JPH08198050A - Hybrid inflator with valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inflate an air/safety bag by a predetermined amount within a predetermined time by including valve means operated in conjunction with at least one gas generator inlet port for substantially inhibiting flow between an inflator housing and a gas generator housing through the gas generator inlet port. SOLUTION: The free end of a valve 320 moves radially inwardly toward a central axis 220 or the valve 320 is collapsed in at least regions radially aligned with gas generator inlet ports 316 to permit the desired flow of gas through the gas generator inlet ports 316. However, the valve 320 is retained by its connection with a second housing 278. When the gas generator inlet ports 316 are exposed, flow of gas from a high-pressure gas housing 204 into a second chamber 324 is initiated. The valve 320 is movable from a first position to a second position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflatable safety system for a motor vehicle, and more particularly to a hybrid inflator capable of rapidly inflating an air / safety bag.

[0002]

2. Description of the Related Art With the development of inflators for inflatable safety systems for motor vehicles, inflators exclusively for pressurized gas, inflators exclusively for propellants and hybrid inflators have been developed. Of course, many designs are possible for each of the above inflators. In all three systems, the main design requirement is that the air / safety bag must be inflated by a given amount at a given time in order to operate effectively.

Also, in many cases, the weight of the motor vehicle is an important design requirement, so that the weight of the inflator is also an important requirement. In addition, the size of the inflator is also an important design requirement as space is limited in the design of many motor vehicles.

In order to meet the above needs, substantial improvement efforts have been directed to the method of setting the flow path between the inflator and the air / safety bag and the method of supplying flow to the air / safety bag. In a hybrid inflator that requires both the release of stored pressurized gas and the ignition of the gas and / or heat generating propellant, a configuration that allows rapid gas supply to the air / safety bag should meet the above requirements. Must be presented to.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its purpose is to inflate an air / safety bag by a predetermined amount within a predetermined time. To provide a hybrid inflator.

[0006]

In order to achieve the above object, the hybrid inflator of the present invention comprises an inflator housing containing a pressurized medium. The gas generator includes a gas generator housing, a propellant contained in the gas generator housing, at least one gas generator inlet communicating the gas generator housing and the inflator housing, and the gas generator housing and air. / Has at least one gas generator outlet communicating with a safety bag. An assembly for igniting a propellant is connected to the gas generator. A valve means is provided between the inflator housing and the gas generator housing through the at least one gas generator inlet until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount after the assembly is actuated. Is operated in cooperation with the at least one gas generator inlet to substantially block the flow of the gas.

It is desirable that the pressure inside the inflator housing and the pressure inside the gas generator housing be kept substantially equal before the operation of the assembly. The hybrid inflator preferably further comprises a plurality of gas generator inlets, the valve means being operative in cooperation with each gas generator inlet.

The gas generator housing preferably comprises a first chamber and a second chamber in communication with each other,
Desirably, the propellant is contained in the first chamber and the second chamber is located between the at least one gas generator outlet and the first chamber.

The hybrid inflator further includes a closure disc located between the at least one gas generator outlet and an air / safety bag, and a gas generator at a speed greater than the rate of pressurization against the inflator housing after ignition of the propellant. It is desirable to have means for pressurizing the second chamber of the housing and means for including the pressurizing means and for opening the closing disc.

Desirably, the pressurizing means includes an aspirator nozzle disposed between the first chamber and the second chamber. Further, the pressurizing means may include means for forming a vortex flow in the second chamber.

A preferred valve means is moveable from a first position to a second position, the valve means being disposed in the first position in use to substantially block said flow and pressure within the inflator housing. Moves to a second position to allow the flow when the pressure in the gas generator housing exceeds a predetermined amount. The second position is located inside the first position in the radial direction.

The valve means preferably comprises a flexible member disposed within the gas generator housing, the flexible member being pressed into substantial abutment against the gas generator housing, whereby The at least one gas generator inlet is closed until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount. Further, the flexible member is separated from the gas generator housing after the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount, so that the flexible member passes through the at least one gas generator inlet. A flow is formed from the gas to the gas generator housing.

The flexible member may be formed of a metal thin film. The valve means may also be formed from a plug provided corresponding to the gas generator inlet, the plug having a first position for closing the gas generator inlet and a second opening for opening the gas generator inlet. Is movable to and from the position. The stopper is preferably supported by a flexible member.

The inflatable safety system described above operates through the following steps. That is, a propellant gas is formed from the propellant and at least a portion of the propellant gas is provided from the first chamber to the second chamber. The flow of propellant gas from the second chamber to the inflator housing is substantially prevented during performance of the first portion of the propellant gas formation step. The main closing disc is opened using the substantially blocking step. Flowing from the inflator housing to the second chamber is allowed after performing the substantially blocking step and during performing the second portion of the forming step. After performing the opening step, the flow is guided towards the air / safety bag.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. The present invention relates to a hybrid inflator for an inflatable safety system for a motor vehicle. That is, the present invention relates to an inflator that utilizes both a stored pressurized gas and a gas and / or heat generating propellant. Various hybrid inflators are disclosed in US Pat. No. 5,230,531 to Hamilton et al.

An overview of one embodiment of an inflatable safety system for a motor vehicle is shown in FIG. Inflatable safety system 10
The main components of the detector are the detector 14, the inflator 26 and the air / safety bag 18. The detector 14 detects situations (eg, predetermined deceleration) that require inflation of the air / safety bag 18.
Is sensed, a signal is transmitted to the inflator 26 to expel gas or other suitable fluid from the inflator 26 to the air / safety bag 18 via line 22.

The inflator 30 shown in FIG. 2 is a hybrid inflator and can be used in place of the inflator 26 in the inflatable safety system 10 of FIG. Therefore, the inflator 30 supplies the air / safety bag 18 (FIG. 1) with a bottle or inflator housing 34 having a pressurized medium 36 that is supplied to the air / safety bag 18 and a propellant to supply air / safety.
A gas generator 82 is provided to increase the flow to the safety bag 18 (eg, by heating to expand the pressurized medium 36 and / or generate additional gas). As described in more detail below, a gun-type propellant (e.g., a high temperature multi-fuel propellant) is used to form the propellant grains 90 located in the gas generator 82 and the pressurizing medium 36 includes at least one non-propellant. A mixture of active gas (eg argon) and oxygen has been used. Pressurized medium 36 preferably includes from about 70% to about 92% inert gas and from about 8% to about 30% oxygen on a molar basis. More preferably, it is desirable to include from about 79% to about 90% inert gas and from about 10% to about 21% oxygen on a molar basis.

The inflator housing 34 and the gas generator 82 are communicated with each other, and the gas generator 82 is arranged inside the inflator housing 34 to narrow the space required for the inflator 30. More specifically, the hollow boss 66
A hollow diffuser 38 is welded to one end (e.g., about 1.25 inches (3.18 cm) in diameter). The diffuser 38 has multiple rows of discharge holes 40 (eg, 80 discharge holes 40 each having a diameter of about 0.100 inches (0.254 cm)) through which the "non-thrust output" is provided. A screen 58 is provided adjacent to the discharge hole 40. A closure disc 70 is suitably positioned within the boss 66 and welded to the boss 66 to initially retain the pressurized medium 36 within the inflator housing 34. When it is necessary to release the gas, a projectile 50 having a substantially conical head is used to close the closing disk 7.
It is propelled to penetrate 0. More specifically, the projectile 50 is positioned in the barrel 54 on the convex side of the closure disc 70 and upon activation of the initiator 46 upon receipt of the proper signal from the detector 14 of the inflatable safety system 10 (FIG. 1). Be promoted. Initially, a ring 62 is provided to hold projectile 50 in the proper position prior to ignition.

An orifice sleeve 74 is welded to the ends of the closure disc 70 and / or the boss 66. Orifice sleeve 74 is hollow and includes a plurality of orifice ports 78 (eg, each having a diameter of about 0.201 inches (0.
511 cm) with four orifice ports 78),
When the closure disk 70 is ruptured by the projectile 50, it connects the interior of the inflator housing 34 with the interior of the boss 66 and diffuser 38. Further, in order to complete the communication between the inflator housing 34 and the gas generator 82, the gas generator 82, more specifically, the gas generator housing 86 is welded to the orifice sleeve 74.

The gas generator housing 86 contains a plurality of propellant grains 90 which, when ignited, carry combustion propellant gases of heated propellant for increasing flow to the air / safety bag 18 (FIG. 1). Supply. The propellant grains 90 are held inside the gas generator housing 86 by a propulsion sleeve 94, which propels the screen 1
04 and a baffle 100 separate the gas generator inlet nozzle 98 at the end 96 of the gas generator housing 86. As shown below, propellant grain 90
Can be manufactured from gun-type propellants. However, the propellant grains 90 are generally cylindrical with one hole extending through the center. Other forms of propellant grains may be suitable and depend at least in part on the method of making the propellant used.

A single (or composite) gas generator suction nozzle 98 (eg, about 0.516 inches (1.3 inches) in diameter).
1 cm) suction nozzle 98) is the gas generator housing 8
It is located at the end 96 of 6, and is usually oriented away from the closure disc 70. The gas generator housing 86 also has a plurality of outlets or discharge nozzles 200 circumferentially spaced on its sidewalls (eg, each having a diameter of about 0.221 inches (0.561 cm)). 1
Four discharge nozzles 200 in a "row". Although it may be desirable to change the axial position of these discharge nozzles 200 (typically in the middle of the gas generator housing 86),
The position close to the outlet enhances the action. Furthermore,
It may be desirable to change the number of ejection nozzles 200. The discharge nozzle 20 is provided on the side wall of the gas generator housing 86.
0 and a suction nozzle 98 at the end 96 of the gas generator housing 86, the propellant grains 90
The pressurized medium 36 is drawn into the gas generator housing 86 via the suction nozzle 98 during combustion of the gas, and the mixed gas from the inside of the gas generator housing 86 is discharged from the discharge nozzle 200.
Through the gas generator housing 86 via. More specifically, a pressure difference is generated by the flow of the pressurized medium 36 near the side wall of the gas generator housing 86, which causes the pressurized medium 36 to pass through the suction nozzle 98 and the gas generator housing 8.
It is drawn into 6. As described in more detail below, this significantly improves the performance of the inflator 30 when producing at least some propellant gas.

The gas generator 82 is timely propellant grain 9
An ignition assembly 114 for igniting zero is provided. Ignition assembly 114 is disposed at least partially within gas generator housing 86, between projectile 50 and propellant grains 90, and typically includes actuating piston 12
4, having at least one percussion primer 120 and an ignition / booster agent 144 as an activator. More specifically, the actuation guide 140 engages the end of the orifice sleeve 74 and the inner wall of the gas generator housing 86 so that the actuation guide 140 is located therein.
4 and at least partially fulfills the function of guiding the working piston 124. The detonator holder 116 engages one end of the actuation guide 140 and houses a plurality of conventional percussion tubes 120 located generally adjacent the ignition / booster agent 144. Ignition / booster agent 144 is typically held adjacent to percussion tube 120 by a charge cup 148. A preferred example of an ignition / booster agent 144 is the RDX aluminum booster agent with 89% RDX, 11% aluminum powder and 0.5% hydroxypropyl-cellulose added.
A cage 1 between the detonator holder 116 and the propulsion sleeve 94.
08 and the baffle 112 are arranged. If the gas generator housing 86 is attached to the orifice sleeve 74 by crimping rather than welding, it may tend to extend during operation. Therefore, for example, the retainer 108 and the baffle 11 are required to ensure the mutual interaction of the parts.
A corrugated spring washer can be placed between the two (not shown).

The actuating piston 124 is slidably disposed within the actuating guide 140 and comprises one continuous projecting rim 128 substantially aligned with the percussion cap 120.
As will be appreciated, a plurality of protruding members (not shown) may be used in place of one substantially continuous protruding rim 128. A counter washer 136 is located between the actuation guide 140 and the actuation piston 124 (via spacer 126) and engages a portion of both, initially actuation piston 12
The position 4 is kept away from the percussion tube 120.
As a result, the likelihood that the actuation piston 124 will erroneously engage the percussion tube 120 and activate the gas generator 82 is reduced. However, after the projectile 50 has passed through the closure disc 70, the energy transferred by the projectile 50 to the actuating piston 124 is sufficient to overwhelm the counter washer 136 and the projecting rim 128 has at least one strike. The detonator 120 can be engaged with a force sufficient to ignite the detonator 120. This, in turn, causes the ignition / booster agent 144 to ignite, causing the propellant grains 90 to ignite.

During operation of the gas generator 82, a percussion primer 120
May also corrode and allow propellant gas generated by the combustion of propellant grains 90 to flow through percussion primer 120. Such propellant gas leaks may adversely affect the performance consistency of the inflator 30. However, such gas desirably acts on the actuating piston 124 causing it to move into sealing engagement with the actuating guide 140. This provides a seal for the gas generator housing 86 that limits virtually any gas leakage.
Therefore, the propellant gas preferably flows through the gas generator suction nozzle 98.

To summarize the operation of inflator 30, detector 14 (FIG. 1) transmits a signal to initiator 46,
Propel projectile 50. The projectile 50 first passes through the closure disc 70, opening the passageway between the inflator housing 34 and the air / safety bag 18 (FIG. 1). The projectile 50 continues to advance and eventually strikes the working piston 124, causing the projecting rim 12 mounted on the working piston 124 to
8 strikes at least one array strike detonator 120.
As a result, the ignition / booster agent 144 is ignited and then the propellant grains 90 are ignited. Gas generator housing 8
During combustion of the propellant grains 90 in 6, the pressurized medium 36 from the inflator housing 34 is drawn into the gas generator housing 86 via the suction nozzle 98 located at the end 96 of the gas generator housing 86. Be done. This results from the flow of the pressurized medium 36 near the sidewalls of the gas generator housing 86 which creates a pressure differential. This "pull-in" of the pressurized medium 36 promotes the mixing of the propellant gas and the pressurized medium 36 within the gas generator housing 86. As will be detailed below, this is particularly desirable when the pressurized medium 36 contains oxygen and reacts with a propellant gas that is high in carbon monoxide and hydrogen. However, this gas is exhausted from the gas generator housing 86 via the discharge nozzle 200 on the sidewall of the gas generator housing 86. Thus, by mixing the pressurized medium 36 with the combustion products from the gas generator housing 86, the flow to the air / safety bag 18 is preferably increased (FIG. 1).

