JPH0976870A - Small-sized hybrid inflator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inflate an air/safety bag to a specified exhaust within a specified time by a diffuser shaping into a cap, having a peripheral wall and a top wall, providing the interior of the peripheral wall with an opening connecting with an outlet and providing the peripheral wall with a plurality of holes connecting with the opening. SOLUTION: A first and a second disk 652, 636 and a diffuser 630 are disposed on the axis 617 of an inflator housing 622, so that a whole inflater can be formed in a compact cylinder type. The diffuser 630 is shaped like a cap, provided with a peripheral wall 630a, a top wall 630b and an opening 630c connecting with an outlet 634. The peripheral wall 630a is provided with a plurality of holes 632 connecting with the opening 630c. When gas is discharged from the inflator housing 622, it is injected in all directions from the holes 632 to inflate an air/safety bag more efficiently.

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, there are many designs for each of the inflators described above. 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. Moreover, it is to provide a hybrid inflator that can be miniaturized.

[0006]

In order to achieve the above object, the inflator according to the first aspect of the present invention includes an inflator housing containing a pressurized medium. A storage chamber that stores a propellant is provided in the inflator housing. The inflator includes an ignition assembly for igniting the propellant. The communication hole communicates the accommodation chamber with the inflator housing. The first disc always closes its communication hole and is destroyed by the gas generated by the ignition of the propellant. An outlet is provided in the inflator housing for supplying the pressurized medium and gas from the inflator housing to the air / safety bag. The second disc always closes its outlet and, like the first disc, is destroyed by the gas generated by the ignition of the propellant. A diffuser is connected to the outlet of the inflator housing.
The first disc, the second disc and the diffuser are arranged on the same axis. The diffuser has a cap shape and a peripheral wall and a top wall. The peripheral wall has an opening communicating with the outlet, and the peripheral wall having a plurality of holes communicating with the opening.

A second aspect of the inflator according to the present invention comprises an inflator housing containing a pressurized medium. A storage chamber that stores a propellant is provided in the inflator housing. The inflator includes an ignition assembly for igniting the propellant. The communication hole communicates the accommodation chamber with the inflator housing.
The first disc is destroyed by the ignition assembly.
An outlet is provided in the inflator housing for supplying the pressurized medium and gas from the inflator housing to the air / safety bag. The second disc always closes its outlet and is destroyed by the gas generated by the ignition of the propellant. A diffuser is connected to the outlet of the inflator housing. The first disc, the second disc and the diffuser are arranged on the same axis. The diffuser has a cap shape and a peripheral wall and a top wall. The peripheral wall has an opening communicating with the outlet, and the peripheral wall having a plurality of holes communicating with the opening.

In the inflators of the first and second aspects, it is desirable that the pressurized medium contains an inert gas and oxygen. Desirably, the propellant generates a flammable gas, which gas reacts with oxygen in the pressurized medium. If the combustible gas comprises carbon monoxide and hydrogen, they are converted to carbon dioxide and water by oxygen in the pressurized medium.

The distance between the first disc and the second disc is preferably about 20 mm to about 70 mm. The amount of pressurized medium in the inflator housing is, for example, about 40 cm ³ to about 100 cm ³ . More preferably, it is about 50 cm ³ to about 90 cm ³ .

[0010]

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 of 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 U.S. 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. Detector 14 detects a condition that requires inflation of air / safety bag 18 (eg, a predetermined deceleration).
Is detected, a signal is transmitted to the inflator 26 and gas or other suitable fluid is released from the inflator 26 via line 22 to the air / safety bag 18.

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. Thus, 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 to generate additional gas). As described in more detail below, a gun-type propellant (eg, a high-temperature multi-fuel propellant) is used to form the propellant grains 90 located in the gas generator 82, and the pressurized medium 36 includes at least one non- A mixture of an active gas (eg, argon) and oxygen has been used. Pressurized medium 36 desirably includes from about 70% to about 92% inert gas and from about 8% to about 30% oxygen on a molar basis. More preferably, it contains 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 a plurality of rows of discharge holes 40 (e.g., 80 discharge holes 40 each having a diameter of about 0.100 inches (0.254 cm)) through which "non-thrust output" is provided from the inflator 30. The 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 located on the convex side of the closure disk 70 in the barrel 54 and upon receiving the appropriate signal from the detector 14 of the inflatable safety system 10 (FIG. 1), the actuation of the initiator 46 Will be promoted. Initially, a ring 62 is provided to hold projectile 50 in the proper position before ignition.

An orifice sleeve 74 is welded to the ends of the closure disc 70 and / or boss 66. The orifice sleeve 74 is hollow and includes a plurality of orifice ports 78 (e.g., each having a diameter of about 0.201 inch (0.5.
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, the gas generator 82, more specifically, the gas generator housing 86 is welded to the orifice sleeve 74 to complete the communication between the inflator housing 34 and the gas generator 82.

The gas generator housing 86 contains a plurality of propellant grains 90 which, when ignited, carry the combustion propellant gas of the 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
A gas generator inlet nozzle 98 at the end 96 of the gas generator housing 86 is isolated by a baffle 04 and a baffle 100. As shown below, propellant grain 90
Can be manufactured from gun-type propellants. However, the propellant grains 90 are substantially cylindrical, with one hole passing 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 located in the gas generator housing 8
6 and is typically oriented away from the closure disk 70. The gas generator housing 86 also has a plurality of circumferentially spaced outlets or discharge nozzles 200 on its side walls (eg, each having a diameter of about 0.221 inches (0.561 cm)). 1
4 rows of ejection nozzles 200). It may be desirable to change the axial position of these discharge nozzles 200 (usually located in the middle of the gas generator housing 86),
The effect is enhanced by the position close to the outlet. 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 due to the flow of the pressurized medium 36 near the side wall of the gas generator housing 86, whereby the pressurized medium 36 is transmitted through the suction nozzle 98 to 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. An ignition assembly 114 is disposed at least partially within the gas generator housing 86 between the projectile 50 and the propellant grains 90 and typically includes the working piston 12.
4, having at least one squib primer 120 and an igniter / booster agent 144 as activator. More specifically, the actuating guide 140 engages the end of the orifice sleeve 74 and the inner wall of the gas generator housing 86, so that the actuating guide 140
4 and at least partially fulfills the function of guiding the working piston 124. The primer holder 116 engages one end of the actuation guide 140 and contains a plurality of conventional firing primers 120 located substantially adjacent to 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.
Cage 1 between the primer 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 have the property of extending during operation. Therefore, to ensure that the parts interact, for example, the retainer 108 and the baffle 11
2, a wave-shaped spring washer can be arranged (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 primer 120.
As will be appreciated, a plurality of projecting members (not shown) may be used in place of a single substantially continuous projecting 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 actuating piston 124 will erroneously engage the squib 120 and activate the gas generator 82 is reduced. However, after the projectile 50 has passed the closing disk 70, the energy transferred by the projectile 50 to the actuation piston 124 is sufficient to overwhelm the countersunk washer 136, and the projecting rim 128 has at least one It can be engaged with the firing squib 120 with sufficient power to ignite the squib 120. In turn, this causes ignition of the igniter / booster agent 144 and the propellant grains 90 ignite.

During operation of the gas generator 82, a percussion primer 120
May corrode, allowing propellant gas generated by the combustion of the propellant grains 90 to flow through the squib 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 results in a seal for the gas generator housing 86 that limits any gas leakage.
Accordingly, 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 disk 70, opening the passage between the inflator housing 34 and the air / safety bag 18 (FIG. 1). The projectile 50 continues to advance and finally strikes the working piston 124, and the projecting rim 12 attached to the working piston 124
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 sidewall of the gas generator housing 86 and creating a pressure differential. This “pull-in” of the pressurized medium 36 promotes 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 discharged from the gas generator housing 86 via the discharge nozzle 200 on the side wall 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 noted 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. The gun type propellants used herein are hot multi-fuel propellants such as single base, double base or triple base propellants and nitramine propellants such as LOVA or HELOVA propellants.
More specifically, conventional gun-type propellants comprise about 2,500
~ 3,800 ° K, usually about 3,000
It is a propellant with a combustion temperature above ° K and is multi-fuel in that it generates large amounts of CO and H ₂ in the absence of excess oxygen. Normally, the in obtaining the CO ₂ and H ₂ O by reacting an excess fuel from these propellants, it is necessary to add 5 to 25 mole%, or sometimes 15 to 40 mole% of the oxygen pressure gas .

