JP2002225666A - Instrument panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument panel with an air bag door part that is easily moldable, can reduce a man-hour for assembly and excels in rigidity when torn apart. SOLUTION: The instrument panel 1 comprises a panel body part 2 and the air bag door part 3 integrally formed in part of the panel body part 2. The air bag door part 3 has a sandwich structure using as outer layers 20 a panel forming synthetic resin 21 constituting the panel body part 2, and as an inner layer 30 a soft synthetic resin 31 softer than the panel forming synthetic resin 21. A boundary portion 4 between the panel body part 2 and the air bag door part 3 has a thickened portion 11 to which the inner layer 30 is extended and thickened. The thickened portion 11 has a grooved tear portion 41 expanding from a back face 102 thereof to the inner layer 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument panel having an airbag door that opens when an airbag is activated.

[0002]

2. Description of the Related Art Conventionally, in an automobile, it is known to provide an airbag device on an instrument panel provided in a front portion of the interior of the automobile in order to protect a person riding on a passenger seat of the automobile. As shown in FIG. 8A, the airbag device 95 is installed on the back side 901 of the instrument panel 9, and the instrument panel 9 has the airbag bag 9 of the airbag device 95.
An airbag door 93 is provided so that the airbag 51 can be inflated in the vehicle.

The airbag door 93 has a hooking claw 931 which can be hooked on the opening end 921 of the panel main body 92 of the instrument panel 9. The stop claw 931 is connected to the open end 9
21 is attached to the instrument panel 9. Then, when the airbag device 95 is activated at the time of a collision of a car or the like, the airbag bag body 951
Due to the inflating force of the airbag, the locking claw 931 is released and the airbag door 93 is opened, and the airbag body 951 is opened.
Are expanded in the vehicle.

[0004]

However, in the above-described conventional mounting structure of the airbag door 93, a gap groove 94 formed between the airbag door 93 and the opening end 921 of the panel body 92 is formed on the design surface. It is exposed. The width of the gap groove 94 may vary due to a molding error of the airbag door 93 and the panel main body 92, and in some cases, the external appearance may be impaired.

Therefore, as shown in FIG. 8B, the air back door 93 having a sandwich structure of an inner layer 930 made of a soft synthetic resin and an outer layer 920 made of a hard synthetic resin is attached to the panel body 92. It is conceivable that they are integrally formed and a groove-shaped tear portion 941 is formed on the back surface side 901 of the instrument panel 9. However, in this case, since a soft synthetic resin is used for the airbag door 93, the rigidity of the airbag door 93 and the panel main body 92 formed when the airbag door 93 is broken at the tear portion 941 are formed. Opening 922
The rigidity of the device decreases. For this reason, the above-mentioned stable fracture is not performed, and in some cases, small fragments of the hard synthetic resin generated by the fracture may be scattered in the vehicle.

The present invention has been made in view of such conventional problems, and has an air back door portion which is easy to form, can reduce the number of assembling steps, and has excellent rigidity at break. It is intended to provide an instrument panel.

[0007]

According to a first aspect of the present invention, there is provided a panel main body and an airbag door provided integrally with a part of the panel main body. An instrument panel having a sandwich structure in which a panel synthetic resin constituting a panel main body is an outer layer and a soft synthetic resin softer than the panel synthetic resin is an inner layer, wherein the panel main body and the airbag are provided. At the boundary with the door portion, a thickened portion is provided in which the inner layer is extended to increase the thickness of the inner layer, and the thickened portion has a grooved tier extending from the back side surface to the inner layer. The instrument panel according to any one of the preceding claims, further comprising:

What is most notable in the present invention is that the thickened portion is provided at the boundary portion, and the thickened portion has a grooved tier extending from the back surface to the inner layer. That is, a part is provided.

Next, the operation and effect of the present invention will be described.
The airbag door according to the present invention is provided integrally with a part of a panel main body of the instrument panel. Therefore, the airbag door portion and the panel body portion can be simultaneously molded using the same molding die, and this molding is easy. In addition, costs for molding can be reduced. In addition, the airbag door can be assembled at the same time as the instrument panel is assembled to the vehicle. Therefore, the man-hour for assembling the airbag door to the instrument panel becomes unnecessary.

