JPH1095298A - Installment panel provided with air bag door part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reliable and smooth breakage in breakage planned parts in expanding of an air bag, by embedding a thin and long breaking resin material whose extending and puling strength is inferior to that of a skin in the breakage planned parts of a synthetic resin skin. SOLUTION: In an installment panel 20, an air bag A is expanded when large impact is generated by collision, and an air bag door part core material 33 is pressed from the back side. Pressing force is concentrated on slits 21a of a synthetic resin foamed layer 21 and breakage planned parts 25 of a skin 22, and a synthetic resin foamed layer 21 and the skin 22 are broken at the parts. An air bag door part D1 is opened to the inside of the car chamber, and the air bag A is developed. In this case, since the strength in the breakage planned parts 25 is decreased lower than the other parts by a fragile breaking resin member 27 embedded inside it, the breakage planned parts 25 are quickly and reliably broken, the air bag door part D1 is instantaneously opened, and smooth development of the air bag A is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an instrument panel having an airbag door.

[0002]

2. Description of the Related Art In an automobile, an instrument panel is provided from a lower portion of a front window to a front passenger seat for holding instruments and protecting a passenger.
As the instrument panel, a panel in which a synthetic resin skin is provided on the surface of a synthetic resin foam layer is often used.

[0003] In recent years, an airbag device for protecting a passenger in a passenger seat at the time of a vehicle collision has been provided on a rear surface of an instrument panel of an automobile interior material on a passenger seat side. In the airbag device, a folded airbag and an inflator (actuator) are housed in a canister (airbag housing case). The upper portion of the canister is an opening for deploying the airbag into the vehicle interior, and the opening is covered with an airbag door. Then, when the vehicle collides, the inflator is activated, and the inflated airbag pushes the airbag door portion open from the back side and deploys into the vehicle interior.

As an instrument panel to which the airbag device is attached, there is an instrument panel in which an airbag door portion is formed integrally with the instrument panel. This integrated instrument panel has an advantage that there is no problem such as troublesome assembling of the airbag door portion and variation at the time of assembling, as compared with a case where the airbag door is attached later.

Conventional integrated instrument panels include those shown in FIGS. 19 and 20. FIG. The instrument panel P has a synthetic resin skin 102 integrally on the surface of the synthetic resin foam layer 101, and defines an airbag door portion D at a predetermined position of the skin 102 corresponding to the airbag deployment opening O. A thin break scheduled portion 105 is formed. In the drawing, reference symbol A denotes an airbag, C denotes a canister, and I denotes an inflator. 106 is a core material,
107 is an airbag door core provided on the back surface of the airbag door D, and 109 is a canister C and core 1
Reference numeral 06 and a fixing member for fixing the core material 107 for the airbag door portion, and T is an imaginary line which is an expected breaking line of the synthetic resin foam layer.

[0006] The to-be-broken portion 105 of the skin 102 is formed by pressing the skin 102 into a predetermined shape by powder slush molding, vacuum molding, or the like, and then pressing a high-frequency welder, a hot blade, a cold press cutter, or the like against the back of the skin 102. It is formed by providing a notch or a V-groove. Then, the skin 102 is placed in a foaming mold, and a synthetic resin foam material is injected into the back side of the skin 102 to form a synthetic resin foam layer 101 integrated with the skin 102, whereby the airbag door portion is formed. An instrument panel P having D is obtained. At the time of foam molding of the synthetic resin foam layer 101, the core material 1 is placed in the foam mold.
06 and the airbag door core 107 are arranged,
It is integrated with the synthetic resin foam layer 101.

In the instrument panel P having this structure, as described above, when the airbag A is actuated and inflated, the airbag door portion D of the airbag deployment opening O is pushed from the back surface, which is generated. The stress that occurs is epidermis 102
The airbag door portion D is opened as shown in FIG. 21 by the outer skin 102 and the synthetic resin foam layer 101 breaking along the expected break portion 105, and the airbag A is placed in the vehicle interior. expand. Reference numeral 105 in FIG.
Reference numerals a and 105b denote broken portions of the skin 102, and Ta and Tb denote broken portions of the synthetic resin foam layer.

