JP3049693U - Apparatus for inflating vehicle occupant restraint and hybrid inflator for airbag - Google Patents

Abstract

(57) Abstract: In a hybrid inflator for an airbag, harmful particles are effectively removed from gas released from the inflator. An apparatus for generating inflation gas for inflating an occupant restraint system of a vehicle includes a storage chamber, and the storage chamber includes a filter. The filter 98 diverts the gas and removes particles from at least a portion of the hot gas released from the first chamber 34 containing the gas generating material. This forms a hot gas with a significantly reduced particle content. The device 10 comprises at least one control orifice 32 and at least one outlet port 94
And a diffuser having: The inflation gas is released through the diffuser into the occupant restraint. The hot gas turns a total of at least about 180 degrees from contact with the filter 98 to entering the diffuser as the inflation gas.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an inflatable restraint device, and more particularly to an inflator device used in such a restraint device and to gas treatment prior to discharge from the inflator.

[0002]

[Prior art]

 Many inflators have been proposed to inflate an airbag for an inflatable restraint system. One prior art selectively releases a large amount of stored compressed gas, thereby inflating the airbag. Another prior art uses a combustible material as a gas source, which is ignited to generate a large amount of gas and inflate an airbag. Yet another prior art technique inflates airbags with a combination of stored compressed gas and combustible combustion gases. This scheme is commonly referred to as an augmented gas inflator or a hybrid inflator.

[0003] Conventional hybrid inflators have several disadvantages. For example, glass-to-metal bonding and other complex bonding methods are required to maintain sealing pressure. Alternatively, it requires mechanical or ignited actuation means to open the flow path to the airbag. Many hybrid inflators emit cold inflation gas first and then hot gas. This is disadvantageous for an airbag type driver restraint. Hybrid expansion devices generally use a diffuser, which is often located at the end. This arrangement makes it difficult to incorporate the inflator into the module.

[0004] Hybrid expansion devices and other types of expansion devices that involve the burning of gas generating materials produce undesirable particles when the gas generating igniting and igniting materials burn. Various methods have been proposed to address the release of inflated gas containing such particles.

[0005] One method is to inflate the airbag by releasing the inflation gas containing the particles as it is. As a result, particulate material may be discharged from the airbag into the vehicle. Particles vary in size and contain large amounts of particles that humans can inhale. Such particles make human breathing uncomfortable. These particles also diffuse into the air and look like smoke. The result is a false impression of a fire inside or around the vehicle.

Another method filters the gas exiting the ignition section of the hybrid inflator. For example, U.S. Pat. No. 5,131,680 places a circular screen 128 between the ignition material and the orifice. Gas generated by the ignition passes through the orifice into the pressure gas chamber of the hybrid expansion device. U.S. Pat. No. 5,016,914 also uses a metal disk having a plurality of appropriately sized openings. This disk has a function of capturing large particles contained in the generated gas.

[0007] The technique of filtering out the gas emitted from the ignition portion of the hybrid inflator and contacting it with the pressure gas stored in the inflator slows the transfer of the generated hot gas and particle heat to the stored gas. Or hinder. Generally, in a hybrid expansion device, it is preferable that heat be transferred to the stored gas in order to promote gas expansion. Thus, delayed or impeded heat transfer reduces the capacity of the expansion device. Filtering the particles at the gas outlet of the ignition chamber also adversely affects the gas flow in the expansion device. For example, the flow of gas from the ignition chamber is restricted, which can increase the pressure in the ignition chamber and damage the ignition chamber.

[0008] US Pat. No. 5,016,914 directs the flow of gas into a tortuous path and is created by the combustion of gas generating material as the gas flows toward an inflatable vehicle occupant restraint. Larger particles are separated from the mixed gas. This disclosure combines the various components of the vehicle occupant restraint to form the tortuous path. One of these components is an opening in the container that guides the gas to the outer cylindrical diffuser. The container includes gas guide vanes and a discharge disk. These control the gas flow generated by the combustion of the gas generating material. In a preferred embodiment of this disclosure, a paint (coating material) such as silicone grease is applied to the interior surface of the container to prevent particles from melting into the paint and returning to the jet of nitrogen gas.

[0009] However, such surface coatings are inferior in some important respects, such as effects and functions, from the viewpoint of particle removal, for example, compared to the use of filters. First, the nature of the particles' melting and adhesion with the paint is a surface phenomenon, and the particle removal effect is directly related to the available surface area. In practice, surface coatings provide a relatively limited contact area. Also, the effectiveness of the surface treatment decreases as the available surface area is occupied.

[0010] Although the interior coating is somewhat effective at melting solid particles, it is not very effective at trapping liquid phase particles. The process of coagulation of liquid phase particles in an expansion device generally involves the transfer of heat to the target contact surface. In the case of surfaces coated with the grease, such heat transfer promotes gasification of the paint and generates by-product gases from the paint. This by-product gas makes the gas emitted from the expansion device toxic.

[0011] Furthermore, in the case of an inflator using paint, there is a concern that the paint may affect the gas flow in the inflator. For example, when high-temperature combustion gas generated in the expansion device collides with the paint, the paint is often peeled off. At high temperatures, this tendency is particularly pronounced because the paint softens.

[0012] There is a need for a device and technique for safely, simply, effectively and economically removing particles from the inflation device outgass. Removal of such particulate material can prevent or reduce discomfort experienced by occupants of the vehicle when using the inflation device. In addition, vehicle occupants can view the particulate material released into the vehicle and suspended in the air, and can be prevented from misunderstanding that a fire has occurred in the vehicle and needlessly causing a panic.

