Single-level cylindrical passenger inflator

Abstract

To provide a cylindrical inflator assembly for passengers in vehicles that has repeatable usability and compliant deformability and meets all industry standards.SOLUTION: An airbag inflator assembly includes a cylindrical housing, an initiator assembly secured to an upstream end of the cylindrical housing, and a generant disposed in the cylindrical housing adjacent to the initiator assembly. Internal components define a tortuous path for products of combustion and define a plurality of debris collection areas. A rupture disk assembly is secured over an exit aperture, and a diffuser region downstream of the rupture disk assembly includes an output opening through which the products of combustion are vented into the airbag.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 549,813, filed on February 5, 2024, the entire content of which is incorporated herein by reference.

[0002] Statement Regarding Federally Sponsored Research or Development Not applicable.

[0003] The present invention relates to an inflator assembly for an airbag or other safety device, and more particularly to an inflator assembly having a cylindrical housing for vehicle passengers that has reusability, is capable of conforming deformations, and meets all industry standards.

Background Art

[0004] Conventional airbag inflator assemblies come in various shapes, and the most recent versions are toroidal in shape. In newly designed vehicles, especially electric vehicles (EVs), due to the limited space for the airbag assembly, there is a need for an inflator assembly with a cylindrical housing having a small outer diameter.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inflator assembly of the described embodiments is developed to meet all structural and safety requirements and to optimize the performance output range. The goal is to manufacture a cylindrical inflator assembly for vehicle passengers that has reusability, is capable of conforming deformations, and meets all industry standards.

[0006] This design achieves a performance output, assembly weight, and envelope profile (overall length and outer diameter) suitable for application to EV technology. These optimizations provide a competitive advantage over conventional passenger designs.

[0007] The assembly of the described embodiment uses a meandering path ignition system to meet the performance targets of the inflator assembly while reducing the particle levels emitted from the inflator assembly. [Means for solving the problem]

[0008] In exemplary embodiments, the airbag inflator assembly includes a cylindrical housing, an initiator assembly fixed to the upstream end of the cylindrical housing, a generator positioned adjacent to the initiator assembly within the cylindrical housing, and an internal nozzle for the flow of combustion products. In some embodiments, the internal nozzle engages with the inner wall of the cylindrical housing. A debris canister is positioned downstream of the internal nozzle within the cylindrical housing. The internal nozzle is configured to guide combustion products into the debris canister. The debris canister includes a radial orifice adjacent to its upstream end. The outer diameter of the debris canister is spaced apart from the inner wall of the cylindrical housing to define an annular passage. A screen canister positioned above the debris canister includes a plurality of openings. A molded end plate fixed above the screen canister includes an outlet opening. A rupture disc assembly is fixed above the outlet opening of the molded end plate, and a diffuser region downstream of the rupture disc assembly includes an outlet opening for discharging combustion products into the airbag.

[0009] Airbag inflator assembly The device may also include a spring fixed between the internal nozzle and the generating agent. The spring may be a coil spring with a closed upper spring.

[0010] Airbag inflator assembly This may include a plurality of debris collection areas, including the downstream end of the debris canister, the upstream end of the debris canister, the interface between the cylindrical housing and the molded end plate, the interface between the screen canister and the debris canister, and the downstream end of the screen canister.

[0011] The screen canister may be press-fitted and engaged with the casing of the debris canister. The openings of the screen canister may define an alternating or offset hole pattern. The rupture disc assembly may include a rupture disc configured to rupture upon combustion products generated after the activation of the initiator assembly. The diffuser area may include a diffuser screen and an outlet for discharging combustion products into the airbag. The cylindrical housing may have an outer diameter of 35 mm or less.