In general, a vehicle interior member such as an instrument panel of an automobile is exposed to sunlight rays entering the vehicle interior or high heat in the vehicle interior, and the skin 102 may deteriorate and shrink over time. Are known. It is also known that the deterioration and shrinkage easily cause poor appearance such as cracks in the thin portion of the skin 102.
Therefore, the notch or the like of the portion to be broken 105 must be formed accurately while taking this into consideration and ensuring that the break is performed reliably and smoothly.

However, in the conventional instrument panel, as described above, the predetermined
However, since it is often provided by forming a notch or the like after the formation of the skin 102, the thickness of the rupture scheduled portion 105 tends to vary, which has been a factor of the cracks and the like with the aging. In addition, forming the scheduled fracture portion 105 by post-processing after forming the skin has a problem of poor workability.

Further, in the case of a molded product in which the synthetic resin skin 102 and the synthetic resin foam layer 101 are in contact with each other, such as the instrument panel, the plasticizer contained in the vinyl chloride resin or the like constituting the synthetic resin skin 102 is used. However, over time, the amine migrates to the synthetic resin foam layer 101 or the amine contained as a cross-linking agent or a catalyst in the synthetic resin foam layer 101 migrates to the synthetic resin skin 102, thereby promoting the deterioration of the skin 102. It is known to cause. Therefore, discoloration, crack generation, and the like of the thin-walled portion to be fractured 105 were more likely to occur due to the transition.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and there is little deterioration in a portion of a skin defining an airbag door that is to be broken, and the portion to be broken can be easily formed. Another object of the present invention is to provide an instrument panel having an airbag door portion that can be reliably and smoothly ruptured at the rupture portion when the airbag is inflated.

[0012]

SUMMARY OF THE INVENTION The present invention relates to an instrument panel having a synthetic resin skin integrally formed on a surface of a synthetic resin foam layer with a portion to be ruptured defining an airbag door portion. The present invention relates to an instrument panel having an airbag door portion, wherein an elongated breaking resin member having lower elongation and lower tensile strength than the skin is embedded in a portion to be broken. Preferably, the breaking resin member is weakly adhered to the skin.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an instrument panel integrally having an airbag door portion according to one embodiment of the present invention, FIG. 2 is a 2-2 sectional view thereof, and FIG. 3 is an enlarged sectional view of three portions of FIG. FIG. 4 is a perspective view showing a part of the breaking resin member in the embodiment, and FIG. 5 is a sectional view showing the air bag in the embodiment when the airbag is inflated.

6 to 13 show an example of manufacturing the instrument panel of the present invention. FIG. 6 is a sectional view showing a powder slush molding apparatus for a synthetic resin skin, and FIG. FIG. 8 is a cross-sectional view showing a state in which a first molten resin film is formed in the example, FIG. 8 is a cross-sectional view showing a state in which a breaking resin member is placed, FIG. 9 is an enlarged cross-sectional view of a portion 9 in FIG. FIG. 11 is an enlarged cross-sectional view of a portion 11 of FIG. 10, and FIG. 12 is a cross-sectional view showing a state where a synthetic resin foam material is injected into the back surface of the skin in the embodiment. FIG. 13 is a cross-sectional view showing the foam molding state.

FIG. 14 is a cross-sectional view showing another example of the breakable resin member according to the present invention. FIG. 15 is a cross-sectional view showing an example of the skin using the breakable resin member of FIG. FIG. 16 is a cross-sectional view showing a portion to be broken of another skin using the resin member for breakage of FIG. 14, and FIG. 17 is a cross-sectional view showing a portion to be broken for a skin using another resin member for breakage. FIG. 18 is a cross-sectional view showing a portion to be ruptured for a skin using another rupture resin member.

The instrument panel 20 of the present invention shown in FIGS.
It has a synthetic resin skin 22 integrally formed with a breakable portion 25 that defines the airbag door portion D1. The airbag door portion D1 in this embodiment is a single-opening type, and the breakable portion 25 is formed in a substantially U shape as shown in FIG. 1, but it is a double-opening type and other types. In that case, in that case, a substantially H shape, a substantially cross shape,
It is formed in an appropriate shape such as a substantially one-letter shape. Reference numeral 30 denotes a core material of the instrument panel 20. The airbag device attached to the instrument panel 20 has the same structure as that described in the section of the prior art, in which reference numeral A denotes an airbag, I denotes an inflator, and C denotes an inflator.
Is a canister.

