JP5194662B2 - Airbag door - Google Patents

Description

  The present invention relates to an airbag door. More specifically, the present invention is an airbag door formed invisible on various vehicle interior materials having a skin on the base material, and the base material and the skin are preferably synchronized with each other when the airbag is inflated and deployed. The present invention relates to an airbag door that is broken in a site-by-site breaking order and that ensures good breakage of a side line of the airbag door.

  For example, an airbag device provided for a passenger seat of an automobile is generally disposed on the back side of an instrument panel that is a vehicle interior material. In this case, normally, a continuous tear groove in the shape of an air bag door is formed as a primary tearing process on the back surface of the panel base material in a corresponding portion of the instrument panel. This tear groove is often formed in the shape of a double-opening type air bag door comprising a pair of doors. Further, the bottom portion of the tear groove is further subjected to a certain tearing process so that the airbag door can be quickly broken and opened by the inflation pressure when the airbag is deployed.

  By the way, various vehicle interior materials such as instrument panels are generally formed into a laminated structure having a skin on a base material via a foam layer. As a tearing process of such a laminated structure, a tearing process capable of breaking the base material and the skin is required apart from the foam layer having a very small breaking resistance. The formation of the tear groove belongs to a tear process for breaking the base material. These tear processes are performed from the base material side which is the back side of the vehicle interior material in consideration of so-called invisibility.

In the airbag storage cover disclosed in Japanese Patent Publication No. 6-94266, a concave portion is provided deeply at a distance from a continuous groove portion including a central tear line and a pair of end tear lines. In the vicinity of the center of the tear line, the depth of the groove is increased.

JP, 2004-331046, A In the lid member of the air bag device indicated by above-mentioned patent documents 2, a concave hole was provided in the crevice provided so that the tear line which tears at the time of air bag inflation may be formed, and it may be spaced apart. The groove of the portion to be provided and to start the tearing is formed deeper than the groove of the other portion. The configuration of the tear line when the lid member is accompanied by an epidermis is not disclosed.

JP, 2003-191815, A The air bag door indicated by above-mentioned patent documents 3 has a tear line provided in an instrument panel provided with at least a core material and a surface material, and this tear line is an instrument. It is composed of holes of two types of depths, which are formed intermittently in broken lines from the back side of the panel. There is no disclosure regarding the formation of the tear groove. The deep hole penetrates the core material and reaches the surface material, and the shallow hole does not reach the surface material.

JP, 2003-212075, A The tear line structure of the air bag door indicated by the above-mentioned patent documents 4 is provided in the instrument panel which laminated the base material, the foamed resin layer, and the skin, and is made into the shape of a tear groove on the base material. The provided developed portion includes a long hole-shaped removal portion 11 that penetrates the base material and reaches the middle of the foamed resin layer, and a dot-shaped hole 6 that penetrates the base material and the foamed resin layer and reaches the skin. ing.

(First issue)
By the way, when the airbag door formed on the vehicle interior material with the skin is ruptured / opened, it is important that the base material and the skin are ruptured in synchronism with each other in a preferred rupture order for each region. According to the research of the present inventor, when the base material and the skin do not break in such a preferable pattern, there is a possibility of causing the following problems (1) to (3), for example.
(1) In some cases, it is difficult to ensure a rapid and sufficient deployment mode of an air bag based on the correct breaking and opening of the air bag door.
(2) The base material is not ruptured clearly, and burrs or the like are formed at the ruptured portion, which may damage the deployed airbag.
(3) When an appropriate rupture of the skin cannot be ensured, the rupture of a certain portion of the base material may be hindered by excessive restraint of the skin.

  In patent document 1 and patent document 2, the technique which adjusts the groove depth of the airbag door shape provided in an airbag storage cover etc. for every site | part, and regulates the fracture | rupture order according to the site | part is recognized. However, since these are premised on tearing the base material without the epidermis, there is no disclosure regarding tearing of the epidermis. There is no disclosure of any means for regulating the rupture order for each part of the epidermis synchronized with the rupture order.

