MXPA00001747A - Integral airbag door configuration - Google Patents

Abstract

An inflatable restraint assembly for passengers in automotive vehicles including an air bag door (12) integrally formed in an automotive trim (14) of a first material. The integral air bag door is defined at least in part by a tear guide (18) when in a closed position. The air bag door is movable from the closed position to provide a path for an air bag (12) to deploy through. The air bag door is movable out of the closed position by at least partially separating from the trim panel (14) along a door seam (20) at least partially defined by the tear guide (18). A retaining structure is configured to preclude at least a portion of the air bag door from departing the immediate vicinity of the trim panel during air bag deployment. According to one embodiment a hinge (22) comprising a second material (24) may be embedded at least partially within the first material and spans the door seam (20). According to another embodiment a tubular channel (214) may be disposed along the tear guide (18) to create a substantial strength differential with the door seam and help confine tearing to the tear guide during air bag deployment.

Description

CONFIGURATION OF DOOR WITH INTEGRAL AIR BAG DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates generally to an air bag door that is formed integrally with an interior trim panel of a vehicle and, more particularly, to that air bag door configured to open by breaking and / or tearing at a predictable way and a method to manufacture such a door. BACKGROUND OF THE INVENTION It is desirable that inflatable restraint or restraint systems having integrally formed doors for airbags, include some means to ensure that the airbag doors open by breaking and / or tearing in a generally predictable manner. This is true for inflatable passenger-side restraint systems (DSIRs), inflatable restraint systems for the passenger side (PSIRs) for passenger-side inflatable restraint systems-) and inflatable fastening systems on vehicle door panels, quarter panels, other side wall structures, seats, headboards, uprights, etc. Doors for air bags in such systems are opened to provide a path for an air bag to deploy through it. It is also desirable that such systems include means to ensure that portions of the door are not separated from the system, when the airbag is deployed and forcing the door to open. To develop tearing and / or breaking, airbag doors that are integrally formed with automotive interior trim or instrument panels will sometimes include regions of weakened, reduced-thickness or scratched materials, to which commonly referred to as "tearing seams". Torn seams are weak areas designed to tear and / or break when an airbag is deployed and force the door to open. Some of these systems also employ ties and / or hinges that retain or secure the airbag door to the instrument panel or interior finish after the door has been torn and / or broken when opened. For example, U.S. Patent No. 5,569,959, issued to Cooper et al., Discloses an inflatable restraint or restraint assembly comprising a retainer portion of the air bag door integrally formed in a panel retainer of automotive instruments and defined by a door seam. A tear guide is included in a cover placed on a layer of foam that extends through the opening of the door. A hinge or metal joint panel is embedded within the retainer of the instrument panel and extends over a portion of the door seam. Cooper et al. Also disclose a method for making such an inflatable restraint or restraint assembly. The method includes pre-molding or pre-molding the hinge panel on the hard portion of the instrument panel retainer, so that the hinge panel extends over the door seam. With many current systems, tear seams and / or hinges are formed in a hard portion of the instrument panel retainer. They can be created during molding or they can be made by means of a second operation such as cutting, grinding or laser notching performed after a manufacturing step when integrally molding the instrument panel and the door. Current systems also include tear seams formed on the posterior surfaces opposite to the exterior surfaces class A of the integral instrument panel or the door structures for air bag to improve the aesthetic appearance of the instrument panel by concealing the presence of the door. To date, most tear seams formed in hard instrument panel seals during molding are created with a material of reduced thickness. Nevertheless, this method has proven to be unreliable where the structure of one side of the tear seam is limited to the nominal thickness of the panel. In this instance the tearing action tends to move away from the intended tear path which is unacceptable. Consequently, secondary operations are often used to increase the repetition and thickening of the tear seam which has a negative impact on the cost of cutting. At least one automotive instrument panel, as shown and described in U.S. Pat. No. 5,162,092, issued to Klobucar et al, discloses an instrument panel that has a gas channel and a method to form the channel in the panel. The gas channel is a tubular structure formed integrally in the panel by injecting the gas into molten panel material in a mold. The gas channel in the instrument panel of Klobucar et al. Adds structural rigidity. However Klobucar et al. Do not disclose an air bag door or any other supplemental inflatable restraint or restraint component. What is needed is a supplemental inflatable restraint or restraint system that includes an integrally formed air bag door that has a restraint or restraint structure that retains the door during deployment of the air bag and can be formed with the air bag door instead of requiring a second operation. What is also needed is a system that