As mentioned above, the hybrid inflator 30 may use a mixture of oxygen and at least one inert gas for the gun-type propellant and pressurized medium 36 for the propellant grains 90. Gun-type propellants used herein are high temperature multi-fuel propellants such as single base, double base or triple base propellants as well as nitramine propellants such as LOVA or HELOVA propellants.
More specifically, conventional gun-type propellants have about 2,500
In the range of up to 3,800 ° K, usually about 3,000
It is a propellant with a combustion temperature above ° K and is multi-fuel in that it produces large amounts of CO and H ₂ in the absence of excess oxygen. Usually, in order to react the excess fuel from these propellants to obtain CO ₂ and H ₂ O, it is necessary to add 5 to 25 mol% or sometimes 15 to 40 mol% oxygen to the propellant gas. ..

Propellant grain 9 of hybrid inflator 30
One particular "conventional" gun-type propellant that can be used for HP is HPC-96. This is about 76.6% nitrocellulose, about 20.0% nitroglycerin, about 0.6% ethyl centrallarite, about 1.5% nitric acid, about 13.25% nitrogen by weight. A composition of barium, about 0.9% potassium nitrate and about 0.4% graphite, a double base smokeless propellant.
HPC-96 is a product of Wilmington, Del.
available from Hercules, Inc. of Washington, DC. Since this double-base propellant contains nitrocellulose as the main component, it produces the desired ballistic properties, but it does not meet the current long-term heat resistance criteria of the automotive industry.

LOVA propellant (low brittle ammunition) and HE
LOVA propellant (high energy, low brittle ammunition) is another "conventional" gun-type propellant that can also be used in propellant grain 90. This is about 76.
0% RDX (hexahydrotrinitrotriazine), about 12.0% cellulose acetate butyrate, about 4.0%
Nitrocellulose (12.6% nitrogen), about 7.60
There is a M39 LOVA propellant consisting of a composition of% acetyltriethyl citrate and about 0.4% ethyl centralralite. The M39 LOVA propellant is available at The Naval Naval War Center (The Naval Center) in Indian Head, Maryland, USA.
Available at the Surface Warfare Center) and Bofors, Europe (Sweden), it produces approximately 32 mole percent CO and 30 mole percent H ₂ in the absence of excess oxygen. LOVA and HELO
VA propellants are preferred over existing double base propellants.
This is because the latter has not passed the current heat resistance standard of the US automobile industry, but the former has. However, stable combustion of LOVA and HELOVA propellants requires a relatively high operating pressure. HPC-96
And despite the properties of LOVA propellants, HPC-96
And LOVA propellants serve to illustrate at least some of the principles / features of the present invention.

Due to the performance characteristics of gun-type propellants when used as the formation of propellant grains 90, coupled with the use of oxygen as part of the pressurized medium 36, for example, assignee of the present patent application. Compared to the current design with 20-30 g of FN 1061-10 available from
It is possible to reduce the amount of propellant required in the gas generator 82 (FN 1061-10 composition is about 7.93% polyvinyl chloride by weight percent, 7.17%.
Dioctyl adipate, 0.05% carbon black, 0.35% stabilizer, 8.5% sodium oxalate, 75% potassium perchlorate and about 1% lecithin. ). For example, gun-type propellants that can be used to form propellant grains 90 typically have a total grain weight of about 1
It is in the range of 0 to 12 g (when used on the passenger side), preferably less than about 15 g. In this case, about 150-1
It is preferred to use 90 g of pressurized medium 36 with about 10-30% oxygen of pressurized medium 36 on a molar basis. More specifically, when about 169 g of pressurized medium 36 is used with about 15% oxygen of the pressurized medium 36 on a mole percent basis, the total weight of propellant grains 90 is about 1%.
It is 0.4 g. When used on the driver's side, the desired / required amount of propellant grains 90 is about 5 g, and when used on a side inflator is about 1.5 g.

The reduction in the amount of gun-type propellant described above relative to the composition of FN 1061-10 propellant described above can also be expressed as a weight ratio of pressurized medium 36 to total weight of propellant grains 90. . Currently FN 1061-1
For propellants, the assignee of this patent application is FN 10
A ratio of about 7.04 is used for the weight of 61-10 propellant by weight of argon (i.e., high pressure gas, which corresponds to the pressurized medium 36 of the present invention). For the use of gun-type propellants, the weight ratio of pressurized medium 36 to the total weight of propellant grains 90 is about 10 to obtain an inflator having the same power, weight and dimensions as an inflator using FN 1061-10. 20, more preferably about 14-18, optimally about 15 or more. As will be appreciated, the use of higher temperature propellants can further increase these ratios and reduce the amount of propellant required. In this regard, the output gas of the gun-type propellant is essentially free of hot particulate matter, which allows the inflator to produce output gas at a higher temperature than particle-loaded inflators such as modern hybrid inflators. Due to this temperature rise, the hot gas is relatively expansive,
The inflator is smaller and lighter. In addition to the above, the structural size and weight of the inflator can generally be reduced when using gun-type propellants. For example, 7.04 for a gun-type propellant in an inflator.
The same output is obtained with the same ratio of FN 1061-10, but the inflator with gun type propellant is about 50% lighter than the inflator with FN 1061-10, and small. 7.
The ratio of 04 can be used equally favorably as described above regardless of whether it is used on the driver's seat side or the side inflator.

The reduction in the amount of gun-type propellant described above compared to the composition of FN 1061-10 propellant described above is due to the total gas power (ie, propellant gas plus additive gas) relative to the total weight of propellant grains 90. It can also be expressed as a ratio of gram moles of the mixture with the pressure medium 36). Currently FN 1
For the 061-10 propellant, the assignee of the present patent application uses a ratio of about 0.192 g moles of output gas to weight of propellant per gram of propellant. In contrast, typically for gun-type propellants for inflators of the same power, weight and size, the ratio of moles of output gas to total weight of propellant grains 90 is about 0. 35-0.6 gmol, more preferably about 0.4-0.5 gmol, optimally about 0.5 gmol. As mentioned above, in a hybrid inflator using a gun type propellant and further using a ratio of 0.192 gmol / g propellant, the output of the inflator is FN.
Similar to the hybrid inflator using 1061-10, but the gun-type propellant inflator reduces weight and size by about 50%.

The use of multiple gases for the pressurized medium 36 may be used to form at least a gun-type propellant in the propellant grains 90. Typically, the pressurized medium 36 comprises at least one inert gas and oxygen. Suitable inert gases include argon, nitrogen, helium and neon, of which argon is preferred. The oxygen portion of the pressurized medium 36 is multifunctional. Initially, the gaseous combustion products of the gun-type propellant of propellant grains 90 react with oxygen to provide a heat source that causes the inert gas to expand. This may at least partially reduce the amount of propellant required for the gas generator 82. In addition, the reaction of oxygen with the propellant combustion products reduces the existing toxicity levels of propellant gases to acceptable levels. For example, oxygen is preferably a substantial portion of existing carbon monoxide to carbon dioxide (eg, at least about 85% of CO to CO ₂ ) and existing hydrogen to water vapor (eg, at least about 80% of H ₂ ). To H ₂ O) and a substantial portion of the unburned hydrocarbons are similarly removed (eg, at least 75% of the hydrocarbons are removed). Thus, the performance of the gas generator 82 is greatly improved as described above. That is, the pressure medium 36 containing oxygen has an end portion 96 of the gas generator housing 86 due to the pressure difference generated by the flow of the pressure medium 36 near the side wall of the gas generator housing 86 having the discharge nozzle 200 on the side wall. Is drawn into the gas generator housing 86 via the suction nozzle 98 at. As a result, the pressurized medium 36 and the combustion products rich in CO and hydrogen of the gas generation source are mixed, and the total combustion efficiency of the gas generation source, the combustion products of the gas generation source and the pressurized medium 36 rich in oxygen. The burning rate of the mixed and propellant grains 90 is significantly improved. Then, the gas is extracted from the discharge nozzle 200 on the side wall of the gas generator housing 86. Thus, the above configuration of the gas generator housing 86 significantly improves the performance of the inflator 30 (eg, by mixing oxygen and propellant gas quickly and efficiently).

Usually, the amount of at least one inert gas is about 70-90% on a molar basis and the amount of oxygen is about 10-30% on a molar basis. In general, it is desirable to use an amount of oxygen that exceeds the theoretical conversion-based amount. However, it is also generally desirable not to have more than about 20% (mol) oxygen in the output gas (ie, the mixture of propellant gas and pressurized medium).

The inflator 30 is assembled as follows. First, the gas generator 82 is assembled as follows. 1) Baffle 100 and screen 104 are inserted into gas generator housing 86 so as to be adjacent to discharge end 96, 2) Propulsion sleeve 94 is inserted into gas generator housing 86, and 3) Propellant grain 90 Is placed in the propulsion sleeve 94 and 4) the baffle 112 in the gas generator housing 86 is adjacent to the end of the propulsion sleeve 94 in the opposite direction of the discharge end 96 of the gas generator 82.
And retainer 108, and 5) insert ignition / booster agent 144 and charge cup 148 together with detonator holder 116 into gas generator housing 86, and 6) operate guide 14
0, the plate washer 136 and the working piston 124 are inserted into the gas generator housing 86. After this, the various parts are interconnected as follows. After the gas generator housing 86 is welded to the orifice sleeve 74 and the projectile 50 and the initiator 46 are placed on the diffuser 38, the diffuser 38 is welded to the boss 66 and a closing disc between the boss 66 and the orifice sleeve 74. Weld 70 and boss 66 to inflator housing 34. The inflator housing 34 having the above structure is secured.
The pressurized medium 36 can be introduced into the inside. In this regard, in the case of multiple gases, argon and oxygen can be introduced separately into the inflator housing 34 via end plugs 42 welded to the ends of the inflator housing 34 (eg, first argon and / or other). Of the inert gas and then oxygen, or vice versa.), Or in a premixed state.

The following examples further serve to describe various features associated with the use of gun-type propellants in hybrid inflators. Example 1: The above HPC-96 propellant was used to form a total weight of 18 g of propellant grain 90. Each propellant grain 90 has the shape shown schematically in FIG. 2, having a length or thickness of about 0.52 inch (1.32 cm) and an outer diameter of about 0.12.
The thickness was 29 inches (0.737 cm), and the drug thickness was about 0.105 inches (0.267 cm) (1/2 of the difference between the inner diameter and the outer diameter of the propellant grain 90). In addition, HPC-96 propellant exhibited the following properties when ignited under air. Exercise power of 363,493 ft-lbs / lb, explosion heat of 1,062 calories / g, TV of 3,490 ° K, gas molecular weight of 26.7 g / mol, specific heat ratio of 1.21.
96, and the solid phase density was 1.65 g / cm ³ . Based on the theoretical calculation of normal composition, the composition of the gas assumed to be burned at the gun pressure expanded to atmospheric pressure is about 26.5% carbon monoxide and about 19.1% water on a mole percent basis. , About 26.2% carbon dioxide, about 13.7% nitrogen,
It was about 14.2% hydrogen and about 0.3% other gases.

HPC-96 propellant grain 90 began to discolor within about 40 minutes and ignited within about 5 hours when exposed to a temperature of 120 ° C. in the industry standard Taliani heat resistance test. This reduces the relevance of using HPC-96 propellant for propellant grains 90. that is,
One current industry standard stipulates that propellants for inflatable safety systems will not deteriorate significantly when exposed to a temperature of 107 ° C for 400 hours, and will then ignite when exposed to an auto ignition temperature. This is because However, HPC-
96 propellants are described herein to demonstrate certain principles of the invention.

For HPC-96 propellant grain 90, about 169 g of pressurized medium 36 was provided in the inflator housing 34 and was composed of about 5% oxygen and about 95% argon on a mole percent basis. The inflator 30 includes four orifice ports 78 on the orifice sleeve 74, each having a diameter of about 0.676 cm.
(0.266 inches) and the diameter of the gas generator suction nozzle 98 was about 1.191 cm (0.469 inches). The discharge nozzle 200 was not provided on the side wall of the gas generator housing 86. Thus, during operation, the pressurized medium 36 was not drawn into the gas generator 82, and all discharge was done through the suction nozzle 98.

The pressure fluctuation inside the inflator housing 34 during the operation of the inflator 30 was as shown in FIG. 10 connected to the inflator 30
The internal pressure of the 0 liter tank is the pressure as shown in FIG. 4, which schematically represents the pressure increase in the air / safety bag 18. The gas output from the inflator 30 is about 1.2% carbon monoxide, about 1.5% carbon dioxide, about 2% or more hydrogen and about 60 ppm NO on a weight percent basis.
Contains X. Therefore, the use of the above proportions of oxygen and argon significantly reduced the amount of carbon monoxide and hydrogen compared to the theoretical gas output of the HPC-96 propellant described above. In this example, without radial holes,
Only one gas generator outlet was used.

Example 2: The steps of Example 1 were repeated. However, propellant grain 90 used 10.4 g of HPC-96 propellant and about 164.4 g of pressurized medium 36 with a composition of about 15% oxygen and about 85% argon on a mole percent basis. . The performance curves when the inflator 30 is operated with these propellant grains 90 are shown in FIGS. The inflator 30 was shaped as discussed in Example 1. Further, the gaseous output from the inflator 30 is about 2.4% carbon dioxide, about 1,000 ppm carbon monoxide, about 70 ppm on a mole percent basis.
Of NOx, about 38 ppm NO ₂ and about 0 ppm hydrogen. Therefore, by increasing the oxygen amount from 5% in Example 1 to 15%, the carbon monoxide amount was significantly reduced without increasing NO and NO ₂ so much. In addition, this also drastically reduced the amount of propellant used.

Example 3: Using 10.4 g of HPC-96 and 169.0 g of pressurized medium 36 with a composition of about 15% oxygen and about 85% argon on a mole percent basis, the procedure of Example 1 is repeated twice. Repeated. The performance curve of the inflator 30 is similar to that of FIGS. 3 and 4, and the inflator 30 has the shape as discussed in Example 1. Furthermore, the inflator 3
The gaseous output from 0 is about 1,000 ppm, 8
00ppm carbon monoxide, about 1.0%, 1.2% carbon dioxide, about 60ppm, 50ppm NOx, about 23p
pm, containing 20 ppm NO ₂ . Therefore, 15%
By increasing the oxygen content and reducing the HPC-96 content, the carbon monoxide content was reduced without significantly affecting NO and NO ₂ . Furthermore, the amount of propellant used has decreased due to the increase in the amount of oxygen.

