WO2005015117A1 - Hybrid inflator - Google Patents

Hybrid inflator Download PDF

Info

Publication number
WO2005015117A1
WO2005015117A1 PCT/JP2004/011527 JP2004011527W WO2005015117A1 WO 2005015117 A1 WO2005015117 A1 WO 2005015117A1 JP 2004011527 W JP2004011527 W JP 2004011527W WO 2005015117 A1 WO2005015117 A1 WO 2005015117A1
Authority
WO
WIPO (PCT)
Prior art keywords
inflator
gas
pressurized gas
inflator housing
housing
Prior art date
Application number
PCT/JP2004/011527
Other languages
French (fr)
Inventor
Naoki Matsuda
Nobuyuki Katsuda
Original Assignee
Daicel Chemical Industries, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daicel Chemical Industries, Ltd. filed Critical Daicel Chemical Industries, Ltd.
Priority to DE112004001437T priority Critical patent/DE112004001437T5/en
Publication of WO2005015117A1 publication Critical patent/WO2005015117A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/268—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous release of stored pressurised gas
    • B60R21/272—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous release of stored pressurised gas with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B3/00—Blasting cartridges, i.e. case and explosive
    • F42B3/04—Blasting cartridges, i.e. case and explosive for producing gas under pressure
    • F42B3/045—Hybrid systems with previously pressurised gas using blasting to increase the pressure, e.g. causing the gas to be released from its sealed container
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/268—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous release of stored pressurised gas
    • B60R21/274—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous release of stored pressurised gas characterised by means to rupture or open the fluid source

