JP3695557B2 - Structure of the airbag door part of the instrument panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an instrument panel of an automobile integrally having an airbag door portion, and more particularly to a structure of the airbag door portion.
[0002]
[Prior art]
In an automobile, an instrument panel P as shown in FIG. 6 is provided on the inner side of the lower part of the front window for holding instruments and protecting passengers. Some instrument panels P integrally have an airbag door portion D for airbag deployment on the passenger side. This does not require the airbag door part D to be prepared as a separate body, and does not produce a gap around the airbag door part D due to variations in the dimensions of the airbag door part D or during assembly. Is good.
[0003]
As an example of a conventional integrated type instrument panel, there are those shown in FIG. 6 and FIG. 7 which is a 7-7 sectional view thereof, and FIG. 8 which is an enlarged sectional view of an 8 part thereof. This instrument panel P has a synthetic resin skin 72 such as soft vinyl chloride resin integrally on the upper surface of the synthetic resin foam layer 71, and a thin wall that defines an airbag door portion D at a predetermined position on the back surface of the skin 72. Are scheduled to break 73.
The thinly-scheduled fracture portion 73 of the skin 72 is formed by cutting or forming a V-groove with a high-frequency welder, a hot blade, a cold press cutter, or the like after the skin 72 is formed.
In the figure, reference numeral 74 denotes a back side core material of the instrument panel P, 75 denotes an airbag door core material provided on the back surface of the airbag door portion D, and T denotes a planned tearing portion of the instrument panel P.
[0004]
In the instrument panel P, an airbag device is attached to the back side of the airbag door portion D. As shown in FIG. 7, the airbag apparatus is configured such that a folded airbag A is accommodated in an accommodation case C called a canister together with an actuator I called an inflator. The upper portion of the airbag housing case C is configured as an opening O for the airbag A to be deployed in the vehicle compartment, and the deployment opening O is covered by the airbag door portion D. Reference numeral 76 denotes an attachment member for fixing the airbag housing case C, the core member 74 of the instrument panel, and the core member 75 for the airbag door.
[0005]
Then, when the actuator I is activated by the collision of the automobile and the airbag A is inflated, the airbag door portion D at the upper portion of the airbag deployment opening O is pushed from the back side, and the thinning of the skin 72 is broken by the pushing force. As the stress concentrates on the planned portion 73 and breaks, it breaks from the planned tear portion T of the instrument panel, and the airbag door portion D opens as shown in FIG. At this time, a portion between both ends of the planned fracture portion 73 acts as the hinge portion H. Reference numerals 73a and 73b in FIG. 9 represent fractured portions to be broken of the skin 72, and Ta and Tb represent fractured portions to be broken. As the air bag door portion D is released, the air bag A is deployed in the passenger compartment.
[0006]
However, in the instrument panel P having the above structure, when the air bag door D is released due to the expansion of the air bag A, if the interior of the vehicle is in a low temperature state, the epidermis around the planned break portion 73 (73a) as shown in FIG. When cracks run in 72 or on the other hand, the skin 72 may peel from the synthetic resin foam layer 71 around the planned fracture portion 73 (73a) as shown in FIG. In particular, the cracks and separation may reach between both ends of the planned fracture portion 73, that is, to the hinge portion H. In this case, the opening of the airbag door portion D may not be constant.
[0007]
The crack of the skin 72 is considered to occur because the skin 72 becomes brittle in a low temperature atmosphere and is easily damaged by an impact. On the other hand, it is considered that the peeling of the skin 72 occurs because the skin 72 is easily stretched in a high temperature atmosphere and the adhesiveness between the skin 72 and the synthetic resin foam layer 71 is lowered.
[0008]
In order to prevent the skin 72 from being cracked or peeled off, the thickness of the planned fracture portion 73 of the skin 72 is extremely reduced to about 0.2 mm, and the planned fracture portion 73 is extremely easily broken when the airbag is inflated. It is possible to make it possible.
[0009]
However, in the case of an automobile instrument panel, the epidermis deteriorates and shrinks over time due to the sun rays radiated into the passenger compartment and the high heat in the passenger compartment. It is known that it tends to cause appearance defects such as cracks. Accordingly, it is not a preferable solution to make the planned breakage portion 73 of the skin 72 extremely thin, because it tends to cause a crack or the like due to deterioration in the planned breakage portion 73 of the skin 72 and easily causes an appearance defect. .
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems. When a thin-walled portion to be broken is provided on the skin of the instrument panel, the portion to be broken is poor in appearance such as a crack due to deterioration or shrinkage of the skin. There is provided a structure of an airbag door portion of an instrument panel that does not easily cause cracking and peeling of the skin around the airbag door portion including the hinge portion. Is.