[0013]

[Problems to be solved by the invention]

 The basic purpose of the present invention is to improve an inflation device for inflating a vehicle occupant restraint. A more specific object of the present invention is to solve the problems of the prior art. It is an object of the present invention to provide a hybrid inflator that does not require a complicated seal such as a joint between glass and metal to maintain a high-pressure seal.

Another object of the present invention is to provide a hybrid inflator that does not require mechanical or ignited actuation means to open the flow path of inflation gas to the airbag. Yet another object of the present invention is to provide an airbag inflation device that releases all of the hot gas into the airbag. Yet another object of the present invention is to provide a diffuser located in the center of the hybrid inflator. The diffuser of the hybrid inflator is generally located at the end of the inflator. In comparison, the centrally located diffuser is easier to integrate into the module.

[0015]

[Means for Solving the Problems]

To achieve the above and other objects, a hybrid inflator according to the present invention has an elongated gas storage or second chamber that is generally cylindrical. This storage room stores high-pressure inert gas. The inert gas is, for example, argon or nitrogen gas at a pressure of 2000 to 4000 psi (140 to 280 kg / cm ² ). The expansion device further includes an ignition heater. The ignition heater has a combustion chamber or first chamber that burns a particulate mixture of potassium boron nitrate (BKNO ₃ ) and other suitable ignition materials to heat the stored gas. A diffuser will be installed in the storage room. A thin metal diaphragm (hereinafter, referred to as a second diaphragm) is provided between the diffuser for the expansion device and the storage chamber, and pressure sealing is performed. The diffuser has a plurality of gas orifices or outlet ports, thereby uniformly discharging gas into the airbag assembly. The gas storage chamber is sealed from the combustion chamber of the ignition heater by a thin metal diaphragm (hereinafter, referred to as a first diaphragm). The periphery of the first diaphragm is welded to the end of the ignition heater container. Also, the first diaphragm is supported by a solid metal plug or solid plug means. The solid metal plug rests on an adjacent shoulder that covers the nozzle orifice or gas outlet nozzle of the combustion chamber, thereby supporting the entire surface of the first diaphragm. As a result, the first diaphragm can withstand the load of the high-pressure gas stored in the storage chamber.

The gas generating operation will be described. Upon receiving the control signal, the ignition device in the ignition heater ignites the ignition agent (BKNO ₃ ). When the pressure in the combustion chamber rises and exceeds the high pressure of the inert gas in the storage chamber, the solid metal plug comes off. As a result, the thin, unsupported first diaphragm ruptures, and the hot gases and particles from the burned igniter heat the stored gas, causing the pressure in the storage chamber to rise sharply. When the pressure in the storage chamber exceeds the structural strength of the thin second diaphragm in the diffuser, the second diaphragm ruptures. As a result, the heated gas is released into the air bag assembly through the gas orifice of the diffuser. There is at least one throttle or control orifice between the second diaphragm and the storage chamber to throttle the flow of gas from the storage chamber and to provide a suitable rate of filling the airbag assembly.

[0017] One embodiment of the present invention provides an apparatus for inflating a vehicle occupant restraint. The apparatus includes a container having a first chamber for storing gas generating material and a second chamber for diverting gas. The gas generating material generates a hot gas when ignited. This gas contains particles of the gas generating material and its by-products. The hot gas is released from the first chamber into the second chamber through at least one gas outlet nozzle.

[0018] The second chamber accommodates a filter arranged along an inner wall opposite to the gas outlet nozzle. The filter diverts the gas and removes particles from at least a portion of the impinging hot gas emitted from the first chamber. The hot gas, which has significantly reduced particulates, forms an inflation gas to inflate the vehicle occupant restraint system. The device further has a diffuser. The diffuser has at least one control orifice. The control orifice passes at least a portion of the inflation gas within the vessel. The diffuser has at least one outlet port. At least a portion of the inflation gas that has passed through the control orifice is discharged into the vehicle occupant restraint system through the outlet port.

In such a device, the inflation gas undergoes a total of at least about a 180 degree turn after first contacting the filter and before entering the diffuser. Another basic object of the present invention is to provide a hybrid inflator with improved gas handling.

[0020] At least a part of this object can be achieved in an expansion device of a vehicle occupant restraint device according to the present invention. The device has an elongated cylindrical container. The container has a first chamber for storing gas generating material and a second chamber for storing high-pressure gas and for changing the direction of the gas. The gas generating material generates a high temperature gas when ignited. The hot gas contains particles of the gas generating material and its by-products. The hot gas may be discharged from the first chamber into the second chamber through at least one gas outlet nozzle.

The second chamber accommodates a filter arranged along an inner wall opposite to the gas outlet nozzle. The filter redirects gas and removes particles. The removal of the particles is realized by condensing at least some of the particles of the high-temperature gas discharged from the first chamber or by collision of the particles. As a result, the hot gas has a very low particle content. At least a portion of the hot gas mixes with the gas stored in the second chamber to form an inflation gas for inflating the vehicle occupant restraint.

[0022] The device further comprises a diffuser. The diffuser has at least one control orifice. The control orifice passes at least a portion of the inflation gas from the vessel. The diffuser has at least one outlet port. At least a portion of the inflation gas entering the diffuser is discharged into the vehicle occupant restraint through the outlet port. The gas turns a total of at least about 180 degrees between impacting the filter and entering the diffuser.

The present invention further provides a hybrid inflator for an airbag. The expansion device includes a storage chamber or a second chamber for storing high-pressure inflation gas, an ignition heater, a collision filter material or filter, a first diaphragm, a diffuser, and a second diaphragm.