  On the other hand, Patent Document 3 and Patent Document 4 disclose a technique for performing tear processing for base material fracture and tear processing for skin fracture in an instrument panel with a skin. However, there is no technical idea to regulate the breaking order of each part of the base material or the skin by these tearing processes and to synchronize the breaking order of both.

  The regulation of the base material breaking order and the regulation of the skin breaking order differ greatly in the form of tear processing and the distribution of the processing parts in the entire tear line. By analogy from the means for restricting the order of breakage, it is difficult to conceive of means for restricting the order of breakage of each part of the skin. It is even more difficult to conceive a means for regulating the site-specific break order of the skin in synchronization with the site-by-site break sequence.

(Second problem)
Furthermore, it is also important to ensure good breakage of the side line when breaking and opening a normal airbag door having a center line and a pair of side lines. Even if the center line breaks well, if the side line does not break well, there is a possibility that the pair of doors of the airbag door may not be opened sufficiently, which may hinder sufficient deployment of the airbag.

  In the above-mentioned Patent Document 1 to Patent Document 4, although an example of tearing in consideration of the breakage of the center line of the airbag door can be seen, no special measures have been proposed for favorably breaking the sideline.

  Therefore, the present invention is formed invisible in a vehicle interior material having a skin on a base material, and the base material and the skin are favorably broken in a suitable part-by-site breaking order when the airbag is inflated and deployed. It is a technical problem to be solved to provide an airbag door in which a good line breakage is ensured.

(First invention)
The structure of the first invention of the present application for solving the above problems is that a continuous tear groove having an airbag door shape is formed on the back surface of the base material of the vehicle interior material with a skin, and the base material penetrates from the bottom of the tear groove. An air bag door provided with a long hole-like tear hole that does not reach the skin at an interval, and (1) the base material remaining thickness of the groove portion of the center line of the air bag door by adjusting the groove depth of the tear groove (2) In the groove portion of the center line, dot-like tear holes that penetrate the base material and reach the epidermis are provided at intervals, and (3) a pair of sides of the airbag door The groove portion in the vicinity of the meeting portion with the center line in the line is an airbag door subjected to side line processing for reducing the breaking strength of the base material at this portion.

  In the airbag door of the first invention, from the bottom of the continuous tear groove of the airbag door shape, a long hole tear hole for breaking the substrate, and a dot tear hole that penetrates the substrate and reaches the skin (that is, Dot-like tear holes for skin breaking). Therefore, the breakage between the base material and the skin is ensured.

  Also, in the groove part of the center line of the airbag door, the base material remaining thickness of the tear groove, which is part of the base material tearing process, is set smaller than other parts, and the dot-like tear hole for skin breaking is also this It is provided selectively at the site. For this reason, a correct breaking order is ensured in which the base material and the skin start to break in synchronism from the center line portion of the airbag door.

  On the other hand, with respect to the side line of the airbag door, side line processing for reducing the breaking strength of the base material is performed in the groove part in the vicinity of the meeting part with the center line in the pair of side lines. Therefore, since the side line is also broken well, it is possible to prevent such a problem that the pair of doors of the airbag doors are not sufficiently opened and the airbag is sufficiently deployed.

  As described above, in the airbag door of the first invention, the base material and the epidermis are favorably broken in a suitable part-by-part breaking order when the airbag is inflated and deployed, and a pair of side lines is also good. To break. As a result, a rapid and reliable deployment mode of the airbag can be ensured, and the burrs or the like that can interfere with the airbag that has been broken and cleared are not formed.

(Second invention)
The configuration of the second invention of the present application for solving the above-described problem is that any one of the following tiers (a) to (c), in which the sideline processing according to the first invention is applied to a groove near the meeting portion in the sideline. It is an airbag door which is processing.
(A) Dot-shaped tear holes penetrating the base material and not reaching the epidermis were provided at intervals in the space between the long hole-shaped tear holes.
(B) The base material remaining thickness was set smaller than other parts.
(C) The relative length Pn of the interval portion of the long hole tier hole with respect to the long diameter Pd of the long hole tier hole was set to be smaller than other portions.

  The side line processing defined in the first invention is not limited in content as long as it is a tier processing that appropriately reduces the breaking strength of the base material at the pair of side lines in the airbag door, but more specifically, Is preferably exemplified by any one of (a) to (c) defined in the second invention.