Definitions

  • the present invention relates to a hybrid inflator which is suitable for use in an air bag system of an automobile.
  • vehicle body and a passenger in a vehicle cabin is smaller than that between the front side of the vehicle body and the
  • a main body 2 and a reservoir 3 are disposed in
  • Paragraph 9 of the pressurized gas is provided in Paragraph 9 as a mixture
  • An object of the present invention is to provide a hybrid inflator having an elongated form which is suitable for use
  • the present invention provides a hybrid inflator serving as means for achieving the object, having an elongated inflator housing as an outer shell, wherein a combustion chamber is provided on one end side of the inflator housing, with a gas generating agent and an igniter for igniting and burning the gas generating agent being accommodated inside the combustion chamber, a gas discharge port is provided on another end side of the inflator housing, a ventilation channel between the
  • housing is charged with a pressurized gas, a ratio (L/V) between
  • the elongated inflator housing refers to a housing having
  • the inflator housing preferably takes an elongated form due to restrictions on the attachment location on the side face of the vehicle body, and when the pressurized gas charging amount is increased, the length of the inflator housing must be increased even further.
  • the inflator housing takes an elongated form in this manner, and is constituted with the rupturable plate and the combustion chamber at each end, the time period required for
  • the present invention provides a hybrid inflator, comprising an elongated inflator housing constituting an outer
  • inflator housing for accommodating therein an igniter and a
  • the present invention f rther provides a hybrid inflator, wherein the pressurized gas is helium.
  • Helium is a fast gas with a theoretical sound velocity
  • the rupturable plate blocking the gas discharge port ruptures can be advanced, enabling discharge of the pressurized gas to
  • the sound velocity (20°C) of the pressurized gas used in the present invention is preferably at least 800ms "1 , and
  • 850ms "1 , and helium is cited as a favorable pressurized gas.
  • another gas may be mixed in with
  • the present invention provides a hybrid inflator, wherein the inflator housing is cylindrical , and the combustion chamber is disposed in series and concentrically with the inflator housing.
  • the present invention provides a hybrid inflator, wherein the igniter, the gas generating agent, the rupturable plate blocking the ventilation channel between the interior of the inflator housing and the gas discharge port, and the gas discharge port are co-linear. When the various elements are co-linear in this manner,
  • the present invention provides a hybrid inflator
  • the communicating hole is blocked by the rupturable
  • the communicating hole is blocked by the rupturable plate and the gas generating agent is accommodated in an ambient pressure atmosphere, pressure does not cause the gas generating agent to deteriorate.
  • the desired gas output can be realized, thus ensuring the reliability of the inflator.
  • the igniter and rupturable plate preferably face each other directly, and the rupturable plate is desirably co-linear with the igniter, the gas generating agent, a rupturable plate,
  • the present invention provides a hybrid inflator
  • the gas generating agent has a gas output of at least
  • the pressure (impact wave) can be increased.
  • rupturable plate is ruptured increases, enabling a reduction
  • this effect (the shortening of the period from activation of the igniter to discharge of the pressurized gas) is achieved as the length of the pressurized gas charging space, i.e., the length of the inflator, becomes longer.
  • requests for alterations to the length of the inflator can be dealt with easily while maintaining good performance in terms of passenger safety.
  • the hybrid inflator of the present invention may be
  • hybrid inflator of the present invention may also be applied
  • the hybrid inflator of the present invention is capable of
  • Fig. 1 is a conceptual diagram showing an axial cross section of a hybrid inflator.
  • a hybrid inflator of the present invention will be
  • Fig. 1 is an axial sectional view
  • FIG. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual diagram showing a hybrid inflator. Note that Fig. 1 is a conceptual
  • a hybrid inflator 10 comprises an elongated inflator
  • inflator housing 12 as an outer shell.
  • the interior of the inflator housing 12 forms a
  • pressurized gas charging space 14 into which an inert gas such as
  • the inflator housing 12 preferably has a circular cross section in the width direction, but does not necessarily have to be a perfect circle. Instead, the inflator housing 12 may
  • a combustion chamber 20 is provided on one end side of
  • combustion chamber 20 is formed by a combustion chamber housing 22 provided
  • a combustion chamber may be formed by partitioning
  • combustion chamber housing 22 inside the end portion of the inflator housing 12.
  • the combustion chamber 20 is disposed in series and concentrically with the inflator housing 12.
  • a first dividing wall 16 having a first communicating hole 18 is provided between the pressurized gas charging space 14 and the combustion chamber 20, and the first communicating hole 18 is blocked by a disk- form first rupturable plate 26. (Note, however, that the drawing shows a state in which the first rupturable plate 26 is deformed into a bowl shape by the pressure of the pressurized gas) .
  • the pressurized gas in the pressurized gas charging space 14 does not flow into the
  • combustion chamber 20 enabling the interior of the combustion chamber 20 to remain at ambient pressure inside the combustion
  • the gas output is preferably at least 1.2 mol/lOOg
  • this gas generating agent may be used as this gas generating agent.
  • discharge ports 28 may be provided on the other end side of the inflator housing 12, for example, a diffuser portion 30
  • the outer shell of the diffuser portion 30 is formed by a diffuser housing 32, and the diffuser portion 30 is partitioned from the pressurized gas charging space 14 by a second dividing wall 34 having a second communicating hole 35.
  • the second communicating hole 35 is blocked by a second rupturable plate 36.
  • the diffuser portion may be formed by partitioning the end portion of the inflator housing
  • a filter formed from wire mesh or the like may be disposed
  • rupturable plate 36 and first rupturable plate 26 from escaping outside through the gas discharge ports 28.
  • the igniter 24 the gas
  • the igniter 24 is activated to ignite the gas generating agent charged inside the combustion chamber 20.
  • a flame and high- temperature combustion gas are generated, causing the first rupturable plate 26 directly facing the igniter 24 to rupture.
  • the first rupturable plate 26 ruptures, the first
  • communicating hole 18 opens, and hence the combustion gas flows into the pressurized gas charging space 14 to raise the pressure
  • the igniter 24 the gas
  • the impact wave advances directly without attenuating.
  • the first rupturable plate 26 and second rupturable plate 36 are ruptured with ease and with certainty.
  • helium which has a high sound velocity, is charged as the pressurized gas, the propagation time of the impact wave is shortened, and hence the period from activation of the igniter 24 to discharge of the pressurized gas and combustion gas from the gas discharge port 28 is reduced.
  • first rupturable plate 26 and second rupturable plate 36 is
  • the time required for the impact wave to pass along the length L differs by approximately 0.80 msec when

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Air Bags (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Abstract

