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

Definitions

• the invention relates to a gas generator for an occupant protection system of a vehicle according to the preamble of claim 1 and according to the preamble of claim 18.
• Gas generators for occupant protection systems in vehicles are used to fill and inflate gas bags to protect the occupants in the event of an accident.
• the gas pressure in the gas bag be maintained over a longer period of time, in particular over several seconds. This is particularly necessary in the case of airbags for side protection, since a vehicle rollover generally lasts for a certain period of time, within which the airbag should be filled to the protection of the occupants.
• Such a long service life can be achieved with a cold gas generator in which a cold compressed gas is used as the filling gas.
• the hot gases generated by a pyrotechnic gas generator would lead to an equally rapid drop in pressure within the gas bag due to their rapid cooling.
• Cold gas generators generally have a compressed gas store in which the stored compressed gas is stored under high pressure.
• a pyrotechnic solid charge is usually used to open the compressed gas storage device and can simultaneously contribute to filling the gas bag.
• hybrid gas generators One then speaks of so-called hybrid gas generators.
• a compressed gas storage is sealed gas-tight with a rupture disc.
• the rupture disc is supported against the internal pressure of the container on a support device which can be partially destroyed and / or moved by the pressure generated during the combustion of a pyrotechnic solid charge.
• the object is achieved by a gas generator for an occupant protection system of a vehicle according to claim 1.
• the gas generator has a compressed gas store having an outflow opening for storing a compressed gas, the outflow opening being closed with a bursting device and a triggering device generating a gas being provided for opening the outflow opening.
• at least one further bursting device is provided, the bursting devices being supported against one another when the compressed gas gas valve is closed, and an increased pressure being able to be built up between the bursting devices by means of the gas generated by the triggering device.
• the basic idea of the invention is therefore to close the compressed gas store by means of at least two bursting devices.
• the bursting devices can in particular be designed as rupture disks or other membranes.
• the other burst devices will also be destroyed under the internal pressure of the compressed gas storage device.
• the opening of the compressed gas storage is achieved.
• the destruction of a first burst device is achieved according to the invention in that an increased pressure can be built up between the burst devices by means of the gas generated by the triggering device.
• the pressure of the gas produced by the triggering device and, in addition, the part of the internal pressure of the compressed-gas storage device which is transmitted from the internal bursting devices to the external bursting device therefore acts on the outer one of the bursting devices becomes.
• the internal pressure of the compressed gas accumulator minus the increased pressure of the gas generated by the triggering device and minus the force input on the external bursting devices affects the internal bursting devices.
• the outermost bursting device will therefore first burst when a critical pressure built up by the triggering device is reached.
• the inner bursting devices can then no longer withstand the internal pressure of the compressed gas store and likewise burst. This opens the compressed gas storage. On the one hand, this ensures that the compressed gas storage is securely closed by the at least two bursting devices and, on the other hand, that the compressed gas storage is opened efficiently and quickly.
• a cavity is advantageously formed between at least two bursting devices, in which cavity an increased pressure can then be built up by means of the gas generated by the triggering device.
• the two bursting devices are supported against one another by means of a spacer element, since the dimensioning of the cavity can be easily adjusted via the spacer element.
• the gas generated by the triggering device is advantageously conducted via a gas line between the at least two bursting devices.
• this gas line is integrated directly into a holding device holding the bursting devices.
• This holding device can also be integrated directly into the housing of the compressed gas storage device, so that here, by shaping the housing of the compressed gas storage device, the holding device for the bursting devices and the gas line for conducting the gas generated by the triggering device can be produced at the same time.