includes a tear guide structure that guides tearing during deployment of the air bag and that may be formed with the air bag door instead of requiring a second operation. BRIEF STATEMENT OF THE INVENTION In accordance with the present invention there is provided an inflatable restraint or restraint assembly for passengers in automotive vehicles that includes a hinge or joint comprising a first material and a second material embedded at least partially between the first material and cross a door seam. The assembly also includes an air bag door integrally formed in an automotive instrument panel comprising the first material. The integral airbag door is defined at least in part by a tear guide when the door is in the closed position. The air bag door is movable from the closed position to provide a path for an air bag to deploy therethrough and away from the closed position to at least partially separate from the instrument panel along a door seam defined at least partially by the tear guide. A restraining structure or restraint is configured to prevent at least a portion of the airbag door from coming out of the immediate vicinity of the instrument panel during deployment of the airbag. In accordance with another aspect of the invention, the hinge is configured to be at least substantially invisible by being seen from the outer surface of class A of the instrument panel. This improves the aesthetic appearance of the class A surface and prevents interference. In accordance with another aspect of the invention, the hinge includes a first end embedded in a portion of the first material forming the door and a second end embedded in a portion of the first material forming the instrument panel. A middle portion of the hinge is disposed between the first and the second end and has an outer surface covered with a portion of the first material forming the outer class A surface of the door and the instrument panel. The middle portion also has an exposed internal surface disposed opposite to the outer surface that is not covered with the first material. In accordance with another aspect of the invention the second material includes either one or more materials from a group of materials including thermoplastic rubber, matte glass, fabric and metal. In accordance with another aspect of the invention a cover is supported on the decorative panel and a layer of foam can be placed between the decorative panel and the cover. In accordance with another aspect of the invention the ornament panel generally includes a second tubular channel positioned generally parallel to the first tubular channel and along one side of the hinge opposite the first tubular channel. In accordance with another aspect of the invention, the tear guide comprises a region of reduced force leading to tearing during deployment of the air bag. A first tubular channel is generally placed along the tear guide to create a substantial differential force with the seam of the door. This helps to ensure that tearing and tearing are limited to the tear seam. In accordance with another aspect of the invention the first tubular channel includes an extended arcuate outer wall. The arched outer wall does not include sharp ends. According to another aspect of the invention, the tear guide comprises a region of reduced thickness. Reducing the thickness allows the force to be reduced without incorporating a second, weaker material. In accordance with another aspect of the invention the first tubular channel is positioned opposite an outer surface of class A of the air bag door and the instrument panel. Again, this helps preserve the aesthetic appearance of the Class A exterior surface of the airbag door and the instrument panel. In accordance with another aspect of the invention a second generally tubular channel is positioned adjacent and parallel to the first tubular channel, the tear guide being positioned between the first and second tubular channels. According to another aspect of the invention, the tear guide is defined by an elongated space placed between the first and second tubular channels. In other words, the space serves itself as a tear guide avoiding the need to form a separate tear guide such as a groove or a series of openings. According to another aspect of the invention an elongated groove is placed on the outer surface of class A opposite the elongated space. The groove improves the ability of the tear guide to prevent tearing from spreading outside the tear guide. In accordance with another aspect of the invention there is provided a method for manufacturing an inflatable restraint or restraint assembly for passengers in automotive vehicles. The method includes providing a mold configured to form the figure of the integral air bag door and the instrument panel and inserting a layer of the second material into the mold in a position crossing a mold region configured to form the door seam. The first material is introduced in melted form into the mold in such a way that the sheet of the second material is at least partially embedded in the first material. The first material is allowed to cure between the mold and the first cured material and at least the partially inlaid sheet of the second material is removed from the mold. In accordance with another aspect of the invention, a second method for manufacturing an inflatable restraint or restraint assembly for passengers in automotive vehicles is provided. The second method includes providing a mold configured to form the figure of the integral air bag door and the instrument panel and the tubular channel and providing resin into the mold. Gas is injected into a portion of the resin that is placed within a portion of the mold configured to form the tubular channel. The resin is then allowed to cure between the mold and removed from the mold.