Propellant grain 9 of hybrid inflator 30
One particular "conventional" gun-type propellant that may be used at 0 is HPC-96. It consists of about 76.6% nitrocellulose, about 13.25% nitrogen by weight, about 20.0% nitroglycerin, about 0.6% ethylcentralite, about 1.5% nitric acid Composition of barium, about 0.9% potassium nitrate and about 0.4% graphite, is a double base smokeless propellant.
HPC-96 is a product of Wilmington, Del.
available at Hercules, Inc. Although this double base propellant contains nitrocellulose as a major component, it produces the desired ballistic properties but fails to meet current automotive industry long term heat resistance criteria.

LOVA propellant (low brittle ammunition) and HE
LOVA propellants (high energy, low fragility ammunition) are another "conventional" gun-type propellant that can be used in propellant grains 90. This includes about 76.
0% RDX (hexahydrotrinitrotriazine), about 12.0% cellulose acetate butyrate, about 4.0%
Nitrocellulose (12.6% nitrogen), about 7.60
There is an M39LOVA propellant consisting of a composition of acetyl triethyl citrate and about 0.4% ethyl centralialite. The M39 LOVA propellant is available from The Naval Naval Battle Center in Indianhead, Maryland, USA
Surface Warfare Center) and available in Europe (Boforu Sweden) (Bofors), no excess oxygen is present when generating of H ₂ to about 32 mole percent CO and 30 mole percent. LOVA and HELO
VA propellants are preferred over existing double base propellants.
The latter does not pass the current US automotive industry heat resistance standards, while the former does. However, relatively high operating pressures are required for stable combustion of LOVA and HELOVA propellants. HPC-96
And HPC-96 despite the properties of the LOVA propellant
And LOVA propellants help illustrate at least some aspects 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 for the gas generator 82 (the composition of FN 1061-10 is about 7.93% polyvinyl chloride by weight, 7.17%
Dioctyl adipate, 0.05% carbon black, 0.35% stabilizer, 8.5% sodium oxalate, 75% potassium perchlorate and about 1% lecithin. ). For example, a gun-type propellant that can be used to form propellant grains 90 typically has a total grain weight of about 1
It is in the range of 0 to 12 g (when used on the passenger seat side), preferably less than about 15 g. In this case, about 150-1
Preferably, 90 g of pressurized medium 36 is used with about 10-30% oxygen of pressurized medium 36 on a molar basis. More specifically, when about 169 grams of pressurized medium 36 is used with about 15% oxygen of pressurized medium 36 on a mole percent basis, the total weight of propellant grains 90 is about 1%.
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
0 propellant, the assignee of the present patent application is FN 10
A ratio of about 7.04 by weight of argon (i.e., high pressure gas and corresponding to pressurized medium 36 in accordance with the present invention) to weight of 61-10 propellant is used. With respect to 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 the 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 require less propellant. 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 expandable,
Inflators are 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 as when using the same rate of FN 1061-10, but the inflator with the gun type propellant is about 50% lighter than the inflator using FN 1061-10, and small. 7.
The ratio of 04 can be equally suitably used as described above regardless of whether it is used on the driver's seat side or in 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, the 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, for a gun-type propellant for an inflator of the same power, weight and dimensions, the ratio of moles of output gas to the total weight of propellant grains 90 is typically about 0,0 g / g propellant. 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 also using a ratio of 0.192 gmol / g propellant, the output of the inflator is FN
Same as a hybrid inflator using 1061-10, but with a weight and size reduction of the gun type propellant inflator of 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 the 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 the propellant gas to acceptable levels. For example, oxygen preferably converts a substantial portion of existing carbon monoxide to carbon dioxide (eg, at least about 85% of CO to CO ₂ ) and existing hydrogen to steam (eg, at least about 80% of H ₂ ). To H ₂ O) and a significant portion of the unburned hydrocarbons is removed as well (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 pressurized medium 36 containing oxygen is caused to flow to the end 96 of the gas generator housing 86 by a pressure difference generated by the flow of the pressurized 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).

Generally, 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 that based on theoretical conversion. 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.
5) Insert the primer holder 116 with the ignition / booster agent 144 and the charging cup 148 into the gas generator housing 86;
0, the plate washer 136 and the working piston 124 are inserted into the gas generator housing 86. Thereafter, the various components are interconnected as follows. After the gas generator housing 86 has been welded to the orifice sleeve 74 and the projectile 50 and the initiator 46 have been placed in the diffuser 38, the diffuser 38 is welded to the boss 66 and a closing disc is provided between the boss 66 and the orifice sleeve 74. 70, and the boss 66 is welded to the 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 separately introduced into the inflator housing 34 via an end plug 42 welded to the end of the inflator housing 34 (eg, first with argon and / or other , 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 HPC-96 propellant described above was used to form a propellant grain 90 with a total weight of 18 g. 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, the HPC-96 propellant exhibited the following properties when ignited under air: Exercise power 363,493 ft-lbs / lb, explosion heat 1,062 calories / g, TV 3,490 ° K, gas molecular weight 26.7 g / mol, specific heat ratio 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 an industry standard Taliani heat resistance test. This reduces the relevance of using HPC-96 propellant in propellant grains 90. that is,
One current industry standard specifies that propellants for inflatable safety systems do not degrade significantly when exposed to a temperature of 107 ° C. for 400 hours, and then ignite when exposed to the auto-ignition temperature. Because it is. However, HPC-
96 propellants are described herein to demonstrate certain principles of the present 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. Inflator 30 has four orifice ports 78 on orifice sleeve 74, each having a diameter of about 0.676 cm.
(0.266 inch) and the diameter of the gas generator suction nozzle 98 was about 1.191 cm (0.469 inch). The discharge nozzle 200 was not provided on the side wall of the gas generator housing 86. Thus, the pressurized medium 36 was not drawn into the gas generator 82 during operation, and all discharges were performed 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 communicated with the inflator 30
The internal pressure of the 0 liter tank is as shown in FIG. 4 and schematically represents a 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.
X. Thus, the use of the above proportions of oxygen and argon significantly reduced the amounts of carbon monoxide and hydrogen compared to the theoretical gas output of the HPC-96 propellant described above. In this example, without using radial holes,
Only one gas generator outlet was used.

Example 2: The process of Example 1 was repeated. However, the propellant grains 90 used 10.4 g of HPC-96 propellant and used 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 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 greatly 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 curves of the inflator 30 were the same as those shown in FIGS. Furthermore, inflator 3
The gaseous output from 0 is about 1,000 ppm and 8 respectively.
00 ppm carbon monoxide, about 1.0%, 1.2% carbon dioxide, about 60 ppm, 50 ppm NOx, about 23 p
pm, contained 20 ppm of NO ₂ . Therefore, 15%
To increase the amount of oxygen, by that reducing the amount of HPC-96, the amount of carbon monoxide without affecting significantly the NO and NO ₂ is reduced. Furthermore, the amount of propellant used 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,
Do not pass industry standards for long-term storage (for example,
400 hours at 107 ° C). In the LOVA gun propellant,
Failure to burn the propellant at high pressures (eg, over 9,000 psi) will prove to be an inadequate system performer, which will increase design weight, cost and complexity. Normally, it is desirable that the operating pressure used for inflator 30 be only about 4,000 psi. Under these conditions, there is no propellant suitable for this example, so a new method of forming a propellant that constitutes a new kind of propellant was developed. That is, the ballistic properties of the double base propellant (excellent in ignition and combustion at low pressure) and the storage properties of the nitramine LOVA propellant (10
(Excellent after storage at 400C for 7 hours at 7 ° C). This type of propellant is called a hybrid propellant.