[0011]
[Means for Solving the Problems]
The present invention, on the upper surface of the synthetic resin foam layer in the instrument panel with a synthetic resin skin which breakable portion of the thin defining an air bag door portion are integrally formed, the back surface of the skin the breakable portion The airbag door portion of the instrument panel is characterized in that a synthetic resin adhesive is raised on the outer periphery of the outer airbag door portion to form a frame-shaped reinforcing protrusion that surrounds the outer periphery of the airbag door portion. Related to the structure.
The synthetic resin adhesive preferably has an embrittlement temperature of −20 ° C. or lower.
[0012]
According to the structure of the present invention, when the airbag is inflated and the back side of the airbag door portion is pushed, stress concentrates on the thin-walled planned breaking portion formed on the skin and breaks at the planned breaking portion, As a result, the airbag door portion is opened in the vehicle interior, and the airbag is deployed in the vehicle interior. At that time, there is a frame-shaped reinforcing protrusion made of synthetic resin adhesive on the outer periphery of the airbag door part on the back of the skin, and the strength of the skin is high at that part, so the skin is still at low temperatures Cracks do not occur on the outside of the frame-shaped reinforcing projection, that is, on the outside of the airbag door. Further, under high temperature, the reinforcing action by the frame-shaped reinforcing protrusions suppresses the elongation of the skin at the outer peripheral portion of the airbag door portion, and the skin is quickly broken at the planned breaking portion. Skin peeling due to elongation is prevented.
[0013]
In particular, if a brittle temperature of −20 ° C. or lower is used as the synthetic resin adhesive constituting the frame-shaped reinforcing protrusion, the interior of the vehicle is generally lowered to −20 ° C. in a normal automobile running state. Therefore, the skin on the outer periphery of the airbag door portion can be reliably reinforced even at low temperatures, and it is possible to reliably prevent the skin on the outer periphery of the airbag door portion from cracking when the airbag door portion is released.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of an embodiment of an instrument panel having the structure of the present invention cut along the vehicle width direction at the airbag door portion, and FIG. 2 is along the front-rear direction of the airbag door portion of the embodiment. 3 is a cross-sectional view taken along the line, FIG. 3 is a view showing the back surface of the skin in the vicinity of the airbag door in the same embodiment, FIG. 4 is a cross-sectional view showing the vicinity of the airbag door in another embodiment, and FIG. It is a figure which shows the skin back surface of the airbag door part vicinity in FIG.
[0015]
An instrument panel 10 shown in FIG. 1 and FIG. 2 is used as an instrument panel of an automobile, has the same outer shape as the instrument panel P shown in FIG. 6 of the prior art, and has an airbag door portion D1. Have one. 1 is a cross-sectional view of the airbag door portion D1 cut along the vehicle width direction (at a position corresponding to line 1-1 in FIG. 6), and FIG. 2 shows the airbag door portion D1 front and rear. It is sectional drawing cut | disconnected along the direction (at the position equivalent to the 7-7 line | wire of FIG. 6).
[0016]
The instrument panel 10 includes a back-side core member 21, an airbag door core member 31, a synthetic resin foam layer 41, and a synthetic resin skin 45, and an airbag device is attached to the back side. The airbag device has the same structure as that described in the section of the prior art. Reference numeral A is an airbag and C is an airbag housing case. Reference symbol T1 indicates a planned tearing portion of the instrument panel, and is a portion where the synthetic resin foam layer 41 is broken when the airbag is inflated.
[0017]
The back-side core material 21 is a core part of the passenger compartment side material 10, and is formed into an instrument panel 10 shape by injection molding or the like from a hard resin such as polypropylene resin or acrylonitrile-styrene copolymer resin. An air bag deployment opening 22 for allowing the airbag A to be deployed in the vehicle compartment is formed in the back side core member 21 in accordance with the opening of the airbag housing case C. A fixing hole 23 for the airbag door core 31 and the airbag housing case C is formed in the front window side peripheral edge 22a of the airbag deployment opening 22.
[0018]
The air bag door core 31 constitutes the back surface of the air bag door part D1 so that the air bag door part D1 can be opened quickly when the air bag A is inflated. It consists of a board, and is attached on the said back side core material 21 so that the airbag expansion | deployment opening part 22 may be plugged up. The air bag housing case C is attached by inserting bolts 33 through the fixing holes 32 formed in the front window side edge of the airbag door core 31 and the fixing holes 23 formed in the back core 21. At the same time, the nut 34 is tightened.
[0019]
The synthetic resin foam layer 41 is for imparting buffering properties to the surface side of the instrument panel 10 and improving the surface feel, and is made of polyurethane foam or the like.
[0020]
The skin 45 constitutes the surface of the instrument panel 10 and is made of a synthetic resin and is made of a synthetic resin sheet such as a soft vinyl chloride resin. The skin 45 is formed in the outer shape of the instrument panel 10 by powder slush molding, vacuum molding, or the like.