BRIEF DESCRIPTION OF THE DRAWINGS To better understand and appreciate the invention, refer to the following detailed description with reference to the accompanying drawings: Figure 1 is a cross-sectional view of a hinge constructed in accordance with the present invention; Figure 2 is a cross-sectional view of a tear / tear seam. a first embodiment of a door for integral air bag and instrument panel constructed in accordance with the invention; Figure 3 is a cross-sectional view of a tear / tear seam of a second embodiment of a door for integral airbag and instrument panel constructed in accordance with the invention; Figure 4 is a cross-sectional view of a tear / tear seam of a third embodiment of a door for integral air bag and instrument panel constructed in accordance with the invention; Figure 5 is a partial perspective bottom view of a door for integral air bag and instrument panel of Figure 2; Figure 6 is a partial perspective bottom view of a door for integral air bag and instrument panel of Figure 3; Figure 7 is a bottom partial perspective view of a door for integral air bag and instrument panel of Figure 4; and Figure 8 is a cross-sectional view of a hinge constructed in accordance with a fourth embodiment of the invention.

DESCRIPTION OF THE PREFERRED MODALITIES OF THE INVENTION A first embodiment of an inflatable restraint or restraint assembly for passengers in automotive vehicles manufactured in accordance with the present invention is generally shown as 10 in Figures 1, 2 and 5. The second, third and fourth embodiment of the invention are shown as 310 in Figures 3 and 5, as 410 in Figures 4 and 7, and as 510 in Figure 8, respectively. Figures 1, 2 and 5 show the closed position of an airbag door 12 formed integrally in an automotive instrument panel 14 in accordance with the first embodiment. The air bag door composite 12 and the instrument panel 14 comprises a first plastic material 16 and includes a tear guide 18 defining the air bag door 12. The tear guide 18 is constructed to ensure that the door for air bag 12 breaks and / or tears when opened in a generally predictable manner. The air bag door 12 is moved from the closed position to provide a path for an air bag to inflate through. The air bag door 12 is moved out of the closed position causing the air bag door 12 to at least partially separate from the instrument panel 14 along a door seam 20 which is at least partially defined by the tear guide 18. The remainder of the door seam 20 defined by an integral restraint or restraint structure in the form of a hinge 22. The hinge 22 is configured to prevent at least a portion of the air bag door 12 from being apart from the immediate proximity of the instrument panel 14 during deployment of the airbag. The immediate proximity of the instrument panel 14 is an area surrounding (or around) the instrument panel 14 that is sufficiently separate from any occupant passenger compartment so that no portion of the air bag door 12 can touch the occupant during the deployment of the airbag. The hinge 22 allows the air bag door 12 to open when the air bag deploys but ensures that the door 12 does not separate under the deployment force of the air bag. The hinge 22 includes a hinge panel 24 comprising a second material that is at least partially embedded between the first material 16 and crosses the door seam 20. The second material can include any one or more of a number of compatible materials for include a thermoplastic rubber such as Santoprene ©, matte glass, clothes or fabric and metal. The hinge panel 24 is invisible being seen from an exterior surface of class A 26 of the instrument panel 14. A first end 28 of the hinge panel 26 is embedded in a portion of the first material 16 that forms the door 12. A second end 30 of the hinge panel 26 is embedded in a portion of the first material 16 that forms the instrument panel 14. A middle portion 32 of the hinge panel 24 is positioned between the first and the second end 28, 30. The middle portion 32 of the hinge panel 26 has an outer hinge panel surface 34 covered with a portion 36 of the first material 16 that forms the outer surface of the A class of the door 12 and the instrument panel 14. The portion 36 of the first material covering the outer surface 34 of the middle portion 32 of the hinge panel 24 continues the outer surface of class A 26 on the hinge panel 24 and between the door 12 and the instrument panel 14, concealing the essence of the hinge panel 14 and the dividing line or stitching 20 between the door 12 and the instrument panel 14. The middle portion 32 also has an interior surface of exposed hinge panel 38 positioned opposite the outer surface of the hinge panel 34 The interior surface of the hinge panel 38 is left exposed to promote bending along the seam. As shown in Figures 2 and 5, the tear guide 18 comprises a region of reduced thickness delineating the integral air bag door 12 in the panel fastening instrument 14. The tear guide 18 conducts tearing and / or breakage during deployment of the airbag. Additionally, a generally tubular channel 214, sometimes referred to as a gas structural channel, is positioned in the air bag door 12 along the tear guide 18. The tubular channel 214 comprises a tube 216 which generally has a section in circular cross section. The tube 216 is partially defined by an elongated arched wall 218 extending integrally from an inner surface 220 of the air bag door 12. The arched wall 218 and the air bag door 12 and the instrument panel 14 are placed together as a single piece by means of gas assisted injection molding as described in