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

[0038]

[Table 1]

Generally, one desires to combine certain ballistic properties with long term heat resistance (eg, the ballistic properties of double base propellants as well as the long term aging or long term thermal stability of LOVA propellants). To obtain), the secondary explosive is combined with the binder system as a formation of propellant grains 90 ("hybrid propellant" as described above). As used herein, the term "binder system" refers to one or more compounds useful for modifying the physical, chemical, and / or ballistic properties of a propellant and 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 mixed propellant for the propellant grains 90 in the mixed inflator 30 exhibits excellent ballistic properties (ie, burn rate and temperature at relatively low operating pressures) and reasonable long-term stability (eg, One of the industry tests for evaluating 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 the hybrid propellant have a viscosity of about 2,000-3.8.
Combustion temperature of 00K, about 0.1-1 inch / sec
(0.25-2.5 cm / sec), about 4,000
Combustion is performed at an operating pressure (pressure in the gas generator housing 86) of 0 psi (27.6 MPa) or less. More preferably,
The propellant grains 90 formed from the hybrid propellant have about 2,
Combustion temperature of 000-3,800 K, about 0.3-0.5
It burns at a speed of inches / sec (0.76-1.26 cm / sec) and at 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 explosives and about 10-50 wt% binder system. More generally, the formation of these propellants requires about 60-80 wt% of a secondary explosive and about 20-80 wt.
Contains 40 wt% binder system. Preferably, the propellant formation contains about 70-80 wt% of the specific secondary explosive and about 20-30 wt% of the binder system. Other additives and unavoidable impurities may be present in the composition of these propellants in trace amounts (i.e., less than about 5 wt% composition).

Usually, the resinous binder is the propellant grain 90.
A part of the binder system for the formation of a hybrid propellant for use. Ordinary solvents (ie acetone, lower alcohols, etc.)
Almost 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 burns at the desired combustion temperature and operating pressure described above. Further, when used with a plasticizer, it is, of course, desirable that the binder be compatible with the plasticizer. Typical binders suitable for use in the propellant composition include CA (cellulose acetate), CAB (cellulose acetate butyrate), EC
(Ethyl cellulose), PVA (polyvinyl acetate), C
Examples include, but are not limited to, AP (cellulose acetate propiolate), azido polymer, polybutadiene, hydrogenated butadiene and polyurethane, and mixtures thereof. The azido polymer may be a homopolymer or 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. Become. In addition, GAP as a binder element
(Active glycidyl azide polymer), which is
It burns substantially more vigorously. In this case, it may be desirable to use only GAP as a binder together with the secondary explosive. However, due to the current significant cost differences between GAP and CA, the formation of hybrid propellants requires GAP and CA.
Both elements are included. Plasticizers can also be used as part of the binder system for forming the hybrid propellant for propellant grains 90. As noted above, the plasticizer should be compatible with the binder. Furthermore, 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 (e.g., nitramine), i.e., a plasticizer that is capable of stable combustion at the operating temperatures and pressures described above. Useful active plasticizers include TMETN (trimethylolethane trinitrate), BTTN (butanetriol trinitrate),
And nitrate ester plasticizers such as TEGDN (triethylene glycol dinitrate), glycidyl azide plasticizers and NG (nitroglycerin) and BDNPA /
Other compounds such as, but not limited to, 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, can degrade when exposed to certain temperatures and affect ignition of the propellant grains 90 (i.e., certain temperatures). 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), and improve the long-term stability of the formation of the hybrid propellant. For example, in the case of nitrates, stabilizers useful in forming the propellant include those that are activators but are nitrate receptors. Suitable stabilizers include, but are not limited to, ethyl centralialite (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 use 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 centralite). Typically, the formation of this hybrid propellant is at least about 70 watts.
t% RDX, about 5 to 15 wt% CA, about 5 to 15 w
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 hybrid propellants. However, if the propellant grains 90 are formed by extrusion from this formation, it will be understood that it is necessary to refine relative amounts within the above numerical ranges.

Also, at least about 70% by weight of the propellant.
RDX (hexahydrotrinitrotriazine),
About 5 to about 15% by weight of CA (cellulose acetate)
And about 5 to about 15% by weight of one of GAP (glycidyl azide polymer) and ATEC (acetyl ethyl citrate). Generally, when a mixture of a binder, a plasticizer and a stabilizer is used as a binder system, the mixing ratio of each agent 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 and a binder system comprising CA and GAP (glycidyl azide polymer) as binders and a suitable plasticizer (eg, GAP plasticizer, TMETN, ATEC and combinations thereof). Generally, the hybrid propellant will be 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 provide the desired impact and long-term aging properties for the hybrid propellant.
s). 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. For hybrid propellants including double base propellants and LOVA propellants of the large amounts of carbon monoxide and hydrogen are formed during the combustion (e.g., 35% CO and 19% H ₂ is formed during combustion) . The formation of carbon monoxide and hydrogen gas by 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 (eg, 95%) of carbon monoxide and hydrogen is converted to harmless carbon dioxide and water vapor during or as part of the post-combustion reaction. Pressurized medium 3
6 contains oxygen. The use of hyperbaric oxygen is particularly desirable because the use of hyperbaric oxygen eliminates the need to include an oxygen source (eg, potassium perchlorate) in the hybrid propellant.
In addition, the exothermic reaction that occurs between the combustion gas formed from the propellant and the high pressure oxygen increases the propellant's heating value, thereby minimizing the amount of propellant needed to inflate the air / safety bag. The exothermic reaction is particularly preferable in order to minimize the reaction.

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 specified 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. As described above, “Wt%” indicates percent by weight. 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 curves for this generally corresponded approximately 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 to 15
wt% cellulose acetate, and about 5-15 wt%
A hybrid propellant composition comprising GAP (glycidyl azide polymer) was prepared, wherein the propellant composition was about 1.6885.
Formed as cylindrical grains having an average density of 7 g / cc. A 10 g sample was inserted into a bomb chamber with a thick wall and exploded into the tank. The sample is 4,000
About 2,357 ° K at 0 psi (27.6 MPa)
Having a combustion temperature of and acceptable impact properties (ie,
0.48 inches / sec (1.18 cm / sec)).
The performance curves for this generally corresponded approximately with the curves shown in FIGS. The gas formed is about 37% carbon monoxide, about 25% hydrogen, about 25% nitrogen, about 10%
Water vapor and about 3% carbon dioxide. An evaluation of the long-term thermal stability of the hybrid propellant composition was performed and the results confirmed that the long-term thermal stability of the composition was within acceptable limits (eg, propellant over 400 hours). The propellant did not ignite when exposed to a temperature of 107 ° C. The propellant did not ignite when exposed to a temperature of 107 ° C. for 400 hours in a hybrid inflator. Although the agent was activated, the performance of the inflator was substantially unaffected by the heat treatment).

Other propellants used in one or another embodiment of the present invention are hexogen (RD
X) 1 to 99 parts by weight and Octogen (HMX) 99 to
The binder is contained in an amount of 5 to 50 parts by weight based on 1 part by weight and further 100 parts by weight of RDX and HMX in total. Preferably, 80 to 95 parts by weight of hexogen (RDX), 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 generally includes a pressurized gas chamber containing a pressurized gas, a gas generating 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 during a vehicle collision to produce gaseous, oxygen-reactive combustion products, namely, carbon monoxide and hydrogen.
Carbon monoxide and hydrogen react with oxygen in the pressurized gas to generate carbon dioxide and water vapor, while increasing the pressure in the gas chamber. Then, the rupturable plate is broken, 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 propellant is hexogen (RDX),
It is composed of Octogen (HMX) and a binder. The ratio of RDX, HMX, and binder is HMX99 with respect to 1 to 99 parts by weight of RDX.
バ イ ン ダ ー 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 the binder to 100 parts by weight of RDX and HMX in total.

The binder that can be used 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 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 usable in the above-mentioned propellant, for example, ethyl centrallite, diphenylamine, resorcinol, acardite, amyl alcohol, urea, petroleum jelly, etc. can be used.