The synthetic resin foam layer 21 imparts cushioning to the instrument panel, and is made of polyurethane foam or the like. A slit 21a is formed on the back surface of the skin 22 at a position corresponding to the portion 25 to be broken, and air is blown. When the bag is inflated, it breaks from the slit 21a.

The skin 22 is composed of the instrument panel 20.
And is made of a soft vinyl chloride resin (hereinafter, referred to as PVC), a thermoplastic polyurethane resin (hereinafter, referred to as TPU), a polyolefin-based thermoplastic elastomer (hereinafter, referred to as TPO), or the like. It is formed in a predetermined instrument panel shape. In this embodiment, the epidermis 22 is made of soft PVC.

As shown in FIG. 3, an elongated breaking resin member 27
Is buried. Although the thickness of the skin of the portion to be broken 25 is not particularly limited, the resin member for breaking 27 and the skin 22 are so arranged that the portion to be broken 25 is more easily broken.
D1 (corresponding to the thickness of a first molten resin film described later) between the front surface 22a and the thickness d1 between the back surface 22b
2 (corresponding to the thickness of a second molten resin film described later) is preferably formed so as to be thinner than the thickness d3 between the front and back of the other part of the skin 22.

The elongated breaking resin member 27 enables the breakable portion 25 of the skin 22 to be easily and reliably broken when the airbag is inflated, and is included in the resin on the front side of the breakable portion 25 of the skin 22. The migration of the plasticizer to the synthetic resin foam layer 21 is reduced, and the amine contained in the synthetic resin foam layer 21 causes
5 is prevented from being shifted to the front side, and deterioration in the rupture scheduled portion 25 of the skin 22 is suppressed. The breaking resin member 27 is made of a material having lower elongation and tensile strength than the skin 22, and is embedded in the skin 22 during powder slush molding of the skin 22 described later. The elongation of the breaking resin member 27 is 100% or less, and the tensile strength is 2 MPa or less, particularly 0.5 MPa or more (in each case, JI
In the range of S-6732), it is preferable to appropriately select according to the elongation and the tensile strength of the skin 22. It is more preferable that the elongated breaking resin member 27 is weakly adhered (semi-adhered) to the skin 22 during powder slush molding of the skin 22.

The breaking resin member 27 as described above is a mixture of a resin compatible with the material constituting the skin 22 and a resin incompatible with the material constituting the skin. A sintered body can be used.

For example, when the outer skin 22 is PVC, a mixed powder of PVC powder: TPO powder (polyethylene, polypropylene, etc.) of about 8: 2 to 5: 5,
When 2 is TPO, PVC powder: TPO powder is 2:
When the mixed powder of about 8 to 5: 5 and the skin 22 are TPU, a mixed powder of TPU powder: TPO powder of about 8: 2 to 5: 5 is prepared, and the mixed powder is heated. The resin member for fracture 27 is obtained by depositing and sintering on a formed mold, and thereafter cutting the obtained sintered body into a desired shape as required.

As described above, the breaking resin member 27 obtained by sintering the resins incompatible with each other is obtained by powder slush molding for melting and solidifying the same or similar thermoplastic resin. Compared to the outer skin 22, the elongation and the tensile strength are inferior, the brittleness is broken, and it is broken by a weak force.
Moreover, since the sintered body is a sintered body in a state where the powder is simply mixed, and is joined by countless lumps, the surface thereof has countless irregularities, and is weakly adhered to the skin 22 (half). Bonding). For this reason, the break at the breakable portion 25 of the skin 22 is more reliably and smoothly realized.