The storage compartment is formed by a hollow cylindrical sleeve. One end of the sleeve is closed by a pouring or pouring means and the other end is closed by the ignition heater. The ignition heater is provided to be recessed in the sleeve. The ignition heater has a combustion or first chamber containing an igniter, a nozzle orifice or gas outlet nozzle, and solid plug means abutting a shoulder adjacent the nozzle orifice. The impingement filter material is provided on the inner wall of the ignition heater opposite to the nozzle orifice. The diffuser has a plurality of orifices or outlet ports. The orifice uniformly discharges inflation gas from the storage chamber into the airbag. The second diaphragm seals the diffuser against the storage room. The first diaphragm is supported by the solid plug means against the high pressure of the gas stored in the storage chamber. When the igniter is ignited and the pressure in the combustion chamber rises and exceeds the pressure of the inflation gas in the storage chamber, the solid plug means comes off and the first diaphragm ruptures. As a result, the high temperature gas from the burned igniter heats the gas in the storage chamber and rapidly increases the pressure in the storage chamber. When the pressure in the storage chamber exceeds the structural capacity of the second diaphragm, the second diaphragm ruptures and the hot gas is discharged into the airbag through the orifice of the diffuser. The impingement filter material of the expansion device is located on the inner wall of the injection plug means opposite the nozzle orifice of the ignition heater.

As used herein, the term “thrust neutral” refers to a zero thrust generated by an inflator during normal operation for use or accidental operation during transportation, storage, handling, or the like. Means That is, the gas discharge openings in the expansion device are arranged so as to discharge gas in opposite directions. Therefore, no force is generated to cause physical movement of the inflation device. Thus, the inflator does not move to release energy.

Further, in the present specification, “metal mesh (knitted matals)” means a metal wire knitted into a mesh structure. This metal mesh can have various densities. Typically a mesh having a numerical aperture of 48, 76, 100, and 130 per inch (2.54 cm). The metal mesh can be compressed into a selected shape. Such metal meshes are available from Metex Corporation of Edison, New Jersey. According to the Metex Corporation document, the braided metal has a lattice structure of interconnected loops, and these loops are movable with respect to each other so that no permanent deformation occurs. As long as it is not deformed beyond the yield point, the original shape is restored when the stress is removed. High elasticity can be maintained even when compressed into a special shape. According to the Metex Corporation documentation, metal meshes can be formed from a variety of materials that can be drawn through in wire form.

[0027] As used herein, "percent density" refers to the degree of compression of a metal mesh when making a filter from the metal mesh. In other words, "percent density" is the ratio of the volume of metal to the total volume of the unit after compression, and is generally expressed as a percentage of the volume of the unit. As used herein, "significantly reduced" with respect to the particle content of the gas according to the invention and the process gas (e.g., the hot gas released from the gas generating material storage chamber and impinging on the filter). The expression means that at least about 20% to about 80%, generally at least about 50%, of the suspended particles are removed from the gas containing such particles. The gas thus reduced in particle content can then be used to form an inflation gas. The suspended particle content of such an inflation gas is below an allowable value, and is suitable as an inflation gas for the inflatable restraint device.

[0028]

[Embodiment of the invention]

 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 to 6 show a hybrid inflator assembly 10 for inflating a vehicle occupant restraint such as an airbag. The inflator assembly 10 includes a pressure vessel 12 having a storage chamber 14. The “storage room 14” corresponds to the “second room for storing the pressurized gas and changing the direction of the gas” described in the claims for utility model registration. The storage chamber 14 is filled with a pressurized inert gas. The inert gas is argon, nitrogen, etc., and is typically pressurized to a pressure in the range of 2000-4000 psi.

The storage compartment 14 is defined by an elongated cylindrical sleeve 16. An injection plug 18 is hermetically attached to the first end 22 of the sleeve 16 by a circumferential weld 20. The “injection plug 18” corresponds to the “injection plug means” described in the claims for utility model registration. An ignition heater (pyrotechnic heater) 24 is hermetically disposed at a position retracted from the second end 26 of the sleeve 16 toward the interior of the storage compartment 14. Diffuser 28 extends from outer surface 30 of sleeve 16 at an angle of approximately 90 degrees, intermediate ends 22 and 26. The diffuser 28 is sealingly arranged with respect to the sleeve 16. The wall of the sleeve 16 has a normally closed throttle orifice 32. This "throttle orifice 32" corresponds to the "control orifice which forms a passage through which at least a part of the inflation gas enters the diffuser from the container" described in the claims for utility model registration. Gas from the pressure chamber 14 flows into the diffuser 28 through at least one throttle orifice 32.

The ignition heater 24 has a housing 34. The enlarged outer end 36 of the housing 34 mates with the second end 26 of the sleeve 16. Sleeve 16 and outer end 36 of housing 34 are hermetically connected by circumferential weld 38. The inner end 40 of the housing 34 is provided with a central opening or nozzle orifice 42. This “nozzle orifice 42” corresponds to the “gas outlet nozzle” described in the claims for utility model registration. The nozzle orifice 42 is usually covered by a solid metal stopper 44 and a thin metal diaphragm 46 (hereinafter, referred to as a first diaphragm). This “solid metal plug 44” corresponds to “solid plug means contacting the shoulder adjacent to the gas outlet nozzle” described in the claims for utility model registration. The periphery of the first diaphragm 46 is connected to the inner end 40 of the housing 34 by a circumferential weld 48 to seal it. The solid metal stopper 44 supports the entire thin first diaphragm 46. Thus, the thin first diaphragm 46 can withstand the load of the high-pressure gas stored in the storage chamber 14. As shown in FIGS. 4 and 6, the surface 50 of the solid metal plug 44 adjacent to the first diaphragm 46 is flush with the inner end 40 of the housing 34, and the solid metal plug 44 is adjacent to the nozzle orifice 42. Abuts the shoulder 52 to be formed.