The amount of plasticizer added is RDX, HMX,
And 0 to 30 with respect to a total of 100 parts by weight of the binder.
Parts by weight are preferred. The amount of the stabilizer added is RDX, H
For a total of 100 parts by weight of MX and binder, 0
-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: A substance having the following composition is mixed into pellets,
It was loaded into a hybrid inflator composed of a pressurized gas chamber, a gas generation chamber, an ignition assembly, and a rupturable plate. Then, the hybrid inflator was operated. As a result, no smoke composed of KCl was 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: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

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: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

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: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

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, binders (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 10: A substance having the following composition was mixed into pellets, charged in the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

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, the binder (CAB, GAP) for 100 parts by weight of RDX and HMX. Is about 32 parts by weight. Example 11: A substance having the following composition was pelletized and charged in the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

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 substance having the following composition was pelletized, charged in the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was 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 Ethyl centralralite 2 parts by weight Incidentally, relative to 100 parts by weight of RDX and HMX. 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 was 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 Trimethylolethane trinitrate 20 parts by weight (TMETN) RDX The content of the binder (CAB, GAP) is about 32 parts by weight based on 100 parts by weight of HMX. Example 14: A substance having the following composition was formed into pellets, loaded into the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was 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 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 with respect to 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 with respect to the design of the inflator 202 is that it provides or allows for sufficient mixing between the propellant gas and pressurized medium formed by ignition and combustion of the propellant grains 258. As a result, the inflator 202 uses at least one of the aforementioned gun-type propellant composition and the hybrid propellant composition as a composite pressurized medium (eg, one component is oxygen and another component is at least one non- It is particularly suitable for use with a complex pressurized medium which is an active gas. 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 increases the rapid inflation capability of the inflator 202 to initiate gas flow to the air / safety bag (see FIG. 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. In addition, the initiator 228 is 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 mainly comprises propellant grains 258 which, when ignited, cause the air / safety bag 18
Propelling 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 or combustion chamber. Propellant grain 2
To assist ignition of 58, a suitable ignition / booster agent 240 (e.g., RDX / aluminum booster agent containing 89 wt% RDX and 11 wt% aluminum powder, or 0 of the same RDX / aluminum booster agent) Between 0.5 and 5.0 wt% RDX and 0.5 to 5.0 wt% hydroxypropylcellulose can be used as a booster agent) between initiator 228 and propellant grains 258.
It can be arranged at a position matching the discharge from the initiator 228. As described in more detail below, the gas product formed by the ignition of the igniter / booster agent 240 can be chemically reacted with the pressurized medium to further enhance the characteristics of the onset of flow by rapid inflation of the inflator 202. It is. A suitable booster cup 244 or the like retains the igniter / booster agent 240 (typically in the form of a powder or slurry dry body) therein, and the end of the initiator adapter 224 and the first end. Can be suitably secured to at least one of the ends of the housing 216 (eg, held between the adapter 224 and the housing 216 via a weld 248). The first chamber 254 has a screen 266 or the like to discharge a propellant gas into the second chamber 324 as described above, while retaining particulate matter of a particular size therein. I can do it. In addition, the inflator 2
02 has a capacity of the high-pressure gas housing 204 in the second chamber 3.
24 is set larger than the capacity.

The first chamber 254 is the high pressure gas housing 2
In general, the at least one bleeding orifice or bleeding port 262 (two bleeding ports are formed in this embodiment) communicates with the at least one bleeding orifice. As a result, the first chamber 254 contains a large amount of pressurized medium in a static state.
The bleed port 262 extends radially (ie, the bleed port 262 has its origin on the central axis 220 and extends along a radius extending in a direction perpendicular to the central axis 220). ). To properly adjust the performance of the inflator 202, the use of the bleed port 262 and the bleed port 262
Size and / or quantity can be selected.

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 housing 2 for high pressure gas.
You will be guided in 04. Propellants of the type described above (e.g., gun-type propellants, hybrid propellants) and pressurized media (e.g.,
If a mixture of oxygen and an inert fluid (including at least one inert gas) is used, a second combustion, i.e., a further combustion of the propellant gas, occurs in the high-pressure gas housing 204. Part of the propellant gas is transferred to the first chamber 254.
Guiding into the high-pressure gas housing 204 from
It can be used to achieve a desired output or discharge to the air / safety bag 18, ie, to achieve a desired inflation rate of the air / safety bag 18. As will be described in more detail below, the propellant gas is supplied 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 time.
4 is preferably provided. Generally, less than half of the propellant gas formed to achieve the desired result (e.g., no more than about 40% of the propellant gas, more typically no more than about 30% of the propellant gas). Is guided into the housing for high pressure gas 204 during operation.
It needs 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 significant pressure build-up typically associated with ignition of propellant grains 258 is substantially confined within 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 rate of propellant gas) is directed to the gas generator housing 212 by the primary flow. 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 provided in the first chamber 25.
Gas flow from 4 into second chamber 324 (mainly propellant gas)
Through which the desired communication is formed. The afterburner nozzle 274 is connected to the first housing 21.
Prior to properly connecting 6 to second housing 278 (eg, by welding at weld 250), shoulder 2 formed inside first housing 216
70 and the first housing 216
It is arranged inside.

In this embodiment, the gas generator housing 21
One end of the second second housing 278 is engaged with the inner surface of an afterburner adapter 282 having at least one gas generator outlet 286 therein. O-ring 328 is located between second housing 278 and adapter 282 to provide a suitable seal. Adapter 282 for afterburner is boss 294
(For example, the welded portion 308).
The boss 294 is fixed to the high-pressure gas housing 204 (for example, fixing by welding at the welding portion 312). Second room 324
Has a large amount of pressurized medium in the static state,
These two fixings are preferably performed so as to form a hermetic seal. In order to properly hold the pressurized medium in the inflator 202 until the desired time is reached, the second closing disc 290 is connected to the afterburner adapter 2.
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. Second chamber 324 controlled based on the method detailed below
Due to the sudden pressure increase in the second closure disc 290
Is opened at the appropriate time and the gas flow from the inflator 202 is directed to the diffuser 298 and then into the air / safety bag 18 (see FIG. 1). Diffuser 298 includes a plurality of diffuser ports 300 to provide less disruptive output to air / safety bag 18 (see FIG. 1). The retention of certain particulate matter in the inflator 202 and the mixing or reaction of the propellant gas and pressurized medium before the propellant gas and pressurized medium pass into the air / safety bag 18 (see FIG. 1). The diffuser 298 may include a diffuser screen 304 to achieve at least one of further facilitation.

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 a 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, in a specific application, the flow direction of this specific gas flow can be controlled. In particular, valve 320 can be located adjacent to 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 a connection without hermeticity 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 above the gas generator inlet 316 includes a filler material comprised of a generally cylindrical roll (eg, 300 series stainless steel). And has a thickness of 0.002 inches (approx.
m) thing). A cantilever connection can be used between the valve 320 and the inner wall of the second housing 278. At this time, the rear part of the valve 320 (that is, the part sufficiently separated from the inlet 316) is connected to the second housing 278, and the front part and the intermediate part of the valve 320 are not connected to the other. As a result, the valve 320 can move or deflect freely.

From the above, the high-pressure gas housing 2
It can be seen that the pressures spreading inside each of the housing 04 and the gas generator housing 212 are substantially equal in the static state. However, dynamic conditions or propellant grains 25
After the ignition of 8, the pressure in each chamber of the inflator 202 is different from each other to achieve the desired performance. When the ignition of the propellant grains 258 is performed, the formed propellant gas begins to flow into at least the second chamber 324 to increase the pressure in the second chamber 324. With the inflator 202 having at least one bleed port 262, a portion of the propellant gas is
4 and the high pressure gas housing 20
4 results in a small pressure increase. Second room 32
The pressure increase rate in the housing 4 for high pressure gas
Preferably, it is even faster than the pressure increase rate in the pressure 4. The difference between the pressure increasing rates is generated based on the flow of the propellant gas into each of the second chamber 324 and the high-pressure gas housing 204 and the relative volume difference therebetween. This pressure difference causes the valve 320 to be pressed against the inner wall of the gas generator housing 212, more specifically, the portion of the second housing 278 that is aligned with the valve 320. As a result, the high-pressure gas housing 204
The gas generator inlet 316 is separated from the second chamber 324 by being shut off by the valve 320. The cantilever connection of the valve 320 allows movement of the 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 will open, rupture or break it. 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.
Enables the timely initiation of gas flow into the safety bag 18 (see FIG. 1). In certain designs, the use of the valve 320 allows the second closure disc 29
The second chamber 324 can be rapidly pressurized at such a speed that the zero can be opened in a timely manner. If 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 pressurized chamber, which allows the air / safety bag 18
The time required to start the flow of gas to (see FIG. 1) is reduced. In certain designs, as described in detail below, the volume of the second chamber 324 is sufficiently small and the propellant and pressurized medium are adjusted to achieve satisfactory operation without the use of the valve 320. At least one of the selections can be performed (e.g., formed by combustion of at least one of propellant grains 258 and / or igniter / booster agent 240 to perform rapid pressurization in second chamber 324). Utilizing the combustion of gas that has been used).