Further, the breaking resin member 27 is
Is embedded in the breakable portion 25 of the skin 22 in the planned breakage portion 25 between the front side and the back side,
The plasticizer contained in the resin on the front side of the rupture portion 27 of the skin 22 is prevented by the rupture resin member 27 even if it attempts to migrate to the synthetic resin foam layer 21 on the back side of the rupture portion 25. The migration of the amine to the resin on the front side of the to-be-broken portion 25 of the skin 22 is also prevented by the breaking resin member 27. Therefore, in the scheduled break portion 25 of the skin, the migration of the plasticizer and the amine is prevented at the front side portion thereof. Therefore, the influence of the migration of the plasticizer and the amine is reduced in the entire scheduled break portion 25, and deterioration is reduced. You.

The breaking resin member 27 of this embodiment is used.
Used a sintered body formed from a mixed powder of 70% PVC and 30% TPO. Further, the elongation and tensile strength of the skin 22 and the breaking resin member 27 of this embodiment are determined by JI.
According to the measurement based on S-6732, the elongation was 305% for the skin 22 and 93% for the breaking resin member 27, and the tensile strength was 12MPa for the skin 22 and 1.1MPa for the breaking resin member 27.

Further, a pyrolytic foaming agent is previously mixed into one of the constituent materials of the breakable resin member 27,
It may be foamed at the time of forming the sintered body. Examples of the blowing agent include azo compounds such as azodicarbonamide (ADCA), nitroso compounds such as dinitropentamethylenetetramine (DPT), and benzenesulfonyl hydrazide (B
SA) and other sulfonyl hydrazide compounds.

Further, the breaking resin member 27 in this embodiment has a shape having a pointed protruding portion 27a along the longitudinal direction at the center of one side of the elongated plate-like body as shown in FIG. The thickness d3 of the protrusion 27a is about 3 mm, the thickness d4 of both ends 27b is about 1 mm, and the total width d5 is about 15 mm
It has become. If the protruding portion 27a having a sharp tip is provided, the thickness of the back surface of the skin 22 becomes particularly thin near the protruding portion 27a during the powder slush molding of the skin 22,
The portion to be broken 25 of the skin 22 is more easily broken, which is favorable.

Of course, the breaking resin member 27 is not limited to the above-mentioned shape. For example, as in the case of the resin member for breaking 40 shown in FIG. 14, the central portion may be a bent projection 40a having a substantially V shape. FIG. 15 is a cross-sectional view showing an expected break portion 41a of the skin 41 when the breakable resin member 40 is used so that the back surfaces of the bent protrusions 40a are fitted together, and FIG. 16 is a view in which the back surface of the bent protrusion 40a is closed. FIG. 4 is a cross-sectional view of a scheduled break portion 43a of the skin 43 when used so as not to be present. Although not shown here, a cavity may be formed on the back side of the bent projection 40a of the skin 43. Also, as shown in FIG. 17, a breakable portion 46a of the skin 46 may be formed using a breakable resin member 45 having two mountain-shaped protrusions 45a, or as shown in FIG. Alternatively, the to-be-ruptured portion 49a of the skin 49 may be formed by using a plate-shaped breaking resin member 48 having no protrusion.

The core member 30 includes the instrument panel 2
No. 0 is used to reinforce the back surface and is formed by injection molding or the like from hard vinyl chloride resin, polypropylene, or the like. In this embodiment, an airbag deploying opening 31 is formed at a position corresponding to the airbag door portion D1, and an airbag door core 33 made of a metal or resin plate is provided in the airbag deploying opening 31. The airbag deployment opening 31 is mounted on the mounting member 35 so that the airbag deployment opening 31 can be opened by bending toward the outer skin 22 by the pressure of the bag A due to inflation. The core material 30 corresponding to the edge of the airbag door core 33 is replaced with the airbag deployment opening 31 and the airbag door core 33.
A slit or V-groove or the like may be formed on the surface of the core member 30, and a portion of the core material 30 surrounded by the slit or V-groove may be set as an airbag deployment opening scheduled portion so as to be broken and opened by pressing the airbag A. .