The ignition housing 34 has a pyrotechnic charge 54 consisting of a particulate mixture of BKNO ₃ and an initiator 56. This “ignition agent 54” corresponds to the “gas generating material” described in the utility model registration claims. The initiator 56 is held in the housing 34 by a hollow cylindrical mounting adapter 58. The mounting adapter 58 is located at the center of the outer end 36 of the housing 34 and is sealed by an O-ring seal 61. A circumferential crimp 62 formed on the outer end 36 of the housing 34 securely holds the mounting adapter 58 within the opening 60. The electrical contact pin 57 connects the detonator 56 to a collision detecting means (not shown).

The detonator 56 has a conical portion 63. The conical portion 63 engages and mates with a similarly shaped conical portion provided on the mounting adapter 58. The other part of the mounting adapter 58 forms a crimp 64 over the inverted cone 65 of the detonator 56. This ensures that the detonator 56 is held in the opening 60. The igniter 54 is contained in a container 66 having a generally cylindrical shape. The container 66 has a closed indentation 68 which accommodates the initiator 56 in a non-contact state. The other end of the container 66 is closed by a hat-shaped container 70. The container 66 and the container 70 form a combustion chamber. This “combustion chamber” corresponds to the “first chamber for storing gas generating materials” described in the claims for utility model registration. The open end of the container 70 includes a relatively wide rim 72. The open end of the container 70 is sealed by an aluminum foil seal 74. Adhesive 76 can be used to attach aluminum foil seal 74 to rim 72.

The container 70 contains an igniter material 78. In order to facilitate insertion of the container 70 into the open end of the container 66 and to make it closely adhere to the inner wall surface of the container 66, the outer peripheral edge of the rim 72 is preferably rounded, as best seen in FIG. The seal between the container 66 and the container 70 can be made with a suitable sealant 80, such as silicone rubber, suitably cured in a known manner. Desirably, the edge 82 of the open end of the container 66 is rounded inward as shown to conform to the shape of the inner wall of the ignition housing 34. At this time, the surface of the container 70 remote from the aluminum foil seal 74 is brought into good thermal conductive contact with the inner wall of the end of the housing 34 and the adjacent end of the solid metal plug 44.

Various igniting materials (pyrotechnic mateial) can be used as the igniting agent 54 in the container 66, and a preferable material is a particulate mixture of 25% by weight of boron (boron) and 75% by weight of potassium nitrate. It is. When this mixture burns, it produces a hot flame, which is suitable for heating the gas stored in the storage compartment 14 according to the invention. The initiator 78 in the container 70 can be any particulate powder or other material that is stable over time at temperatures up to 250 ° F (121 ° C). The initiator 78 self-ignites at a desired temperature of about 350 ° F. (177 ° C.), emits hot gas, and ignites the igniter 54 in the container 66. A preferred initiator 78 is DuPont IMR 3031 from EIDuPont de Nemours & Co. of Wilmington, Delaware. Due to the long expected service life, the initiator must be stable over a long period of time. That is, automobiles placing the hybrid inflator 10 may have more than 10 years of life, detonator also long-term stability is required.

The material of the housing of the container 66 may be 0.010-0.020 inch (0.0254-0.0508 cm) aluminum foil or steel foil. The adhesive 76 must have high temperature adhesive properties up to the auto-ignition temperature. The purpose of the container 66 and the priming agent 78 is to operate the inflator 10 quickly when the auto-ignition temperature of the particles of the priming agent 78 is reached. To accomplish this, the priming agent 78 is positioned to provide good heat conduction with the walls of the ignition housing 34. When the initiator 78 self-ignites, the hot gas is directed toward the igniter 54 in the container 66.

The diffuser 28 includes a generally cylindrical sleeve 84. One end of the sleeve 84 is connected to the sleeve 16 by a circumferential weld 88 at a recess 86 in the surface 30 of the sleeve 16. A throttle orifice 32 is provided in the recess 86. The other end of the sleeve 84 is connected to and sealed by a gas-impermeable lid plate 90. Thin metal diaphragm 92 (hereinafter, referred to as second dust diaphragm and) seals the aperture Ri orifice 32 formed in the wall of the sleeve 16 defining a storage chamber 14. The sleeve 84 of the diffuser 28 has a plurality of orifices 94. These "orifices 94" correspond to "an outlet port for discharging at least a part of the inflation gas entering the diffuser into the vehicle occupant restraint system" described in the claims for utility model registration. The orifice 94 uniformly discharges inflation gas from the storage chamber 14 into an airbag assembly (not shown).

A rough screen or a perforated metal plate 96 is provided in the diffuser 28. The perforated metal plate 96 covers the orifice 94 and prevents debris of the diaphragm from entering the airbag assembly. If filtering is required, it is possible to use Rutsutsumi shaped filter assembly body, such a general metal and / or ceramic fiber materials in those the art instead of the coarse screen 96.

As described in detail below, the placement of the collision filter material 98 can further achieve a filtering effect. This “collision filter material 98” corresponds to the “filter” described in the claims for utility model registration. This impingement filter material 98 is based on another feature of the present invention and is provided on the central opening 42 of the ignition heater 24 or on the inner surface of the injection port end plug 18 opposite the nozzle. The filter 98 is formed of woven or woven metal and / or ceramic fibers to provide a large surface area on which the impinging gas contains liquid phase particles which may condense on this large surface area. And / or particles can be captured.