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 particular pressure differential is created between the high pressure gas housing 204 and the second chamber 324, the valve 320
Is moved by the pressing force caused by this pressure difference so as to expose. 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 indents the valve 320 at least in a region 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
Is exposed, the flow of gas from the high-pressure gas housing 204 into the second chamber 324 is started. The valve 320 is movable from the first position to the second position. That is, the valve 320 is positioned in the first position in use to substantially block the 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 has a radius. It is located inside the first position along the direction.

Second chamber 3 after the second closing disc 290 has been ruptured by the rapid pressurization of the second chamber 324.
The primary function of 24 is to provide or allow for effective mixing of the propellant gas and pressurized medium before the propellant gas and pressurized medium are expelled into air / safety bag 18 (see FIG. 1). That is. Propellant compositions of the type described above (e.g.,
When a gun-type propellant, a hybrid propellant) and a pressurized medium of the type described above (for example, a mixture of an inert fluid and oxygen typified by one containing at least one inert gas), this mixture is used. Promotes to provide the aforementioned effects, including, for example, reducing toxicity and reducing the total amount of propellant used in the inflator 202 by further burning and increasing the expansion capacity resulting from the burning. This 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 the ignition of the ignition / booster agent 240 occurs, and more preferably about 100% of such combustion occurs in the inflator 202. This is air / safety bag 1
8 (see FIG. 1) to reduce 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 described in more detail 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 out 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 the pressurized medium that reacts with the propellant gas until the flow of the pressurized medium from the high-pressure gas housing 204 to the second chamber 324 is started by the movement of the valve 320 is increased. Is preferably included from the beginning.

In order to realize the above-mentioned 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 portion or the foremost portion of all gas generator inlets 316 (each of the gas generator inlets 316) facilitates further mixing of the propellant gas and the pressurized medium. (Defined by the center line) is positioned along the length of the second housing 278 in alignment with the end of the afterburner nozzle 274, and the portion located further forward is the afterburner as shown in the figure. -It is preferable that the nozzle 274 be disposed further rearward (that is, in a direction approaching the initiator 228).

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 depends on the use of the inflator. For example, the capacity of the inflator housing 204 ranges from about 150 cm ³ to about 450 c.
m ³ , the volume of the first chamber 254 is from about 10 cm ³ to about 40
cm ³ , and the volume of the second chamber 324 is from about 1 cm ³ to about 50 cm ³ .

In order to show the principle of the present invention, its dimensions in one embodiment will be exemplified below. 1) The diameter of the high-pressure gas housing 204 is 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 formed from a mild steel tube and its wall has a thickness of about 2.5 mm.
4) The internal volume of the high-pressure gas housing 204 (the volume of the portion of the interior of the high-pressure gas housing 204 that includes the pressurized medium, including the volume of the gas generator 208 located at the center thereof. No) is about 375cc.
5) The diameter of the first housing 216 of the gas generator housing 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
Thickness. 8) Gas generator housing 212
The inner volume of the first chamber 254 is 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 thickness of about 1.25 mm. 12) The interior volume of the second chamber 324 of the gas generator housing 212 is about 14 cc. 13) The inflator 202 is about 3 mm
Are provided. 1
4) The inner diameter of the afterburner nozzle 274 is about 2.5
mm. 15) Outlet 286 for gas generator is about 10m
m. 16) All gas generator inlets 316 are located about 76 mm away from gas generator outlets 286. 17) The nozzle 274 is located at a distance of about 75 mm from the gas generator outlet 286. 18) The internal volume of the diffuser 298 is 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,
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 a pressurized medium. 85 of the same pressurized medium
Percent (mol percent) is argon and 15% (mol 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.
D and FIGS. 7A to 7D. As shown in FIGS. 6A and 7A, the second closure disk 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 a suitable signal indicating that deployment of air / safety bag 18 (see FIG. 1) is required is detected by detector / sensor 14 (see FIG. 1). Activation of the initiator 228 ruptures the first closure disk 236 and ignites the igniter / booster 240, which ignites the propellant grains 258. The combustion of the propellant grains 258 forms a propellant gas in the first chamber 254. The propellant gas is supplied to the second chamber 3 of the gas generator housing 212.
24 and into the high-pressure gas housing 204. The presence of the hot propellant gas in the first chamber 254 and the flow of the hot propellant gas into the second chamber 324 and the high-pressure gas housing 204 allows for these "vessels".
A corresponding increase in pressure takes place 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.
4 is designed to be even faster than the pressure increase rate in the high-pressure gas housing 204 by guiding the hot propellant gas into it. 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 present in the second chamber 324 in the static state becomes smaller between the high-pressure gas housing 204 and the second chamber 324. It must be of sufficient quantity 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 through the diffuser 298 and the air / safety bag (see FIG. 1). However, as shown in FIGS. 6C and 7C, the valve 320 blocks gas flow directly 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 formed between the high-pressure gas housing 204 and the second chamber 324, the pressure difference is transferred from the high-pressure gas housing 204 to the second chamber 324. The valve 320 is spaced from the gas generator inlet 316 to form a pressurized medium flow. For example, the structure of the valve 320 shown here (eg, a cylindrical roll of metal foil) may cause the valve 320 to form when the specified pressure differential is created in a region adjacent or aligned with the gas generator inlet 316. The front of the indents or moves inward along the radial direction. However, the rear of valve 320 maintains a connection with second housing 278.

Thus, the design of the inflator 202 is a system that includes the propellant (eg, gun-type propellant, hybrid propellant) and pressurized medium (eg, a mixture of oxygen and at least one inert gas) as 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
In 24, a second combustion of the propellant gas and the pressurized medium occurs. 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 length of the second chamber 324 is long, in particular, the afterburner nozzle 274 and the gas generator outlet 286 of the gas generator inlet 316.
And the gas generator outlet 286, the distance between the gas generator outlet 286 and the gas generator outlet 286 is sufficient to allow a second combustion to occur before the gas flows out to the air / safety bag 18 (see FIG. 1). Time is gained.

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 using a propellant of the type described above and a pressurized medium. The propellant is oxidized under pressure in the second chamber 324 (eg,
A propellant gas that can be further combusted is formed by mixing with an inert fluid, such as one containing one or more inert gases, and an oxidizing pressurized medium composed of a composite of oxygen. In this case, the combustion of the propellant gas occurring in the second chamber 324 and the second combustion of the gas formed by the ignition of the igniter / booster agent 240 is such that the pressure increase or pressure is sufficient such that the valve 320 is not required. Brings 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%.
%. In this case, the second chamber 32
The initiation of flow by rapid pressurization can be realized using 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, the inflator 350 is formed particularly adapted for use on the driver's side. Inflator 350 may include a propellant of the type described above (e.g., gun-type propellant, hybrid propellant) and a composite pressurized medium (e.g., an inert fluid typified by one containing at least one inert gas) and oxygen. The use of a mixture can 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 pressurized medium therein. The main advantage of the inflator 350 is that the inflator 350 can open the second
Adjacent to a second closure disk 428 (the second closure disk 428 separates the gas flow between the inflator 350 and the air / safety bag 18 (see FIG. 1)) to exert a fluid pressure directly on 8 This is a point that acts on the rapid pressurization in the region that has been set. Further, as will be described in greater detail below, another advantage of the inflator 350 is that it provides a substantial pressure increase primarily within the gas generator 362 associated with propellant activation. 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 reduced as compared with the conventional hybrid inflator). The weight of 350 can be reduced.