  In particular, the dot-shaped tear hole that penetrates the base material and does not reach the skin (that is, the dotted tear hole for base material breakage), which is the tearing process of (a), is a preceding step in the processing process of the airbag door. This can be performed as a post-process after the formation of the tear groove and the long hole-like tear hole. Therefore, considering and taking into account the finish status of the previous process, etc., adjust the content of the sideline processing so that it balances well with the previous process (for example, the dot-shaped tear holes that penetrate the substrate and do not reach the skin) There is an advantage that the setting pitch can be slightly changed).

(Third invention)
The configuration of the third invention of the present application for solving the above-described problem is that the base material remaining thickness of the groove portion of the center line according to the first invention or the second invention is set to be particularly small in the center part of the center line, and the base material Dot-shaped tear holes (dot-shaped tear holes for breaking the skin) that penetrate through the skin and are selectively provided in the groove at the center of the center line and the groove near the meeting point of the side line at the center line It is an airbag door.

  According to the third aspect of the present invention, the breakage order of each part of the airbag door described above with respect to the first aspect is ensured more reliably and smoothly. That is, (1) the center part of the center line which is particularly easy to break is broken first, then (2) the whole center line is broken until reaching both ends, and (3) following (2) above Or a pair of sidelines breaks simultaneously with (2).

  In the third aspect of the invention, since the dotted tear hole for skin breaking provided in the groove portion in the center line in the vicinity of the meeting portion with the side line functions in cooperation with the side line processing, The breaking operation is converted from the center line to the side line, particularly smoothly.

(Fourth invention)
The configuration of the fourth invention of the present application for solving the above-mentioned problem is that the vehicle interior material according to any one of the first invention to the third invention comprises a skin on a base material via a foam material layer. It is an airbag door.

  Examples of the vehicle interior material that forms the airbag door include those having a skin on a base material, but those having a skin on a base material via a foam layer are preferable. In this case, the long hole-shaped tear hole and the dot-shaped tear hole for breaking the base material defined in (a) of the second invention can be provided so as to penetrate the base material and reach the foam material layer.

  According to the present invention, there is provided an airbag door in which a base material and an outer skin are broken in a suitable breaking order in synchronism when the airbag is inflated and deployed, and a favorable side line breaking is ensured.

  Next, modes for carrying out the first to fourth inventions of the present application will be described including the best mode.

[Airbag door]
The airbag door of the present invention is formed in a vehicle interior material with a skin. The type of vehicle interior material is not limited, but automotive interior materials are preferably exemplified, and more specifically, automotive instrument panels, ceiling materials, front seat rear materials, rear deck materials, pillar garnishes and the like are exemplified. .

  Examples of the vehicle interior material with a skin include those in which the skin is directly formed on the base material of the vehicle interior material, and more preferably those in which the skin is formed on the base material via an intermediate layer, for example, a foam material layer. It is done. An adhesive layer can be interposed between the base material and the foam layer.

  The base material, the foam material layer, and the constituent material of the skin can be appropriately selected. For example, an appropriate thermoplastic resin such as polypropylene is used for the constituent material of the base material, foamed polypropylene or foamed polyurethane is used for the constituent material of the foam layer, and an appropriate type of polyolefin is used for the constituent material of the skin. be able to.

  A vehicle interior material having a skin through a foam material layer on a base material is, for example, a concave vacuum forming method in which a skin having a foam material layer laminated on the back surface is vacuum-formed and simultaneously pressure-molded to the base material. Can be advantageously produced. In this case, for process reasons, not only the tear groove but also the long hole-like tear hole and the dot-like tear hole for skin breaking and substrate breaking are formed on the substrate side (the back side of the vehicle interior material) after forming the laminate. ).

  The shape of the airbag door is defined by a continuous tear groove formed on the back surface of the base material, and is preferably a double-opening type airbag door composed of a pair of door bodies. It is also possible to provide a single-opening type airbag door composed of a single door. The door body can be connected to a known retainer for attaching an airbag via a hinge member on the back surface side.