greater detail below. The gas channel 214 provides the reinforcement and structure that creates a substantial force differential with the door seam 20. In other embodiments, the channel 214 can be filled at least partially with a lower density core instead of being hollow. In other embodiments, the tubular channel 214 may have a tubular cross-section that is not circular and that may be extended integrally from the instrument panel 14 instead of the air bag door 12. In either case, the tubular channel 214 is positioned opposite a class A outer surface 222 of the airbag door 12 and the instrument panel 14. In this position the gas channel 214 is hidden from the view of the occupants of the vehicle and helps to hide the presence of the vehicle. supplementary restraint or restraint system. As shown in Figure 5, the channel 214 extends around a rear edge 224 and the side edges 226, 228 of the "air bag" door 213. While a single "C" shaped door is shown in FIG. Figure 5, the same approach can be used for double doors in the form of "H", doors in the shape of "X", etc. As shown in figures 3 and 6, the second embodiment 310 of the invention includes two channels tubular channels 312, 314. The tubular channels 312, 314 are positioned adjacent and parallel to each other Channels 312, 314 run over and define an elongated space or space 316 defining an integral air bag door 318 in a detent instrument panel 320. Seam 316 also serves as a tear guide between the two tubular channels 312, 314. As shown in Figure 3, a cover 40 may be supported on the inner finish panel retainer 320 and the foam layer 42 may be positioned between the inner finish panel retainer 320 and the foam layer 40. As shown in Figure 4, the third embodiment 410 of the invention includes two tubular channels 412, 414. The tubular channels 412, 414 are positioned adjacent and parallel to one another. Channels 412, 414 run along either side of them and define an elongated seam or space 416 defining an integral air bag door 418 in an instrument panel retainer 420. Seam 416 also serves as a tear guide between the two tubular channels 412, 414. Unlike the third embodiment 310, the fourth embodiment 410 also includes an elongated groove, shown as 422 in Figures 4 and 7, placed on the outer surface of class A 426 opposite the elongated space 416. The elongated groove 422 further reduces the thickness of the plastic material where it is not of interest to hide the inflatable restraint or restraint system 410. As shown in Figure 8, the fourth embodiment 510 of the invention includes two tubular gas channels 512, 514 placed along either side of an embedded hinge panel 524. Similar to the third embodiment 410, the fourth embodiment 510 includes an elongated groove 522 positioned on the outer surface of case A 526. In the fourth embodiment 510 the reduction in thickness provided by the groove 522 reduces the resistance to bending of the hinge 522. The tubular channels 512, 514 help reduce the possibility of failure in the hinge by adding structural rigidity on either side of the hinge panel to ensure that the bending takes place on the hinge panel 524. In practice, the hinge 22 of the inflatable restraint or restraint assembly can be manufactured by first providing a mold configured to form the figure of the bag door. integral air 12 and the instrument panel 14. Then a layer 18 of the second material is placed in the mold in a position crossing a mold region configured to form the door seam 20. The first material 16 is then introduced in melted form inside of the mold so that the layer 18 of the second material is at least partially embedded in the first material 16. Then the first material 16 is left or cure inside the mold. Finally, the first cured material 16 and the at least partially inlaid layer 18 of the second material are removed from the mold. The tear seam 18, 316, 416-422 of the inflatable restraining or restraining assembly can be manufactured in accordance with the present invention primarily by providing a mold configured to form the figure of the integral air bag door 12, 318, 418 and the instrument panel 14, 320, 420 and the tubular channel 214 or the tubular channels 312, 314, 412, 414. The resin is then injected into the mold. The gas is then injected into a portion of the resin placed in a portion of the mold configured to form the tubular channel 214 or the tubular channels 312, 314, 412, 414. While the gas is injected, the tube (s) is formed ( s) of gas channel 216 and helps to expel resin within the narrow regions of the mold along the tear seam 18, 316, 416-422. Then the resin is allowed to cure inside the mold before being removed. The use of gas channels to form tear seams has the advantage of providing relatively latear guide structures without using laamounts of material to create regions of thickness that could result in crevice formation. If laamounts of material were used to thicken the panel on either side of the desired tear seam, shrinkage could occur during curing at the discontinued surface in the form of depressions or slits. The description and drawings are illustratively directed to the embodiments of the invention that are currently preferred. We try that the description and the drawings describe these modalities instead of limiting the scope of the invention. Obviously, it is possible to modify these modalities as long as they remain within the scope of the following claims. Therefore, within the scope of the claims, the invention may be practiced in a manner other than that of the description and drawings that has been specifically shown and described.