[0012] In another exemplary embodiment, the airbag inflator assembly includes a cylindrical housing, an initiator assembly fixed to the upstream end of the cylindrical housing, a generator positioned within the cylindrical housing adjacent to the initiator assembly, and internal components that define a meandering path for combustion products and define a plurality of debris collection areas. The internal components include an outlet opening. A rupture disc assembly is fixed above the outlet opening, and a diffuser region downstream of the rupture disc assembly includes an outlet opening for discharging combustion products into the airbag.

[0013] The meandering path may include at least four turns between the generating agent and the outlet opening. In some embodiments, the meandering path includes six turns between the generating agent and the outlet opening.

[0014] Airbag inflator assembly The internal components may additionally include at least two debris collection areas. In some embodiments, the airbag inflator assembly It may include five fragment collection areas among its internal components. [Brief explanation of the drawing]

[0015] These and other embodiments and advantages will be described in detail with reference to the attached drawings.

[0016] [Figure 1]Figure 1 showing an exemplary single-stage airbag inflator assembly. [Figure 2] Figure 2 showing an exemplary single-stage airbag inflator assembly. [Figure 3] Showing a molded end plate fixed to the exhaust end of the pressure vessel. [Figure 4] Showing an exemplary screen canister. [Figure 5] Showing an exemplary external diffuser. [Figure 6] An enlarged view of the exhaust end of the pressure vessel showing the debris collection region. [Figure 7] An enlarged view of the exhaust end of the pressure vessel showing the serpentine path of the combustion products. [Figure 8] Showing a first modification of the internal components. [Figure 9] Showing a second modification of the internal components. [Figure 10] Showing a third modification of the internal components. [Figure 11] Showing a fourth modification of the internal components. [Figure 12] Showing an exemplary alternative booster propellant retention option with a booster tube design. [Figure 13] Showing a modification with an altered initiator assembly and an exemplary alternative booster propellant retention option including a canister and lid for housing the booster assembly.

Best Mode for Carrying Out the Invention

[0017] Figures 1 and 2 show an exemplary single-stage airbag inflator assembly 10 and its internal components. The inflator assembly includes a cylindrical housing 12 and an initiator assembly 14 fixed to the upstream end of the cylindrical housing 12. In a preferred structure, the outer diameter of the cylindrical housing 12 is 35 mm or less. The external attachment functional part 13 can be applied for module retention.

[0018] The initiator assembly 14 includes a cover disc 16, which is press-fitted into the inner surface of the cylindrical housing 12 and engages with it, securing the initiator assembly 14 in place together with the igniter body 18. Since the structure, function, and operation of the initiator assembly 14 are publicly known, a detailed description is omitted. Any suitable initiator assembly 14 may be used in the airbag inflator assembly 10 of the described embodiment.

[0019] The booster pouch 20 is positioned adjacent to the cover disc 16, and the generator 22 is positioned within the cylindrical housing 12 adjacent to the initiator assembly 14 and the booster pouch 20.

[0020] The internal nozzle 24 guides the combustion products into the debris accumulator (DA) canister 26 located downstream of the internal nozzle 24. As shown, the internal nozzle 24 engages with the inner wall of the cylindrical housing 12. The internal nozzle 24 may be integrated with the DA canister 26. The DA canister 26 includes a radial orifice 28 adjacent to its upstream end. Continuing to refer to Figure 1, the outer diameter of the DA canister 26 defines an annular passage 30 spaced apart from the inner wall of the cylindrical housing 12.

[0021] The coil spring 34 is fixed between the internal nozzle 24 and the generating agent 22, and the generating agent 22 may be fixed inside the propellant chamber. The coil spring 34 may also be a closed upper spring that serves to provide a surface that blocks larger particles during deployment.

[0022] The screen canister 36 is positioned on top of the DA canister 26 and may be spaced apart from the inner wall of the cylindrical housing 12. The screen canister 36 is secured by interference fitting with the DA canister 26. The screen canister 36 includes a plurality of openings 38. In some embodiments, the openings 38 define an alternating or offset hole pattern.