If desired, a pressure monitoring device (not shown) may be included on the injection port end plug 18. The operation of the hybrid gas generator will be described. When an electric signal indicating the occurrence of a collision is received, it is necessary to inflate the airbag, so that the detonating device 56 in the ignition heater 24 is ignited, and the ignition agent 54 is ignited. When the pressure in the combustion chamber in the vessel 66 rises and exceeds the high pressure of the gas stored in the storage chamber 14, the solid metal plug 44 closing the central orifice 42 of the ignition housing 34 comes off. As a result, when the combustion pressure of the ignition heater 24 exceeds the gas storage pressure in the gas storage chamber 14, the thin diaphragm 46 is not supported, and the diaphragm 46 ruptures. The hot gases and particles from the burning igniter 54 heat the stored gas. As a result, the pressure in the storage room 14 rises sharply. When the pressure of the stored gas exceeds the structural capacity of the thin metal diaphragm 92 in the diffuser 28, the diaphragm 92 ruptures and the heated gas is discharged through the orifice 94 of the diffuser 28 into the airbag assembly. At least one orifice 32 is arranged between the diaphragm 92 of the diffuser 28 and the storage room 14. The throttle orifice 32 throttles the flow of gas from the storage chamber 14. This gives the gas released into the airbag an adequate filling rate. A coarse screen or perforated metal plate 96 prevents debris of diaphragms 46 and 92 from entering the airbag assembly. The impingement filter 98 on the injection port end plug 18 provides additional filtering by condensing liquid phase particles contained by the impinging gas onto the impingement filter 98 and trapping the particles from the gas.

FIG. 7 shows the tank performance of the hybrid expansion device 10 at high, ambient, and low temperatures. FIG. 8 shows the airbag inflation pressure curve of the hybrid inflator 10 at ambient temperature. FIG. 9 shows a combustion pressure curve of the hybrid expansion device 10 at an ambient temperature. In FIG. 9, position 100 on curve 99 indicates that the squib 56 has been activated in response to the ignition signal. Reference numeral 101 indicates that the combustion pressure in the ignition heater 24 has exceeded the stored gas pressure. Reference numeral 102 indicates a heating period of the stored gas in the storage room 14. Reference numeral 103 indicates that the second diaphragm 92 has ruptured and the heated gas is released from the storage chamber 14. Reference numeral 104 indicates a period during which gas is released from the storage room 14.

As described above, the hybrid expansion device of the present invention seals and maintains a high-pressure inert gas in a storage room without requiring a complicated sealing method such as sealing between glass and metal. Furthermore, the hybrid inflator of the present invention does not require any mechanical actuation or ignition actuation to open the flow path from the compressed gas storage chamber to the airbag. The hybrid inflator of the present invention has a feature of discharging all of the heated gas to the airbag. Further, the hybrid expansion device of the present invention is characterized in that a diffuser is arranged at the center of the device. For this reason, it can be easily incorporated into a module as compared with an end-position type diffuser usually used in a hybrid expansion device.

In the embodiment of the present invention described above, the filter is arranged in the expansion device. This filter significantly reduces the particulate component of the hot gas formed in the inflation device and forms an inflation gas with an appropriate particle content for inflating the vehicle occupant restraint system. FIG. 10 shows a hybrid inflator assembly 110 for inflating an inflatable restraint cushion for the passenger side of a vehicle. In the following description, the present invention relates to a passenger side assembly for vehicles including vans, pickup trucks, and especially automobiles, but the present invention applies to other types of such assemblies including driver side assemblies. Applicable.

There is a physical difference between the passenger side assembly and the driver side assembly. For example, passenger side airbags are generally much larger than those used in driver side assemblies. Therefore, such passenger side assemblies typically require a larger volume of inflation gas. The present invention is particularly useful for passenger side assemblies. In FIG. 10, the inflation device 110 includes an elongated pressure vessel or vessel 112 having a generally cylindrical shape. However, in the practice of the present invention, the container may have various sizes and shapes as required, such as a cylindrical shape, a donut shape, a spherical shape, and other intermediate shapes.

The container 112 includes a storage room 114. The “storage room 114” corresponds to the “second room that stores the pressurized gas and changes the direction of the gas” described in the claims for utility model registration. The storage chamber 114 is useful for diverting gas and storing pressurized gas. For example, as noted above, an inert gas such as argon or nitrogen, typically at a pressure in the range of 2000-4000 psi (140-280 kg / cm ² ), is used to fill and pressurize the inflator chamber. Can be done. However, the container 112 can store gases selected from carbon dioxide, air, other inert gases, or a combination of these gases, and / or their storage pressure can be selected as needed.

The storage chamber 114 is defined by an elongated cylindrical sleeve 116. End plug 120 is hermetically attached to first end 124 of sleeve 116 by girth weld 122. The “end plug 120” corresponds to the “injection plug means” described in the claims for utility model registration. End plug 120 includes a passageway (not shown) for introducing gas into storage chamber 114. When the storage chamber 114 is filled with gas at the required pressure, the passage is closed. The end plug 120 has a known pressure switch (not shown) as a separate component or as an integral component. This pressure switch is generally called a low pressure sensor (LPS). The sensor can monitor the gas pressure in the storage chamber 114, and can warn a vehicle occupant when the pressure falls below a predetermined value.

