinafter referred to as the surface of the base material layer 112). ), A convex portion 132 (see the broken line in FIG. 3A) protruding toward the foamed layer 114. The convex portion 132b is shown in FIG. 3B. As a result, the foam layer 114 formed on the base material layer 112 is recessed into a shape corresponding to the convex portion 132b, and a weak portion is formed in the portion of the broken-line circle 114a of the foam layer 114, and stress concentration occurs in the weak portion. . Therefore, when the PAB 120 is inflated and deployed, the foamed layer 114 can be cleaved starting from the depression (a concave part 134 described later), and regular cleaving is possible not only in the base material layer 112 but also in the foamed layer 114.

  When forming the foam layer 114 on the base material layer 112 described above, foaming is performed by pouring a liquid foam resin on the surface of the base material layer 112 (the surface to be in contact with the foam layer 114). It is good to let them. Thereby, the liquid foamed resin is foamed along the shape of the convex portion 132 on the base material layer 112. Therefore, at the time of forming the foam layer 114 in the manufacturing process of the airbag cover 110, the concave portion 134 that becomes the above-described depression can be formed on the surface of the foam layer 114 that faces the base material layer 112. For this reason, an increase in cost and a decrease in production efficiency are not caused.

  As illustrated in FIG. 3A, the convex portion 132 of the present embodiment is disposed in the vicinity of the tear line 130 and has a locus along the tear line 130. That is, the convex portion 132 includes a plurality of convex portions 132a to 132c, the convex portion 132a is along the first tear line 130a, the convex portion 132b is along the second tear line 130b, and the convex portion 132c is the second tear line. 130c. In this way, by making the convex portion 132 a locus along the tear line 130, the cleavage location of the base material layer 112 and the cleavage location of the foam layer 114 are substantially in the same position, and therefore, the rapid expansion and deployment of the PAB 120 is promoted. Is possible.

  In addition, in this embodiment, since the convex part 132 on the base material part 112 is illustrated with a broken line in FIG. 3A, the convex part 132 is an intermittent linear shape along the tear line. Is a continuous line. However, the present invention is not limited to this, and the convex portion 132 may be an intermittent linear shape as illustrated in FIG.

  In particular, in this embodiment, in the longitudinal section in the direction substantially orthogonal to the tear line 130, that is, in the section in the thickness direction of the base material layer 112, the tear line 130 and the protrusion 132 are arranged in the longitudinal direction (thickness in the cross section of the base material layer 112. In the direction). In other words, if the 2nd tear line 130b and the convex part 132b are illustrated, as illustrated in FIG.3 (b), they are arrange | positioned in the position shifted | deviated to the horizontal direction (plane direction of the base material layer 112). Thereby, since the increase in the thickness of the tear line 130 part by the convex part 132 can be avoided, there is no possibility that the convex part 132 affects the cleavage of the base material layer 112, and the base material layer 112 can be reliably and efficiently split. It becomes.

  Furthermore, in this embodiment, the convex part 132a formed along the 1st tear line 130a and the convex part 132b and 132c formed along the 2nd tear line 130b and 130c are arrange | positioned in the position which does not mutually cross. Specifically, as illustrated in FIG. 3A, since the first tear line 130a extends between the second tear lines 130b and 130c, the protrusions 132b and 132c are connected to the second tear lines 130b and 130c. It is arranged outside. In other words, the protrusions 132b and 132c are disposed on the opposite side of the first tear line 130a with respect to the second tear lines 130b and 130c. Accordingly, interference (intersection) between the convex portion 132a and the convex portions 132b and 132c does not occur, so that the convex portion 132a is not cut off by the convex portions 132b and 132c. Therefore, even if a plurality of intersecting tear lines (first tear line 130a, second tear line 130b and 130c) are formed, regular tearing of the foam layer 114 can be realized more suitably.

  In addition, although the convex part 132 mentioned above illustrated all the cases where it paralleled with the tear line 130, these are illustrations to the last, and "the convex part follows a tear line" of this embodiment, the convex part 132 is a tear line. It does not mean that it is strictly parallel to 130. Hereinafter, another embodiment of the positional relationship between the tear line 130 and the convex portion will be described in detail.