The present invention provides a hybrid inflator (10) in which the time up to the beginning of pressurized gas discharge during an operation is shortened. The present invention provides a hybrid inflator (10) having an elongated inflator housing (12) as an outer shell, wherein: a combustion chamber (20) is provided on one end side of the inflator housing (12), a gas generating agent and an igniter for igniting the gas generating agent being accommodated inside the combustion chamber (20); a gas discharge port (28) is provided on another end side of the inflator housing (12), a ventilation channel (35) between the interior of the inflator housing (12) and the gas discharge port (28) being blocked by a rupturable plate (36); and the interior of the inflator housing (12) is charged with a pressurized gas (preferably helium), a ratio (L/V) between a length L (m) of the inflator housing (12) and a sound velocity V (m/s, 20°C) of the pressurized gas being no more than 0.00046s.

Description

Description HYBRID INFLATOR
Field of the Invention
The present invention relates to a hybrid inflator which is suitable for use in an air bag system of an automobile. Background Art
When an inflator used in an air bag system installed in an automobile is of the type which inflates an air bag by discharging pressurized gas charged at high pressure, the rupturing of blocking means (a rupturable plate) which enable the pressurized gas to be discharged is of great importance. In the case of side air bags and curtain air bags, a housing with an elongated form in the axial direction is preferable due to problems concerning installation space. Further, since the distance between a side structure of a
vehicle body and a passenger in a vehicle cabin is smaller than that between the front side of the vehicle body and the
passenger in the driving seat or front passenger seat, the
expansion time of the air bag must be shortened, and hence it
is important to reduce the time period from rupturing of the
rupturable plate to discharge of the pressurized gas . In JP-A 2003-81050, an elongated hybrid inflator is
disclosed. A main body 2 and a reservoir 3 are disposed in
series, the main body 2 containing two types of powder 13, 14
and an igniter 16 for igniting these powders 13 , 14. An example
of the pressurized gas is provided in Paragraph 9 as a mixture
of helium, argon, nitrogen, and nitrous oxide. In this hybrid inflator, activation of the igniter 16
causes the powder 14 to burn, whereby a rupturable plate blocking a communicating hole in the main body of the reservoir ruptures such that combustion gas is discharged into the reservoir 3, causing the pressure therein to rise. As a result of the impact wave caused when the combustion gas flows into
the reservoir 3 and the increase in pressure, the rupturable plate provided on a channel 8 ruptures. Since this hybrid inflator has an elongated form, the
distance between the igniter 16 disposed at one end of the housing and the rupturable plate of the channel 8 is large, leading to an increase in the time required for the impact wave
to reach the rupturable plate. To ensure that the passenger
is protected, however, the air bag must be expanded as quickly
as possible.
Among air bag systems , the distance between the passenger
and the part of the vehicle structure in which the air bag system is installed is particularly small in the case of side air bags
and curtain air bags, and it is therefore important in these
cases to reduce the time period from activation of the igniter
to discharge of the pressurized gas.
Disclosure of the Invention
An object of the present invention is to provide a hybrid inflator having an elongated form which is suitable for use
as a side inflator or curtain inflator, in which the period up to the discharge of a pressurized gas can be shortened. The present invention provides a hybrid inflator serving as means for achieving the object, having an elongated inflator housing as an outer shell, wherein a combustion chamber is provided on one end side of the inflator housing, with a gas generating agent and an igniter for igniting and burning the gas generating agent being accommodated inside the combustion chamber, a gas discharge port is provided on another end side of the inflator housing, a ventilation channel between the
interior of the inflator housing and the gas discharge port
being blocked by a rupturable plate, and a pressurized gas charging space inside the inflator
housing is charged with a pressurized gas, a ratio (L/V) between
a length L (m) of the pressurized gas charging space and a sound velocity V (msA 20°C) of the pressurized gas being no more