The gas generator housing 130 is hermetically formed from the second end 132 of the sleeve 116 toward the inside of the storage chamber 114. The color 134 of the gas generator housing 130 is located approximately at the center of the gas generator housing 130 and is attached to the sleeve 116 by circumferential welding 136. Gas generator housing 130 includes a gas generation chamber 140. The “gas generating chamber 140” corresponds to the “first chamber for storing gas generating materials” described in the claims for utility model registration. Gas generating chamber 140 stores gas generating materials. The gas generating material may, for example, an extrudable solid propellants or BKNO ₃ such as a mixture of binding agents used as fuel, ignition, such as a granular mixture of a solid oxidizing agent (pyrotec hnic charge) Yes, for example, an igniter such as a mixture of polyvinyl chloride (fuel) and potassium nitrate or potassium perchlorate (oxidizer).

The gas generation chamber 140 has an inner end 142. Inner end 142 has a central opening or nozzle orifice 144. This “nozzle orifice 144” corresponds to the “gas outlet nozzle” described in the claims for utility model registration. Hot gas generated as the gas generating material ignites is discharged into the storage chamber 114 through the nozzle orifice 144. The number, arrangement, and shape of the nozzle orifices 144 can be appropriately modified according to design requirements based on specific installation conditions, as known to those skilled in the art.

Typically, the hot gas contains particles of the gas generating material and its by-products. The nature of the particles depends, at least in part, on the nature of the gas generating material itself. For BKNO _3, typical particle has the property of boron and / or compounds of potassium. Inside the storage chamber 114, along the inner wall 146 of the first end 124, near the end plug 120, and opposite the nozzle orifice 144, a filter structure 150 is received. This “filter structure 150” corresponds to the “filter” described in the claims for utility model registration. The filter structure 150 is constructed from a woven metal wire filter material 152 having a selected diameter and percentage density. Effective metal meshes use, for example, 0.020 inch (0.51 millimeter) diameter stainless steel wire with a percent density in the range of 10% to 50%. Such a stainless steel mesh filter structure 150 is formed into the desired shape by pressure or compression molding and fitted into the end 124 of the expansion device 110 opposite the nozzle orifice 144. This end 124 is provided with a low pressure sensor (LPS) as required.

The material used for filter structure 150 should withstand the high temperatures of solids or gases generated by the ignition of the gas generating material. The filter structure of the present invention is housed in the gas mixing chamber of the hybrid inflator. Since the gas velocity at this location is relatively low, the filter structure is not subjected to such severe conditions. Thus, in the practice of the present invention, a relatively wide range of filter materials or media can be used for the filter structure. For example, a filter structure can be composed of one or more combinations of filter materials as needed. Filter materials include ceramic paper, such as LYTHERM ™ from Lydall Inc., ceramic fabrics such as KAO-TEX ™ from Thermal Ceramics Inc., stainless steel metal fabric from National Standard Co., and Metex Corporation's stainless steel. These include woven stainless steel, sintered stainless steel non-woven metal mats from Memtec America Co., and vapor-deposited foam materials of mesh-ceramic or metallic ceramic made of silica-carbide.

In the filter structure according to the present invention using a metal knitted filter material or a metal mesh, the type of metal, the thickness of the metal wire, the percent density, and the shape of the filter structure can be easily determined by those skilled in the art. Can be found in Also, by referring to the present specification, it is possible to appropriately select the installation conditions such as the characteristics of the ignition method without performing additional experiments. The filter structure 150 redirects the gas and, within the storage chamber 114, removes particles from at least a portion of the hot gas that enters the storage chamber 114 from the combustion chamber 140 and impinges on the filter structure 150. Remove. That is, the filter structure 150 forms a filter body against which the hot gas containing particles impinges, and at least a portion of the hot gas enters the filter body of the filter structure 150. In this way, the filter structure 150 performs gas redirection and particle removal. In the practice of the present invention, as will be described in detail below, the removal of the particles is realized by performing the condensation of the liquid phase particles and the capture of the particles in the filter.

By removing the particles, the filter structure 150 forms a hot gas with significantly reduced particles. At least a portion of the gas mixes with the gas stored in the storage chamber 114 to form an inflation gas for inflating the vehicle occupant restraint. In the embodiment of FIG. 10, the gas generator housing 130 has a diffuser 154. The diffuser 154 is adjacent to the ignition storage chamber 140 and is integral with the ignition storage chamber 140. The diffuser 154 includes a generally cylindrical sleeve 156. The first end 158 of the sleeve 156 is connected to the ignition storage chamber 140. A second end 160 of the diffuser 154 extends out of the container 112. Four generally equally spaced control orifices 162 are disposed around the cylindrical sleeve 156 adjacent the first end 158. These "control orifices 162" correspond to the "control orifice forming a passage through which at least a part of the inflation gas enters from the container into the diffuser" described in the claims for utility model registration. Control orifice 162 provides a conduit for directing inflation gas from container 112 into diffuser 154. This inflation gas can then be released from the inflation device 110 through the gas outlet port 164. Gas outlet port 164 is spaced adjacent second end 160 of diffuser 154.

In the illustrated apparatus, four generally elliptical gas outlet ports 164 are spaced around the diffuser second end 160. These "gas outlet ports 164" correspond to the "outlet ports for discharging at least a part of the inflation gas entering the diffuser into the vehicle occupant restraint system" described in the claims for utility model registration. The four gas outlet ports 164 are generally equally spaced about 90 degrees around the second end 160. This arrangement helps to more uniformly release gas around the inflator assembly 110 and helps the inflator assembly achieve neutral thrust. The number, spacing, and shape of the gas outlet ports can be appropriately changed according to installation conditions and design conditions, as will be apparent to those skilled in the art.