The central housing 358 is the inflator 35.
The central housing 358 is disposed around a central axis 352 extending in the length direction of the gas generator 362.
It has a diffuser 458 aligned with the gas generator 362 along its length direction and spaced from the gas generator 362. Gas generator 362 and diffuser 458 are at least partially formed 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 is provided below the central housing 358 and the high pressure gas housing to form a corresponding hermetic seal. 354 are properly coupled to both (eg,
Connection by welding at the welding portion 442). Ignition assembly holder 370 is provided with a suitable ignition assembly 374
(Eg, an electric igniter tube or other suitable explosive device) and an O-ring 372 may be used to form a seal. To form a hermetic seal for separating the ignition assembly 374 from the pressurized medium in the gas generator 362, a first closing disc (secondary closing disc) 3 is formed.
Reference numeral 78 is suitably connected to the end of the ignition assembly holder 370 (for example, connection by welding at the welding portion 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.
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 holder 370 for the ignition assembly, 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 has a propellant grain 404 that increases the flow of gas to the air / safety bag 18 (see FIG. 1) upon ignition. Propellant gas is formed to achieve this. As a result, the first chamber 394 can be characterized as a propellant chamber. To assist in igniting the propellant grains 404, a suitable igniter / booster 408 (eg, an RDX / aluminum booster containing 89 wt% RDX and 11 wt% aluminum powder, or the same RDX / aluminum.
0.5 to 5.0 wt% of the booster agent RDX and a booster agent in which aluminum is replaced with 0.5 to 5.0 wt% of hydroxypropylcellulose may be used) at least a portion of the ignition assembly 374. It may be centrally located in the first chamber 394 for alignment. A suitable screen 412, booster cup or the like can separate the propellant grains 404 from the ignition / booster 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, the pressurized medium is also contained in the first chamber 394 in a static state as described above. In this embodiment, the bleed ports 400 extend in a radial direction (ie, the bleed ports 400 are each arranged to extend along a radius having its origin on the central axis 220), and extend in a substantially horizontal direction. (Ie, center axis 352
Are included in a plane that extends in a direction orthogonal to. Selection of the size and / or quantity of the bleed ports 400 can be used to properly adjust the performance of the inflator 350 as described above in the 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
The 50 can be further chemically reacted with the pressurized medium to further enhance the properties of the onset of flow by rapid pressurization.

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 will be described in more detail below, the propellant gas is supplied 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.
4 is preferably provided. Generally, less than half of the propellant gas formed to achieve the desired result (e.g., no more than about 40% of the propellant gas, more typically no more than about 30% of the propellant gas). During the operation of the high-pressure gas housing 354).
It needs 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 large pressure increases that generally accompany ignition of the propellant grains 404 are 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 (4,000 psi) per square inch (6.45 square centimeters), the high pressure gas housing 354 may be used. The maximum required wall thickness of the wall 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.
(Referred to as "afterburner" for the reasons described above). The second chamber 418 of the gas generator housing 366 is connected to the first chamber 39 of the gas generator housing 366.
4, at least one propellant gas vent 416
The propellant gas vents 416 extend through the gas generator partition 390. As will be described in further detail below, the primary flow path for the pressurized medium present in the high pressure gas housing 354 to the air / safety bag 18 (see FIG. 1) is further directly connected into the second chamber 418. I have. In order to achieve sufficient mixing of the propellant gas flowing from the first chamber 394 into the second chamber 418 and the pressurized medium flowing into the second chamber 418 from the high pressure gas housing 354 (e.g. 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 so as to remain within the second chamber 418 for a sufficient amount of time. It is possible. One way to create this vortex is to form the propellant gas vent 416 of the gas generator to extend substantially linearly, as shown in FIG. The vents 416 are arranged so as to be inclined to opposite sides in the corresponding plane.

Second chamber 4 of gas generator housing 366
18 are aligned with the first chamber 394 along its length and are separated by a gas generator partition 390 into the first chamber 3.
94 and a housing 354 for high pressure gas.
Are arranged along its outer periphery. Second room 4
Reference numeral 18 denotes an intermediate portion of the central housing 358, the gas generator partition 390, and the gas generator end cap assembly 4.
20. The gas generator end cap assembly 420 is suitably coupled to the central housing 358 (eg, by welding at a weld 454), with the upper portion of the central housing 358 relative to the upper portion of the high pressure gas housing 354. Appropriately connected (for example, connection by welding at the welded portion 450). Since the second chamber 418 has a large amount of pressurized medium in a static state, the welds 450, 454 preferably form a hermetic seal. The gas generator end cap assembly 420 has at least one gas generator outlet 424 (one shown). To form a hermetic seal for properly holding the pressurized medium in the inflator 350, particularly the second chamber 418, for a desired time, the second closure disk 428 is attached to the gas generator end cap assembly 420. (For example, connection by welding at the welding portion 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. Due to the rapid pressure build-up in the second chamber 418 based on the control detailed below, the second closing disc 428 is opened at the appropriate time. As a result, the gas flow 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 closure disc debris within the inflator 350 and provides the propellant gas and pressurized medium before the propellant gas and pressurized medium pass into the air / safety bag 18 (see FIG. 1). A diffuser screen (not shown) to achieve at least one of mixing the medium and / or further enhancing the 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, a 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 the flow. In particular, valve 438 can 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 retained in the second chamber 418 in a static state, and a connection that is not hermetically sealed 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-shaped filling material (eg, 0.
002 inches (about 0.05 mm) of stainless steel). A cantilever connection can be used between the valve 438 and the inner wall of the gas generator housing 366. That is, the rear of the valve 438 is
And the valve 438 is movable / deflectable because it is coupled between the septum 390 and the front of the valve 438 is not coupled to the other.

The shape of the valve 438 is preferably the present one, but the individual plugs 438a and 438b (see FIG. 14).
(A), (B)) can be arranged in each entrance 432. These plugs 438a and 438b are desirably connected to the inflator 350 by a tether 439 or the like (shown only in FIG. 14B). Further, it is desirable that the plugs 438 a and 438 b be supported in the inlet 432 by the flexible member 433. Plug 438
a, 438b can also be used with the other hybrid inflators described herein.

From the above, the high-pressure gas housing 3
It can be seen that the pressure spreading inside each of 54 and gas generator 362 is approximately equal in the static state. However, in the dynamic state or after ignition of the propellant grains 404, the pressure in each chamber of the inflator 350 is different from each other to achieve the desired performance. Propellant grain 404
When the ignition is performed on the second chamber 4
Begin flow into at least the second chamber 418 to increase the pressure in 18. When the inflator 202 has at least one bleed port 400, a part of the propellant gas flows into the high-pressure gas housing 354, and
The pressure in the high-pressure gas housing 354 is increased.
The rate of pressure increase in the second chamber 418 is preferably faster than the rate of pressure increase in the high-pressure gas housing 354. The difference in the rate of pressure increase is the second chamber 418
And the high-pressure gas housing 354 due to the flow of the propellant gas and their relative volume differences. This pressure differential causes valve 438 to have a matched gas generator housing 366 with valve 438.
Is pressed against 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 valve 320 is
0 movement is possible. If the pressure in the second chamber 418 reaches a predetermined pressure value, the fluid pressure will open, break or break the second closure disk 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 particular, in certain designs, the use of valve 438 allows the second chamber 418 to be rapidly pressurized at a rate that allows the second closing disk 428 to be opened in a timely manner. Inflator 35
If the zero has no 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 disk 428 can be broken. However, the use of the second chamber 418 provides a smaller pressurized chamber, which reduces the time required to initiate gas flow to the air / safety bag 18 (see FIG. 1). As will be described in more detail below, the volume of the second chamber 418 may be sufficiently small in certain designs, and the propellant and pressurized medium may be adjusted to achieve satisfactory operation without the use of the valve 438. At least one of the selections can be performed (e.g., propellant grains 404 and ignition / booster agent 4 to affect rapid pressurization in second chamber 418).
18 by utilizing the combustion of the gas formed by the combustion of at least one of 18).