• a simple assignment of the triggering device to the compressed gas store is achieved in that a gas outlet opening of the triggering device is arranged directly opposite the gas line, it being possible for there to be a gap between the gas outlet opening and the gas line. Since the gas of the triggering device emerges from the gas outlet opening at high speed, the resulting gas jet can be aimed directly into the gas line. A direct connection of the gas outlet opening to the gas line is therefore not necessary. This can considerably simplify the assembly of the gas generator. In a further variant, however, it is also possible to connect the gas outlet opening to the gas line in a sealing manner.
• the gas of the triggering device is to be used to fill a gas bag at the same time, it makes sense to let the triggering device flow directly into a prechamber and then to lead it from this prechamber into the gas line. The pressure of the triggering device built up in the prechamber can then continue to be used for filling an airbag.
• a particularly compact size of the gas generator is achieved in a development of the invention in that a gas-generating propellant charge of the triggering device is provided between the bursting devices.
• the gas-generating propellant charge can either be located over the entire area of the outflow opening of the compressed gas storage or only in a partial area between the bursting devices.
• the bursting devices can in particular also be supported against one another via the propellant charge.
• This embodiment in which a propellant charge of the triggering device lies between the bursting devices, enables the gas generator to have a very compact structural dimension. The dimension is essentially determined only by the expansion of the compressed gas storage. The triggering device is then essentially in the closure of the outflow opening of the compressed gas store.
• the object is further achieved by a gas generator for an occupant protection system with the features of claim 18.
• the gas generator has a compressed gas storage device having an outflow opening for storing a compressed gas, the outflow opening being closed with a bursting device and a triggering device being provided for opening the outflow opening.
• the bursting device is supported on at least one support band when the compressed gas reservoir is closed, the triggering device acting on the support band for the bursting of the bursting device.
• the support band can be fixed to the gas generator at at least two opposite ends.
• the release device then acts on the support band between the two fixed ends in such a way that the support band is severed by the release device.
• the support band can be severed in particular by means of a hot gas jet from the triggering device.
• the support band is fixed at one end to the gas generator and at its opposite end in the triggering device.
• the support band in the release device can be released from the release device to open the outflow opening. This can be done, for example, using suitable mechanics.
• the support band After the support band has been severed, the internal pressure of the compressed gas reservoir presses on the bursting device in such a way that it bursts.
• the bursting device and the support band therefore open the outflow opening of the compressed gas storage.
• the support band is guided in an advantageous form in a backdrop.
• This backdrop can be integrated, for example, in the holding device for the bursting device.
• Reliable support of the bursting element can be achieved in that the support band completely covers the bursting element in the entire area of the outflow opening. In a less expensive variant, the support band only partially covers the bursting device in the area of the outflow opening.
• the bursting device is in turn designed in such a way that it only withstands the internal pressure of the compressed gas reservoir when it is supported on the support band.
• Fig. 1 is a sectional view through a gas generator in the area of
• Fig. 2 is a sectional view through a gas generator in the area of
• Outflow opening of a compressed gas store the outflow opening being closed by two bursting devices and between the
• Bursting devices a cavity is formed
• FIG. 3 shows a sectional illustration of a gas generator in the region of the outflow opening of a compressed gas store with two bursting devices which are supported against one another by means of a spacer element;
• Fig. 4 is a sectional view through a further gas generator in the area of
• Outflow opening of a compressed gas storage device in which gas can first be flowed into an antechamber from a triggering device; 5 shows a sectional illustration through a gas generator in the region of the outflow opening of a compressed gas store, a gas-generating propellant being arranged between two bursting devices; and
• FIG. 6 shows a sectional view through a gas generator in the region of the outflow opening of a compressed gas storage device, a bursting device being supported here by a support band.
• FIG. 1 shows a section of a section of a gas generator according to the invention.