In the embodiment of FIG. 10, the gas released from the ignition chamber 140 is directed to an end plug 120 and a filter structure 150 disposed therein. The control orifice 162 is located adjacent the end 132 opposite the end 124 on which the filter structure 150 is located, so that the gas released from the ignition chamber 140 and contacting the filter structure 150 is filtered. It collides with the structure 150 and changes its direction by about 180 degrees toward the diffuser 154.

In the general practice of the present invention, in order to remove particles contained in the generated gas more efficiently, it is preferable to arrange the filter at the position where the gas velocity is the lowest, for example, at the position where the flow direction is reversed. When the heat of the particles is removed, the phase changes and the condensed particles collect on the surface of the filter. This condensation is promoted when the gas containing the particles contacts the filter at a slow rate. The particles can be further removed by trapping them in the filter. As a result, the solid particles are physically separated from the medium (gas).

The filter device according to the invention significantly reduces the particle content of the gas. For example, at least about 20% to 80%, and generally at least about 50%, of the suspended particles can be removed from the gas by condensation and / or entrapment. In addition, the present invention achieves this without relying on various organic and inorganic coatings. The filter device of the present invention can be rigidly mounted at a predetermined location and can maintain stability under normal operating conditions such as temperature and flow.

The filter structure of the present invention reduces the amount of particles emitted by the hybrid expansion device. This reduction in particle content is not limited to the removal of relatively large particles. As a result, the toxicity and the amount of particles in the exhaust gas of the inflator can be kept within allowable limits. In the embodiment shown in FIG. 10, the filter structure 150 is spot welded to the end plug 120. Alternatively, the filter structure 150 is otherwise suitably located within the inflator assembly 110.

In the above, the embodiment of the present invention in which the filter is arranged inside the hybrid expansion device has been described. The present invention is applicable to other types of expansion devices that achieve similar gas flow characteristics. For example, an expansion device that generates a gas flow substantially in one direction from the gas generation chamber and reverses the gas flow (for example, at least about 180 degrees in total from contact with the filter to inflation gas entering the diffuser). That have a change in gas flow direction). If necessary, the present invention provides an ignition chamber (similar to the gas generating chamber 140 in FIG. 10) and a filter accommodating chamber (similar to the gas storage chamber 114 in FIG. 10; There is no storage of primary high pressure gas for use in inflating vehicle occupant restraint systems).

Although the above description has been made for the understanding of the present invention, these descriptions do not unnecessarily limit the present invention. As will be apparent to those skilled in the art, various modifications can be made to the present invention without departing from the scope of the present invention. According to the present invention, when the gas generating material stored in the first chamber is ignited, a hot gas containing particles of the gas generating material and its by-products is generated, and the hot gas is supplied to the gas outlet of the first chamber. The pressurized gas is discharged through the nozzle into the stored second chamber. The high-temperature gas discharged into the second chamber collides with a filter disposed along the inner wall of the second chamber on the side opposite to the gas outlet nozzle, and as a result, the gas generating material contained in the high-temperature gas and its By-products and particles are removed from the hot gas and the hot gas is redirected. Since the filter is thus arranged along the inner wall of the second chamber opposite to the gas outlet nozzle, particles of the gas generating material and its by-products contained in the hot gas discharged from the gas outlet nozzle are It collides with the filter while maintaining a high density state without being diffused by the pressure gas stored in the second chamber. Thus, the particles of the gas generating material and its by-products generated by the ignition of the gas generating material can be efficiently removed from the high-temperature gas by the filter.

[Brief description of the drawings]

FIG. 1 is a front view showing a hybrid inflator according to an embodiment of the present invention.

FIG. 2 is a side view of the hybrid expansion device of FIG. 1;

FIG. 3 is an end view of the hybrid expansion device of FIG. 1;

4 shows the hybrid expansion device of FIGS. 1 to 3;
It is sectional drawing which followed the 4 line.

5 shows the hybrid expansion device of FIGS. 1 to 3; FIG.
It is sectional drawing along line 5.

FIG. 6 is an enlarged sectional view showing a part of the hybrid expansion device of FIG. 4;

FIG. 7 is a diagram showing tank performance of the hybrid expansion device shown in FIGS. 1 to 3 at high temperature, ambient temperature, and low temperature.

FIG. 8 is a diagram showing an airbag inflation pressure curve at an ambient temperature of the hybrid inflator shown in FIGS.

FIG. 9 is a diagram showing a combustion pressure curve at an ambient temperature of the hybrid expansion device shown in FIGS. 1 to 3;

FIG. 10 is a schematic partial cross-sectional view of a hybrid inflation device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Hybrid expansion device assembly 12 ... Pressure vessel 14 ... Gas storage chamber 16 ... Sleeve 18 ... Injection plug 24 ... Ignition heater 28 ... Diffuser 32 ... Restriction orifice 34 ... Ignition housing 42 ... Nozzle orifice 44 ... Solid metal stopper 46 ... First diaphragm 54 ... Ignition agent 56 ... Initiator 66 ... Container 70 ... Container 74 ... Aluminum foil seal 78 ... Initiator 84 ... Sleeve 90 ... Gas impervious lid plate 92 ... Second diaphragm 94 ... Orifice 96 ... Perforated Metal plate 98 Impact material 110 Hybrid injection device 112 Pressure vessel 114 Storage chamber 116 Sleeve 120 End plug 130 Gas generator housing 140 Gas generation chamber 144 Nozzle orifice 150 Filter structure 154 … Diffuser 156… sleeve 162… control Office 164 ... gas outlet port

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Walter A. Moore United States, Utah 84401, Ogden, Swan Street 1638 (72) Inventor Bradley W. Smith United States, Utah 84401, Ogden, West 3740 South 2550

Claims (13)