The valve 438 maintains its deployed position after the second closure disc 428 has been opened to form the 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 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 is located at the gas generator housing 366.
Is maintained in a coupled state. 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 second closing disk 42 is pressed by the rapid pressurization.
The main function of the second chamber 418 after the breakage of the propellant gas and pressurized medium is before the propellant gas and pressurized medium are discharged into the air / safety bag 18 (see FIG. 1). To provide or tolerate effective mixing of Propellant compositions of the type described above (eg, gun-type propellants, hybrid propellants) and pressurized media of the type described above (eg, an inert fluid and oxygen, such as those containing at least one inert gas). If used, this mixture provides significant benefits, including, for example, reducing toxicity and reducing the total amount of propellant by further burning and increasing the expansion capacity associated therewith. This results in 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 igniter / booster agent occurs in the inflator 350, more preferably about 100% of such combustion. This reduces the risk of damage to the air / safety bag 18 (see FIG. 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 in the second chamber 418 to supplement the use of the "short" second chamber 418 when using the inflator 350 on the driver side, This mixing is performed by the high pressure gas housing 354 to promote mixing of the pressurized medium and the propellant gas from the second chamber 4.
This may be achieved by introducing a vortex into the gas flow to 18 (primarily a pressurized medium, or a large amount of propellant gas and / or gas formed by 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, and The central axis of the inlet 432 extends in the longitudinal direction of the inflator 350 as shown in FIG.
Can be realized by orienting them so as not to pass through. That is, the substantially linearly extending inlet 432 may extend radially outward from a longitudinally extending central axis 352 to connect the second chamber 418 and the high pressure gas housing 354. Absent. Alternatively, a portion of any of the inlets 432 is located on one radially extending line, and another portion of any of the inlets 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 effect further mixing of the propellant gas and the incoming pressurized medium, the propulsion gas vent 416 shown in FIGS. Can be formed.

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 8.26 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 3.05 cm). 4) High-pressure gas housing 35
The internal volume of 4 is about 5 cubic inches (about 82 cubic centimeters). 5) The interior volume of the first chamber 394 of the gas generator housing 366 is about 7 cc. 6) The interior volume of the second chamber 418 of the gas generator housing 366 is about 2 cc. 7) Inflator 350 is about 1.5
It has two bleed ports 400 with a diameter of mm.
8) 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, and the propellant grains include a composition of the type described above with RDX, CA, TMETN and stabilizers. 10) The static pressure in the high-pressure gas housing 354 is about 4,000 psi, and the high-pressure gas housing 354 contains about 40 g of the pressurized medium, and 85% (mol percent) of the pressurized medium. Is argon and 15% (molar percent) is oxygen. 11) The inflator 350 is made of mild steel. 12) The wall thickness of the high pressure gas housing 354 is about 0.075 inches (1.91 mm) and the pressure rating (breakdown) is about 18,000 psi.
It is. 13) The wall thickness of the central housing 358 is approximately 0.0625 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 an appropriate signal is transmitted 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, Further, ignition of the ignition / booster agent 408 is performed. The propellant grains 404 are then ignited by the ignition of the ignition / booster agent 408. Propellant grain 404
Propellant gas is formed in the first chamber 394 by the combustion of
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 it is mixed with the pressurized medium. The presence of the hot propellant gas in the first chamber 394 and the flow of the hot propellant gas into the second chamber 418 and the high-pressure gas housing 354 also increase the pressure in 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. As shown in FIG. 11A, this pressure differential urges valve 438 against the inner wall of gas generator housing 366 to separate high pressure gas housing 354 from second chamber 418 in this region. This stops the supply of the pressurized medium that reacts with the propellant gas, so that the pressurized medium in the second chamber 418 in a static state prior to establishing communication between the high pressure gas housing 354 and the second chamber 418 The total amount of the second room 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, valve 438 closes gas generator inlet 432, thereby preventing direct gas flow from high pressure gas housing 354 into second chamber 418. After a certain pressure difference is formed between the high pressure gas housing 354 and the second chamber 418,
This pressure differential causes the valve 438 to move or deflect away from the gas generator inlet 432 to form a flow of pressurized medium from the high pressure gas housing 354 to the 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 flow into the second chamber 418 through the second chamber 418.
The flow of the pressurized medium and the propellant gas into the vortex may be swirling.
This allows the pressurized medium and the propellant gas to flow through the air / safety bag 1
8 (see FIG. 1) may increase the time that the mixture of pressurized medium and propellant gas is held in the second chamber 418 before being fed into 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.
13D is almost the same as the curve shown in FIG. The initial static pressure in the inflator 350 is about 4,000 psi. At time T1 (about 5 milliseconds), the inflator 3
50 was activated and the propellant grains 404 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 increased due to the propellant gas generated by the ignition of the propellant grains 404. The maximum pressure in the first chamber 394 and the second chamber 418 was established at time T2, at which point the second closure disk 428 broke. Time T2
At about 1 millisecond after activation, the pressure in the first chamber 394 is increased from a static state of 4,000 psi to about 10,000
0 psi and the pressure in the second chamber 418 is 4.0
From a static state of 00 psi to about 7,000 psi, and the pressure in the high pressure gas
It increased from a static state of 00 psi to about 4,500 psi.

After the second closing disc 428 was opened, the pressure in the second chamber 418 dropped. At time T3, the pressure difference between the high pressure gas housing 354 and the second chamber 418 has 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 elapse of the 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 to a maximum of about 4,750 psi at time T4, after which the pressure decreased. This time substantially coincided with the time at which a maximum pressure of about 5,000 psi was built up in the high pressure gas housing 354. At this time, the pressure increase 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. Furthermore, the desired pressure can be provided to the air / safety bag 18 (see FIG. 1) because the internal pressure of the second chamber 418 is relatively constant (only varies between 4000 and 4600 psi).

In a particular design, as described above, the inflator 350 may be constructed as described above except for the use of the valve 438. This can be achieved by the use of a propellant and a pressurized medium of the type described above, which propellant in the second chamber 324 includes an oxidized pressurized medium (e.g., containing one or more inert gases such as argon and nitrogen). By mixing with an inert fluid and an oxidizing pressurized medium composed of a composite of oxygen (typified by an oxygen fluid), a propellant gas that can be further combusted in the second chamber 418 is formed. In this case, the "second" combustion of the propellant gas occurring in the second chamber 418 and the second combustion of the gas formed by the ignition of the ignition / booster agent 408 is such that valve 438 is not required. Produces a sufficient pressure increase or rate of pressure increase. For example, the second chamber 41 after activating the inflator 350
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%.
%. In this case, the second chamber 41
The initiation of flow by rapid pressurization can be realized using the chemical reaction in 8, which reduces 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 realized without using the valve 438. This is a particular type of propellant and pressurized medium that provides for combustion of gas in the second chamber 418 to provide rapid pressurization in the second chamber 418 to open the second closure disk 428. This is basically caused by using.

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. I 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 of FIG. Therefore, the second chamber 502 has a much smaller capacity 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 transmission tube 503 has a hollow shape, and has a plurality of ventilation holes 504 on the peripheral wall thereof. Therefore, the first chamber 501 is divided into the second chamber 502 by the heat 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 closing disk 290 located near 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 a static state,
Since the valve 320 is not in close contact with the inner wall of the second chamber 502, it is open. 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 valve 320 to move toward the wall of second chamber 502, closing 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. Thus, the pressurized medium enters the second chamber 502 as well as the pipe 505 through the inlet 316. Thereafter, the 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 to be converted into carbon dioxide and water. These high-pressure carbon dioxide, water, and argon in the pressurized medium pass through an outlet 286 and are supplied from a diffuser 508 to an airbag (not shown) 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.

In addition, a large number of vent holes 5 are provided in the first chamber 501.
Since the heat transfer tube 503 provided with the fuel gas 04 is disposed, the flow velocity of the combustion gas when passing through each ventilation hole 504 can be increased. This assists in the early destruction of the disk 290.

The transfer tube 503 can 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 the numerical ranges for propellant grains, propellant gases and pressurized media.

[0128]

[Table 2]

When each characteristic value shown in Table 2 is below the lower limit value,
Not enough gas is available to inflate the air safety bag. Further, when each characteristic value exceeds the upper limit value, the whole inflator cannot be sufficiently reduced in size. Further, in the inflator of the present invention, it is indispensable to provide 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 in another embodiment embodying the present invention.
Can be incorporated into the inflatable safety system 10. The inflator 614 includes a cylindrical inflator housing 622 with a pressurized medium 620 for supplying the air / safety bag 18 (FIG. 1), and a pressurized medium 620.
A gas generator 624 that generates propellant gas to inflate the airbag and increases 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 an inert gas such as argon and oxygen.

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 disposed inside the inflator housing 622. A propellant 64 that generates a propellant gas during combustion is provided in a storage chamber 645 of the gas generator housing 644.
6 are accommodated, and an ignition assembly 648 is mounted. Gas generator housing 644 and ignition assembly 648 are aligned with axis 6 of inflator housing 622.
17.