[Tear groove]
A continuous tear groove having an airbag door shape is formed on the back surface of the base material of the vehicle interior material with skin. From the bottom of the tear groove, a long hole-like hole, which will be described later, a dot-like tear hole for breaking the skin, and a dot-like tear hole for breaking the base material in some cases, are spaced from each other in the direction of the skin. Set up. The overall shape of the tear groove is arbitrary according to the shape of the airbag door to be formed. For example, in a double-opening type airbag door, the shape of the “day” character corresponds to a pair of door bodies. Or “H” shape.

  The remaining thickness of the base material at each groove is defined by the depth of the tear groove at that portion. The tear groove is basically formed at a constant depth of, for example, about half or about one third of the thickness of the base material. However, it is formed deeper in the groove portion of the center line of the airbag door, and more preferably deeper in the groove portion in the center portion of the center line. As an example, when the thickness of the base material is A, the basic remaining base material thickness B at the groove is about B = 0.5 to 0.7A, and the remaining base material thickness B at the center line groove is B = about 0.4A to 0.5A, and further, the remaining base material thickness B at the groove at the center of the center line can be about B = 0.2 to 0.4A. The difference in the remaining thickness of the base material defines the ease of breakage by site in the groove portion of the base material.

  In addition, as will be described later in the section “Sideline processing”, the remaining base material thickness at a predetermined portion of the sideline may be approximately the same as the groove portion of the centerline.

[Long hole tear hole]
The long hole-like tear hole is formed at a depth that penetrates the base material and does not reach the skin from the bottom of the tear groove along the formation direction of the tear groove. In this specification, “through the base material does not reach the skin” means that the skin is formed on the base material through a foam layer or the like even when the skin is formed on the base material. Furthermore, it refers to a state of “penetrating through the substrate but not leading to perforation of the epidermis”. When a foam material layer or the like is interposed, the long hole-like tear hole is usually formed to a depth reaching the foam material layer or the like.

  The setting part and the setting frequency of the long hole-like tear hole in the tear groove are not particularly limited as long as the base material constituting the airbag door can be ensured to be broken and opened and the effect of the present invention is not hindered. Preferably, a long hole-like tear hole having a constant major axis at a constant interval can be formed over the entire portion of the tear groove. In this case, the ratio between the long diameter Pd of the long hole-like tear hole and the length Pn of the interval part where the long hole-like tear hole is not formed in the tear groove is not limited, but for example, Pd: Pn = 4: 6 or so. be able to.

  Note that, as described in the “side line processing” section below, the ratio of Pn to Pd may be set to be smaller than that of other parts at a predetermined part of the side line.

[Dotted tear holes for skin rupture]
The dotted tear hole for skin breakage is a dot-like cut hole formed to a depth reaching the skin through the base material from the bottom of the tear groove. When a foam material layer is interposed between the substrate and the skin, the foam material layer also penetrates. However, it reaches the epidermis at a depth that does not penetrate the epidermis and is not likely to become visible from the vehicle interior due to thermal strain after tearing. This depth is not limited, but can be set to reach, for example, half the thickness of the epidermis.

  The dotted tear holes for skin breakage are selectively provided in the groove portion of the center line, but more preferably selectively in the groove portion in the center portion of the center line and the groove portion in the vicinity of the meeting portion of the center line with the side line. Provided.

  Since the hole diameter and the set density (set pitch) of the dotted tear holes for skin rupture are appropriately set in consideration of the rupture strength of the skin, etc., it is difficult to define them uniformly. This dot-shaped tear hole is provided at the bottom of the long hole-shaped tear hole and the interval part where the long hole-shaped tear hole is not formed because of the set pitch. There is no difference in the effect as a tearing process.

[Sideline processing]
In the side line processing, for the purpose of favorable breakage of the side line in the airbag door, the groove part in the vicinity of the meeting part with the center line in the pair of side lines (hereinafter, the groove part in this part of the side line is simply referred to as “meeting part”. This is a tearing process applied to the “proximate groove portion”.