  FIG. 4 is a diagram illustrating another embodiment of the positional relationship between the tear line 130 and the convex portion, FIG. 4 (a) is a diagram corresponding to FIG. 3 (a), and FIG. 4 (b) is a diagram. 4 (a) is a sectional view taken along line DD, FIG. 4 (c) is a sectional view taken along line EE in FIG. 4 (a), and FIG. 4 (d) is a sectional view taken along line FF in FIG. 4 (a). It is. In addition, about the element which has the substantially same function and structure as the component demonstrated above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 4A, the base material layer 212 of the airbag cover 210 also has a first tear line 130a, a second tear line 130b, and a second tear line 130c, similar to the base material layer 112 of the airbag cover 110. A tear line 130 is formed.

  In FIG. 3A, the linear protrusion 132b extending parallel to the second tear line 130b is disposed in the vicinity of the second tear line 130b, whereas in FIG. 4A, the protrusion disposed in the vicinity of the second tear line 130b. The portion 232b has a locus that moves away from the second tear line 130b as it goes from one end to the other end. Even if it is not strictly parallel to the second tear line 130b as in the convex portion 232b, it is included in the definition of “the convex portion follows the tear line” in the present embodiment as long as the locus follows the second tear line 130b. .

  Further, in FIG. 3A, the linear protrusion 132c extending parallel to the second tear line 130c is disposed in the vicinity thereof, whereas in FIG. 4A, the linear protrusion 132c is disposed in the vicinity of the second tear line 130c. The convex portion 232c is partially curved so as to bypass the intersection C between the first tear line 130a and the second tear line 130c. Even if a part of the convex part 232c deviates from the convex part 132c, as long as most part is along the convex part 132c (if it follows), the "convex part is along the tear line" in this embodiment. Is included in the definition.

  Further, in FIG. 3 (a), the linear protrusion 132a extending parallel to the first tear line 130a is disposed, whereas in FIG. 4 (a), it is disposed in the vicinity of the first tear line 130a. The convex portion 232a is bent in two stages in the middle and intersects the first tear line 130a. Even if it is not a straight line as in the tear line, such as the convex portion 232c, it partially intersects with the tear line, as long as the majority other than the intersecting portion is along the convex portion 132a. If so, it is included in the definition of “the convex portion is along the tear line” in the present embodiment.

  In addition, in the convex portion 232a, the straight line portion other than the intersecting portion is one side of the first tear line 130a in the DD cross section shown in FIG. 4B (the lower side of the first tear line 130a in FIG. 4 (b) is located on the left side of the first tear line 130a, and in the FF cross section shown in FIG. 4 (d), the other side of the first tear line 130a (in FIG. 4 (a), the upper side of the first tear line 130a, FIG. 4 (b) is located on the right side of the first tear line 130a. And in the cross | intersection part of the convex part 232a and the 1st tear line 130a, as shown to the EE cross section of FIG.4 (c), the 1st tear line 130a and the convex part 232a are vertical direction (thickness of the base material layer 212). In the direction). Therefore, the thickness of the tear line 130a is increased by the thickness of the protrusion 232a at the intersection of the protrusion 232a and the first tear line 130a, but this is only a part of the linear first tear line 130a. The base layer 212 is not adversely affected by the cleavage.

  As described above, according to the airbag cover 110 according to the present embodiment, the convex portion 132 formed in the base material layer 112 causes a depression (concave portion 134) in the foam layer 114 and stress concentration on the foam layer 114. A portion (inside the broken line circle 114a in FIG. 3B) can be formed. Thus, when the airbag (PAB 120) is inflated and deployed, the base material layer 112 is regularly cleaved starting from the tear line 130 and the foamed layer 114 is cleaved from the depression (recessed portion 134). Therefore, irregular breakage of the foam layer 114 when the airbag cover 110 is opened can be prevented, and scattering of fragments of the foam layer 114 can be prevented.

  In the above-described embodiment, the case where the airbag cover 110 covers the PAB 120 (see FIG. 2B) is described as an example, but the present invention is not limited to this. As illustrated in FIG. 1, the vehicle 102 includes a driver airbag 190 (Driver AirBag) that protects the head and upper body of an occupant (not shown) inflated and deployed from the steering wheel 180 and seated on the driver's seat 106. DAB), a knee airbag 192 (Knee AirBag; KAB) that inflates and deploys from the bottom of the instrument panel 104 to protect the occupant's knee, and protects the occupant's knee by inflating and deploying from the glove box 104a (see FIG. 2); Glovebox knee airbag 194 (Door Mount Inflatable Curtain), a door-mounted inflatable curtain airbag 196 that inflates and deploys in a curtain shape upward from the side door 182 to protect the side of the upper body of the passenger An airbag such as an airbag (DMIC) is provided. The present invention is also applicable to an airbag cover that covers these airbags.