[0021]
On the back surface of the skin 45, an airbag door D1 is demarcated, and a thin-walled scheduled break portion 46 that is quickly broken when the airbag A is inflated is formed as a V-shaped groove by a hot blade or the like. The fracture portion 46 is formed along the edge of the air bag door core 31, and its planar shape is substantially U-shaped opening on the front window side, as is apparent from FIG. 3 showing the back surface of the skin 45. It has become. Further, in this embodiment, the skin 45 is made of a soft vinyl chloride resin sheet having a thickness of 0.8 mm, and the planned fracture portion 46 is formed with a thickness of 0.3 mm.
In addition, when the skin 45 is a powder slush molding product, the thin-walled fracture portion 46 may be formed at the time of the powder slush molding.
[0022]
Further, on the back surface of the skin 45, a reinforcing projection 11 surrounding the outer periphery of the airbag door part D1 defined by the thin planned break portion 46 is formed in a frame shape outside the planned break portion 46. . The reinforcing protrusion 11 reinforces the outer peripheral portion of the airbag door portion D1, and when the skin 45 breaks at the planned breakage portion 46 due to the expansion of the airbag A, the reinforcing skin 11 is formed on the outer skin 45 of the airbag door portion D1. This makes it difficult for cracks and peeling from the synthetic resin foam layer 41 to occur.
[0023]
The reinforcing protrusion 11 is made of a synthetic resin adhesive raised on the back surface of the skin 45 so as to surround and surround the outer periphery of the airbag door portion D1.
A variety of synthetic resin adhesives are used, and those having good adhesion to the skin 45, low elongation at high temperatures that can occur in automobiles, and low embrittlement at low temperatures are preferable. In particular, a low temperature that hardly occurs in a normal vehicle, that is, a brittle temperature of −20 ° C. or less is preferable. Examples of these synthetic resin adhesives include epoxy-based elastic adhesives, urethane-based and polyester-based hot melt adhesives. Among these, as a hot melt adhesive, a trade name Aron Melt PES and a grade name PES-110H (manufactured by Toa Gosei Co., Ltd.) are suitable.
[0024]
The reinforcing protrusion 11 can be easily formed by applying a synthetic adhesive to a predetermined position on the back surface of the skin 45 and raising it. For example, when the synthetic resin adhesive constituting the reinforcing protrusion 11 is a polyester hot melt adhesive, the adhesive may be heated and melted and applied to the back surface of the skin 45 with a predetermined thickness. At that time, if the skin 45 is an olefin-based material that is difficult to adhere to the synthetic resin adhesive, a primer may be appropriately applied to the back surface of the skin 45 and a synthetic resin adhesive may be applied thereon.
[0025]
The height (thickness), width, and the like of the reinforcing protrusion 11 are appropriately determined depending on the material of the synthetic resin adhesive to be used, the type and thickness of the skin 45 and the synthetic resin foam layer 41, the thickness of the planned fracture portion 46, and the like. The For example, as shown in FIG. 4 showing another example of the present invention, the reinforcing protrusion 11A may be bonded to the back surface 45A of the outer periphery of the airbag door portion D2 and the back-side core material 21A. In this case, since the outer skin 45A is bonded to the back side core member 21A via the reinforcing protrusion 11A on the outer periphery of the airbag door portion D2, the reinforcing effect of the outer skin 45A on the outer periphery of the airbag door portion D2 is higher. It will be a thing.
[0026]
In this embodiment, the instrument panel 10 is molded by using the backside core 21 in a state in which the airbag door core 31 is disposed in the airbag deployment opening 22 as the skin 45 on which the reinforcing protrusion 11 is formed. In addition, the foamed raw material is placed between the back side core material 21 and the outer skin 45, and the synthetic resin foam layer 41 is formed integrally with the back side core material 21, the airbag door core material 31, and the outer skin 45. This can be done easily. At that time, bolts 33 are inserted into the fixing holes 32 and 23 of the airbag door core 31 and the back-side core 21 in advance.
[0027]
As shown in FIGS. 1 and 2, the instrument panel 10 thus configured has the back side of the airbag door portion D <b> 1 fixed to the airbag housing case C by the bolt 33 and the nut 34 that is screwed therewith.
[0028]
When an impact is applied to the automobile due to the impact, the inflator I in the airbag housing case C is actuated to inflate the airbag A and push the back side of the airbag door portion D1. Due to the pressing force, stress concentrates on the thin planned break portion 46 formed on the skin 45 and breaks at the planned break portion 46, and the synthetic resin foam layer 41 breaks at the planned break portion T1, The airbag door portion D1 is bent into the vehicle interior with the end portion of the planned break portion 46 as a hinge H portion, whereby the airbag door portion D1 is opened and the airbag A is deployed in the vehicle interior.