  The most preferable form of sideline processing is a dot-like tear hole (dot-like tear hole for breaking the substrate) that penetrates the base material and does not reach the epidermis in the gap portion of the elongated hole-like hole in the groove portion near the meeting part. It is to provide at intervals. Since the hole diameter and the set pitch of the dot-shaped tear holes are appropriately set in consideration of the breaking strength of the base material in the side line, it is difficult to uniformly define, for example, for the above-described skin breaking It can be made equal to the hole diameter of the dot-like hole and the set pitch.

  Another preferable form of the side line processing is to set the remaining thickness of the base material to be smaller than that of other portions in the groove portion near the meeting portion. Although the specific base material remaining thickness is not limited uniformly, For example, it can be made into the same grade as the base material residual thickness B (B = about 0.4A-0.5A) of the groove part of an above-described centerline.

  Another preferred form of the side line processing is to set the relative length Pn of the interval portion of the long hole-like tear hole to the long diameter Pd of the long hole-like tear hole smaller than the other part in the groove part near the meeting part. It is. For example, when the ratio of Pd: Pn in the tier groove is about Pd: Pn = 4: 6 in all other regions, the Pd: Pn = 5: 5 to 6: 4 may be set in the vicinity of the meeting portion. it can.

  Next, an embodiment of the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited by the following examples.

  The airbag door 1 of a present Example is formed in the instrument panel of a motor vehicle. The airbag door 1 seen from the back surface side of the instrument panel is shown in FIGS.

FIG. 1 shows a state after completion of the previous process (formation of a tear groove and a long hole-like tear hole) in the tearing process, and FIG. 4 shows a state after the completion of the tearing process. In these drawings, the tear groove is represented by a solid line having no width, and the long hole-like tear hole is not shown.
(Airbag door after completion of previous process)
As can be seen from FIG. 2, which is a cross-sectional view taken along line AA in FIG. 1, the instrument panel is a laminated structure in which a foam material layer 3 and a skin 4 are formed on a base material 2. The base material 2 constituting the back surface of the instrument panel is made of polypropylene and has a thickness of 3 mm. The foam material layer 3 is in contact with the base material 2 and is made of foamed polypropylene and has a thickness of 2 mm. The skin 4 in contact with the foam material layer 3 constitutes the surface of the instrument panel and is made of polyolefin and has a thickness of 0.6 mm.

  As shown in FIG. 1, an airbag door 1 including a pair of double-opening door bodies 6 is formed by continuously providing tear grooves 5 in the shape of a “day” on the back surface of the base material 2. doing. The width of the tear groove 5 is 1 mm. As shown in FIG. 2, a retainer 7 for attaching an airbag is attached by vibration welding to the back surface of the instrument panel at a position corresponding to the airbag door 1, and the pair of door bodies 6 and the retainer 7 are These are connected to the retainer 7 through hinge members formed integrally. Thereby, scattering of the airbag door 1 at the time of airbag deployment is prevented. In FIG. 1, the retainer 7 is not shown.

  The tear groove 5 corresponds to a center line 8 that is a boundary line between the pair of door bodies 6, side lines 9 on both sides corresponding to both side ends of the door bodies 6, and upper and lower ends of the airbag door 1. The upper and lower horizontal lines 10 are parallel to the center line 8.

  In the tier groove 5, a difference is provided in the groove depth (remaining thickness of the base material 2) for each part. This point will be described with reference to FIG. FIG. 3A is a cross-sectional view along the groove direction of the tear groove 5 at an arbitrary portion of the side line 9 or the lateral line 10. In these portions of the tear groove 5, the remaining thickness B of the substrate 2 is relative. The largest is 2.0 mm. In the center line 8, the remaining thickness B of the base material 2 is relatively small. That is, FIG. 3B shows a cross-sectional view along the groove direction of the tear groove 5 at the side portion 12 adjacent to both sides of the center portion 11 in the center line 8. Thickness B is 1.3 mm. Further, FIG. 3C shows a cross-sectional view along the groove direction of the tier groove 5 in the central portion 11 of the center line 8, but the remaining thickness B of the base material 2 is relatively smallest at this portion. 0 mm.

  3A to 3C are the same as shown in FIG. 3D because there is no difference except for the depth of the tier groove 5 in each case.