As noted above, two existing "conventional" gun-type propellants were initially considered in this example.
A conventional double base gun propellant and a low fragility nitramine (LOVA) gun propellant. The system works as expected with conventional double-base gun propellants,
Does not pass industry standards for long-term storage (eg,
400 hours at 107 ° C). In LOVA gun propellant,
Combustion of the propellant at high pressures (eg, 9000 psi and above) proves to be inadequate system performance, which adds to design weight, cost and complexity. Generally, it is desirable that the operating pressure used for inflator 30 be only about 4,000 psi. Under these conditions, no propellant suitable for this example currently exists, and thus a new method for forming a new propellant that constitutes a new type of propellant was developed. That is, the ballistic characteristics of the double base propellant (excellent in ignition and combustion at low pressure) and the storage characteristics of the nitramine LOVA propellant (10
It has excellent performance after storage at 7 ° C. for 400 hours). This type of propellant is called a mixed propellant.

Heat-resistant gun-type propellants, unlike nitrocellulose-based propellants such as HPC-96, are secondary explosives in the case of LOVA propellants, namely nitramine, when used as the formation of propellant grains 90. (RDX) is contained. Other secondary explosives suitable for use in forming propellant grain 90 include other nitramines, namely HMX.
(Cyclotetramethylene tetranitramine) and P
There is also ETN (pentaerythritol tetranitrate) and TAGN (triaminoguanidine nitrate).
Table 1 below shows the combustion characteristics of RDX, HMX and PETN secondary explosives.

[0043]

[Table 1] Usually to combine certain ballistic properties with long-term heat resistance as desired (eg, to obtain ballistic properties of double-base propellants as well as long-term aging properties or long-term thermal stability of LOVA propellants). A secondary explosive is combined with the binder system to form the propellant grains 90 ("hybrid propellant" as described above). The term "binder system" as used herein refers to one or more compounds that are useful for modifying the physical, chemical and / or ballistic properties of the propellant and are added to the propellant. Useful binder systems include binder systems that incorporate a propellant additive selected from the group consisting of binders, plasticizers, stabilizers, opacifiers and these compounds.

The hybrid propellant for propellant grains 90 in the hybrid inflator 30 exhibits excellent ballistic properties (ie, burn rate and temperature at relatively low operating pressures) and has reasonable long-term stability (eg, One of the industry tests to evaluate the long-term heat resistance is a statistically sufficient number of samples that can withstand a temperature of 107 ° C. for 400 hours (without ignition). Another test is an inflator 30 that can withstand a temperature of 100 ° C. for 400 hours without unacceptable performance degradation (typically set / specified by the customer). More specifically, the propellant grains 90 formed from mixed propellants have a weight of about 2,000 to 3,8.
Combustion temperature of 00 ° K, about 0.1-1 inch / sec
(0.25-2.5 cm / sec), about 4,000
It burns at an operating pressure (pressure inside the gas generator housing 86) of 0 psi (27.6 MPa) or less. More preferably,
Propellant grains 90 made from mixed propellants have about 2,
Combustion temperature of 000-3,800 ° K, about 0.3-0.5
It burns at a speed of inch / sec (0.76 to 1.26 cm / sec) and an operating pressure of about 4,000 psi (27.6 MPa) or less.

Generally, about 50-90 is used to form the mixed propellant.
It contains wt% secondary explosive and about 10-50 wt% binder system. More generally, about 60-80 wt% of secondary explosive and about 20-80 wt% are used to form these propellants.
It contains 40 wt% binder system. Preferably, the propellant formulation contains about 70-80 wt% of the particular secondary explosive and about 20-30 wt% of the binder system. Other additives and unavoidable impurities may be present in trace amounts in the composition of these propellants (ie, composition amounts of about 5 wt% or less).

Usually, the resinous binder is the propellant grain 90.
Be part of a binder system for the formation of a hybrid propellant for a vehicle. Ordinary solvent (ie acetone, lower alcohol, etc.)
Generally, any type of binder that is soluble in can be used. However, it is generally desirable that the binder be an active compound. That is, it is desirable that the binder easily burn at the desired burning temperature and operating pressure. Moreover, when used with a plasticizer, it is, of course, desirable that the binder be compatible with the plasticizer. Typical binders suitable for use in propellant formulations include CA (cellulose acetate), CAB (cellulose acetate butyrate), EC
(Ethyl cellulose), PVA (polyvinyl acetate), C
There are, but are not limited to, AP (cellulose acetate propiolate), azido polymer, polybutadiene, hydrogenated butadiene and polyurethane, and mixtures thereof. The azido polymer is at least one of a homopolymer and a copolymer having a monomer selected from the group consisting of GA (glycidyl azide) monomer, BAMO (3,3-bis (azidomethyl) oxetane) monomer, AMMO (azidomethylmethyloxetane) monomer. Including one. In addition, GAP (active glycidyl azide polymer) is used as a binder element, which burns substantially more vigorously than CA. This makes it desirable to use only GAP as the binder together with the secondary explosive. However, due to the current significant cost differences between GAP and CA, the formation of hybrid propellants involves both GAP and CA components. Plasticizers can also be used as part of the binder system for the formation of hybrid propellants for propellant grains 90. As mentioned above, the plasticizer should be compatible with the binder. Further, it is generally desirable to use an extrudable binder system. In addition, it is desirable to use an active plasticizer for at least some secondary explosives (eg nitramine), i.e., a plasticizer capable of stable combustion at the operating temperatures and pressures described above. Useful active plasticizers include nitrate ester plasticizers such as TMETN (trimethylolethane trinitrate), BTTN (butanetriol trinitrate), and TEGDN (triethylene glycol dinitrate), glycidyl azide plasticizer and NG (nitroglycerin). )
And other compounds such as, but not limited to, BDNPA / F (bis (2,2-dinitropropyl) acetal / formal), ATEC (acetyltriethylcitrate).

Stabilizers can also be included in the binder system for the formation of hybrid propellants for propellant grains 90. For example, certain binders and / or plasticizers, such as the nitrate ester plasticizers described above, may decompose when exposed to certain temperatures, affecting the ignition of the propellant grains 90 (ie, at certain temperatures). When exposed to, the nitrate ester plasticizer thermally decomposes to the extent that ignition occurs. Thus, a stabilizer is included in the formation of the hybrid propellant to "react" with the pyrolytic binder and / or plasticizer to maintain stability (eg,
Reduce the risk of pre-ignition of the propellant), improve the long-term stability of the formation of mixed propellants. For example, in the case of nitrate esters, stabilizers useful in the formation of propellants include stabilizers that are activators but nitric acid acceptors. Suitable stabilizers include, but are not limited to, ethyl centralite (sym-diethyldiphenylurea), DPA (diphenylamine) and resorcinol.

One of the formation of a hybrid propellant having desired ballistic properties and sufficiently showing suitable long-term stability is to form the nitramine secondary explosive RDX (hexahydrotrinitrotriazine) and a binder. There is a combination with CA (cellulose acetate), the plasticizer TMETN (trimethylolethane trinitrate) and the stabilizer EC (ethyl centrallite). Typically, this hybrid propellant formation is at least about 70 w.
t% RDX, about 5-15 wt% CA, about 5-15w
It consists of t% TMETN and only about 2 wt% EC. These approximate relative amounts provide the desired ballistic and long-term aging properties for the hybrid propellant. However, it will be understood that if the propellant grains 90 are formed from this formation by extrusion, it is necessary to refine the relative amounts within the above numerical range.

Also, at least about 70% by weight of the propellant.
RDX (hexahydrotrinitrotriazine) of
About 5 to about 15% by weight CA (cellulosic acetate)
And about 5 to about 15% by weight of either GAP (glycidyl azide polymer) or ATEC (acetylethyl citrate). Generally, when a mixture of a binder, a plasticizer and a stabilizer is used as a binder system, the mixing ratio of each drug is about 5% by weight.
To 30% by weight, 0% to 20% by weight and 0% by weight
To 5% by weight is desirable.

Another hybrid propellant with the desired impact properties and suitable long-term stability is Nitramine secondary explosive RD.
X, a binder system containing CA and GAP (glycidyl azide polymer) as binders, and suitable plasticizers (eg GAP plasticizer, TMETN, ATEC and combinations thereof). Generally, the hybrid propellant is at least about 70 wt%, typically about 70-80 wt%.
RDX, about 5-15 wt% CA, and about 5-15w
It has t% GAP and about 5-15 wt% plasticizer. These relative amounts give the desired impact and long-term aging properties to the mixed propellant.
s) is added. However, if the propellant grains 90 are formed from this hybrid propellant by extrusion, adjustment of the relative amounts within the above ranges may be required. In the case of hybrid propellants, including the double base propellants and LOVA propellants described above, large amounts of carbon monoxide and hydrogen are formed on combustion (eg 35% CO and 19% H ₂ are formed on combustion). . The formation of carbon monoxide and hydrogen gas from the combustion of inflator propellants is not generally acceptable in inflatable safety systems for motor vehicles. But,
When these types of hybrid propellants are used in the hybrid inflator 30, nearly all of the carbon monoxide and hydrogen (eg 95%) is converted to harmless carbon dioxide and water vapor as part of the reaction during or after combustion. Pressurizing medium 3
6 contains oxygen. The use of high pressure oxygen is particularly desirable because it eliminates the need to include an oxygen source (eg potassium perchlorate) in the hybrid propellant.
In addition, the highly exothermic reaction that occurs between the combustion gases formed from the propellant and the high pressure oxygen increases the heating value of the propellant, thereby minimizing the amount of propellant required to inflate the air / safety bag. The same highly exothermic reaction is particularly preferable in order to suppress the reaction to the limit.

When the mixed propellant is formed as a propellant grain 90 and is inserted into the mixed inflator 30, it can be used in the specific amounts shown in the gun-type propellant above, and the propellant grain 90. And may specifically include the features described above with respect to the relative amount of pressurized medium 36. Further, the relative amounts of oxygen and one inert gas used in the pressurized medium 36 can be used in the hybrid propellant disclosed herein.

The following example illustrates the properties associated with a mixed propellant containing a secondary explosive and a binder system. In addition, as described above, "Wt%" indicates weight percent. Example 4: At least about 70 wt% RDX (hexahydrotrinitrotriazine), about 5-15 wt% CA.
(Cellulose acetate), TME of about 5-15 wt%
TN (trimethylolethane trinitrate) and about 2
A mixed propellant composition containing less than wt% ethyl centrallalite was prepared, the propellant composition containing about 1.7132 g.
Formed as a cylindrical grain with an average density of / cc. Insert 10g of sample into bomb chamber with thick wall,
And it exploded into the tank. The sample is 4,000
It has a combustion temperature of about 2,578 ° K at psi (27.6 MPa) and has acceptable impact properties (ie, 0.
47 inches / second (1.18 cm / second). The performance curve for this was generally in good agreement with the curves shown in FIGS. The gas formed had about 36% carbon monoxide, about 24% nitrogen, about 19% hydrogen, about 16% steam and about 5% carbon dioxide. An evaluation of the long-term thermal stability of the hybrid propellant composition was conducted, and as a result it was confirmed that the long-term thermal stability of the composition was within the acceptable range (for example, propellant was maintained for 400 hours). The propellant did not ignite when exposed to a temperature of 107 ° C. Also, the propellant was placed in a mixed inflator,
The propellant did not ignite when exposed to a temperature of 107 ° C. for 400 hours. After that, the propellant was activated, but the performance of the inflator was not substantially affected by the heat treatment).

Example 5: At least about 70 wt% RDX
(Hexahydrotrinitrotriazine), about 5-15
wt% cellulose acetate, and about 5-15 wt%
A mixed propellant composition comprising GAP (Glydyl Azide Polymer) of about 1.685 was prepared.
It was formed as a cylindrical grain with an average density of 7 g / cc. A 10 g sample was inserted into a bomb chamber with thick walls and exploded into the tank. 4,000 samples
About 2357 ° K at 0 psi (27.6 MPa)
Impact characteristics (i.e.,
0.48 inch / sec (1.18 cm / sec)).
The performance curve for this was generally in good agreement with the curves shown in FIGS. The gas formed is about 37% carbon monoxide, about 25% hydrogen, about 25% nitrogen, about 10%.
Of water vapor and about 3% carbon dioxide. An evaluation of the long-term thermal stability of the mixed propellant composition was conducted, and as a result it was confirmed that the long-term thermal stability of the composition was within the acceptable range (for example, the propellant was maintained for 400 hours). The propellant did not ignite when exposed to a temperature of 107 ° C. Also, the propellant did not ignite when exposed to a temperature of 107 ° C. in a hybrid inflator for 400 hours. The agent was activated, but the inflator performance was not substantially affected by the heat treatment).

Another propellant used in one or another embodiment of the present invention is hexogen (RD
X) 1-99 parts by weight and Octogen (HMX) 99-
1 part by weight, and further contains 5 to 50 parts by weight of a binder based on 100 parts by weight of RDX and HMX in total. Preferably, 80 to 95 parts by weight of hexogen (RDX) and 20 to 5 parts by weight of octogen (HMX), and further R
The binder is contained in an amount of 5 to 50 parts by weight based on 100 parts by weight of DX and HMX in total.

The propellants described above are used in the hybrid inflators described herein. A hybrid inflator is generally composed of a pressurized gas chamber containing a pressurized gas, a gas generation chamber containing a propellant, an ignition assembly, a rupturable plate and the like. The pressurized gas consists essentially of an inert fluid and oxygen. The propellant is ignited and burned by the ignition assembly in the event of a vehicle collision, producing gaseous combustion products capable of reacting with oxygen, namely carbon monoxide and hydrogen.
Carbon monoxide and hydrogen react with oxygen in the pressurized gas to generate carbon dioxide and water vapor, while at the same time increasing the pressure in the gas chamber. Then, the rupture plate is destroyed, and carbon dioxide, water vapor, and an inert fluid are supplied to the airbag 18 (FIG. 1) from the outlet of the inflator, and the airbag 18
(Fig. 1) expands.

The above propellants are hexogen (RDX),
It is composed of octogen (HMX) and binder. The ratio of RDX, HMX, and binder is HMX99 with respect to 1 to 99 parts by weight of RDX.
1 to 1 part by weight, preferably 80 to 95 parts by weight of RDX, 20 to 5 parts by weight of HMX, and 5 to 50 parts by weight of binder to 100 parts by weight of RDX and HMX in total.