[0010] The thickened portion at the boundary portion is provided with the groove-shaped tier portion. Therefore, when the airbag of the vehicle equipped with the instrument panel operates, the stress concentration can be easily generated in the tier portion by the expanding force of the airbag.
Therefore, the airbag door portion can be easily broken at a narrow portion having a reduced thickness due to the formation of the tier portion.

[0011] In the thickened portion at the boundary portion, a step is formed by the outer layer by increasing the thickness of the inner layer. The step portion is formed on both sides of the tier portion in the thickened portion. One of the step portions constitutes an edge portion of the airbag door portion, and the other portion has a broken airbag door portion. It constitutes the opening of the panel body which is sometimes formed. For this reason, the airbag door portion and the opening portion of the panel main body have a larger second moment of area, which is a measure of rigidity, and are bent as compared with those having a substantially uniform thickness as a whole. The strength against external forces such as torsion and torsion increases.

As described above, the edge of the airbag door and the opening of the panel main body are constituted by the steps, and have high rigidity. Therefore, the edge and the opening can easily respond to the pressure when the airbag is inflated and the impact due to the breakage when the airbag is activated. Therefore, the instrument panel having the airbag door portion has excellent rigidity at the time of breakage, and can stably perform the breakage, and minute pieces of the synthetic resin for the panel are scattered in the vehicle due to the breakage. Can be prevented.

Further, the groove-shaped tier portion is provided so as to extend from the back surface of the thickened portion to the inner layer. Therefore, in the state before the breakage, the tier portion is not exposed to the design surface in the vehicle, and the instrument panel can have an appearance as if no airbag is mounted. Therefore, the instrument panel can exhibit excellent appearance design.

Next, as in the second aspect of the present invention, it is preferable that the groove-shaped tier is formed in a V-shape or a U-shape. Thereby, stress concentration can be easily generated in the tier portion, and the airbag door portion can be easily broken at the narrow portion.

Next, it is preferable that the thickness of the thickened portion is 5 mm or more. Thus, the edge of the airbag door and the opening of the panel body can be easily made rigid. In this case, it is preferable that the thickness of the portion other than the thickened portion, that is, the thickness of the airbag door portion and the thickness of the panel main body portion be 2 to 4 mm.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment An instrument panel according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 (a),
As shown in (b), the instrument panel 1 in this example includes a panel main body 2 and an airbag door 3 provided integrally with a part of the panel main body 2. The airbag door portion 3 is formed on the passenger side of the instrument panel 1. The periphery of the airbag door 3 including the airbag door 3 is the panel body 2.
Is formed as an outer layer 20 and a soft synthetic resin 31 which is softer than the panel synthetic resin 21 as an inner layer 30.

At the boundary 4 between the panel body 2 and the airbag door 3, there is provided a thickened portion 11 in which the inner layer 30 is extended to increase its thickness. The thickened portion 11 is provided with a groove-shaped tier portion 41 extending from the back side surface 102 to the inner layer 30.

Hereinafter, this will be described in detail. As shown in FIG. 2A, the groove-shaped tier portion 41 is provided with the thickened portion 11.
The narrow portion 42 is formed on the front side surface 101 of the thickened portion 11 on the back side surface 102 of the V-shaped portion. Note that, as shown in FIG. 2B, the tear portion 41 may be formed in a U-shape instead of a V-shape.

The panel synthetic resin 21 forming the outer layer 20 is a polypropylene resin (PP), while the soft synthetic resin 31 forming the inner layer 30 is
It is an olefin-based elastomer which is one of thermoplastic elastomers. The polypropylene resin and the olefin-based elastomer have similar molding shrinkage and linear expansion coefficient. Thus, the instrument panel 1 is formed by two-color molding.

As shown in FIG. 2A, the narrow portion 42
Is a broken end 4 when the airbag door 3 is broken.
A virtual fracture surface 421 that forms 22 (see FIG. 3B)
(Represented by a broken line in FIG. 2A). The thickness t1 of the thickened portion 11 is 5 mm,
The thickness of the airbag door 3 and the panel body 2
Has a thickness t2 of 4 mm.

In the thickened portion 11 at the boundary 4, a step 45 is formed by the outer layer 20 by increasing the thickness of the inner layer 30. Since the tier portion 41 is provided so as to extend from the back side surface 102 of the thickened portion 11 to the inner layer 30, the tier portion 4 is provided.
The soft synthetic resin 31 and the synthetic resin 21 for the panel are exposed on the surface of 1. The outer layer 20 is formed on the entire instrument panel 1, that is, the thickened portion 1.
1, the airbag door 3 and the panel body 2 have a substantially uniform thickness.