As shown in FIGS. 3 (a) to 3 (d), a long hole-like tear hole 13 that penetrates the base material 2 and reaches the foam material layer 3 is fixed from the bottom of all the portions of the tear groove 5. Are provided at intervals. The short diameter of the long hole-shaped tear hole 13 is 1 mm which matches the width of the tear groove 5. The long diameter of the long hole-shaped tear hole 13 is uniformly 4 mm, and the length of the interval portion 14 where the long hole-shaped tear hole 13 is not formed is uniformly 6 mm.
(Airbag door after tiering)
A predetermined dot-shaped tear hole is further processed on the airbag door 1 after the completion of the preceding process, and the tear processing of the airbag door 1 is completed. The airbag door 1 after completion of the tearing is shown in FIGS.

  In the groove portion 14 in the vicinity of the meeting portion between the center portion 11 of the center line 8 and the side line 9 in the center line 8, dot-like tear holes 15 that penetrate the base material 2 and the foam material layer 3 and reach the skin 4 are provided. ing. The dot-shaped tear hole 15 reaches approximately half the depth of the thickness of the skin 4. These states are shown in FIG. 5C, which is a cross-sectional view along the groove direction of the tear groove 5 in the center portion 11 of the center line 8, and in the groove portion 14 in the vicinity of the meeting portion of the center line 8 with the side line 9. FIG. 5B is a cross-sectional view of the tear groove 5 along the groove direction.

  In FIG. 4, the dot-shaped tear holes 15 are symbolically indicated by “●”. However, individual ● does not represent the hole diameter, the set number or the set pitch of the dot-shaped tear holes 15. The diameter is 1 mm, which matches the width of the tear groove 5, and the set pitch is 2 mm. Because of such a set pitch, the dot-shaped tear holes 15 are set in both the long hole-shaped tear hole 13 and the interval portion 14.

  The setting range of the dot-shaped tear holes 15 can be determined as appropriate according to the design needs. For example, in the central portion 11 of the center line 8, the base material remaining thickness B is 1.0 mm. It can be generally coincident with the range, or more preferably a somewhat narrower range. Further, in the groove portion 14, the range from the meeting portion with the side line 9 in the center line 8 to the center portion can be set to the same range as that in the center portion 11.

  Next, side line processing is applied to the groove 16 in the vicinity of the meeting portion of the side line 9 with the center line 8. In the present embodiment, as sideline processing, dot portions that do not reach the skin 4 though penetrating the base material 2 and reaching the foam layer 3 in the gap portions 14 where the long hole-like tear holes 13 are not formed in the groove portion 16 are formed. Tier holes 17 are provided at intervals. This state is shown in FIG. 5A, which is a cross-sectional view along the groove direction of the tear groove 5 in the groove portion 16.

  The dot-shaped tear holes 17 are symbolically indicated by “◯” in FIG. 4, but each circle does not represent the hole diameter, the set number or the set pitch of the dot-shaped tear holes 15. The diameter of the dot-like tear hole 17 is 1 mm which matches the width of the tear groove 5, the setting part thereof is limited to the interval portion 14, and the setting pitch is 2 mm.

  The setting range of the dot-shaped tear holes 17 can be determined as appropriate according to the design needs. For example, the length of the side line 9 is 1 / centered around the meeting portion of the side line 9 with the center line 8. The range can be about 2 to 1/3.

  5A to 5C is different in each case except for the depth of the tear groove 5 or the type of the dot-like tear hole 15 or the dot-like tear hole 17. Therefore, the same appears as shown in FIG.

Since the width of the tear groove 5 described above, the short diameter of the long hole-shaped tear hole 13, the diameter of the dot-shaped tear hole 15 and the dot-shaped tear hole 17 are all equal to 1 mm, for example, the same process is performed using the same end mill. Can be formed continuously.
(Operation and effect of this embodiment)
Since the airbag door 1 of the present embodiment is configured as described above, when the airbag is inflated and deployed, the airbag 2 starts to break at the center portion 11 of the center line 8 where the breaking strength of the base material 2 and the skin 4 is the weakest. To do. Next, the momentum of the breakage extends to the whole center line 8 having a relatively low breaking strength, and the whole center line 8 breaks at once.