than 4.6*10~4s. The elongated inflator housing refers to a housing having
a well-known form (a long form in which the length is
considerably greater than the diameter) such as that disclosed in Fig. 1 of JP-A 2003-81050.
When applied as an inflator for a side air bag or an
inflator for a curtain air bag, the inflator housing preferably takes an elongated form due to restrictions on the attachment location on the side face of the vehicle body, and when the pressurized gas charging amount is increased, the length of the inflator housing must be increased even further. When the inflator housing takes an elongated form in this manner, and is constituted with the rupturable plate and the combustion chamber at each end, the time period required for
an impact wave produced by the high- temperature gas that is generated in the combustion chamber to reach the rupturable
plate increases. However, by setting L/V at no more than
4.6χ10"4s, this time period can be maintained appropriately. Hence, the present invention can respond to variation
in the form of the inflator, variation in the form and volume
of the air bag, and so on easily.
The present invention provides a hybrid inflator, comprising an elongated inflator housing constituting an outer
shell , a combustion chamber provided on a first end of the
inflator housing for accommodating therein an igniter and a
gas generating agent, a gas discharge port provided on a second end of the
inflator housing, directly opposite the first end, the gas
discharge port having a ventilation channel between an interior of the inflator housing and the gas discharge port, said ventilation channel being blocked by a rupturable plate, and a pressurized gas charging space inside the inflator housing charged with a pressurized gas, a ratio (L/V) between a length L (m) of the pressurized gas charging space and a sound
velocity V (ms"1, 20°C) of the pressurized gas being no more than 4.6><10"4s. The present invention f rther provides a hybrid inflator, wherein the pressurized gas is helium.
Helium is a fast gas with a theoretical sound velocity
value of 1010ms"1 (23°C) , and hence the propagation velocity of the impact wave produced when high- temperature gas is
generated upon activation of the igniter is higher than that
of other pressurized gases. As a result, the timing at which
the rupturable plate blocking the gas discharge port ruptures can be advanced, enabling discharge of the pressurized gas to
begin earlier.
The sound velocity (20°C) of the pressurized gas used in the present invention is preferably at least 800ms"1, and
more preferably 850ms"1, and helium is cited as a favorable pressurized gas. However, another gas may be mixed in with
the helium provided that these numerical values are maintained.
The present invention provides a hybrid inflator, wherein the inflator housing is cylindrical , and the combustion chamber is disposed in series and concentrically with the inflator housing. The present invention provides a hybrid inflator, wherein the igniter, the gas generating agent, the rupturable plate blocking the ventilation channel between the interior of the inflator housing and the gas discharge port, and the gas discharge port are co-linear. When the various elements are co-linear in this manner,
the pressure (impact wave) produced by combustion of the gas
generating agent following activation of the igniter advances
directly to reach the rupturable plate without attenuating.
Thus, the force with which the rupturable plate is ruptured
increases, enabling a reduction in the time required for
discharge of the pressurized gas to begin. The present invention provides a hybrid inflator,
wherein a communicating hole is provided between the
pressurized gas charging space in the interior of the inflator
housing and the combustion chamber. In accordance with this
invention, the communicating hole is blocked by the rupturable
plate so that the pressure in the interior of the combustion chamber is ambient.
Since the communicating hole is blocked by the rupturable plate and the gas generating agent is accommodated in an ambient pressure atmosphere, pressure does not cause the gas generating agent to deteriorate. Hence the desired gas output can be realized, thus ensuring the reliability of the inflator. Note that the igniter and rupturable plate preferably face each other directly, and the rupturable plate is desirably co-linear with the igniter, the gas generating agent, a rupturable plate,
which blocks the ventilation channel between the interior of the inflator housing and the gas discharge port, and the gas discharge port. The present invention provides a hybrid inflator,
wherein the gas generating agent has a gas output of at least