The thickness t3 of the narrow portion 42 is 0.6 m
m. Note that the thickness t3 of this narrow portion is 0.4
It is preferably about 0.8 mm. Thereby, the airbag door portion 3 can be more easily broken at the narrow portion 42.

As shown in FIG. 2C, the boundary 4
The thickened portion 11 in which the tier portion 41 and the narrow portion 42 are formed, the hinge portion 43 serving as a center of rotation when the airbag door portion 3 breaks and opens in the narrow portion 42. Consists of That is, the airbag door section 3 is formed continuously with the tier section 41 and the narrow section 42 and the panel body section 2 and the tier section 41 is formed.
And a hinge portion 43 that forms the outer shape of the airbag door portion 3 together with the narrow portion 42.

The hinge 43 has a sandwich structure in which the panel synthetic resin 21 is an outer layer 20 and the soft synthetic resin 31 is an inner layer 30. In addition, hinge part 4
3 is not provided with the tier portion 41 and the narrow portion 42 (see FIGS. 3A and 3B). The airbag door 3 has a rear portion and left and right sides formed by the tier portion 41 and the narrow portion 42, and a front side formed by the hinge portion 43.

The airbag door 3 can be opened with the hinge 43 as the center of rotation when the narrow portion 42 is broken. Also,
The hinge portion 43 can prevent the airbag door portion 3 after opening from flying away from the instrument panel 1.

It should be noted that the airbag door portion 3 may be formed so as to be entirely surrounded by the tier portion 41 and the narrow portion 42 with respect to the structure in this embodiment. In this case, the rear side surface 102 of the airbag door 3 is provided so that the airbag door 3 does not fly away from the instrument panel 1 when it breaks at the narrow portion 42. A detachment prevention device to be fixed is provided.

As shown in FIG. 3A, an airbag door 3 is provided on the passenger seat side of an instrument panel 1 provided in the front of the vehicle, and a rear side surface 102 of the airbag door 3 is provided. Is provided with an airbag device 5. The airbag device 5 includes an airbag case 51 having an opening on the instrument panel 1 side and an inflator 52 provided on a bottom 511 of the airbag case 51.
And an airbag body 53 connected to the inflator 52 and housed inside the airbag case 51.

Then, as shown in FIG. 3B, when the airbag device 5 is operated due to a collision of a car or the like, the inflator 52 instantaneously generates a high-pressure gas. The airbag body 53 is inflated by the high-pressure gas to break the airbag door portion 3 at the narrow portion 42 and spread inside the vehicle.

Next, the operation and effect of this embodiment will be described. The airbag door section 3 in this example is provided integrally with a part of the panel main body section 2 of the instrument panel 1. Therefore, the airbag door 3
And the panel main body 2 can be simultaneously molded using the same mold, and this molding is easy. Also,
Costs for molding can be reduced. In addition, the airbag door section 3 can be assembled at the same time as the instrument panel 1 is assembled to an automobile. Therefore, the man-hour for assembling the airbag door section 3 to the instrument panel 1 is not required.

The thickened portion 11 at the boundary 4 is provided with the groove-shaped tier portion 41. for that reason,
When the airbag device 5 of the automobile equipped with the instrument panel 1 is operated, stress concentration can be easily generated in the tier portion 41 by the inflating force of the airbag bag 53. Therefore, the airbag door portion 3 can be easily broken at the narrow portion 42 whose thickness is reduced by the formation of the tier portion 41.

In the thickened portion 11 at the boundary 4, a step 45 is formed by the outer layer 20 by increasing the thickness of the inner layer 30. The step portion 45 is provided in the tier portion 4 in the thickened portion 11.
1, one of the steps 45 constitutes the edge 32 of the airbag door 3, and the other is the panel body formed when the airbag door 3 is broken. The opening 22 of the section 2 is configured. Therefore, the opening 22 of the airbag door 3 and the panel main body 2 is formed.
Is compared to the one made of almost uniform thickness as a whole.
The second moment of area, which is one measure of stiffness, increases, and the strength against external forces such as bending and torsion increases.