• a compressed gas storage device in the form of a compressed gas bottle 1 with a housing 11 is filled with a compressed gas which, when the gas generator is triggered, is used to act on, for example, a gas bag.
• an outflow opening 100 is provided, from which the compressed gas stored in the compressed gas bottle 1 can flow out.
• This outflow opening is closed by two bursting devices in the form of membranes 2, 3.
• the two membranes 2, 3 are supported on one another and in the embodiment shown in FIG. 1 are bulged outwards by the internal pressure prevailing in the compressed gas bottle 1.
• the two membranes 2, 3 are designed such that they can only withstand the internal pressure prevailing in the compressed gas bottle 1 together. However, a single one of the two membranes 2, 3 cannot withstand the internal pressure and bursts under the applied pressure. A reliable sealing of the compressed gas bottle 1 can only be achieved by supporting the two membranes 2, 3 against one another.
• the two membranes 2, 3 are held in a holding device 12 which is fastened to the housing 11 of the compressed gas bottle 1.
• a gas-tight closure of the interior of the compressed gas bottle 1 is achieved by the two membranes 2, 3, the actual seal being achieved by the membrane 2 directed in the direction of the interior.
• a gas supply line 10 is provided in the holding device 12, with which a gas generated by a schematically indicated triggering device 5 can be passed between the two membranes 2, 3.
• the triggering device 5 has in particular a pyrotechnic propellant charge and is used to trigger the gas generator.
• a known solid gas generator can serve as a triggering device 5.
• the gas generated in the triggering device 5 escapes through an opening 51 of the triggering device. This opening 51 is arranged opposite the gas line 10, so that the gas flows selectively into the gas line 10 at a high outflow speed.
• An air gap 53 can also be bridged between the opening 51 and the gas line 10. Gas line 10 and opening 51 are therefore not gas-tight.
• a gas-tight seal in which the opening seals directly with the gas line, is provided in a further development, not shown here, of the embodiment shown in FIG.
• an increased pressure can be built up between the two membranes 2, 3 by the gas of the triggering device. If this pressure reaches a critical level, one of the two membranes 3 bursts, whereby the remaining membrane 2 is then subjected to the full internal pressure of the compressed gas bottle 1. The second membrane 2 also collapses under this internal pressure, so that the outflow opening 100 of the compressed gas bottle 1 is open.
• the opening of the outflow opening 100 is thus achieved here by a combination of two membranes that cannot withstand the internal pressure of the compressed gas bottle alone, and an additional action on the membranes by a gas generated by a triggering device.
• one of the two membranes 2, 3 is destroyed by the gas provided by the triggering device, whereupon the second membrane also collapses due to the internal pressure prevailing in the compressed gas bottle 1.
• FIG. 1 A development of this principle is shown in FIG.
• a compressed gas bottle 1 is closed with two membranes 2, 3.
• the inner membrane 2 is held in a holding device 12 integrated in the housing 11 of the compressed gas bottle 1 in such a way that it only comes into contact with the second membrane 3 after a significant bulge.
• Different curvature structures of one or both membranes 2, 3 can be achieved by different design of the membranes 2, 3, in particular with regard to their radii, their material and / or their thickness. Due to the curvature, a cavity 23 is created between the two membranes. This cavity is essentially gas-tight and communicates in the exemplary embodiment shown in FIG. 2 via a gas line 10 with a triggering device 5 directly connected to it.
• the opening of the outflow opening 100 of the compressed gas bottle 1 is again achieved by building up an increased pressure between the two membranes 2, 3 by the gas generated in the triggering device 5.
• the gas generated in the triggering device 5 passes via the gas channel 10 into the cavity 23 located between the two membranes 2, 3.
• An increased pressure quickly builds up here, which acts both on the outside membrane 3 and on the inside membrane 2.
• a pressure therefore acts on the internal membrane, which is composed of the internal pressure of the compressed gas bottle 1 minus the pressure built up in the cavity 23 - that is, a reduced pressure.
• the increased pressure built up in the cavity 23 by the inflowing gas acts on the outer membrane 3 plus the part of the internal pressure of the compressed gas bottle 1 transmitted by the membrane 2 - that is, an increased pressure.
• the outer membrane 3 will therefore usually collapse first.
• the inner membrane 2 is then fully acted upon by the outer membrane 3 after the support is no longer supported by the outer membrane 3 and is therefore likewise destroyed.
• the outflow opening 100 is thus opened.