1.2mol/l00g.
By setting the gas output of the gas generating agent
to a predetermined value or more, the pressure (impact wave) can be increased. As a result, the force with which the
rupturable plate is ruptured increases, enabling a reduction
in the time required for discharge of the pressurized gas to
begin. Moreover, the proportion of combustion gas to the
amount of gas required to expand the air bag can be increased, enabling a reduction in the pressurized gas charging amount,
a corresponding reduction in the thickness of the inflator housing, and as a result, a reduction in the overall weight of the inflator.
Note that in the present invention, this effect (the shortening of the period from activation of the igniter to discharge of the pressurized gas) is achieved as the length of the pressurized gas charging space, i.e., the length of the inflator, becomes longer. Hence requests for alterations to the length of the inflator can be dealt with easily while maintaining good performance in terms of passenger safety. The hybrid inflator of the present invention may be
applied to various inflators used in an air bag system, but is particularly suited to an inflator for use in a side air
bag or an inflator for use in a curtain air bag. However, the
hybrid inflator of the present invention may also be applied
as an inflator for use with a driver side air bag or front
passenger side air bag. The hybrid inflator of the present invention is capable
of shortening the time required from activation of an igniter
to discharge of a pressurized gas.
Brief Description of the Drawing
Fig. 1 is a conceptual diagram showing an axial cross section of a hybrid inflator.
Explanation of Reference Numerals 10 hybrid inflator 12 inflator housing 14 pressurized gas charging space
20 combustion chamber 24 igniter
26 first rupturable plate
28 gas discharge port
30 diffuser portion
36 second rupturable plate
Preferred Embodiment of the Invention
A hybrid inflator of the present invention will be
described using Fig. 1. Fig. 1 is an axial sectional view
showing a hybrid inflator. Note that Fig. 1 is a conceptual
diagram for describing the present invention, and has been subjected to overall simplification. And, a constitutional
element of a known hybrid inflator may be used as each of the
constitutional elements.
A hybrid inflator 10 comprises an elongated inflator
housing 12 as an outer shell. The interior of the inflator housing 12 forms a
pressurized gas charging space 14 into which an inert gas such
as helium or argon, or a pressurized gas such as nitrogen gas, is charged. Note, however, that helium alone is preferable. The charging pressure of the pressurized gas differs according to the amount of gas generated from a gas generating agent, but is preferably between approximately 10 and 66 MPa . The inflator housing 12 preferably has a circular cross section in the width direction, but does not necessarily have to be a perfect circle. Instead, the inflator housing 12 may
be modified appropriately in accordance with the shape and so on of the space which serves as an attachment portion for the inflator 10 to take an elliptical form or a polygonal form which
is close to a perfect circle.
A combustion chamber 20 is provided on one end side of
the inflator housing 12. An outer shell of the combustion
chamber 20 is formed by a combustion chamber housing 22 provided
separately, and a gas generating agent (not shown) and an igniter 24 for igniting the gas generating agent are
accommodated inside the combustion chamber 20. Note that
rather than providing the combustion chamber housing 22
separately, a combustion chamber may be formed by partitioning
the end portion of the inflator housing 12 or disposing the
combustion chamber housing 22 inside the end portion of the inflator housing 12.
The combustion chamber 20 is disposed in series and concentrically with the inflator housing 12. A first dividing wall 16 having a first communicating hole 18 is provided between the pressurized gas charging space 14 and the combustion chamber 20, and the first communicating hole 18 is blocked by a disk- form first rupturable plate 26. (Note, however, that the drawing shows a state in which the first rupturable plate 26 is deformed into a bowl shape by the pressure of the pressurized gas) . As a result, the pressurized gas in the pressurized gas charging space 14 does not flow into the
combustion chamber 20, enabling the interior of the combustion chamber 20 to remain at ambient pressure inside the combustion
chamber 20 so that pressure does not cause the gas generating
agent to deteriorate.
There are no particular limitations on the charging