[0023] The molded end plate 40 is friction-welded to the exhaust end of the pressure vessel / cylindrical housing 12. Figure 3 shows a perspective view of the molded end plate 40. The molded end plate 40 serves as the interface for the screen canister 36. The rupture disc holder assembly 42 secures the rupture disc 44 to the opening in the molded end plate 40. The rupture disc 44 may have a flat, smooth surface portion, or an alternative design with a cross-shaped / hatch feature on the surface. For example, the rupture disc may be a cross-shaped disc where this portion opens like a "petal." This design reduces the likelihood of disc fragments being ejected into the airbag. The rupture disc holder assembly is modified to accommodate the larger diameter of the modified rupture disc.

[0024] Therefore, the molded end plate 40 also provides a mounting surface for the rupture disc holder assembly 42.

[0025] The molded end plate 40 and screen canister 36 provide a "hard stop" for the internal components to be stacked. For ball filling operations, the outer surface provides a robust surface for gas filling operations utilizing the weld of the rupture disc holder assembly. The disc holder / rupture disc weld provides a surface for welding a single rupture disc assembly, which serves as an exhaust port for performance output.

[0026] The diffuser screen 46, which includes multiple screen openings 48, is fixed onto a molded end plate 40 and a rupture disc holder assembly 42. Thus, the molded end plate 40 also functions as the mounting interface for the diffuser screen 46. Figure 4 shows an exemplary perspective view of the diffuser screen 46.

[0027] The diffuser 50 is fixed on the diffuser screen 46 and secured to the end of the cylindrical housing 12 by welding or other means. The diffuser 50 includes an outlet opening of appropriate size and shape. Combustion products flow into the airbag through the outlet opening. Figure 5 shows a perspective view of an exemplary diffuser 50. The exemplary diffuser 50 includes one large elliptical opening 52 and two smaller elliptical openings 54. Other configurations may be suitable for specific applications.

[0028] The initiator assembly 14 activates the ignition train by deploying directly into the propellant booster 22. The booster propellant then ignites the propellant chamber, and the internal pressure begins to increase due to the internal combustion of the propellant and storage gas mixture in the pressure vessel.

[0029] As the generating agent burns and mixes with the storage gas, the combustion products pass through a series of media and channels that serve as collection areas for larger particles generated in the combustion process. As previously mentioned, the inclusion of a closed upper portion in the spring 34 not only allows the spring to load the propellant bed but also provides a surface to block larger particles.

[0030] Referring to Figure 6, the combustion products flow through the internal nozzle 24, which directs the flow into the debris canister 26, where the particles are collected in region #1. The flow is redirected by the debris canister 26 along its sidewall toward the radial orifice 28. A second particle collection area, labeled region #2, is located at the corner of the debris canister 26 as the flow makes its second turn away from the radial orifice 28. The flow is then directed toward the top of the debris canister 26 (right side in Figure 6), where another collection area, labeled region #3, is located at the internal friction weld / flush area between the cylindrical housing 12 and the diffuser 50. As the flow continues through the opening 38 into the screen canister 36, debris is also collected at the crimp / interference fitting area (region #4) between the debris canister 26 and the screen canister 36. The debris further accumulates in the compression interference area (region #5) between the screen canister 36 and the molded end plate 40. The flow enters the screen canister 36 through the opening 38, passes through the molded end plate 40, and enters the diffuser region through the rupture disc holder assembly 42. The flow exits the diffuser port through the diffuser screen 46 and the outlet opening of the diffuser 50. Additional particles and larger debris are captured by the diffuser screen 46 before the discharge is released into the airbag.

[0031] The inflator assembly 10 uses a single pressure vessel that holds all internal components and is welded at both ends to seal the gas stored in the housing / pressure vessel 12. The structural welding of the pressure vessel provides a joint surface for structural welding (optional laser welding or friction welding) to create the overall inflator housing. In some embodiments, a low-strength pressure vessel can be used for low-power designs, and a high-strength pressure vessel can be used for high-power designs.