[Utility model registration claims] An apparatus for inflating an occupant restraint system for a vehicle, comprising: a first chamber for storing a gas generating material; and a second chamber for storing a pressurized gas and changing a direction of the gas. Wherein the gas generating material produces a hot gas when ignited, the hot gas containing particles of the gas generating material and its by-products, the hot gas being at least from the first chamber into the second chamber. The gas can be discharged through one gas outlet nozzle, wherein the second chamber contains a filter disposed along an inner wall of the second chamber opposite the gas outlet nozzle, the filter comprising: At least a portion of the hot gas released from the first chamber and impinging on the filter is used to remove particles and to redirect the gas, thereby removing hot gas having a significantly reduced particle content. Vehicles including An inflation gas for inflating the occupant restraint system of the invention, further comprising a diffuser, wherein the diffuser includes at least one control that defines a passage through which at least a portion of the inflation gas enters the diffuser from the container. An orifice and at least one outlet port for discharging at least a portion of the inflation gas contained in the diffuser into an occupant restraint system of the vehicle, wherein the hot gas is used as the inflation gas from contact with the filter. An apparatus for inflating an occupant restraint system for a vehicle, wherein the vehicle turns a total of at least about 180 degrees before entering the diffuser. 2. The apparatus for inflating an occupant restraint system for a vehicle according to claim 1, wherein the filter achieves at least a part of the particle removal by agglomeration of particles. 3. The apparatus for inflating a vehicle occupant restraint system according to claim 1, wherein the filter implements at least a portion of the particle removal by trapping particles. 4. The apparatus for expanding an occupant restraint system for a vehicle according to claim 1, wherein the filter is formed of a metal mesh formed by braiding metal wires. 5. The apparatus for inflating a vehicle occupant restraint system according to claim 4, wherein said braided metal wire comprises stainless steel. 6. The braided stainless steel wire comprises 10
Having a percent density in the range of 50% to 50%,
An apparatus for inflating a vehicle occupant restraint system according to claim 5. 7. An apparatus for inflating an occupant restraint system for a vehicle, the elongated apparatus having a first chamber for storing gas generating material and a second chamber for storing pressurized gas and diverting the gas. A gas cylinder, wherein the gas generating material produces a hot gas when ignited, the hot gas containing particles of the gas generating material and its by-products, wherein the hot gas flows from the first chamber into the second chamber; The second chamber may be discharged through at least one gas outlet nozzle into the chamber, the second chamber containing a filter disposed along an inner wall of the second chamber opposite the gas outlet nozzle. A filter is used to remove particles and redirect the gas from at least a portion of the hot gas emitted from the first chamber and impinging on the filter, thereby significantly reducing the particle content. Hot gas Wherein the filter achieves at least a portion of the particle removal by agglomeration of the particles, and at least a portion of the hot gas having the significantly reduced particle content is mixed with a stored gas in the second chamber. Forming an inflation gas for inflating a vehicle occupant restraint system, further comprising a diffuser, wherein the diffuser defines a passage through which at least a portion of the inflation gas enters the diffuser from the container. At least one control orifice and at least one outlet port for discharging at least a portion of the inflation gas contained within the diffuser into an occupant restraint of the vehicle, wherein the hot gas from impact with the filter. An occupant restraint system for a vehicle that performs a total of at least about 180 degrees of turning before entering the diffuser as the inflation gas. Apparatus for inflating an. 8. The apparatus for inflating an occupant restraint system for a vehicle according to claim 7, wherein the filter implements at least a part of the particle removal by trapping particles. 9. The device for inflating an occupant restraint system for a vehicle according to claim 7, wherein the filter is formed of a metal mesh formed by knitting a metal wire. 10. The device for inflating a vehicle occupant restraint system according to claim 9, wherein said braided metal wire comprises stainless steel. 11. The braided stainless steel wire comprises one
The device for inflating a vehicle occupant restraint system according to claim 10, wherein the device has a percent density in the range of 0% to 50%. 12. A hybrid inflator for an airbag, comprising a second chamber for storing high pressure inflation gas, the second chamber being formed by a hollow cylindrical sleeve, one of the cylindrical sleeves. Is closed by the injection plug means and the other end of the cylindrical sleeve is open, and further comprises an ignition heater closing the other end of the sleeve, wherein the ignition heater is A first chamber having a gas generating material therein, a gas outlet nozzle, a solid plug means abutting a shoulder adjacent to the gas outlet nozzle, A second diaphragm; and a diffuser having a plurality of outlet ports for uniformly discharging inflation gas from the second chamber into the airbag; and a second diaphragm. Is the second diaf Sealed to the diffuser by the diaphragm and sealed to the first chamber by the first diaphragm, the first diaphragm being pressurized by the solid plug means to the high pressure of the inflation gas stored in the second chamber. And the solid plug means disengages as the pressure in the first chamber rises upon ignition of the gas generating material and exceeds the pressure of the stored inflation gas in the second chamber. When the pressure in the chamber exceeds the pressure in the second chamber, the first diaphragm ruptures and hot gas from the burning gas generating material heats the stored inflation gas in the second chamber to cause the second diaphragm to burst. A rapid pressure build-up in the chamber causes the second diaphragm to rupture when the pressure in the second chamber exceeds the structural capacity of the second diaphragm, causing the heated gas to flow through the diffuser of the diffuser. Exit port Further comprising a filter disposed on the inner wall of the injection plug means opposite to the gas outlet nozzle of the ignition heater. Expansion device. 13. The hybrid inflatable device for an airbag according to claim 12, wherein the filter realizes filtration of the hot gas by coagulation of liquid phase particles contained in the hot gas impinging on the filter.