amount, form, composition, and so on of the gas generating agent, but the gas output is preferably at least 1.2 mol/lOOg, and
more preferably at least 1.4mol/100g. The gas generating
agent described in the embodiments and so on of JP-A 11-20598,
for example, may be used as this gas generating agent.
Any component which comprises a required number of gas
discharge ports 28 may be provided on the other end side of the inflator housing 12, for example, a diffuser portion 30
comprising the gas discharge ports 28 may be provided. The outer shell of the diffuser portion 30 is formed by a diffuser housing 32, and the diffuser portion 30 is partitioned from the pressurized gas charging space 14 by a second dividing wall 34 having a second communicating hole 35. The second communicating hole 35 is blocked by a second rupturable plate 36. Note that the diffuser portion may be formed by partitioning the end portion of the inflator housing
12 rather than providing the diffuser housing 32 separately. A filter formed from wire mesh or the like may be disposed
on the diffuser portion 30 to prevent fragments of the second
rupturable plate 36 and first rupturable plate 26 from escaping outside through the gas discharge ports 28.
In the hybrid inflator 10, the igniter 24, the gas
generating agent accommodating space, the first rupturable
plate 26 blocking the first communicating hole 18, the second rupturable plate 36 blocking the second communicating hole 35,
and the gas discharge port 28 are co-linear.
In the hybrid inflator 10, a ratio (L/V) between a length
L (m) of the pressurized gas charging space 14 and a sound
velocity V (ms"1, 20°C) of the pressurized gas (helium) is no
more than 4.6χ10"s, preferably no more than 2.3*10"4s, and more preferably no more than 2.0*10"4s. Next, an operation of the hybrid inflator 10 of the
present invention when incorporated into an air bag system of an automobile will be described. When the automobile collides with an object, the igniter 24 is activated to ignite the gas generating agent charged inside the combustion chamber 20. As a result, a flame and high- temperature combustion gas are generated, causing the first rupturable plate 26 directly facing the igniter 24 to rupture. When the first rupturable plate 26 ruptures, the first
communicating hole 18 opens, and hence the combustion gas flows into the pressurized gas charging space 14 to raise the pressure
therein. At this time, the pressure (impact wave) advances
directly to reach the second rupturable plate 36, thereby
causing the second rupturable plate 36 to rupture.
When the second rupturable plate 36 ruptures, the second communicating hole 35 opens, causing the pressurized gas and
combustion gas to flow into the diffuser portion 30 and escape
from the gas discharge ports 28, as a result of which the air
bag is inflated.
In the hybrid inflator 10, the igniter 24, the gas
generating agent accommodating space, the first rupturable
plate 26 blocking the first communicating hole 18, the second rupturable plate 36 blocking the second communicating hole 35,
and the gas discharge port 28 are co- linear, and hence during such an operation, the impact wave advances directly without attenuating. Thus the first rupturable plate 26 and second rupturable plate 36 are ruptured with ease and with certainty. Moreover, since helium, which has a high sound velocity, is charged as the pressurized gas, the propagation time of the impact wave is shortened, and hence the period from activation of the igniter 24 to discharge of the pressurized gas and combustion gas from the gas discharge port 28 is reduced.
Further, by using a gas generating agent with a gas output of at least 1.2 mol/lOOg, the time required for rupturing the
first rupturable plate 26 and second rupturable plate 36 is
reduced. Note that since the gas generating agent is
accommodated within an ambient pressure atmosphere and is not
subjected to deterioration caused by pressure, the desired gas output is maintained.
For example, when L in Fig. 1 is 400 mm (0.4 m) and the
temperature is 23°C, the period from activation of the igniter to discharge of the pressurized gas from the gas discharge port,
or in other words the time required for the impact wave to pass along the length L, differs by approximately 0.80 msec when
helium (sound velocity 1100 m/sec) is used and when argon (sound
velocity 332 m/sec) is used (this period being approximately 0.40 msec when helium is used and approximately 1.20 msec when argon is used) . This time difference increases as the value of L increases, and hence greatly affects the air bag expansion time when applied to an elongated inflator for use with a side air bag or curtain air bag.