[0032] The initiator assembly 14 uses an igniter housing to hold the initiator used to initiate the deployment process. The igniter housing has design layout and welding operation options. For example, the assembly may be laser welded or friction welded to suit the required structural requirements. Exemplary designs include friction welded designs, laser welded designs, all-metal housings (which can be laser welded or friction welded), or molded connector interface housings (which can be laser welded or friction welded).

[0033] Figure 7 shows the meandering path of the combustion flow after the activation of the initiator assembly 14. Energy from the initiator assembly 14 ignites the booster generator 22, initiating combustion in the chamber and causing it to flow through the spring 34. The internal nozzle 24 guides the combustion products into the debris accumulator canister 26. When the flow contacts the closed upper or recess of the DA canister 26, it makes a 180-degree turn toward the radial orifice 28 of the DA canister 26 (Turn #1). The flow makes a 90-degree turn through the radial orifice 28 (Turn #2), then makes another 90-degree turn outside the DA canister 26 and enters the annular passage 30 between the outer diameter of the DA canister 26 and the inner wall of the cylindrical housing 12 (Turn #3). The flow contacts the friction welding area and makes a 90-degree turn through the opening 38 of the screen canister 36 (Turn #4). Next, the flow makes a 90-degree turn toward the exit orifice of the screen canister 36 (turn #5), passes through the molded end plate 40, and through the rupture disc holder assembly 42. The flow makes a 90-degree turn through the diffuser screen 46 (turn #6) and is then discharged into the airbag.

[0034] Additional or alternative components, such as molded cups with filter tops, may be used to secure the generating agent within the propellant bed. Figures 8–11 show examples. Figure 8 shows a basic design with a coil spring 34 and a screen. Figure 9 shows a dual-cup design with a cup 37 for securing the generating agent 22. Figure 10 shows a debris accumulator with a spring design, and Figure 11 shows a design with a filter, diverter, and spring.

[0035] Booster propellant retention options may be implemented to achieve desired performance output while also meeting safety, structural, and industry requirements. Figure 1 shows a basic assembly with a cover disc 16 and a booster pouch 20. In one alternative, the booster housing may be implemented without the booster pouch. Figure 12 shows another alternative initiator assembly 14' including a booster tube 56. Figure 13 shows a modified version with a modified initiator assembly 114 and a booster pouch 20. The initiator assembly 114 may include an igniter body in the form of an all-metal part, or in the form of half metal and half molded part, as shown. The booster pouch may be replaced with a booster assembly 120 to protect a propellant bag (tea bag material). As shown, the booster assembly 120 may include a canister 122 with a lid to prevent tearing / ripping of the booster pouch 20.

[0036] The inflator assembly of the described embodiment uses a single combustion chamber comprising an initiator assembly, booster propellant, internal components crimped to a hard stop, and loosely filled generating particles that create a release system. Structural welding ensures the robustness required for safety and airtightness requirements. An external rupture disc assembly provides an airtight seal, and the flow is dispersed outside the external diffuser / spring components of the main inflator body.

[0037] While the present invention has been described in relation to the currently most practical and preferred embodiments, it should be understood that the present invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent configurations included in the spirit and scope of the appended claims. [Explanation of Symbols]

[0038] 10 Airbag Inflator Assembly 114 Initiator Assembly 12 Cylindrical Housings / Pressure Vessels 120 Booster Assembly 122 Canisters with Lids 13 External mounting function section 14. Initiator Assembly 14' Alternative Initiator Assembly 16 Cover Discs 18 Igniter body 20 Booster Pouches 22 Genetic Agent 24 Internal Nozzles 26. Debris Accumulator (DA) Canister 28. Radial orifice 30 Circular Passage 34 Coil Springs 36 Screen Canister 37 cup 38 Aperture 40 Molded end plate 42 Rupture Disc Holder Assembly 44 Rapture Discs 46 Diffuser Screen 48 screen aperture 50 diffusers 52, 54 Openings 56 Booster Tubes