• FIG. 3 shows a further development of the embodiment shown in FIG. 2.
• the two membranes 2, 3 are supported against one another via a spacer element 4, which can be designed, for example, as a spacer or spacer ring.
• a spacer element 4 can be designed, for example, as a spacer or spacer ring.
• the cavity 23 formed between the two membranes 2, 3 is enlarged or the bulging of the inner membrane 2 is reduced.
• the desired volumes for the cavity 23 between the two membranes 2, 3 can thus be set via the dimensioning of the spacer element 4.
• FIG. 1 A further embodiment of a gas generator according to the invention is shown in FIG.
• a compressed gas bottle 1 is arranged in a housing 9 of the gas generator, wherein the housing 9 can simply be put over the compressed gas bottle 1.
• the compressed gas bottle 1 is in turn closed with two membranes 2, 3, which are supported against one another via a spacer element 4. Gas can flow into the cavity 23 lying between the two membranes 2, 3 via a gas line 10 lying in the housing 11 of the compressed gas bottle 1.
• the housing 9 has a chamber 90 into which the gas generated by the trigger device 5 can flow. Gas generated by the triggering device 5 can flow into the gas line 10 from the chamber 90 via an opening 91 of the chamber 90 lying opposite the opening of the gas line 10. This creates an air gap between the opening 91 of the chamber 90 and the gas line 10 bridged, since the gas flows out of the opening 91 into the gas line 10 at a high outflow speed.
• the required overpressure in the cavity 23 between the two membranes 2, 3 is therefore achieved due to the high outflow speed of the gas from the opening 91 of the chamber 90.
• the membranes 2, 3 are destroyed in the manner already described and the outflow opening 100 of the compressed gas bottle 1 is opened.
• FIG. 5 shows a further development of the gas generator according to the invention.
• the outflow opening 100 of a compressed gas bottle 1 is in turn via two membranes 2,
• a propellant charge 55 of the triggering device is arranged between the two membranes 2, 3.
• the propellant charge 55 can either extend over the entire area between the two membranes 2, 3, or can only extend in a partial area, in particular a ring, between the two membranes 2, 3.
• the two membranes 2, 3 can therefore be supported against each other via a propellant 55 designed as a solid.
• Ignition contacts 56 are in direct contact with the propellant 55, the ignition contacts being guided through the holding device 12.
• the propellant 55 is now ignited via the ignition contacts 56, as a result of which a gas develops in the intermediate space 23 between the two membranes 2, 3. This gas builds up an increased pressure in the cavity 23, which ultimately leads to the destruction of the two membranes 2, 3 according to the known principle.
• the two membranes are designed such that they can only withstand the internal pressure of the compressed gas bottle 1 together.
• FIG. 1 A development of the invention is shown in FIG.
• a compressed gas bottle 1 is closed with a membrane 2, which is gas-tightly connected to the housing 11 of the compressed gas bottle 1 in a holding device 12.
• the membrane 2 is in turn designed such that it cannot withstand the internal pressure of the compressed gas bottle 1 alone. Therefore, the membrane 2 is supported by a support band 8.
• the support band 8 extends either over the entire area of the outflow opening 10, or only over a partial area of this area. By supporting the membrane 2 on the support band 8, the internal pressure of the compressed gas bottle 1 can be absorbed.
• the support band 8 is fixed to the housing of the gas generator at two opposite ends 80, 81 and introduces the forces exerted by the membrane on the support band 8 into the housing of the gas generator.
• the support band 8 is guided in a backdrop 13, which is provided in the holding device 12. To open the outflow opening 100, the support band is severed by the release device 50. For this purpose, a hot gas jet, which emerges from an outlet opening 52 of the triggering device 50, is directed onto the support band 8.

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

Priority Applications (3)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=33039160

Family Applications (1)

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Families Citing this family (2)

Citations (7)

Family Cites Families (17)

• 2003
  • 2003-04-17 DE DE10318888A patent/DE10318888B3/de not_active Expired - Fee Related
• 2004
  • 2004-04-14 WO PCT/DE2004/000814 patent/WO2004094200A1/de not_active Ceased
  • 2004-04-14 JP JP2006504304A patent/JP2006523564A/ja active Pending
  • 2004-04-14 CN CNB2004800102758A patent/CN100372708C/zh not_active Expired - Fee Related
  • 2004-04-14 EP EP04727234A patent/EP1615807A1/de not_active Withdrawn
• 2005
  • 2005-10-17 US US11/251,198 patent/US7204513B2/en not_active Expired - Fee Related

Patent Citations (7)

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