Claims

Claims
1. A hybrid inflator having an elongated inflator
housing as an outer shell, wherein a combustion chamber is provided on one end side
of the inflator housing, a gas generating agent and an igniter
for igniting the gas generating agent being accommodated inside the combustion chamber, a gas discharge port is provided on another end side of the inflator housing, with a ventilation channel between the interior of the inflator housing and the gas discharge port being blocked by a rupturable plate, and a pressurized gas charging space inside the inflator housing is charged with a pressurized gas, a ratio (L/V) between a length L (m) of the pressurized gas charging
space and a sound velocity V (ms"1, 20°C) of the pressurized gas being no more than 4.6x10"4s.
2. A hybrid inflator, comprising: an elongated inflator housing constituting an outer
shell, a combustion chamber provided on a first end of the
inflator housing for accommodating therein an igniter and a
gas generating agent, a gas discharge port provided on a second end of the
inflator housing, directly opposite the first end, the gas
discharge port having a ventilation channel between an interior
of the inflator housing and the gas discharge port, said
ventilation channel being blocked by a rupturable plate, and a pressurized gas charging space inside the inflator
housing charged with a pressurized gas, a ratio (L/V) between a length L (m) of the pressurized gas charging space and a sound
velocity V (ms"1, 20°C) of the pressurized gas being no more than 4.6*10"s.
3. A hybrid inflator according to claim 1 or 2 , wherein the pressurized gas is helium.
4. A hybrid inflator according to claim 1 or 2, wherein the inflator housing is cylindrical, and wherein the combustion chamber is disposed in series and concentrically with the inflator housing.
5. A hybrid inflator according to claim 1 or 2,
wherein the igniter, the gas generating agent, the rupturable plate, and the gas discharge port are co-linear.
6. A hybrid inflator according to claim 1 or 2,
wherein a communicating hole is provided between the
pressurized gas charging space in the interior of the inflator
housing and the combustion chamber, and wherein the communicating hole is blocked by the rupturable plate so that
the pressure in the interior of the combustion chamber is ambient .
7. A hybrid inflator according to claim 1 or 2,
wherein the gas generating agent has a gas output of at least
1.2 mol/lOOg.
PCT/JP2004/011527 2003-08-11 2004-08-04 Hybrid inflator WO2005015117A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE112004001437T DE112004001437T5 (en) 2003-08-11 2004-08-04 Hybrid gas generator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2003291213A JP2005059711A (en) 2003-08-11 2003-08-11 Hybrid inflator
JP2003-291213 2003-08-11

Publications (1)

Publication Number Publication Date
WO2005015117A1 true WO2005015117A1 (en) 2005-02-17

Family

ID=34131636

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2004/011527 WO2005015117A1 (en) 2003-08-11 2004-08-04 Hybrid inflator

Country Status (3)

Country Link
JP (1) JP2005059711A (en)
DE (1) DE112004001437T5 (en)
WO (1) WO2005015117A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008022755B4 (en) * 2008-05-08 2015-05-13 Trw Airbag Systems Gmbh inflator
FR3005724A1 (en) 2013-05-17 2014-11-21 Herakles PYROTECHNIC GAS GENERATOR

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001042047A2 (en) * 1999-12-09 2001-06-14 Autoliv Asp Vehicle inflator
EP1314622A1 (en) * 2000-08-29 2003-05-28 Daicel Chemical Industries, Ltd. Inflator

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001042047A2 (en) * 1999-12-09 2001-06-14 Autoliv Asp Vehicle inflator
EP1314622A1 (en) * 2000-08-29 2003-05-28 Daicel Chemical Industries, Ltd. Inflator

Also Published As

Publication number Publication date
JP2005059711A (en) 2005-03-10
DE112004001437T5 (en) 2006-06-22

Similar Documents

Publication Publication Date Title
JP4373611B2 (en) Two stage inflator
KR100479307B1 (en) Dual stage airbag inflator
US20070085309A1 (en) Dual stage hybrid inflator
EP0978423B1 (en) Gas generating device for air bag and air bag inflating method
JP2004042893A (en) Low strength two-stage type hybrid inflator
US6948737B2 (en) Gas generator for air bag
WO2023174313A1 (en) Integral ignition structure and compressed-gas-type fuel gas generator
WO2000078580A1 (en) Multi-stage expansion type hybrid inflator
WO2006030967A1 (en) Gas producer
JP5295354B2 (en) Gas generator for automobile safety equipment
US7290797B2 (en) Center discharge hybrid inflator device
JP4190353B2 (en) Multistage ignition gas generator
EP1459946B1 (en) Gas generator for air bag
WO2003002382A1 (en) Hybrid inflator
JP3774181B2 (en) Hybrid gas generator
US20100001497A1 (en) Inflator
WO2004031002A1 (en) Airbag inflator
WO2005015117A1 (en) Hybrid inflator
US20050077713A1 (en) Hybrid inflator
US20030226468A1 (en) Distributed charge inflator system
JP4137347B2 (en) Multistage inflatable hybrid inflator
JP2002166818A (en) Gas generator
JP2004026025A (en) Gas generator for air bag
JP3996806B2 (en) Inflator
JP2002362299A (en) Gas generator

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1120040014379

Country of ref document: DE

122 Ep: pct application non-entry in european phase