As described above, the edge 32 of the airbag door 3 and the opening 22 of the panel main body 2 are formed by the steps 45 and have high rigidity. Therefore, the edge 32 and the opening 22 can easily respond to the pressure when the airbag body 53 is inflated and the impact due to the breakage when the airbag device 5 is operated. . Therefore, the instrument panel 1 having the air back door portion 3 has excellent rigidity at the time of breakage, and can stably perform the breakage. Can be prevented from scattering.

The groove-shaped tier portion 41 is provided from the back side surface 102 of the thickened portion 11 to the inner layer 30. Therefore, in the state before the fracture, the tear portion 41 is not exposed on the design surface in the vehicle, and the instrument panel 1 is
An appearance as if the airbag device 5 is not mounted can be exhibited. Therefore, the instrument panel 1 can exhibit excellent appearance design.

The polypropylene resin forming the panel main body 2 and the olefin elastomer forming the airbag door 3 have similar molding shrinkage and linear expansion coefficient. Therefore, they can be easily fused to each other, and wrinkles are formed on the surface of the panel main body 2 or the airbag door 3 due to the fusion, and the instrument panel 1 is connected to the outer layer 20 and the inner layer 30. It is possible to prevent the portion having the sandwich structure from being broken.

Second Embodiment This embodiment is an example showing a method for manufacturing the instrument panel 1 described in the first embodiment. As shown in FIG. 4A, the molding die 6 of the instrument panel 1 is used.
A first molding die 61 for molding the front surface 101 of the instrument panel 1;
And a second molding die 62 for molding the rear side surface 102 of the second molding die 62.
Further, as shown in FIG. 4B, the second molding die 62 places the concave portion 621 for molding the thickened portion 11 at a position corresponding to the thickened portions 11 on the rear side and both right and left sides of the instrument panel 1. Have.

As shown in FIG. 5A, the molding die 6 forms a cavity 63 for molding the instrument panel 1 when the first molding die 61 and the second molding die 62 are closed. It is configured to be.

As shown in FIG. 5 (b), when molding the instrument panel 1, the synthetic resin 21 for the panel is first injected into the cavity 63,
Next, the soft synthetic resin 31 is injected into the panel synthetic resin 21 at the portion where the airbag door 3 is formed. The panel synthetic resin 21 forms the outer layer 20 of the instrument panel 1 with the soft synthetic resin 31.
Forms the inner layer 30 of the instrument panel 1, and forms the instrument panel 1 having a sandwich structure of the outer layer 20 and the inner layer 30.

Hereinafter, the molding die 6 for molding the instrument panel 1 will be described in detail. In this example,
As shown in FIG. 4A, the first molding die 61 is provided with a first gate 631 which is an injection port of the soft synthetic resin 31 connected to the cavity 63.
2 is provided with a second gate 641 which is an injection port of the panel synthetic resin 21 connected to the cavity 63. Each of the first gate 631 and the second gate 641 may be provided in the first molding die 61 or may be provided in the second molding die 62.

As shown in FIG. 4B, the opening 634 of the first gate 631 is substantially even in the cavity 63 from each of the recesses 621 corresponding to the rear side and the left and right positions of the instrument panel 1. It is provided at a position having a distance, that is, at a substantially middle position surrounded by the recesses 621. The opening 644 of the second gate 641 is formed in the cavity 63 by the recess 62.
1 are provided in the vicinity of the outside.

At the outer end 632 of the first gate 631, an injection nozzle 633 for injecting the soft synthetic resin 31 is provided.
An injection nozzle 643 for injecting the panel synthetic resin 21 is provided at the outer end 642 of the second gate 641. The second molding die 62 is provided with a knockout rod 65 for taking out the instrument panel 1 after molding.

Next, a method for forming the instrument panel 1 will be described in detail. As shown in FIG. 6A, first, the first molding die 61 and the second molding die 62 are closed,
The cavity 63 is formed. Next, as shown in FIG. 6B, the panel synthetic resin 21 is injected into the cavity 63 from the second gate 641. It should be noted that the injection amount of the panel synthetic resin 21 depends on the cavity 6.
The volume is obtained by subtracting the injection amount of the soft synthetic resin 31 from the volume 3.

Next, as shown in FIG. 7A, the soft synthetic resin 31 is injected into the panel synthetic resin 21 in the portion where the airbag door 3 is formed. The injection of the soft synthetic resin 31 is performed when the first synthetic resin 21 is substantially filled in the first cavity 63 while the synthetic resin for panel 21 is being injected.