The propellant 646 is a nitramine type,
For example, those containing about 70% by weight RDX (hexahydrotrinitrotriazine), about 5 to about 15% by weight cellulose acetate and about 5 to about 15% by weight GAP (glycidyldiazide polymer) are desirable. This propellant generates a combustible gas containing carbon monoxide and hydrogen during 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 opening 628 at the left end of the cap has a cap-shaped diffuser 63.
0 is fixed. The diffuser 630 is a peripheral wall 630
a and a top wall 630b, and a plurality of ventilation 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 disk 636 is mounted on the outlet 634, and the outlet 634 is always closed. The diffuser 630 has an opening 630c communicating with the outlet 634. The connector 626 is provided with a cap 64 having a plurality of vents 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 causes the accommodation chamber 64 to break.
5 communicates with the inside of the inflator housing 622, and the inside of the inflator housing 622 communicates with the outlet 634 through a vent 638.

The first disk 652 and the second disk 6
Desirably, the spacing between C.36 and C.36 is between about 20 mm and about 70 mm. If this interval is below the lower limit, not enough gas will be available to inflate the air / safety bag 18 (FIG. 1), and if it is greater than the upper limit, the inflator will not be sufficiently miniaturized. The inflator housing 62
The amount of pressurized medium in 2 is from about 40 cm ³ to about 100 cm
^{Is 3} . The amount of the pressurized medium 620 is set based on the same reason as the above-mentioned interval. More preferably, about 50
cm ³ to about 90 cm ³ . Further, the inside of the inflator housing 622 is maintained 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 combusts to generate combustible gas. This gas contains carbon monoxide and hydrogen. This gas also increases the pressure in the gas generator housing 644 and destroys the first disk 652. Then, the flammable gas flows into the communication hole 650.
Flows 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 combustible gas increases the pressure in the inflator housing 622, which acts on the second disk 636 via the vent 638.
That is, gas must flow around end wall 641 of cap 640 and enter hole 638. This facilitates more complete combustion within the housing 622. Thus, the end wall 641 of the cap 640 functions as a so-called propellant trap and is located 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, the first and second disks 652 and 636 and the diffuser 630 are arranged on the axis 617 of the inflator housing 622, so that the inflator is formed into a compact cylinder type. be able to. Therefore, it can be securely mounted in a limited space such as the inside of a vehicle door or seat without changing the shape of the door or seat.

Further, 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 gas / safety bag 18 (FIG. 1) can be inflated with a gas that is almost harmless to the occupant.

The diffuser 630 is cap-shaped, has a peripheral wall 630a and a top wall 630b, and has 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. 16 (B) shows a modification of the inflator shown in FIG. 16 (A). In this modification, the gas generator housing 624 includes a base portion 660 and a chamber portion 662. Base portion 660 supports ignition assembly 648. The chamber portion 662 includes the propellant 64
It houses six. Disk 664 has a base portion 660
And the chamber portion 662 and are sandwiched therebetween. The disk 664 is provided in the through-hole 6
66 is always closed. The chamber portion 652 has a communication hole 65.
0 and communicates with the inflator housing 622. Therefore, the interior of chamber portion 652 is under pressure.

When the ignition assembly 648 is activated,
The ignition assembly 648 destroys the disk directly and burns the propellant to generate combustible gas. The combustible gas reacts with oxygen in the pressurized medium 620 and is converted into carbon dioxide and water vapor. Thus, 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. The description of the present invention is not intended to limit the present invention to the form disclosed herein. Therefore, changes and modifications considered to be equivalent to the above-described techniques, and changes and modifications based on the related art and the knowledge related thereto, are included in the scope of the present invention. Furthermore, the embodiments disclosed herein illustrate the best mode for carrying out the invention, and others skilled in the art may refer to these embodiments, or other embodiments, for adapting the particular applications or uses of the invention. It is intended to be able to be used together with various changes required for. The claims of the present invention are intended to include other embodiments within the scope permitted by the prior art.

[0147]

As described in detail above, according to the present invention,
The air / safety bag can be inflated by a predetermined amount within a predetermined time, and the inflator can be formed in a small size.

[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 a 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]

18 ... Air / safety bag, 620 ... Pressurized medium, 622 ...
Inflator housing, 630 diffuser, 634
... Exit, 636 ... Second disc, 645 ... Accommodation chamber, 64
6 ... Propellant, 648 ... Ignition assembly, 650 ... Communication hole, 652 ... First disk.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 8, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[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 a 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] valves / valve system various chambers during operation of the inflator of Figure 8 when not in use (the first chamber, the second chamber, the housing and the air / safety bag for high-pressure gas)
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.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 13

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Brent A. Parks United States 80111 Englewood, Colorado South Macon Way 6153 (72) Inventor Mitsuya Enatsu 20-31 Shin-Ashi Rooftop Suita City, Osaka Prefecture

Claims (14)

[Claims] 1. A hybrid inflator for an inflatable safety system for a motor vehicle, including an air / safety bag, comprising: an inflator housing containing a pressurized medium; An ignition assembly for igniting a propellant, a communication hole for communicating the storage chamber with the inflator housing, and a communication hole that is always closed and is destroyed by gas generated by ignition of the propellant. A disc, an outlet provided in the inflator housing for supplying the pressurized medium and gas from the inflator housing to the air / safety bag, and the outlet is always closed, and the propellant is the same as the first disc. A second disc destroyed by gas generated by ignition of the The diffuser connected to the outlet of the housing and the first disc, the second disc and the diffuser are arranged on the same axis, and the diffuser has a cap-like shape and is provided with a peripheral wall and a top wall. A hybrid inflator having an opening communicating with the outlet, and having a plurality of holes communicating with the opening on the peripheral wall. 2. The hybrid inflator according to claim 1, wherein the pressurized medium contains an inert gas and oxygen. 3. The hybrid inflator according to claim 2, wherein the propellant generates a combustible gas, which gas reacts with oxygen in the pressurized medium. 4. The hybrid inflator according to claim 3, wherein the combustible gas comprises carbon monoxide and hydrogen, which are converted to carbon dioxide and water by oxygen in the pressurized medium. 5. The hybrid inflator according to claim 1, wherein the distance between the first disk and the second disk is about 20 mm to about 70 mm. 6. The amount of pressurized medium in the inflator housing is about 40 cm ³ to about 100 cm ^3.
The hybrid inflator described in. 7. The hybrid inflator of claim 6, wherein the amount of pressurized medium in the inflator housing is about 50 cm ³ to about 90 cm ³ . 8. A hybrid inflator for an inflatable safety system for a motor vehicle, including an air / safety bag, comprising: an inflator housing containing a pressurized medium; An ignition assembly for igniting a propellant, a communication hole that communicates the accommodation chamber with the inflator housing, a first disk that is destroyed by the ignition assembly, and the pressurized medium and gas from the inflator housing. / An outlet provided in the inflator housing for supplying to a safety bag, a second disk which is always closed and is destroyed by gas generated by ignition of the propellant, and an outlet of the inflator housing Connected to the diffuser and the first diffuser The disc, the second disk and the diffuser are arranged on the same axis, and the diffuser has a cap shape and a peripheral wall and a top wall, and an opening communicating with the outlet is provided inside the peripheral wall, and an opening is formed in the peripheral wall. And a plurality of holes communicating with the hybrid inflator. 9. The hybrid inflator according to claim 8, wherein the pressurized medium contains an inert gas and oxygen. 10. The hybrid inflator according to claim 9, wherein the propellant generates a combustible gas, which gas reacts with oxygen in the pressurized medium. 11. The hybrid inflator of claim 10, wherein the combustible gas comprises carbon monoxide and hydrogen, which are converted to carbon dioxide and water by oxygen in the pressurized medium. 12. The hybrid inflator according to claim 8, wherein a distance between the first disc and the second disc is about 20 mm to about 70 mm. 13. The hybrid inflator of claim 9, wherein the amount of pressurized medium in the inflator housing is about 40 cm ³ to about 100 cm ³ . 14. The amount of pressurized medium in the inflator housing is from about 50 cm ³ to about 90 cm ^3.
The hybrid inflator according to item 3.