The binder usable in the present invention is not particularly limited, but polyurethanes (PU), ethyl cellulose (EC), cellulose acetate butyrate (CA) are used.
B), cellulose acetate propionate (CAP)
Cellulose derivatives such as, polybutadienes such as hydroxy-terminated polybutadiene (HTPB), glycidyl acid polymers such as glycidyl nitrate polymer (polygulin),
Includes azido polymers such as glycidyl azide polymer (GAP), and polymers of 3-nitrate methyl-3-methyloxymethane (Polynimo). Among these, cellulose acetate butyrate (CAB) and /
Alternatively, glycidyl azide polymer (GAP) is desirable.

Further, the propellant of the present invention may further contain an additive selected from the group consisting of a plasticizer, a stabilizer, and these compounds, and the plasticizer includes TMETN.
(Trimethylolethane trinitrate), BTTN
(Butanetriol trinitrate), TEGDN (triethylene glycol dinitrate), glycidyl azide, NG (nitroglycerin), BDNPA / F (bis (2,2-dinitropropyl) acetal / formal) and ATEC (acetyltriethyl citrate). It is preferably selected from the group consisting of

Further, as the stabilizer which can be used for the above-mentioned propellant, for example, ethyl centrallite, diphenylamine, resorcinol, acardite, amyl alcohol, urea, petroleum jelly and the like can be used.

The amount of plasticizer added is RDX, HMX,
And 0 to 30 with respect to 100 parts by weight of the total amount of the binder.
Parts by weight are preferred. The amount of stabilizer added is RDX, H
0 for 100 parts by weight of MX and binder
-5 parts by weight is preferred.

The propellant of the present invention may be in any form such as powder, granules or pellets, but pellets are preferably used. The following are examples of some compositions suitable for use in the present invention. Example 6: Mixing materials of the following composition into pellets,
It was loaded into a hybrid inflator composed of a pressurized gas chamber, a gas generation chamber, an ignition assembly, and a rupture plate. Then, the hybrid inflator was operated. As a result, smoke composed of KCl was not generated.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, the binder (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 7: Mixing materials of the following composition into pellets,
A hybrid inflator similar to that in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 72 parts by weight Octogen (HMX) 4 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, the binder (CAB and GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 8: Mixing materials of the following composition into pellets,
A hybrid inflator similar to that in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 64 parts by weight Octogen (HMX) 12 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, the binder (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 9: Mixing materials of the following composition into pellets,
A hybrid inflator similar to that in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 75 parts by weight Octogen (HMX) 1 part by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, the binder (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 10: The materials having the compositions shown below were mixed to form pellets, which were loaded into the same hybrid inflator as in Example 6 to operate the hybrid inflator. As a result, no smoke occurred.

Hexogen (RDX) 1 part by weight Octogen (HMX) 75 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, binders (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 11: The material having the composition shown below was pelletized and loaded into a hybrid inflator similar to that in Example 6, and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 38 parts by weight Octogen (HMX) 38 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Incidentally, the binder (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 12: A material having the composition shown below was pelletized and loaded into a hybrid inflator similar to that in Example 6, and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Ethyl centralralite 2 parts by weight Incidentally, relative to RDX and HMX 100 parts by weight. The content of the binder (CAB, GAP) is about 32 parts by weight. Example 13: The materials having the compositions shown below were mixed to form pellets, which were loaded into the same hybrid inflator as in Example 6 to operate the hybrid inflator. As a result, no smoke occurred.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Trimethylolethane trinitrate 20 parts by weight (TMETN) Incidentally, RDX The content of the binder (CAB, GAP) is about 32 parts by weight based on 100 parts by weight of HMX. Example 14: The material having the composition shown below was pelletized and loaded into a hybrid inflator similar to that in Example 6, and the hybrid inflator was operated. As a result, no smoke occurred.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Ethyl centralite 2 parts by weight Trimethylolethane trinitrate 20 parts by weight (TMETN) The content of the binder (CAB, GAP) is about 32 parts by weight based on 100 parts by weight of RDX and HMX.

FIGS. 5-7 show another embodiment of a hybrid inflator that can be used in the inflatable safety system 10 shown in FIG. As shown mainly in FIG. 5, the hybrid inflator 2
02 has a generally cylindrical gas generator 208 and a generally cylindrical high-pressure gas housing 204, and the high-pressure gas housing 204 (third chamber) is the same around the gas generator 208. It is arranged to have the same central axis as the gas generator 208. Generally, the high pressure gas housing 204 has a suitable pressurized medium and the gas generator 208 has a suitable propellant grain 258. The main advantage of the inflator 202 is that its design is such that the second closure disc (main closure disc) 290 (the second closure disc 290 is the inflator 202 and air /
Blocking the flow between the safety bags 18 (see FIG. 1) (see FIG. 1)) allows for rapid pressurization in the area adjacent to the fluid pressure created by the second closing disc. The closing disc 290 to open the 290
Acts directly on. Another important advantage regarding the design of the inflator 202 is that it provides or enables sufficient mixing between the propellant gas and the pressurized medium formed by the ignition and combustion of the propellant grains 258. As a result, the inflator 202 uses at least one of the gun-type propellant composition and the mixed propellant composition as a composite pressurized medium (eg, one component is oxygen and another component is at least one). It is particularly suitable for use with complex pressurized media which are active gases. That is, the design of the inflator 202 is such that the gas formed by the ignition of the propellant gas and propellant grains 258 to facilitate the operation of the inflatable safety system 10 (see FIG. 1) (eg, the ignition / booster described in detail below). At least one of the gases formed by the combustion of agent 240) is effectively provided or allowed with the pressurized medium. This second combustion enhances the rapid pressurization capability of the inflator 202 to initiate the flow of gas into the air / safety bag (see Figure 1).

The gas generator 208 has a cylindrical gas generator housing 212, and the gas generator housing 212 is the first housing 21 in this embodiment.
6 and is axially coupled to the second housing 278. Gas generator housing 2
Since 12 contains a large amount of pressurized medium throughout its interior in the static state, one end of the first housing 216 has an adapter 224 for the initiator to form a hermetic seal.
(For example, by welding at weld 248). Initiator adapter 224 includes a suitable initiator 228 (eg, an electric ignition tube or other suitable explosive device), and
Are used to perform ignition for the propellant grains 258. The initiator 228 is also engageable on its outer circumference along the inner circumference of the O-ring 232 to form a suitable seal. In order to separate the initiator 228 from the pressurized medium contained within the gas generator 208, the first closure disc (secondary closure disc) 236 is welded to the weld 24.
First housing 2 to form a hermetic seal through
It is properly fixed between the end of 16 and the end of the adapter 224 for the initiator.

The first housing 216 of the gas generator housing 212 defines a first chamber 254. The first chamber 254 is disposed adjacent to and axially aligned with the initiator 228. First chamber 25 of gas generator housing 212
4 has primarily propellant grains 258 which, when ignited, provide air / safety bag 18
Propellant gas is formed to increase the flow of gas to (see FIG. 1). As a result, the first chamber 254 can be characterized as a propellant chamber or a combustion chamber. Propellant grain 2
A suitable ignition / booster agent 240 (e.g., an RDX / aluminum booster agent containing 89 wt% RDX and 11 wt% aluminum powder, or 0 of the RDX / aluminum booster agent) to assist ignition of 58. 0.5 to 5.0 wt% RDX and a booster agent in which aluminum is replaced with 0.5 to 5.0 wt% hydroxypropylcellulose) may be used between the initiator 228 and the propellant grain 258.
It can be arranged at a position matching the ejection from the initiator 228. As described in more detail below, the gas product formed by ignition of the ignition / booster agent 240 can chemically react with the pressurized medium to further enhance the properties associated with initiation of flow by rapid pressurization of the inflator 202. Is. A suitable booster cup 244, or the like, holds an ignition / booster agent 240 (generally in the form of a powder or slurry drier) therein and is attached to the end of the adapter 224 for the initiator and the first. Can be suitably secured to at least one of the ends of housing 216 (eg, held between adapter 224 and housing 216 via weld 248). The first chamber 254 has a screen 266 or the like to discharge the propellant gas toward the second chamber 324 as described above while retaining particulates of a particular size therein. You can Inflator 2
02 has a capacity of the high-pressure gas housing 204 of the second chamber 3
It is set larger than the capacity of 24.

The first chamber 254 is the high pressure gas housing 2
04 is generally in communication with at least one bleed orifice or bleed opening 262 (two bleed openings are formed in this embodiment). As a result, the first chamber 254 contains a large amount of pressurized medium in the static state.
The bleed port 262 extends along the radial direction (that is, the bleed port 262 has its origin on the central axis 220 and extends along a radius extending in a direction orthogonal to the central axis 220). ). In order to properly adjust the performance of the inflator 202, the use of the extraction port 262 and the extraction port 262
It is possible to select the size and / or the quantity.

By forming at least one extraction port 262, a certain amount of the flow of the propellant gas formed by the ignition of the propellant 258 can be controlled by the high pressure gas housing 2.
You will be guided in 04. Propellants of the types described above (eg gun-type propellants, hybrid propellants) and pressurized media (eg
If a mixture of oxygen and an inert fluid (containing at least one inert gas) is used, a second combustion, i.e. a further combustion of the propellant gas, takes place in the high-pressure gas housing 204. A portion of the propellant gas is stored in the first chamber 254
To guide into the high pressure gas housing 204 from
It can be used to achieve a desired output or delivery to the air / safety bag 18, i.e., a desired inflation rate of the air / safety bag 18. As described in detail below, the propellant gas is propelled to the high pressure gas housing 20 at a rate that maintains a substantially constant flow of gas from the high pressure gas housing 204 to the second chamber 324 for a sufficient period of time.
It is preferable to provide within 4. Generally, less than half of the propellant gas formed to achieve the desired result (eg, less than or equal to about 40% of the propellant gas, and more typically less than or equal to about 30% of the propellant gas is high pressure gas). The high pressure gas housing 204 during operation)
It is necessary to flow in.

The pressure increase in the high pressure gas housing 204 after ignition of the propellant grains 258 is significantly less than the pressure increase found in many commercial hybrid inflators, even with the bleed port 262. That is, the substantial pressure increase that generally accompanies ignition of the propellant grains 258 is substantially confined within the gas generator 208. As a result, the strength condition of the high-pressure gas housing 204 can be reduced. This allows at least one of reducing the wall thickness of the high pressure gas housing 204 and / or using a lightweight material for the high pressure gas housing 204. Both of these reduce the weight of the inflator 202.

The main flow of propellant gas formed in the first chamber 254 (eg, at least about 50%, and generally at least about 70% of the total flow of propellant gas) is directed to the gas generator housing 212. It is guided into a second chamber 324 (referred to as an "afterburner" for reasons detailed below) formed by a second housing 278. At least one afterburner nozzle or aspirator 274 (first through hole) is located in the first chamber 25.
Gas flow from 4 into the second chamber 324 (mainly propellant gas)
Through which the desired communication is formed. The afterburner nozzle 274 is located in the first housing 21.
Shoulder 2 formed inside first housing 216 prior to properly connecting 6 to second housing 278 (eg, by welding at weld 250).
70 for engaging the first housing 216
Placed inside.

In this embodiment, the gas generator housing 21
One end of the second housing 278 of No. 2 is engaged with the inner surface of the afterburner adapter 282 having at least one gas generator outlet 286 therein. O-ring 328 is disposed between second housing 278 and adapter 282 to provide a suitable seal. Afterburner adapter 282 is boss 294
Properly secured to (eg, weld 308
), And the boss 294 is fixed to the high-pressure gas housing 204 (for example, the welding portion 312 is fixed by welding). Second chamber 324
Has a large amount of pressurized medium in the static state,
These two fixations are preferably made to form a hermetic seal. A second closure disc 290 provides an afterburner adapter 2 to properly hold the pressurized medium within the inflator 202 until the desired time is reached.
It is located between the end of 82 and the boss 294 and is held by the weld 308.

Due to the communication between the first chamber 254 and the second chamber 324, at least a portion of the propellant gas formed by the combustion of the propellant grains 258 and the gas formed by the ignition of the ignition / booster agent 240. Are guided into the second chamber (afterburner chamber) 324. A second chamber 324 controlled according to the method detailed below.
The sudden increase in pressure within causes the second closure disc 290
Is opened at the appropriate time and the flow of gas from the inflator 202 is directed to the diffuser 298 and then into the air / safety bag 18 (see FIG. 1). The diffuser 298 includes a plurality of diffuser ports 300 to provide less disruptive output to the air / safety bag 18 (see FIG. 1). Keeping certain particulates in the inflator 202 and mixing or reaction of the propellant gas and pressurized medium prior to passing the propellant gas and pressurized medium toward the air / safety bag 18 (see FIG. 1). The diffuser 298 may include a diffuser screen 304 to achieve at least one or more of the further enhancements.

Further, the second chamber 324 communicates with the high pressure gas housing 204. At least one, and preferably a plurality of gas generator inlets 316 form communication between the high pressure gas housing 204 and the second chamber 324. As a result, the pressurized medium in the high-pressure gas housing 204 can flow into the second chamber 324 at an appropriate time.
That is, the flow direction of this particular gas flow can be controlled in a particular application. In particular, valve 320 may be located adjacent at least one, and preferably all gas generator inlets 316. In the static state, the valve 320
Need not actually separate the high pressure gas housing 204 from the second chamber 324 in this region. In fact, a large volume of pressurized medium is preferably held in the second chamber 324 in a static state. This allows an unsealed connection to be used for such a supply. One configuration of the valve 320 that does not separate the second chamber 324 from the high pressure gas housing 204 on the gas generator inlet 316 includes a filler material made up of substantially cylindrical rolls (eg, 300 series stainless steel). And has a thickness of 0.002 inches (about 0.0508 m
m)). A cantilever connection can be used between the valve 320 and the inner wall of the second housing 278. At this time, the rear portion of the valve 320 (that is, a portion sufficiently separated from the inlet 316) is coupled to the second housing 278, and the front portion and the intermediate portion of the valve 320 are not coupled to others. As a result, valve 320 is free to move or deflect.