That is, since the soft synthetic resin 31 is injected before the panel synthetic resin 21 cools and hardens,
The soft synthetic resin 31 can easily flow into the inside of the panel synthetic resin 21. Then, the soft synthetic resin 31 flows outside the concave portion 621 beyond the concave portion 621 forming the boundary portion 4.

Next, as shown in FIG. 7 (b), the synthetic resin 21 for the panel is applied to the outer layer 20 of the instrument panel 1.
The soft synthetic resin 31 forms the inner layer 30 of the instrument panel 1. Then, the first molding die 61 and the second
The mold 62 is opened, and the molded instrument panel 1 is taken out.

Finally, as shown in FIG. 7C, the V-shaped tier portion 41 is formed on the back side surface 102 of the thickened portion 11 by laser processing. Note that the tier portion 41 may be formed by ultrasonic processing.
In this way, the instrument panel 1 having a sandwich structure of the outer layer 20 made of the panel synthetic resin 21 and the inner layer 30 made of the soft synthetic resin 31 is formed.

As described above, the instrument panel 1 described in the first embodiment can be formed. And this molded instrument panel 1
Can obtain the same operation and effect as the instrument panel 1 described in the first embodiment.

[0047]

As described above, according to the present invention, there is provided an instrument panel having an airbag door portion which is easy to form, can reduce the number of assembling steps, and has excellent rigidity at break. can do.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional explanatory views showing an airbag door portion of an instrument panel according to a first embodiment, and FIGS.
FIG. 1 is an overall explanatory diagram showing an instrument panel.

FIGS. 2A and 2B are cross-sectional explanatory views showing a tier portion and a narrow portion of an airbag door portion in the first embodiment, and FIG. 2B is a cross-sectional explanatory diagram showing a U-shaped tier portion of another airbag door portion. (C) Explanatory drawing which shows an airbag door part.

FIGS. 3A and 3B are views showing the airbag device according to the first embodiment, and are explanatory diagrams showing a state before operation and a state after operation;

FIGS. 4A and 4B are diagrams illustrating a molding die of an instrument panel according to a second embodiment, wherein FIG. 4A is a cross-sectional explanatory view illustrating a state where a first molding die and a second molding die are opened, and FIG. FIG. 3 is an explanatory perspective view showing a concave portion of the mold.

FIG. 5 is a view showing a molding die of an instrument panel according to a second embodiment, in which (a) a state in which a first molding die and a second molding die are closed, and (b) a state in which the instrument panel is molded. FIG.

FIG. 6 shows a state in which a cavity is formed by closing (a) a first mold and a second mold in the second embodiment;
(B) Sectional drawing which shows the state which injected the synthetic resin for panels into the cavity.

7A and 7B show a state in which a soft synthetic resin is injected into a synthetic resin for a panel, a state in which an instrument panel is molded, and a state in which a laser is applied to a back surface of a thickened portion in a second embodiment. Sectional explanatory drawing which shows the state which formed the V-shaped tier part by processing.

FIG. 8 is a cross-sectional explanatory view showing (a) a structure for mounting an airbag door on an instrument panel, and (b) a structure of an airbag door on another instrument panel in a conventional example.

[Explanation of symbols]

 1. . . 10. instrument panel, . . Thickened part, 102. . . Back side, 2. . . Panel body, 20. . . Outer layer, 21. . . 2. Synthetic resin for panels, . . Airbag door section, 30. . . Inner layer, 31. . . 3. soft synthetic resin; . . Border part, 41. . . Tier part, 5. . . Airbag device,

Claims (3)

[Claims] 1. A panel body comprising: a panel body; and an airbag door provided integrally with a part of the panel body, wherein at least the airbag door is a synthetic resin for a panel constituting the panel body. An instrument panel having a sandwich structure in which a soft synthetic resin softer than the synthetic resin for the panel is used as an outer layer.
At the boundary between the panel body and the airbag door, a thickened portion is provided by extending the inner layer and increasing the thickness thereof, and the thickened portion is provided from the back side thereof. An instrument panel comprising a groove-shaped tier portion extending to the inner layer. 2. The instrument panel according to claim 1, wherein the groove-shaped tier portion is formed in a V-shape or a U-shape. 3. The instrument panel according to claim 1, wherein the thickness of the thickened portion is 5 mm or more.