[0029]
At that time, since the outer periphery of the airbag portion D1 on the back surface of the skin 45 is reinforced by the reinforcing protrusion 11 and has high strength, there is a risk of peeling from the crack or the synthetic resin foam layer 41 even at low or high temperatures. The airbag door part D1 opens constantly. In addition, since the skin 45 is reinforced by the reinforcing protrusion 11 at the portion that becomes the hinge portion H, the skin 45 is not cracked or peeled off at the hinge portion H, and a more constant opening of the airbag door is realized. it can. Furthermore, if the synthetic resin adhesive constituting the reinforcing protrusion 11 has a brittle temperature of −20 ° C. or lower, cracking of the skin can be prevented more reliably at low temperatures.
[0030]
In addition, like the back surface of the skin 51 of another embodiment shown in FIG. 5, the thinly-scheduled breakage portion 52 is formed in an H shape on the back surface of the skin 51, and the airbag door portions D2 and D2 are arranged on the windshield side and the passenger seat. In the double-opening instrument panel that opens to the side, the reinforcing protrusion 53 is provided in a frame shape that surrounds the entire outer periphery of the two airbag door portions D2, D2.
[0031]
【The invention's effect】
As illustrated and described above, in the present invention, the outer periphery of the airbag door portion defined by the thinly-scheduled portion of the skin is surrounded, and the reinforcing protrusion made of the synthetic resin adhesive is provided on the back surface of the skin. Since it provided, the intensity | strength of a skin becomes high in the outer periphery of an airbag door part. Therefore, when the airbag door part is opened due to the expansion of the airbag, the skin is broken at the thinly-scheduled breaking part, so that the outer periphery of the airbag door part is not easily cracked or peeled off, and the opening of the airbag door part is constant. To come.
Moreover, since the reinforcing protrusion is provided so as to surround the outer periphery of the airbag door portion, the reinforcing protrusion constitutes a hinge portion between the ends of the thinly-scheduled portion of the skin, that is, when the airbag door portion is opened. The strength of the epidermis is also increased at the hinge part. As a result, cracks and peeling are less likely to occur at the hinge portion, and the opening of the airbag door portion becomes more constant.
[0032]
Further, in the present invention, the reinforcing protrusion makes it difficult for the crack and peeling to occur when the airbag door is opened. Therefore, in order to prevent the crack and peeling, it is necessary to extremely thin the planned fracture portion of the skin. It is possible to prevent cracks and the like in the planned fracture portion caused by the deterioration of the skin, and to maintain a good appearance of the instrument panel over a long period of time. Further, the outer skin of the airbag door part is reinforced by the reinforcing protrusions, and the strength is increased. As a result, when the airbag is inflated, more stress is concentrated on the breaking protrusions inside the reinforcing protrusions. Will open more smoothly.
In addition, if a synthetic resin adhesive that constitutes the reinforcing protrusion is one with an embrittlement temperature of −20 ° C. or lower, cracks occur in the outer skin of the airbag door when the airbag expands at low temperatures. Can be prevented more reliably.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of an instrument panel having the structure of the present invention cut along the vehicle width direction at an airbag door portion thereof.
FIG. 2 is a cross-sectional view taken along the front-rear direction of the airbag door portion of the embodiment.
FIG. 3 is a view showing a back surface of the skin near the airbag door in the same embodiment.
FIG. 4 is a cross-sectional view showing the vicinity of an airbag door in another embodiment of the present invention.
FIG. 5 is a view showing the back surface of the skin in the vicinity of an airbag door according to another embodiment of the present invention.
FIG. 6 is a perspective view of an example of an instrument panel integrally having a conventional airbag door portion.
7 is a cross-sectional view taken along the line 7-7 in FIG.
8 is an enlarged cross-sectional view of a portion 8 in FIG.
9 is a cross-sectional view showing the airbag of FIG. 7 when inflated.
FIG. 10 is a partial perspective view showing a state in which the skin is cracked in the prior art.
FIG. 11 is a partial perspective view showing a state in which the epidermis is peeled off in the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Instrument panel 11 Reinforcement protrusion 21 Back side core material 31 Core material for airbag doors 41 Synthetic resin foam layer 45 Skin 46 Destination part D1 Airbag door part

Claims (2)

In an instrument panel having a synthetic resin skin integrally formed with a thin-walled portion to be broken to define an airbag door portion on the upper surface of the synthetic resin foam layer, the back surface of the skin has an air outside the portion to be broken. A structure of an airbag door portion of an instrument panel, wherein a synthetic resin adhesive is raised on the outer periphery of the bag door portion to form a frame-shaped reinforcing protrusion that surrounds the outer periphery of the airbag door portion.   The structure of an airbag door portion of an instrument panel according to claim 1, wherein the brittle temperature of the synthetic resin adhesive is -20 ° C or lower.

Images