From the above, the high pressure gas housing 2
It can be seen that the pressures that spread inside the gas generator housing 04 and the gas generator housing 212 are substantially equal in the static state. However, dynamic state or propellant grain 25
After ignition of No. 8, the pressure in each chamber of the inflator 202 is different from each other to achieve the desired performance. When ignition is performed on the propellant grains 258, the propellant gas formed begins to flow into at least the second chamber 324 to increase the pressure in the second chamber 324. Since the inflator 202 has at least one extraction port 262, part of the propelling gas is stored in the high-pressure gas housing 20.
4 and the high-pressure gas housing 20
Within 4, there is a small increase in pressure. Second chamber 32
The pressure increase rate in 4 is the high pressure gas housing 20
It is preferable that the rate of pressure increase within 4 is even faster. This difference in pressure increase rate occurs based on the inflow of the propellant gas into each of the second chamber 324 and the high-pressure gas housing 204 and the relative difference in capacity between them. This pressure differential causes the valve 320 to be pressed against the gas generator housing 212, and more specifically against the inner wall of the portion of the second housing 278 that is aligned with the valve 320. As a result, the high-pressure gas housing 204 is
The gas generator inlet 316 is separated from the second chamber 324 by being blocked by the valve 320. The cantilever connection of the valve 320 described above allows movement of this valve 320. When the pressure in the second chamber 324 reaches a predetermined pressure value, the fluid pressure acting directly on the second closing disc 290 opens, breaks or breaks the same. As a result, the opening of the disc 290 creates a gas flow from the gas generator 208 to the diffuser 298 and the air / safety bag 18 (see FIG. 1).

The valve 320 is an air / air valve for specific applications.
It allows the gas flow to be initiated into the safety bag 18 (see FIG. 1) in a timely manner. In certain designs, the use of valve 320 allows the use of a second closure disc 29.
The second chamber 324 can be rapidly pressurized at a rate such that 0 can be opened in a timely manner. When the inflator 202 does not have the valve 320, the propellant gas flows from the second chamber 324 into the high pressure gas housing 204. In this case, it may take a longer time for the internal pressure of the second chamber 324 to reach a pressure value at which the second closing disc 290 can be broken. However, the use of the second chamber 324 provides a smaller pressure chamber, which allows the air / safety bag 18 to be
The time required to initiate the flow of gas to (see FIG. 1) is reduced. As will be described in more detail below in a particular design, the volume of the second chamber 324 is sufficiently small and the propellant and pressurized medium are used to achieve satisfactory operation without the use of the valve 320. At least one of the selections may be performed (e.g., formed by combustion of at least one of propellant grains 258 and ignition / booster agent 240 to effect rapid pressurization in second chamber 324). Utilizing the combustion of the gas that was made).

The valve 320 maintains its deployed position after the second closure disc 290 has been opened to form a flow of gas to the air / safety bag 18 (see FIG. 1), and thereby the gas. The generator inlet 316 is shut off for a specified time. However, if a certain pressure differential is created between the high pressure gas housing 204 and the second chamber 324, the valve 320 will cause the gas generator inlet 316.
Is moved by the pressing force provided by this pressure difference to expose the. When the valve 320 is formed as described above,
The free end of the valve 320 moves radially inward toward the central axis 220, or recesses the valve 320 into at least a region that is radially aligned with the gas generator inlet 316. This allows the desired gas flow through the gas generator inlet 316.
However, the valve 320 is retained by its connection to the second housing 278. Gas generator inlet 316
When is exposed, the gas starts to flow from the high-pressure gas housing 204 into the second chamber 324. The valve 320 is movable from the first position to the second position. That is, the valve 320 is placed in the first position in use to substantially block said flow. When the pressure in the high pressure gas housing 204 exceeds the pressure in the gas generator housing 212 by a predetermined amount, the valve 320 moves to a second position to allow the flow and the second position is a radius. It is located inside the first position along the direction.

The second chamber 3 after the second closing disc 290 has been broken by the rapid pressurization of the second chamber 324.
The primary function of 24 is to provide or allow effective mixing of the propellant gas and pressurized medium before it is expelled into the air / safety bag 18 (see FIG. 1). That is. Propellant compositions of the type described above (eg,
If a gun type propellant, a mixed propellant) and a pressurized medium of the type described above (for example a mixture of an inert fluid and oxygen represented by those containing at least one inert gas) are used, this mixture Propulsion to provide the aforementioned benefits, including, for example, reducing toxicity and reducing the total amount of propellant used in the inflator 202 by further combustion and increasing the expansion capacity resulting from the combustion. Results in further combustion of the gas. In this case, the second chamber 324
Is further characterized as an afterburner. Preferably at least about 99% of the total combustion of the propellant gas and the gas formed by ignition of ignition / booster agent 240 occurs in inflator 202, and more preferably about 100% of such combustion occurs. This is an air / safety bag 1
8 (see FIG. 1) reduces the risk of damage.

In order to realize the full effect of this second combustion, the second chamber 324 is provided with a gas formed either by its length or by the formation of turbulence, as will be detailed below. And it is necessary to provide or allow sufficient mixing of the pressurized medium. In the embodiment shown in FIG. 5, the afterburner nozzle 274 and the gas generator outlet 28 of all the gas generator inlets 316 are used in the driver side.
The portion closest to 6 is spaced from the gas generator outlet 286 by at least 15 mm. This interval can be set in the range of 4 mm to 80 mm. The increased length of the second chamber 324 allows the high pressure gas housing 204
From the second chamber 324 to a second chamber 324, a sufficient amount of pressurized medium that reacts with the propellant gas formed before the gas flow is initiated can be contained in the second chamber 324 in a static state. Become. That is, a sufficient amount of pressurized medium that reacts with the propellant gas is supplied to the second chamber 324 until the movement of the valve 320 causes the pressurized medium to flow from the high-pressure gas housing 204 to the second chamber 324. It is preferable that it is included from the beginning.

In order to realize the effect of the "long" second chamber 324, the gas generator inlet 316 is preferably formed at a position sufficiently separated from the gas generator outlet 286. Preferably, the most mesial or most forward portion of all gas generator inlets 316 (each of gas generator inlet 316) to facilitate further mixing of the propellant gas and pressurized medium. (Defined by the centerline) is aligned with the end of the afterburner nozzle 274 along the length of the second housing 278, and the portion in front of it is located in the afterburner nozzle 274 as shown. -It is preferable that the nozzle 274 is arranged further rearward (that is, in the direction toward the initiator 228) than the end portion of the nozzle 274.

Although the dimensions of any design of the inflator 202 can be changed, as shown in Table 2, the preferable range of the capacity of the inflator housing 204 varies depending on the use of the inflator. For example, the capacity of the inflator housing 204 is about 150 cm ³ to about 450 c.
m ³ , the volume of the first chamber 254 is about 10 cm ³ to about 40 c
m ³ , and the volume of the second chamber 324 is about 1 cm ³ to about 50
It is cm ³ .

Further, in order to show the principle of the present invention, its dimensions in one embodiment will be exemplified below. 1) The high-pressure gas housing 204 has a diameter of about 59 mm. 2) The length of the high pressure gas housing 204 is about 200 mm.
3) The high pressure gas housing 204 is made of mild steel tube and its wall has a wall thickness of about 2.5 mm.
4) The internal volume of the high-pressure gas housing 204 (the volume of the interior of the high-pressure gas housing 204 containing the pressurized medium, which includes the volume of the gas generator 208 located at the center thereof). No) is about 375 cc.
5) The diameter of the first housing 216 of the gas generator housings 212 is about 20 mm. 6) First room 2
The length of 54 is about 55 mm. 7) The first housing 216 is made of mild steel and its wall is about 1.5 mm.
It has a wall thickness of. 8) Gas generator housing 212
Of the first chamber 254 has an internal volume of about 11 cc. 9) The diameter of the second housing 278 of the gas generator housing 212 is about 17 mm. 10) The length of the second chamber 324 is about 90 mm. 11) The second housing 278 is made of mild steel and its wall has a wall thickness of about 1.25 mm. 12) The internal volume of the second chamber 324 of the gas generator housing 212 is about 14 cc. 13) Inflator 202 is about 3mm
It has six extraction ports 262 each having a diameter of. 1
4) The inner diameter of the afterburner nozzle 274 is about 2.5.
mm. 15) The outlet 286 for the gas generator is about 10 m
It has a diameter of m. 16) All of the gas generator inlets 316 are arranged at positions separated from the gas generator outlets 286 by about 76 mm. 17) The nozzle 274 is arranged at a position separated from the gas generator outlet 286 by about 75 mm. 18) The diffuser 298 has an internal volume of about 4
It is cc. 19) The inflator 202 has twelve diffuser ports 300. 20) The total weight of the propellant grains is about 9 g, and the propellant grains are R
It includes a composition of the above type with DX, CA, TMETN and a stabilizer. 21) The static pressure in the inflator 202 is about 20.7 MPa, and the inflator 202 contains about 140 g of pressurized medium. 85 of the pressurized medium
% (Mole percent) is argon and 15% (mole percent) is oxygen. 22) Inflator 202
Has a total weight of about 1,200 g.

When helium is included in the pressurized medium to detect gas leakage, its composition is on a molar basis.
Preferably about 8% to about 30% oxygen, about 60% to about 91% argon, and about 0.5% to about 10% helium.

The operation of the inflator 202 will be described with reference to FIGS.
This will be described in detail based on D and FIGS. 7A to 7D. As shown in FIGS. 6A and 7A, the second closure disc 290 is intact in the static state and the valve 320 does not need to separate the high pressure gas housing 204 from the second chamber 324. Initiator 228 is activated when the appropriate signal is detected by detector / sensor 14 (see FIG. 1) indicating that air / safety bag 18 (see FIG. 1) needs to be deployed. Activation of the initiator 228 breaks the first closure disk 236, ignites the ignition / booster agent 240, and ignition of the ignition / booster agent 240 ignites the propellant grains 258. Combustion of propellant grains 258 forms propellant gas in first chamber 254. The propellant gas is the second chamber 3 of the gas generator housing 212.
24 and the high-pressure gas housing 204. The presence of the hot propellant gas in the first chamber 254 and the inflow of this hot propellant gas into the second chamber 324 and the housing for high pressure gas 204 causes these "vessels" to enter.
A corresponding increase in pressure occurs within.

In order to rupture the second closure disc 290 at the appropriate time, thereby initiating the flow of gas into the air / safety bag 18 (see FIG. 1), the second chamber 32 is opened.
The pressure increase rate in 4 is designed to be faster than the pressure increase rate in the high pressure gas housing 204 by guiding the hot propellant gas into the inside. As shown in FIGS. 6B and 7B, this pressure differential causes the valve 320 to move to the second housing 324 to isolate the high pressure gas housing 204 from the second chamber 324 to affect the rapid pressurization of the second chamber 324. Press toward the inner wall of 278. Since the supply of the pressurized medium that reacts with the propellant gas is stopped, the total amount of the pressurized medium existing in the second chamber 324 in the static state is between the high pressure gas housing 204 and the second chamber 324. It must be sufficient to react with the propellant gas guided into it before forming direct communication.

As shown in FIG. 6C, when the pressure in the second chamber 324 reaches a predetermined value, the fluid pressure acting directly on the second closing disc 290 causes the second closing disc 290 to rupture. , Which allows the outlet 286 for the gas generator
A gas flow is formed therethrough towards the diffuser 298 and the air / safety bag (see FIG. 1). However, as shown in FIGS. 6C and 7C, the valve 320 blocks direct gas flow from the high pressure gas housing 204 to the second chamber 324 by closing the gas generator inlet 316. As shown in FIGS. 6D and 7D, after a certain pressure difference is created between the high pressure gas housing 204 and the second chamber 324, this pressure difference is transferred from the high pressure gas housing 204 to the second chamber 324. The valve 320 is separated from the gas generator inlet 316 to form the flow of the pressurized medium. For example, due to the structure of the valve 320 shown here (eg, a cylindrical roll of metal foil), the valve 320 may form when the specified pressure differential is created in an area adjacent or aligned with the gas generator inlet 316. The front part of the indentation or moves inward along the radial direction. However, the rear portion of the valve 320 maintains the connection with the second housing 278.

Thus, the design of the inflator 202 is a system that includes the propellants (eg, gun-type propellants, mixed propellants) and pressurized medium (eg, a mixture of oxygen and at least one inert gas) described above. It turns out to be particularly suitable for improving the performance of. For example, if the propellant and pressurized medium described above are used, the second chamber 3
A second combustion of the propellant gas and the pressurized medium occurs within 24. This further combustion causes the gas to expand further. Further expansion of the gas can reduce the amount of propellant required. This reduction in the amount of propellant allows the weight of the inflator 202 to be reduced. Furthermore, this second combustion reduces the toxicity of the propellant gas. The second chamber 324 is long, in particular the afterburner nozzle 274 and the gas generator outlet 286 of the gas generator inlet 316.
The long distance between the portion closest to the air generator and the outlet 286 for the gas generator provides sufficient second combustion before the gas exits towards the air / safety bag 18 (see FIG. 1). You get time.

In a particular design, as described above, the inflator 202 can be constructed as described above except for the use of the valve 320. This can be achieved by the use of propellants and pressurized media of the type mentioned above. The propellant is used in the second chamber 324 to oxidize the pressurized medium (eg,
A further combustible propellant gas is formed by mixing with an oxidizing pressurized medium composed of a complex of an inert fluid and oxygen represented by one or more kinds of inert gas. In this case, the combustion of the propellant gas that occurs in the second chamber 324 and the second combustion of the gas formed by the ignition / ignition of the ignition / booster agent 240 is sufficient to increase the pressure or pressure so that the valve 320 is not required. Results in increased speed. For example, after activating the inflator 202, the second chamber 32
The second combustion occurring within 4 accounts for at least about 30% of the pressure increase or rate of pressure increase, up to about 50%.
It is also possible to occupy%. In this case, the second chamber 32
The initiation of flow by rapid pressurization can be achieved utilizing the chemical reaction in 4 which reduces the need for valve 320.

8 to 11 show another embodiment of the hybrid inflator which can be used in the inflatable safety system 10 shown in FIG. Although the function or operation of the inflator 350 is similar to that of the inflator 202 described above, the inflator 350 is formed specifically for use on the driver side. The inflator 350 includes a propellant of the type described above (eg, gun-type propellant, mixed propellant) and a complex pressurized medium (eg, an inert fluid and oxygen, typified by those containing at least one inert gas). The use of a mixture) may improve the performance of the inflatable safety system 10.