  Further, in the present embodiment, the case where the instrument panel 104 and the airbag cover 110 are separately configured (separate parts) has been described as an example, but this is not limitative. In the instrument panel 104 provided with the airbag apparatus 100 that accommodates the PAB 120 (airbag), an area corresponding to the surface on the passenger compartment side of the PAB 120 (surface on the passenger compartment side of the airbag apparatus 100) is used as an airbag cover. The present invention can be applied even when the instrument panel 104 and the airbag cover 110 are integrally formed.

  For example, in recent years, it is difficult for the occupant to visually recognize the accommodation position of the airbag device by using a part of the instrument panel as an airbag cover without providing an opening and an airbag cover at the accommodation position of the airbag device. Instrument panels with invisible specifications designed to improve design are becoming popular. Thus, even when a part of the instrument panel is used as a cover for covering the airbag, a part of the instrument panel is interpreted as an airbag cover.

  Furthermore, the airbag cover 110 of the present embodiment covers only the surface of the folded PAB 120 (airbag) on the passenger compartment side, but this is not restrictive, and the airbag cover 110 is an airbag vehicle. Not only the chamber side surface but also other surfaces may be covered. In the present embodiment, the airbag cover 110 includes the skin layer 116, but the presence or absence of the skin layer 116 can be changed as necessary. When the skin layer 116 is provided on the airbag cover 110 as in the present embodiment, it is preferable to form the tear line 116a (see FIG. 3B) also on the skin layer 116.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the embodiments described above are preferred examples of the present invention, and other embodiments can be implemented by various methods. Can be carried out. The invention is not limited to the detailed shape, size, configuration, and the like of the components shown in the accompanying drawings unless otherwise specified in the present specification. In addition, expressions and terms used in the present specification are for the purpose of explanation, and are not limited thereto unless otherwise specified.

  Therefore, it is obvious for those skilled in the art that various changes and modifications can be conceived within the scope of the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  INDUSTRIAL APPLICABILITY The present invention can be used for an airbag cover that covers a surface of a folded airbag on the passenger compartment side and is cleaved when the airbag is inflated and deployed.

DESCRIPTION OF SYMBOLS 100 ... Airbag apparatus, 102 ... Vehicle, 104 ... Instrument panel, 104a ... Glove box, 106 ... Driver's seat, 108 ... Passenger seat, 110 ... Airbag cover, 112 ... Base material layer, 114 ... Foam layer, 114a ... Broken line circle 116 ... Skin layer, 120 ... PAB, 130 ... Tear line, 130a ... First tear line, 130b, 130c ... Second tear line, 132, 132a, 132b, 132c ... Convex part, 134 ... Concave part, 180 ... Steering wheel, 182 ... Side door, 190 ... driver seat airbag, 192 ... knee airbag, 194 ... glove box knee airbag, 196 ... door mount inflatable curtain airbag, 210 ... airbag cover, 212 ... base material layer, 232a and 232b・ 232c ... convex part

Claims (5)

An airbag cover that covers the passenger compartment side surface of the folded airbag and is cleaved when the airbag is inflated and deployed,
A base material layer;
A foam layer formed on the substrate layer;
With
The base material layer has a tear line on the surface facing the airbag, which is a tear line when the airbag is inflated and deployed, and is disposed on the surface in contact with the foam layer. An air bag cover having a convex portion protruding toward the front.   The airbag cover according to claim 1, wherein the convex portion is disposed in the vicinity of the tear line and has a locus along the tear line.   The foam layer is formed by foaming along the shape of the convex portion on the base material layer when the foam layer is formed on the base material layer on the surface in contact with the base material layer. The airbag cover according to claim 1, further comprising a recessed portion.   4. The air according to claim 1, wherein the tear line and the convex portion are arranged at a position where they do not overlap in the longitudinal direction in a longitudinal section in a direction substantially orthogonal to the tear line. 5. Bag cover. The tear line includes a first tear line and a second tear line extending in different directions and intersecting,
The convex part formed along the first tear line and the convex part formed along the second tear line are arranged at positions where they do not intersect with each other. The airbag cover according to claim 1.

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