Claims

1. Cylindrical housing and An initiator assembly fixed to the upstream end of the cylindrical housing, A generating agent is disposed within the cylindrical housing adjacent to the initiator assembly, An internal nozzle for the flow of combustion products engages with the inner wall of the cylindrical housing, A debris canister is disposed downstream of the internal nozzle within the cylindrical housing, wherein the internal nozzle is configured to guide combustion products into the debris canister, the debris canister includes a radial orifice adjacent to its upstream end, the outer diameter of the debris canister defines an annular passage spaced apart from the inner wall of the cylindrical housing, and the internal nozzle and the debris canister define a debris collection area adjacent to the radial orifice of the debris canister. A screen canister having multiple openings and positioned on top of the debris canister, A molded end plate, fixed on top of the screen canister and including an outlet opening, A rupture disc assembly fixed above the exit opening of the molded end plate, An airbag inflator assembly, comprising a diffuser region located downstream of the rupture disk assembly, which includes a discharge opening for discharging the combustion products into the airbag.

2. The airbag inflator assembly according to claim 1, further comprising a spring fixed between the internal nozzle and the generating agent.

3. The airbag inflator assembly according to claim 2, wherein the spring is a coil spring including a closed upper spring.

4. The airbag inflator assembly according to claim 1, comprising a plurality of debris collection areas including the downstream end of the debris canister, the upstream end of the debris canister, the interface between the cylindrical housing and the molded end plate, the interface between the screen canister and the debris canister, and the downstream end of the screen canister.

5. The airbag inflator assembly according to claim 1, wherein the screen canister is press-fitted into and engages with the outer casing of the debris canister.

6. The airbag inflator assembly according to claim 1, wherein the openings of the screen canister define an alternating or offset hole pattern.

7. The airbag inflator assembly according to claim 1, wherein the rupture disc assembly includes a rupture disc configured to rupture upon combustion products generated after the activation of the initiator assembly.

8. The airbag inflator assembly according to claim 1, wherein the diffuser region includes a diffuser screen and a discharge opening for discharging the combustion products into the airbag.

9. The airbag inflator assembly according to claim 1, wherein the cylindrical housing has an outer diameter of 35 mm or less.

10. Cylindrical housing and An initiator assembly fixed to the upstream end of the cylindrical housing, A generating agent is disposed within the cylindrical housing adjacent to the initiator assembly, The internal components define a meandering path for combustion products, define multiple debris collection areas, and include an internal nozzle through which the combustion products flow, a debris canister located downstream of the internal nozzle within the cylindrical housing, and an outlet opening, wherein the internal nozzle is configured to guide the combustion products into the debris canister, and the debris canister includes a radial orifice adjacent to its upstream end, defining a turn point for the combustion products at the upstream end, A rupture disk assembly fixed above the aforementioned exit opening, An airbag inflator assembly, comprising a diffuser region located downstream of the rupture disk assembly, which includes a discharge opening for discharging the combustion products into the airbag.

11. The airbag inflator assembly according to claim 10, wherein the meandering path includes at least four turns between the generating agent and the outlet opening.

12. The airbag inflator assembly according to claim 11, wherein the meandering path includes at least six turns between the generating agent and the outlet opening.

13. The airbag inflator assembly according to claim 10, further comprising at least two debris collection areas among the internal components.

14. The airbag inflator assembly according to claim 13, further comprising five debris collection areas among the internal components.

15. The airbag inflator assembly according to claim 10, wherein the cylindrical housing has an outer diameter of 35 mm or less.

16. The aforementioned internal components further A screen canister, which includes multiple openings, is placed on top of the debris canister, It includes a molded end plate fixed on top of the screen canister and having an outlet opening, The airbag inflator assembly according to claim 10, wherein the rupture disc assembly is fixed above the exit opening of the molded end plate.

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