As shown mainly in FIG. 8, the hybrid inflator 350 generally has two main constituent members to realize a hermetic seal, and the two main constituent members are the gas generator 362 and the diffuser. Central housing 3 including 458
58 and a high pressure gas housing 354 mounted along the outer periphery of the central housing 358 (eg, the high pressure gas housing 354 can be coupled to the central housing 358 by welding at welds 442, 450). . The high-pressure gas housing 354 has a donut shape and has a pressurizing medium therein. The main advantage of the inflator 350 is that it has a second closure disc 428 to open.
A second closure disc 428 (the second closure disc 428 separates the gas flow between the inflator 350 and the air / safety bag 18 (see FIG. 1)) for exerting fluid pressure directly on It is a point that acts on rapid pressurization in the region. Further, as described in more detail below, another advantage of the inflator 350 is that it provides a substantial pressure increase, primarily within the gas generator 362, associated with the activity of the propellant. As a result, the wall thickness of the high-pressure gas housing 354 becomes thinner than that of the conventional hybrid inflator (that is, the ratio of the pressure applied to the high-pressure gas housing 354 is smaller than that of the conventional hybrid inflator). The weight of 350 can be reduced.

The central housing 358 is the inflator 35.
0 is arranged around a central axis 352 extending in the length direction of 0, and the central housing 358 includes a gas generator 362,
The diffuser 458 is aligned with the gas generator 362 along its length and is spaced from the gas generator 362. Gas generator 362 and diffuser 458 are formed at least in part by central housing 358. For example, the gas generator 3
62 is a substantially cylindrical gas generator housing 366
The gas generator housing 366 includes a part of the central housing 358, the holder 3 for the ignition assembly.
70, a dome-shaped septum 390, and a gas generator end cap assembly 420. In particular, since the gas generator housing 366 has a large amount of pressurized medium in a static state, the ignition assembly holder 370 has a lower portion of the central housing 358 and a high pressure gas housing to form a corresponding hermetic seal. Properly coupled to both 354 (eg,
(Welding at weld 442). Ignition assembly holder 370 is a suitable ignition assembly 374.
An O-ring 372 may be used to hold the (e.g., electric ignition tube or other suitable explosive device) and form a seal. In order to form a hermetic seal for separating the ignition assembly 374 from the pressurized medium within the gas generator 362, a first closing disc (secondary closing disc) 3
78 is properly coupled to the end of the ignition assembly holder 370 (eg, by welding at weld 446). In this embodiment, the first closure disc 378 is a weld between the end of the main housing 382 of the ignition assembly holder 370 and the end cap 386 of the ignition assembly holder 370 of the ignition assembly holder 370. It is held by 446.

The partition 390 is a gas generator housing 366.
Is separated into a first chamber 394 and a second chamber 418. The first chamber 394 is formed by the lower portion of the central housing 358, the ignition assembly holder 370, and the bottom surface of the partition wall 390, and the first chamber 394 is formed adjacent to the ignition assembly 374. The first chamber 394 of the gas generator housing 366 essentially contains a propellant grain 404 which upon ignition increases the flow of gas to the air / safety bag 18 (see FIG. 1). Propulsion gas is formed to do so. As a result, the first chamber 394 can be characterized as a propellant chamber. A suitable ignition / booster agent 408 (eg, an RDX / aluminum booster agent containing 89 wt% RDX and 11 wt% aluminum powder, or an RDX / aluminum booster agent 408 to assist in igniting the propellant grains 404).
It is also possible to use 0.5 to 5.0 wt% RDX of the booster agent and a booster agent in which aluminum is replaced with 0.5 to 5.0 wt% of hydroxypropyl cellulose) as at least a part of the ignition assembly 374. It may be centrally located in the first chamber 394 for alignment. Suitable screens 412, booster cups or the like can separate the propellant grains 404 from the ignition / booster agents 408.

The first chamber 394 is generally in communication with the high pressure gas housing 354 by at least one bleed orifice or bleed port 400 (two in this example). As a result, as described above, the pressurized medium is also contained in the first chamber 394 in the static state. In the present embodiment, the bleed ports 400 extend in the radial direction (that is, the bleed ports 400 are respectively arranged on the central axis 220 so as to extend along the radius having the origin thereof), and extend in the substantially horizontal direction. (Ie, central axis 352
Included in a plane that extends in a direction orthogonal to. Selection of the size and / or quantity of bleed ports 400 can be used to properly tune the performance of inflator 350 as previously described in inflator 202.

As described in more detail below, the gas formed by the ignition of the ignition / booster agent 408 causes the inflator 3 to
It is possible to react more chemically with the pressurizing medium to further enhance the properties associated with initiation of flow by rapid pressurization of 50.

Guiding a portion of the propellant gas from the first chamber 394 into the high pressure gas housing 354 achieves the desired output or delivery to the air / safety bag 18, ie, air / safety. It can be used to achieve the desired inflation rate of bag 18. As described in more detail below, the propellant gas is propelled to the high pressure gas housing 35 at a rate that maintains a substantially constant flow of gas from the high pressure gas housing 354 to the second chamber 418 for a sufficient period of time.
It is preferable to provide within 4. Generally, less than half of the propellant gas formed to achieve the desired result (eg, less than or equal to about 40% of the propellant gas, and more typically less than or equal to about 30% of the propellant gas is high pressure gas). The high pressure gas housing 354 during operation).
It is necessary to flow in.

The pressure increase in the high pressure gas housing 354 after ignition of the propellant grains 404 is significantly less than many other commercial hybrid inflators, even with the bleed port 400. That is, the substantial pressure increase that generally accompanies ignition of the propellant grains 404 is substantially confined within the gas generator 362. As a result, the strength condition of the high pressure gas housing 354 can be reduced.
This allows at least one of reducing the wall thickness of the high pressure gas housing 354 and / or using a lightweight material for the high pressure gas housing 354. Both of these reduce the weight of the inflator 350. For example, if the high pressure gas housing 354 is formed from mild steel and its internal pressure in the static state is about 4,000 pounds per square inch (6.45 square centimeters) (4,000 psi), the high pressure gas housing 354. Wall thickness is about 0.0
It can be 75 inches (about 1.91 mm).

The main flow of propellant gas from the first chamber 394 (eg, at least about 50%, and more typically at least about 70% of the total flow rate of propellant gas) is transferred to the second chamber 418.
Be guided into (called "afterburner" for the above reasons). The second chamber 418 of the gas generator housing 366 is the first chamber 39 of the gas generator housing 366.
4 for at least one propellant gas vent 416
(Two in this embodiment), the propellant gas vent 416 extends through the gas generator partition 390. As will be described in more detail below, the main flow path for the pressurized medium air / safety bag 18 (see FIG. 1) present in the high pressure gas housing 354 is further in direct communication with the second chamber 418. There is. In order to sufficiently mix the propellant gas flowing from the first chamber 394 into the second chamber 418 with the pressurized medium flowing into the second chamber 418 from the high-pressure gas housing 354 (for example, the gas is The propellant gas vent 416 is oriented to form a vortex (eg, a flow with at least a radial velocity component) within the second chamber 418 (to be retained within the second chamber 418 for a sufficient period of time). It is possible. One method of forming this vortex is to form the propellant gas vent 416 of the gas generator so as to extend substantially linearly as shown in FIG. The vent holes 416 are arranged so as to incline opposite to each other in the corresponding plane.

Second chamber 4 of gas generator housing 366
18 is aligned along its length with the first chamber 394 and is provided by the gas generator partition 390.
Separated from 94, housing 354 for high pressure gas
Are partially arranged along the outer circumference of the. Second chamber 4
18 is an intermediate portion of the central housing 358, a gas generator partition 390, and a gas generator end cap assembly 4
It is formed by 20. The gas generator end cap assembly 420 is suitably coupled to the central housing 358 (eg, by welding at weld 454), with the top of the central housing 358 relative to the top of the high pressure gas housing 354. Properly coupled (eg, by welding at weld 450). The welds 450, 454 preferably form a hermetic seal because the second chamber 418 has a large amount of pressurized medium in a static state. The gas generator end cap assembly 420 has at least one gas generator outlet 424 (one shown). The second closure disc 428 is attached to the gas generator end cap assembly 420 to form a hermetic seal to properly hold the pressurized medium in the inflator 350, and particularly the second chamber 418, until the desired time. Properly joined (for example, by welding at weld 454).

Due to the communication between the first chamber 394 and the second chamber 418, at least one of the propellant gas formed by the combustion of the propellant grains 404 and the gas formed by the ignition of the ignition / booster agent 408. The part is guided into the second chamber 418. The rapid increase in pressure within the second chamber 418 under the control described in detail below causes the second closure disc 428 to open at the appropriate time. As a result, the flow of gas from the inflator 350 is guided to the diffuser 458 and the air / safety bag 18 (see FIG. 1). The diffuser 458 includes a plurality of diffuser ports 462 to provide less disruptive gas output to the air / safety bag 18 (see FIG. 1). The diffuser 458 retains the broken pieces of the closure disc within the inflator 350 and ensures that the propellant gas and pressurized medium prior to passing to the air / safety bag 18 (see FIG. 1). Diffuser screen (not shown) to achieve at least one of media mixing and / or further promoting reaction
It is possible to have

The second chamber 418 is the high pressure gas housing 3
It communicates with 54. In this regard, at least one,
Preferably, the plurality of gas generator inlets 432 provide communication between the high pressure gas housing 354 and the second chamber 418. As a result, the pressurized medium in the high pressure gas housing 354 flows into the second chamber 418 in a timely manner. That is,
In a particular design or application, the flow of this particular gas can control the direction of that flow. In particular, valve 438 may be located adjacent to at least one, and preferably all gas generator inlets 432. In the static state, the valve 438 need not actually separate the high pressure gas housing 354 from the second chamber 418 in this region. In fact, large volumes of pressurized medium are preferably held in the second chamber 418 in a static condition, and a non-hermetically sealed connection can provide such a supply. One form of valve 438 that does not separate the second chamber 418 from the high pressure gas housing 354 over the gas generator inlet 432 is a roll of filler material (eg, 0.
002 inch (stainless steel with a thickness of about 0.05 mm). A cantilever connection can be used between valve 438 and the inner wall of gas generator housing 366. That is, the rear portion of the valve 438 is located at the central housing 358.
And the partition 390, and the front portion of the valve 438 is not connected to the other, the valve 438 can be moved / deflected.

The shape of the valve 438 is preferably the present one, but the individual plugs 438a and 438b (see FIG. 14).
It is also possible to arrange (A) and (B) in each inlet 432. These plugs 438a and 438b are preferably connected to the inflator 350 by a tester 439 or the like (illustrated only in FIG. 14B). It is also desirable to support the plugs 438a and 438b by the flexible member 433 in the inlet 432. Plug 438
The a, 438b can also be used in the other hybrid inflators described herein.

From the above, the high-pressure gas housing 3
It can be seen that the pressure prevailing inside each of 54 and the gas generator 362 is approximately equal in the static state. However, after the dynamic conditions or ignition of the propellant grains 404, the pressures in the chambers of the inflator 350 differ from each other to achieve the desired performance. Propellant grain 404
If ignition is performed on the
Inflow is initiated into at least the second chamber 418 to increase the pressure in 18. When the inflator 202 has at least one extraction port 400, a part of the propelling gas flows into the high pressure gas housing 354, and
The pressure in the high-pressure gas housing 354 is increased.
The pressure increase rate in the second chamber 418 is preferably faster than the pressure increase rate in the high pressure gas housing 354. The difference in the rate of increase in pressure is the difference in the second chamber 418.
And the high-pressure gas housing 354, and the propellant gas is caused to flow into each of the high-pressure gas housing 354 and the relative capacity difference therebetween. This pressure differential causes valve 438 to align with gas generator housing 366 with respect to valve 438.
Is pressed toward a part of the inner wall of the. As a result, the high pressure gas housing 354 is isolated from the second chamber 418 by blocking the gas generator inlet 432. The cantilever connection of the valve 320 is the same as the valve 32.
Allows 0 movement. When the pressure in the second chamber 418 reaches a predetermined pressure value, the fluid pressure opens, breaks or breaks the second closing disc 428. As a result, the opening of disk 428 creates a flow of gas from gas generator 362 to diffuser 458 and air / safety bag 18 (see FIG. 1).

The valve 438 allows timely flow of gas to the air / safety bag 18 (see FIG. 1) in a particular design or application. In a particular design, the valve 438 can be used to rapidly pressurize the second chamber 418 at a rate such that the second closure disc 428 can be opened in a timely manner. Inflator 35
If the 0 does not have the valve 438, the propellant gas flows from the second chamber 418 into the high pressure gas housing 354.
In this case, it takes a longer time for the internal pressure of the second chamber 418 to increase to a pressure value at which the second closing disc 428 can be broken. However, the use of the second chamber 418 provides a smaller pressurized chamber, which reduces the time required to initiate the flow of gas into the air / safety bag 18 (see FIG. 1). As will be described in more detail below, the volume of the second chamber 418 is sufficiently small in certain designs, and propellant and pressurized medium are used to achieve satisfactory operation without the use of the valve 438. At least one of the selections may be performed (e.g., propellant grains 404 and ignition / booster agent 4 to affect rapid pressurization in second chamber 418).
Carried out by utilizing the combustion of the gas formed by the combustion of at least one of the 18).

The valve 438 maintains its deployed position after the second closure disc 428 has been opened to form a flow of gas to the air / safety bag 18 (see FIG. 1), and thereby the gas. The generator inlet 432 is shut off for a specified time. However, if a particular pressure differential is created between the high pressure gas housing 354 and the second chamber 418, the upper free end of the valve 438 will be forced by the pressure force exerted by this pressure differential to expose the gas generator inlet 432. Be moved. As a result, the gas starts to flow from the high-pressure gas housing 354 into the second chamber 418. The lower end of the valve 438 has a gas generator housing 366.
Remain bound to. When the valve 438 is formed from a roll of stuffing material, the valve 438 moves radially inward toward the central axis 352 or is radially aligned with the gas generator inlet 432. The indentation of the valve 438 into the open area allows the desired gas flow therethrough.