Claims (19)

1. An inflatable restraint or restraint assembly for automotive vehicle passengers, the assembly comprises: an airbag door integrally formed in an automotive interior trim panel of a first material, the airbag door is defined at least in part by a tear guide in a closed position; the air bag door moves from the closed position to provide a guide for an air bag to inflate through it, the air bag door being moved from the closed position to at least partially separate from the finishing panel inside along the door seam defined at least partially by the tear guide; a retainer structure configured to prevent at least a portion of the airbag door from being moved away from the immediate vicinity of the interior trim panel during deployment of the airbag; a hinge comprising a second material embedded at least partially within the first material and crossing the door seam.

An inflatable restraint or restraint assembly as defined in claim 1, wherein the first material forms an outer surface of class A of the interior trim panel and the hinge is at least substantially invisible on the outer surface of class A of the interior trim panel.

An inflatable restraining or restraining assembly as defined in claim 1 wherein the hinge includes: a first end embedded in a portion of the first material forming the door; a second end embedded in a portion of the first material forming the interior finishing panel; and a middle portion positioned between the first and the second end, the middle portion has an outer surface covered with a portion of the first material that forms the exterior surface of class A of the door and the interior trim panel, the middle portion has a Exposed interior surface positioned opposite to the exterior surface.

An inflatable restraint or restraint assembly as defined in claim 1 in which the second material includes any one or more materials from a group of materials including thermoplastic rubber, matte glass, fabric or meta.

A fastening or restraining assembly as defined in claim 1 further including a cover placed on the interior trim panel.

6. An inflatable restraint or restraint system as defined in claim 5 which further includes a foam layer between the interior trim panel and the cover.

An inflatable restraint or restraint assembly as defined in claim 1 in which the interior trim panel includes a tubular channel positioned along one side of the hinge.