The instrument panel 20 having the above structure
When a large impact due to a collision or the like is applied, the airbag A inflates as shown in FIG.
3 is pushed from behind. Thereby, the synthetic resin foam layer 2
1, the slit 21a portion and the rupture scheduled portion 2 of the skin 22
The pressing force is concentrated on 5, the synthetic resin foam layer 21 and the skin 22 are broken at that portion, the airbag door portion D1 opens toward the vehicle interior, and the airbag A is deployed. At this time, since the strength of the scheduled break portion 25 of the skin 22 is lower than that of the other portion due to the brittle breaking resin member 27 buried therein, the scheduled break portion 25 is pressed by the airbag A. The airbag door portion D1 is quickly and reliably broken, and the airbag door portion D1 is instantly opened, so that the airbag A is smoothly deployed.

Next, an example of manufacturing the instrument panel 20 having the above structure will be described with reference to FIGS. The same members as those described above are denoted by the same reference numerals. This manufacturing method includes a step of obtaining a skin in which an elongated breaking resin member is embedded in a portion to be broken, and a step of molding a synthetic resin foam layer integrated with the skin by injecting a synthetic resin foam material into the back side of the skin. And the step of performing.

In the step of forming the skin, FIGS.
As shown in the figure, a powder slush molding method using a powder slush molding die 50 is used. In this step,
First, as shown in FIG.
A skin resin material 60 made of a thermoplastic resin powder such as a soft vinyl chloride resin is accommodated in a powder accommodating portion 52 of a bucket 51 combined with the above.

Next, the bucket 51 and the mold 50 are rotated a predetermined number of times as indicated by the arrow a while heating the mold 50 by supplying a heat medium such as heating oil to the heat circulation pipe 53. By the rotation, as shown in FIG.
The inner skin resin material 60 is adhered to the mold surface 54 of the mold 50 and melted by the heat of the mold surface 54 to form a first molten resin film 61 on the mold surface 54. The thickness of the first molten resin film 61 in this embodiment is about 0.8 mm in consideration of heat resistance.

When the first molten resin film 61 is formed on the mold surface 54, the rotation of the mold 50 and the bucket 51 is temporarily stopped, and the bucket 51 is removed from the mold. Then, as shown in FIG. 8 and FIG. 9 in which the nine parts are enlarged, the surface of the first molten resin film 61 formed on the mold surface 54 is formed along the part to be a part to be broken of the skin. The breaking resin member 27 shown in FIG. 5 is placed by a jig or the like. At this time, since the breaking resin member 27 has a semi-adhesive property to the skin resin material as described above, it is weakly adhered (semi-adhered) to the first molten resin film 61.
The breaking resin member 27 is arranged such that the protrusion 27a faces the opposite side to the first molten resin film 61.

Thereafter, the bucket 51 and the mold 5 are again
10 and rotated, and as shown in FIG. 10 and FIG.
7, a skin resin material 60 is further applied to the surface of the first molten resin film 61 in the form of a layer having a thickness of 0.2 mm in this example, and a second layer of a predetermined thickness integrated with the molten resin film 61 is formed. A molten resin film 62 is formed. Also at this time, the breaking resin member 27 is weakly bonded (semi-bonded) to the molten resin film 62. When the second molten resin film 62 is formed, the skin resin material easily moves around at the tip of the protrusion 27a of the breaking resin member 27, so that the thickness of the second molten resin film 62 is reduced. .

Then, the molding die 50 is cooled to cure the molten resin film 63 in which the first molten resin film 61 and the second molten resin film 62 are integrated, and the molded product is released from the molding die. I do. Thereby, the skin 22 having the airbag door portion D1 defined by the breakable portion 25 as shown in FIG. 2 and the like is obtained.

Next, a step of molding the synthetic resin foam layer 21 is performed. In this step, first, as shown in FIG. 12, the skin 22 is arranged on the mold surface 73 of the lower mold 71 of the foaming mold 70 so that the back surface faces inward (upward). The core material 30 to which the core material 33 for the airbag door portion is attached is provided on the mold surface 74 of the upper mold 72.
Is held and arranged by appropriate means.