The rapid closing of the second closing disc 42
The main function of the second chamber 418 after the rupture of 8 is before the propellant gas and pressurized medium is discharged into the air / safety bag 18 (see FIG. 1). Is to provide or allow effective mixing of. Inert fluids and oxygen represented by propellant compositions of the type described above (eg gun type propellants, mixed propellants) and pressurized media of the type described above (eg containing at least one inert gas). Mixture), when used, provides significant benefits, including reducing toxicity and reducing the total amount of propellant due to further combustion and associated increase in expansion capacity. To bring about further combustion of the propellant gas. In this case, the second chamber 418 is further characterized as an afterburner. Preferably at least about 99% of the total combustion of the gas formed by the propellant gas and the ignition / booster agent occurs, and more preferably about 100% of such combustion occurs within the inflator 350. This reduces the risk of damage to the air / safety bag 18 (see Figure 1).

Due to the constraints imposed on the driver side use, it is not practical to use a "long" second chamber 418 as used in the inflator 202 to provide the function as an afterburner. It is possible to further enhance the mixing of the propellant gas and the pressurized medium within the second chamber 418 to compensate for the use of the "short" second chamber 418 when using the inflator 350 on the driver side. This mixing is from the high pressure gas housing 354 to the second chamber 4 to facilitate mixing of the pressurized medium and the propellant gas.
This can be accomplished by introducing a vortex into the flow of gas to 18 (primarily the pressurized medium, or the gas formed by the bulk propellant gas and / or ignition of the ignition / booster agent).
This increases the residence time of the propellant gas and pressurized medium in the second chamber 418 to chemically react the propellant gas and pressurized medium.

As one method of forming the vortex flow, as shown in FIG. 9, a gas generator inlet 432 extending generally in a straight line is arranged in a reference plane extending substantially in the horizontal direction. The central axis of the inlet 432 extends in the longitudinal direction of the inflator 350 as shown in FIG.
It can be realized by orienting so as not to pass through. That is, the substantially linearly extending inlet 432 may extend radially outward from a central axis 352 that extends longitudinally to connect the second chamber 418 and the high pressure gas housing 354. Absent. Alternatively, a portion of optional inlet 432 is located on one radially extending line and another portion of optional inlet 432 is located on another radially extending line. In this case, the flow of gas from the high-pressure gas housing 354 to the second chamber 418 is generally formed along the direction of arrow A shown in FIG. In order to carry out a further mixing of the propellant gas and the incoming pressurized medium, the propellant gas vent 416 shown in FIGS. 9 and 10 is the part where the gas generator inlet 432 further contacts the interior of the second chamber 418. Can be formed to face.

The dimensions of any design of the inflator 350 can vary. In particular, the capacity of each chamber of the inflator 350 differs depending on the use of the inflator. For example,
The total volume of the inflator housing is about 50 cm ³ to about 150 cm ³ , the volume of the first chamber 394 is about 5 cm ³ to about 15 cm ³ , and the volume of the second chamber 418 is about 1 cm ³ to about 20 cm ³ . Further, the dimensions in one embodiment will be exemplified below to show the principle of the present invention. 1) The diameter of the inflator 350 is about 3.25 inches (about 8.2).
6 cm). 2) The height of the central housing 358 is about 1.6 inches (about 4.06 cm). 3) The height of the high pressure gas housing 354 is about 1.2 inches (about 3.0 inches).
5 cm). 4) The internal volume of the high pressure gas housing 354 is about 5 cubic inches (about 82 cubic centimeters).
Is. 5) The internal volume of the first chamber 394 of the gas generator housing 366 is about 7 cc. 6) The internal volume of the second chamber 418 of the gas generator housing 366 is about 2
It is cc. 7) The inflator 350 has two bleed ports 400 with a diameter of about 1.5 mm. 8) The inflator 350 has two propellant gas vents 416 with a diameter of about 2 mm. 9) The total weight of propellant grains 404 is about 3.5 g, which comprises a composition of the above type having RDX, CA, TMETN and a stabilizer. 10) High-pressure gas housing 35
4 has a static pressure of about 4,000 psi, the high-pressure gas housing 354 contains about 40 g of pressurized medium, 85% (mol percent) of which is argon, 15 % (Molar percent) is oxygen. 1
1) The inflator 350 is made of mild steel. 1
2) The wall thickness of the high pressure gas housing 354 is about 0.0.
75 inches (1.91 mm) and pressure ratio (Pr
The essure rating is about 18,000 psi. 13) The wall thickness of the central housing 358 is about 0.0.
It is 625 inches (1.59 mm). 14) The total weight of the inflator 350 is about 400 g.

The operation of the inflator 350 will be described in detail with reference to FIGS. 11A to 11C. As shown in FIG. 11A, when the appropriate signal is sent from the detector / sensor 14 (see FIG. 1), the ignition assembly 374 is activated and the ignition assembly 374 breaks the first closure disc 378, And the ignition / booster agent 408 is ignited. The propellant grains 404 are then ignited by ignition / ignition of the ignition / booster agent 408. Propellant grain 404
Combustion causes the formation of propellant gas in the first chamber 394,
The propellant gas is supplied to the second chamber 4 of the gas generator housing 366.
18 and into the high pressure gas housing 354 where they are mixed with the pressurized medium. The presence of the hot propellant gas in the first chamber 394 and the inflow of the hot propellant gas into the second chamber 418 and the high pressure gas housing 354 also increase the pressure within these vessels.

In order to rupture the second closure disc 428 in a timely manner, thereby initiating the flow of gas to the air / safety bag 18 (see FIG. 1), the second chamber 418 and the housing for high pressure gas 354. Based on the inflow of the high temperature propellant gas into the second chamber 418 and the respective capacities of the high pressure gas housing 354, the pressure increase rate in the second chamber 418 further increases the pressure increase rate in the high pressure gas housing 354. Designed to surpass. This pressure differential urges valve 438 toward the inner wall of gas generator housing 366 to separate high pressure gas housing 354 from second chamber 418 in this region, as shown in FIG. 11A. As a result, the supply of the pressurized medium that reacts with the propellant gas is stopped, so that the pressurized medium in the second chamber 418 in the static state before the communication between the high pressure gas housing 354 and the second chamber 418 is formed. The total amount of the second chamber 4
It must be sufficient to react with the propellant gas flowing into 18.

As shown in FIG. 11B, when the pressure in the second chamber 418 reaches a predetermined pressure value, this pressure causes the second closing disk 428 to break, thereby passing through the gas generator outlet 424. Thus, a flow of gas is formed entering the diffuser 458 and the air / safety bag 18 (see FIG. 1). However, the valve 438 continues to block the direct flow of gas from the high pressure gas housing 354 into the second chamber 418 by closing the gas generator inlet 432. After a certain pressure differential is created between the high pressure gas housing 354 and the second chamber 418,
This pressure differential causes valve 438 to move or deflect away from gas generator inlet 432 to create a flow of pressurized medium from high pressure gas housing 354 to second chamber 418. For example, the valve 43 shown here
Due to the structure of eight (such as stuffing material in roll form), the one-way check valve 438 is recessed by at least the pressure differential into an area adjacent or aligned with the gas generator inlet 432. First chamber 394 as described above
Second chamber 418 to facilitate mixing of the pressurized medium and the propellant gas that continuously flows therethrough into second chamber 418.
The flow of the pressurized medium and the propellant gas into the interior can form a vortex.
This allows the pressurized medium and propellant gas to be air / safety bag 1
8 (see FIG. 1) may increase the amount of time the same pressurized medium and propellant gas mixture is retained in the second chamber 418.

FIG. 12 shows several pressure curves for the test model of the previous example with similar size and characteristics. These curves are shown in FIG. 13A as detailed below.
~ Almost the same as the curve shown in Fig. 13D. Initially, the static pressure in the inflator 350 is about 4,000 psi. At time T1 (about 5 milliseconds), the inflator 3
50 was activated and propellant grains 404 were ignited. At this time, the internal pressure of each of the first chamber 394, the high-pressure gas housing 354, and the second chamber 418 was increased by the propellant gas formed by the ignition of the propellant grains 404. The maximum pressure in the first chamber 394 and the second chamber 418 developed at time T2, at which point the second closure disc 428 ruptured. Time T2
At about 1 millisecond after activation, the pressure in the first chamber 394 is about 10,000 times from a static condition of 4,000 psi.
Increased to 0 psi and the pressure in the second chamber 418 is 4,0
The static pressure of 00 psi increased to about 7,000 psi, and the pressure in the high pressure gas housing 354 was 4,0.
It increased from a static state of 00 psi to about 4,500 psi.

After the second closure disc 428 was opened, the pressure in the second chamber 418 dropped. At time T3, the pressure differential between the high pressure gas housing 354 and the second chamber 418 reached a value sufficient to open the valve 438, thereby exposing the gas generator inlet 432. As a result, the pressure in the second chamber 418 increased again. That is, after the lapse of time T3, the gas flowed from the high-pressure gas housing 354 and the first chamber 394 to the second chamber 418. The pressure in the second chamber 418 increased at time T4 to a maximum value of about 4,750 psi and then decreased. This time was substantially the same as the time when the maximum pressure of about 5,000 psi was formed in the high pressure gas housing 354. At this time, the increase in pressure generated in the inflator 350 was mainly concentrated in the gas generator 362 rather than in the high-pressure gas housing 354. As a result, the wall thickness of the high pressure gas housing 354 can be reduced as described above. Moreover, the relatively constant internal pressure of the second chamber 418 (only transiting between 4000 and 4600 psi) can provide the desired output to the air / safety bag 18 (see FIG. 1).

In a particular design, as described above, the inflator 350 can be constructed as described above, except for the use of the valve 438. This can be accomplished by the use of propellants and pressurized media of the types described above, which include in the second chamber 324 an oxidizing pressurized media (eg, one or more inert gases such as argon and nitrogen). Further, by mixing with an oxidizing pressurized medium composed of a complex of an inert fluid and oxygen represented by, for example, a propelling gas capable of being burned in the second chamber 418 is formed. In this case, the “second” combustion of the propellant gas that occurs in the second chamber 418 and the second combustion of the gas formed by the ignition of the ignition / booster agent 408 does not require the valve 438. Provides sufficient pressure increase or rate of pressure increase. For example, after activating the inflator 350, the second chamber 41
The second combustion occurring within 8 accounts for at least about 30% of the pressure increase or rate of pressure increase, up to about 50%.
It is also possible to occupy%. In this case, the second chamber 41
Initiation of flow by rapid pressurization can be achieved utilizing chemical reactions within 8 thereby reducing the need for valve 438.

13A to 13D show the first chamber 394, the second chamber 418, the high pressure gas housing 354, and the air / safety bag 18 (see FIG. 1) in the inflator 350 having the above-mentioned structure except the valve 438. Figure 3) shows the pressure curves representing the internal pressure of each of the containers with fixed walls. As is clear from the comparison between FIG. 12 and FIGS. 13A to 13C, equivalent performance can be achieved without using the valve 438. This is a particular type of propellant and pressurized medium that provides combustion of gas within the second chamber 418 to provide rapid pressurization within the second chamber 418 to open the second closure disk 428. It is basically due to the use of.

FIG. 15 shows a modified example of the hybrid inflator of the present invention. Since the inflator of this modified example has a configuration similar to that of the inflator of FIG. 5, the same reference numerals are used for the similarities and the description thereof will be omitted. Differences from the inflator of FIG. 5 will be described below. To do.

The first chamber 501 has an inner diameter larger than that of the second chamber 502. The length of the second chamber 502 is set to be significantly shorter than that of the second chamber 324 in FIG. Therefore, the second chamber 502 has a much smaller volume than the first chamber 501. Second chamber 50 in this embodiment
The volume of 2 is about 1/20 of the volume of the first chamber 501.

The transfer tube 503 is arranged on the axis of the first chamber 501 and connects the initiator 228 and the aspirator nozzle 274. The transfer tube 503 is hollow and has a plurality of ventilation holes 504 on its peripheral wall. Therefore, the first chamber 501 is replaced by the second chamber 502 by the transfer tube 503 and the aspirator nozzle 274.
Is in communication with. In addition, the first closing disc 236 always closes the passage 507 between the initiator 228 and the first chamber 501.

The second chamber 502 is connected to the outlet 286 by an afterburner pipe 505. A second closure disc 290, which is arranged in the vicinity of the second chamber 502 and the aspirator nozzle 274, always closes the outlet 286 via the pipe 505.

The extraction port 262 communicates the first chamber 501 with the inside of the high pressure gas housing 204. Entrance 31
6 is provided in the second chamber 502, and in the static state,
The valve 320 is open because it is not in close contact with the inner wall of the second chamber 502. Therefore, in the static state,
The aspirator nozzle 274, the transfer tube 503, the inlet 316, and the bleed port 262 keep the pressure inside the high-pressure gas housing 204, the first chamber 501, and the second chamber 502 substantially uniform. When the initiator 228 is actuated in this state, the first closing disk 236 is destroyed and the propellant 258 is burned. After the combustion gas generated from the propellant increases the pressure in the first chamber 501,
The pressure in the second chamber 502 is increased via the transfer tube 503 and the aspirator nozzle 274. The pressure causes the valve 320 to move toward the wall of the second chamber 502, closing the inlet 316. Then, the combustion gas is injected from the aspirator nozzle 274 into the pipe 505 to destroy the second closing disk 290.

Then, the pressure in the second chamber 502 temporarily drops, and the valve 320 opens the inlet 316. Therefore, the pressurized medium enters the second chamber 502 as well as the pipe 505 through the inlet 316. Thereafter, oxygen in the pressurized medium chemically reacts with carbon monoxide and hydrogen in the combustion gas in the second chamber 502 and the pipe 505, and is converted into carbon dioxide and water. These high-pressure carbon dioxide, water, and argon in the pressurized medium are supplied to the airbag (not shown) from the diffuser 508 through the outlet 286 to inflate the airbag.

As described above, in this embodiment, the second chamber 5
02 is set smaller than the first chamber 501, and the second closing disk 290 is arranged in the vicinity of the aspirator nozzle 274. Therefore, in addition to exhibiting the same effect as the inflator shown in FIGS. 5 and 8,
The pressure of the combustion gas in the first and second chambers 501 and 502 can be rapidly increased so that the disc 290 can be quickly destroyed.

Further, a large number of vent holes 5 are provided in the first chamber 501.
Since the fire transfer tube 503 including 04 is arranged, the flow velocity of the combustion gas can be increased when the combustion gas passes through each vent hole 504. This helps premature destruction of the disk 290.