An inflatable restraint or restraint assembly as defined in claim 7 in which the interior trim panel includes a second tubular channel positioned generally parallel to the first tubular channel and along one side of the hinge opposite the first tubular channel .

An inflatable restraint or restraint assembly as defined in claim 7 in which the interior trim panel includes an elongate groove positioned adjacent and generally parallel to the hinge panel.

10. An inflatable restraint or restraint assembly for automotive vehicle passengers, the assembly comprising: an air bag door integrally formed in an automotive interior trim panel of a plastic material, the integral air bag door defined at least in part by a tear guide in a closed position; the airbag door moves from the closed position to provide a path for an airbag to deploy through it, the airbag moves away from the closed position to at least partially separate the interior trim panel to along a door seam at least partially defined by the tear guide; the tear guide comprises a region of reduced force leading to tearing during deployment of the air bag; and a first generally tubular channel positioned along the tear guide to create a substantial force differential with the door seam.

11. An inflatable restraining or restraining assembly as defined in claim 10 wherein the first generally tubular channel includes an elongate, arcuate outer wall.

12. An inflatable restraint or restraint assembly as defined in claim 10 wherein the tear guide comprises a region of reduced thickness.

An inflatable restraint or restraint assembly as defined in claim 10 in which the first tubular channel is positioned opposite a class A exterior surface of the air bag door and the interior trim panel.

14. An inflatable restraint or restraint assembly as defined in claim 10 further including a second generally tubular channel positioned adjacent and parallel to the first tubular channel, the tear guide being positioned between the first and the second tubular channel.

15. An inflatable restraint or restraint assembly as defined in claim 14 which further includes a second generally tubular channel positioned adjacent and parallel to the first tubular channel, the tear guide being defined by an elongated opening placed between the first and second tubular channel.

16. An inflatable restraining or restraining assembly as defined in claim 15 further including an elongate groove positioned between the outer surface of class A opposite the elongated opening.

17. A method for manufacturing an inflatable restraint or restraint assembly for passengers in automotive vehicles, the assembly comprising an air bag door integrally formed in an automotive interior trim panel of a first material, the integral air bag door is defined at least in part by a tear guide in a closed position, the air bag door moves from the closed position to provide a path for an air bag to deploy through it, the air bag door it moves away from the closed position to at least partially separate from the interior finishing panel a door seam at least partially defined by the tear guide, a retainer structure configured to prevent at least a portion of the air bag door from being apart from the immediate proximity of the finishing panel during deployment of the air bag, and a hinge comprises a second material i embedded at least partially within the first material and crossing the door seam; the method includes the steps of: providing a mold configured to form the figure of the integral air bag door and the interior trim panel; inserting the second material into the mold in a position crossing a mold region configured to form the door seam; introducing the first material in melted form into the mold in such a way that the second material is at least partially embedded in the first material; let the first material solidify inside the mold; and removing the first solidified material and the second material at least partially embedded from the mold.

18. A method for manufacturing an inflatable restraint or restraint assembly for passengers in automotive vehicles, the assembly comprising an air bag door integrally formed in an automotive interior trim panel of a plastic material, the integral air bag door defined at least in part by a tear guide, the air bag door moves from the closed position to provide a path for an air bag to deploy through it, the air bag door moves away from the closed position for separating from the interior finish panel at least partially along a door seam defined at least partially by the tear guide, the tear guide comprises a region of reduced force guiding the tear during deployment of the bag of air, and a tubular channel placed along the tear guide; the method includes the steps of: providing a mold configured to form the figure of the integral air bag door and the interior trim panel and the tubular channel; provide material inside the mold; injecting gas into a portion of material placed in a portion of the mold configured to form the tubular channel; let the material solidify inside the mold; and removing the solidified material from the mold. A method as recited in claim 18 wherein the step of providing a mold includes the step of providing a mold configured to form the figure of an air bag door including a door seam at least partially defined by. a tear guide comprising a region of reduced thickness.