Then, after injecting a predetermined amount of a synthetic resin foam material 81 such as a polyurethane raw material from the head 80 of the injector into the back side of the skin 22 of the lower mold 71, the lower mold 71 and the upper mold 7 are filled.
2 is closed and foam molding is performed. As a result, as shown in FIG. 13, the synthetic resin foam material 81 is foamed and hardened to form the synthetic resin foam layer 21 and is combined with the skin 22 on which the breakable portion 25 defining the airbag door portion D1 is formed. The instrument panel 20 in which the resin foam layer 21 is integrated is obtained.

[0039]

As shown and described above, according to the instrument panel of the present invention, the brittle resin member having a lower elongation and a lower tensile strength than the outer skin is embedded in the portion of the outer skin to be broken. As a result, due to the inflation of the airbag, the portion of the skin that is to be broken is quickly broken, and the airbag door is reliably and smoothly opened.

Further, according to the instrument panel of the present invention, the breaking resin member can be embedded in the portion to be broken at the time of forming the skin, and the portion to be broken by pressing of the cutter, which is conventionally performed in a post-process after forming the skin. It is not necessary to carry out the molding, so that the workability is good. In addition, since the portion to be broken is not made thin by the pressing of the cutter or the like, variation in the thickness at the portion to be broken is small, and deterioration with time of the portion to be broken due to the thickness due to the variation in the thickness is reduced. In addition, the resin material for rupture embedded in the rupture portion of the skin prevents the plasticizer from migrating from the resin on the front side of the rupture portion to the synthetic resin foam layer, and breaks the amine of the synthetic resin foam layer. Since the migration to the resin on the front side of the scheduled portion is suppressed, the promotion of the degradation of the scheduled breaking portion of the skin due to the migration can be suppressed, and the degradation of the scheduled breaking portion over a long period of time can be suppressed in combination with the thickness variation prevention. Can be prevented, and an appearance free from cracks, discoloration, etc. can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of an instrument panel integrally having an airbag door portion according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged sectional view of a portion 3 in FIG. 2;

FIG. 4 is a perspective view showing a part of the breaking resin member in the embodiment.

FIG. 5 is a cross-sectional view showing the airbag of the embodiment when inflated.

FIG. 6 is a cross-sectional view of one example of a powder slush forming apparatus used to manufacture the instrument panel of the present invention.

FIG. 7 is a cross-sectional view showing a state at the time of forming a first molten resin film in the example.

FIG. 8 is a cross-sectional view showing a state in which the breaking resin member is placed in the embodiment.

FIG. 9 is an enlarged sectional view of a portion 9 in FIG.

FIG. 10 is a cross-sectional view showing a state at the time of forming a second molten resin film in the example.

FIG. 11 is an enlarged sectional view of a portion 11 in FIG. 10;

FIG. 12 is a cross-sectional view showing a state at the time of injecting a synthetic resin foam material in the example.

FIG. 13 is a cross-sectional view showing the synthetic resin foam material in the same example when foamed.

FIG. 14 is a sectional view of a breaking resin member of another embodiment.

FIG. 15 is a cross-sectional view of an example of a skin using the breakable resin member of FIG.

FIG. 16 is a cross-sectional view of another portion of the skin using the breakable resin member of FIG.

FIG. 17 is a cross-sectional view showing a portion to be broken of another embodiment of the skin.

FIG. 18 is a cross-sectional view showing a portion to be broken of still another embodiment of the skin.

FIG. 19 is a cross-sectional view of a main part of an instrument panel having a conventional airbag door.

FIG. 20 is an enlarged view of a portion x in FIG. 19;

FIG. 21 is a cross-sectional view showing a state where an airbag door portion is opened in a conventional instrument panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Synthetic resin foam layer 22 Synthetic resin skin 25 Expected break part 27 Break resin member 30 Core material 31 Airbag deployment opening 33 Core material for airbag door part D1 Airbag door part

Claims (2)

[Claims] 1. An instrument panel having a synthetic resin skin integrally formed with a rupture portion defining an airbag door portion on a surface of a synthetic resin foam layer, wherein the skin is supposed to be An instrument panel having an airbag door portion, wherein an elongated breaking resin member having poor elongation and tensile strength is embedded. 2. The instrument panel according to claim 1, wherein the breaking resin member is weakly adhered to the skin.