The transfer tube 503 can also be applied to the embodiment shown in FIG. Regarding the opening area of the aspirator nozzle and the sum of the opening areas of the extraction ports in the embodiments of FIGS. 5 and 8, the pressurized medium is introduced into the first chamber or the combustion gas of propellant is added Depending on whether to guide to the pressure medium side,
It is possible to decide which area to increase.

Table 2 shows the physical characteristics of each inflator shown in FIGS. 5, 8 and 14, that is, the characteristics of the present invention. For example, Table 2 shows numerical ranges for propellant grains, propellant gases and pressurized media.

[0132]

[Table 2] If the respective characteristic values shown in Table 2 are below the lower limit values, a sufficient amount of gas for inflating the air safety bag cannot be obtained. Further, if each characteristic value exceeds the upper limit value, it becomes impossible to sufficiently downsize the entire inflator. Further, it is essential that the inflator of the present invention has the conditions regarding the weight of the propellant shown in Table 2. However, other characteristics can be appropriately selected as needed.

FIG. 16 (A) shows a hybrid inflator according to another embodiment of the present invention.
Of the inflatable safety system 10. The inflator 614 is a cylinder type inflator housing 622 with a pressurized medium 620 for supplying to the air / safety bag 18 (FIG. 1) and a pressurized medium 620.
A gas generator 624 to generate a propellant gas to inflate and increase flow to the air / safety bag 18.

The inflator 614 is mounted on a seat or door of a vehicle and is used to protect an occupant when the vehicle is laterally impacted (for example, a side impact inflator). The pressurized medium 620 contains oxygen and an inert gas such as argon.

A gas generator housing 644 is fixed to the opening 642 at the right end of the inflator housing 622 by welding, and a part of the gas generator housing 644 is arranged inside the inflator housing 622. In the accommodation chamber 645 of the gas generator housing 644, a propellant 64 that generates a propellant gas during combustion is generated.
6 is housed and an ignition assembly 648 is mounted. The gas generator housing 644 and the ignition assembly 648 are aligned with the axis 6 of the inflator housing 622.
It is arranged on 17 above.

The propellant 646 is a nitramine type,
For example, those containing about 70 wt% RDX (hexahydrotrinitrotriazine), about 5 to about 15 wt% cellulose acetate and about 5 to about 15 wt% GAP (glycidyl diazide polymer) are desirable. This propellant generates a combustible gas containing carbon monoxide and hydrogen upon combustion.

The gas generator housing 644 has a communication hole 650 at its inner end, and the communication hole 650 is always closed by the first disk 652. A ring-shaped connector 626 is fixed to the left end opening 625 of the inflator housing 622 by welding. Connector 626
The cap-shaped diffuser 63 is provided in the opening 628 at the left end of the
0 is fixed. The diffuser 630 has a peripheral wall 630.
a and a top wall 630b, and a plurality of vent holes 632 are formed in the peripheral wall 630a. Diffuser 630
Is located on the axis 617 of the inflator housing 622 and is connected to the air / safety bag 18 (FIG. 1).

The right end opening of the connector 626 constitutes an outlet 634 of the inflator housing 622.
A second disc 636 is attached to the outlet 634 and always closes the outlet 634. The diffuser 630 has an opening 630c communicating with the outlet 634. The connector 626 is provided with a plurality of vent holes 638 so as to cover the outlet 634.
0 is installed. Therefore, the inside of the inflator housing 622 is always sealed by the two disks 636 and 652 and the peripheral wall of the inflator housing 622. Further, when the first disk 652 and the second disk 636 are destroyed, the communication hole 650 allows the accommodation chamber 64
5 communicates with the inside of the inflator housing 622, and the inside of the inflator housing 622 communicates with the outlet 634 through the ventilation port 638.

The first disk 652 and the second disk 6
Desirably, the spacing between 36 is about 20 mm to about 70 mm. If this interval is below the lower limit, there will not be enough gas to inflate the air / safety bag 18 (FIG. 1), and if it is above the upper limit, the inflator will not be sufficiently miniaturized. The inflator housing 62
The amount of pressurized medium in 2 is about 40 cm ³ to about 100 cm ³
Is. The amount of the pressurizing medium 620 is set for the same reason as the above interval. More preferably about 50c
It is from m ³ to about 90 cm ³ . The inside of the inflator housing 622 is kept at a high pressure of about 4000 psi.

When the ignition assembly 648 is operated in response to the signal from the detector 612, the propellant 64 is generated.
6 burns to generate combustible gas. This gas contains carbon monoxide and hydrogen. This gas also increases the pressure within the gas generator housing 644 and destroys the first disk 652. Then, the combustible gas passes through the communication hole 650.
Through and into the inflator housing 622 where it is mixed with the pressurized medium 620.

The pressurized medium 620 contains oxygen. This oxygen reacts with carbon monoxide and hydrogen in the combustible gas to produce carbon dioxide and water vapor. The flammable gas increases the pressure inside the inflator housing 622, and the pressure acts on the second disk 636 through the vent hole 638.
That is, the gas must flow around the end wall 641 of the cap 640 and enter the hole 638. This facilitates more complete combustion within the housing 622. Therefore, the end wall 641 of the cap 640 functions as a propellant trap, so to speak, and is arranged at the outlet to the inflator 614.

Further, since the end wall 641 of the cap 640 is arranged on the axis 617, the first disc 652 is formed.
It is prevented that the propelling gas that has destroyed the above is directly injected to the second disk 636. Then, the propelling gas sufficiently reacts with the pressurized medium in the housing 622, then passes through the hole 638 in the peripheral wall of the cap 640, and collides with the second disk 636. Therefore, the carbon monoxide contained in the propellant gas is completely oxidized and then passes through the outlet 634.

Then, the second disk 636 is destroyed,
High-pressure carbon dioxide, water vapor, and inert gas exit 63
4 and through the vent 632 of the diffuser 630 to the air / safety bag 18 (FIG. 1), which effectively inflates the air / safety bag 18 (FIG. 1) by a predetermined amount within a predetermined time.

As described above, in this embodiment, since the first and second disks 652 and 636 and the diffuser 630 are arranged on the axis 617 of the inflator housing 622, the inflator is formed into a compact cylinder type. be able to. Therefore, even in a limited space such as the inside of a vehicle door or seat, the vehicle can be reliably mounted without changing the shape of the door or seat.

In addition, in this embodiment, the propellant 646 generates a combustible gas containing carbon monoxide and hydrogen when it burns. The gas reacts with oxygen in the pressurized medium 620 and is converted to carbon dioxide and water. Thus, the air / safety bag 18 (FIG. 1) can be inflated with a gas that is substantially harmless to the occupant.

The diffuser 630 has a cap shape, a peripheral wall 630a and a top wall 630b, and an opening 630c communicating with the outlet 634.
30a has a plurality of holes 632 communicating with the opening 630c. Therefore, when the gas is discharged from the inflator housing 622, the gas can be injected from the plurality of holes 632 in all directions to inflate the air / safety bag 18 (FIG. 1) more efficiently.

FIG. 16B shows a modification of the inflator in FIG. 16A. In this variation, the gas generator housing 644 comprises a base portion 660 and a chamber portion 662. The base portion 660 supports the ignition assembly 648. Chamber portion 662 is propellant 64
It houses six. The disc 664 has a base portion 660.
And the chamber portion 662, and sandwiched between them. The disk 664 has a through hole 6 in the chamber portion 662.
66 is always closed. The chamber portion 652 has a communication hole 65.
0 to the inflator housing 622. Therefore, the interior of chamber portion 652 is under pressure.

When the ignition assembly 648 is activated,
Ignition assembly 648 directly destroys the disk and burns the propellant to produce combustible gas. The combustible gas reacts with oxygen in the pressurized medium 620 and is converted into carbon dioxide and water vapor. Therefore, the air / safety bag is inflated with a gas that is substantially harmless to the occupant.

The foregoing description of the invention is provided to illustrate and explain the present invention. Also, the description of the invention is not intended to limit the invention to the form disclosed herein. Therefore, variations and modifications that are considered equivalent to the above-described technology, and variations and modifications based on the related technology and knowledge related thereto are included in the scope of the present invention. In addition, the examples disclosed herein show the best mode for carrying out the invention, and other skilled artisans may use the invention to implement these examples, or other embodiments, for particular applications or uses of the invention. It is intended to be used with the various modifications necessary for. The claims of the present invention are intended to include other embodiments within the scope recognized by the prior art.

[0150]

As described in detail above, according to the present invention,
It has an excellent effect that the air / safety bag can be inflated by a predetermined amount within a predetermined time.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an inflatable safety system for a motor vehicle.

FIG. 2B is a vertical cross-sectional view of one embodiment of the hybrid inflator. (A) is an enlarged vertical cross-sectional view of the portion A of (B).

FIG. 3 Inner pressure / time performance curve of the inflator for the propellant composition of Example 2.

FIG. 4 Gas tank pressure / composition of propellant of Example 2
Time performance curve.

FIG. 5 is a vertical sectional view of another embodiment of the hybrid inflator.

6 (A) -6 (D) are enlarged longitudinal cross-sectional views of the valve and closure disc of the inflator of FIG. 5 at different times during operation.

FIG. 7 is an end view of the valve of FIGS. 6 (A)-(D).

FIG. 8 is a longitudinal sectional view of another embodiment of the hybrid inflator.

9 is a sectional view of the central housing taken along line 9-9 of FIG.

10 is a perspective view of the bulkhead of FIG. 8 between the first and second chambers of the gas generator housing showing the placement of the propellant gas vents.

11A-11C are enlarged longitudinal cross-sectional views of the inflator valve and closure disc of FIG. 8 at different times during operation.

12 is a graph showing internal pressures of various chambers during operation of the inflator of FIG.

13 (A)-(D) are various chambers (first chamber, second chamber, housing for high pressure gas and air / when the inflator of FIG. 8 is in operation when the valve / valve system is not used). Safety bag) internal pressure graph.

14A and 14B are cross-sectional views showing a modification of the valve for the hybrid inflator of FIGS. 5 and 8.

FIG. 15 is a vertical sectional view showing another embodiment of the hybrid inflator.

FIG. 16A is a vertical cross-sectional view showing another embodiment of the hybrid inflator. FIG. 16B is a modified example of the hybrid inflator shown in FIG.

[Explanation of symbols]

350 ... Inflator housing, 366 ... Gas generator housing, 374 ... Assembly, 404 ... Propellant,
432 ... Gas generator inlet, 424 ... Gas generator outlet, 438 ... Valve means 438.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Brent A. Parks United States 80111 Englewood South Macon Way 6153 Colorado

Claims (13)

[Claims] 1. A hybrid inflator for an inflatable safety system for a motor vehicle including an air / safety bag, the inflator housing including a pressurized medium, a gas generator housing, and a propulsion housed within the gas generator housing. A gas generator having at least one gas generator inlet communicating with the agent, the gas generator housing and the inflator housing, and at least one gas generator outlet communicating with the gas generator housing and the air / safety bag; An assembly connected to the gas generator for igniting the propellant; and, after the assembly is activated, the at least one of the at least one until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount. An inflator housing and a gas generator inlet In order to substantially prevent flow between the gas generator housing, a hybrid inflator which includes a valve means which is operated in cooperation with the at least one gas generator inlet ports. 2. The hybrid inflator according to claim 1, wherein the pressure in the inflator housing and the pressure in the gas generator housing are kept substantially equal before the operation of the assembly. 3. The hybrid inflator of claim 1, further comprising a plurality of gas generator inlets, the valve means operating in cooperation with each gas generator inlet. 4. The gas generator housing comprises a first chamber and a second chamber in communication with each other, a propellant is contained in the first chamber, and a second chamber is the outlet for the at least one gas generator. The hybrid inflator according to claim 1, wherein the hybrid inflator is arranged between the first inflator and the first inflator. 5. A closure disc located between the at least one gas generator outlet and an air / safety bag, and a first of the gas generator housing at a rate greater than a rate of pressurization against the inflator housing after ignition of the propellant. The hybrid inflator according to claim 4, further comprising: a means for pressurizing the second chamber; and a means for including the pressurizing means and opening the closing disc. 6. The hybrid inflator according to claim 5, wherein the pressurizing means includes an aspirator nozzle disposed between the first chamber and the second chamber. 7. The hybrid inflator according to claim 5, wherein the pressurizing means includes means for creating a vortex flow in the second chamber. 8. The valve means is moveable from a first position to a second position, the valve means being located in the first position to substantially block the flow in use within the inflator housing. The pressure in the gas generator housing exceeds a predetermined amount to move to a second position to allow the flow, and the second position is radially inward from the first position. The hybrid inflator according to claim 1, wherein the hybrid inflator is located. 9. The valve means comprises a flexible member disposed within the gas generator housing, the flexible member being urged to substantially abut against the gas generator housing, whereby The at least one gas generator inlet is closed until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount, and the flexible member causes the pressure in the inflator housing to be equal to the pressure in the gas generator housing. 2. The hybrid inflator of claim 1, wherein the hybrid inflator is spaced apart from the gas generator housing after a predetermined amount above, thereby forming a flow from the inflator housing to the gas generator housing through the at least one gas generator inlet. . 10. The hybrid inflator according to claim 9, wherein the flexible member is made of a metal thin film. 11. The valve means comprises a stopper provided corresponding to the gas generator inlet, the stopper having a first position for closing the gas generator inlet and a second position for opening the inlet. The hybrid inflator according to claim 1, wherein the hybrid inflator is movable to and from a position. 12. The hybrid inflator according to claim 11, wherein the stopper is supported by a flexible member. 13. An air / safety bag and an inflator, the inflator comprising an inflator housing,
A first chamber in communication with the inflator housing, a main closing disc disposed between the pressurizing medium and the air / safety bag, and further in communication with the inflator housing. And a gas generator having a second chamber, the first chamber containing a propellant, the second chamber being located between the first chamber and the main closing disc and in contact with the main closing disc. A method for operating an inflatable safety system, wherein a second chamber is formed so as to be able to communicate with the inflator housing, the method comprising: forming a propellant gas from the propellant; Providing at least a portion of the propellant gas to the chamber of the chamber, and substantially preventing flow of the propellant gas from the second chamber to the inflator housing during performance of the first portion of the forming step. Opening the main closure disc using the substantially blocking step; and performing the second step of the forming step from the inflator housing after performing the substantially blocking step. Allowing the flow into the chamber of the chamber, and guiding the flow towards the air / safety bag after performing the opening step.