  Further, since the dot-like tear hole 17 is provided in the groove portion 16 in the side line 9 in the vicinity of the meeting portion with the center line 8, the breaking operation in the direction of the center line 8 is substantially synchronized and substantially perpendicular thereto. Is smoothly switched to the breaking operation of the side line 9 in the direction intersecting with.

Thus, in the airbag door 1 of the present embodiment, when the airbag is inflated and deployed, the base material 2 and the skin 4 are favorably broken in a suitable site-by-site breaking order, and the sideline Good breakage is also secured (modified example)
As a modified example of the above sideline processing, instead of setting the dot-like tear hole 17 that penetrates the base material 2 and reaches the foam material layer 3 but does not reach the skin 4, the groove portion near the meeting portion in the sideline 9 The remaining base material thickness B can be set smaller than that of other portions, for example, 1.3 mm which is equivalent to that in the side portion 12 of the center line 8.

  As another modification of the side line processing, in the groove portion in the vicinity of the meeting portion in the side line 9, the relative length Pn (mm) of the interval portion 14 with respect to the long diameter Pd (mm) of the long hole-like tear hole 13. Can be set smaller than other parts, for example, Pd: Pn = about 5: 5 to 6: 4. Illustration of these modified embodiments is omitted.

  According to the present invention, there is provided an airbag door in which a base material and an outer skin are favorably broken in a suitable part-by-part breaking order in synchronism with each other when the airbag is inflated and deployed, and a good side line breaking is ensured.

It is a figure which shows the whole shape seen from the instrument panel back surface side in the pre-process completion state of the airbag door which concerns on an Example.

It is sectional drawing which follows the AA line of FIG.

It is a figure which shows the structure for every specific site | part of the tear groove | channel in FIG.

It is a figure which shows the whole shape seen from the instrument panel back surface side in the tear processing completion state of the airbag door which concerns on an Example.

It is a figure which shows the structure for every specific site | part of the tear groove | channel in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airbag door 2 Base material 3 Foam material layer 4 Skin 5 Tear groove 6 Door body 8 Center line 9 Side line 10 Horizontal line 11 Center part 12 Side part 13 Long hole-like tear hole 14 Spacing part 15 Dot form which reaches the skin Tear hole 16 Groove near the meeting part 17 Dot-shaped tear hole that does not reach the epidermis

Claims (4)

A continuous tear groove in the shape of an airbag door is formed on the back surface of the base material of the vehicle interior material with a skin, and a long hole-like tear hole that penetrates the base material from the bottom of the tear groove and does not reach the skin is provided at intervals. (1) By adjusting the groove depth of the tear groove, the base material remaining thickness of the entire groove portion of the center line of the airbag door is set smaller than other parts in the tear groove , (2 ) In the center line groove portion, a dot-like tear hole penetrating the base material and reaching the skin is provided at an interval, and (3) a groove portion in the vicinity of the meeting portion with the center line in a pair of side lines of the airbag door The air bag door is characterized in that side line processing is performed to reduce the breaking strength of the base material at this portion. 2. The airbag door according to claim 1, wherein the side line processing is tiered processing according to any one of the following (a) to (c), which is performed on a groove portion in the vicinity of the meeting portion in the side line.
(A) Dot-shaped tear holes penetrating the base material and not reaching the epidermis were provided at intervals in the space between the long hole-shaped tear holes.
(B) The remaining base material thickness was set to the same level as the remaining base material thickness of the groove portion of the center line .
(C) The relative length Pn of the interval portion of the long hole-shaped tear hole with respect to the long diameter Pd of the long hole-shaped tear hole was made smaller than that in all other long hole-shaped tear hole setting sites. The base material remaining thickness of the groove portion of the center line is set to be particularly small in the center portion of the center line, and the dot-like piercing hole that penetrates the base material and reaches the epidermis, the groove portion in the center portion of the center line and the center line The airbag door according to claim 1 or 2, wherein the airbag door is selectively provided in a groove portion in the vicinity of the meeting portion with the side line. The airbag door according to any one of claims 1 to 3, wherein the vehicle interior material is provided with a skin on a base material via a foam material layer.