WO2001047752A1

WO2001047752A1 - Dual inflator

Info

Publication number: WO2001047752A1
Application number: PCT/JP2000/004097
Authority: WO
Inventors: Jianlin Chen; Toshihiko Tamura
Original assignee: Nippon Koki Co., Ltd.
Priority date: 1999-12-28
Filing date: 2000-06-22
Publication date: 2001-07-05

Abstract

A gas generator for inflating an air bag, comprising an inflator chamber having a side wall in which a plurality of diffusers are provided, a partition cup having a bottom surface on which a nozzle is installed, first and second combustion chambers formed in the inflator chamber by partitioning the inside of the inflator chamber by the partition cup in the vertical direction of the side wall, a sealing member installed on the bottom surface of the partition cup on the first combustion chamber side, gas generating agent filled into the first and second combustion chambers, first igniting means positioned inside the inflator chamber and having an ignition energy injecting part inside the first combustion chamber, second igniting means positioned inside the inflator chamber and having an ignition energy injecting part inside the second combustion chamber, combustion energy propagation means positioned inside the first combustion chamber, forming an area for combustion of gas generating agent by an ignition energy injected from the fist igniting means around the first igniting means and propagating a thermal energy in the combustion area to the gas generating agent inside the first combustion chamber, and a filter positioned inside the inflator chamber and disposed on the front surface side of the diffuser.

Description

Description Dual type frame

The present invention relates to a gas generator for deploying an airbag, and more particularly, to a dual-type inflation system that can freely adjust gas output to an airbag according to a speed at the time of a collision or an occupant's seating posture. . Background art

The development of a dual-type inflation system that can freely adjust the gas output to the airbag according to the speed at the time of the collision or the posture of the occupant is actively being developed.

The dual type inflation system has two combustion chambers in one chamber and can be operated by each ignition system. The operation of the air bag at the time difference or simultaneous operation is suppressed, and the deployment speed of the airbag is suppressed at the time of low-speed collision, so that the bag can be deployed strongly at a stretch in the case of a severe collision. It is also possible to change the speed of bag inspection depending on the occupant's sitting position.

In the dual-type inflation system, two combustion chambers are adjacent to each other in one chamber, and may have thermal and pressure effects on each other. Various measures are needed to eliminate these effects and enable effective control of inflationary output. The structure of the dual-type infra-type that has been disclosed so far is roughly classified into the following three types.

One is to create two combustion chambers by dividing the inside of a cylindrical chamber into right and left by a partition plate having a certain angle (for example, Japanese Patent Application Laid-Open No. 9-183359). The other is that a cylindrical chamber is divided into upper and lower parts by a disk-shaped partition plate to form two combustion chambers (for example, Japanese Patent Application Laid-Open No. H11-599318, Japanese Patent Application Laid-Open No. No. 17055). Third, the first combustion chamber surrounds the second combustion chamber (for example, Japanese Patent Application Laid-Open No. Hei 5-3-1919). Japanese Patent Application Laid-Open No. Hei 11-217705 describes that two combustion chambers are defined by a disk-shaped partition member, and each combustion chamber communicates with each other via a filter member. A gas generator is disclosed.

However, in the structure of the dual-type inflation system disclosed in Japanese Patent Application Laid-Open No. H11-217055, in order to completely separate the two combustion chambers by the partition plate, two filters are used. It is necessary to provide two layers of diffusers. Although it is possible to completely separate the combustion chambers from each other with complete separation, it is considered that the structure becomes complicated, leading to a decrease in productivity and an increase in cost. When one filter is used and the partition is installed inside the filter, the contact with the generated gas in the first combustion chamber that flows from the end of the partition through the fill chamber causes the normal operation of the second combustion chamber. Operation may be adversely affected.

The first combustion chamber igniter is located at the center, and the second combustion chamber igniter is offset, igniting the gas generant pellet at the end of the second combustion chamber that is far away from the igniter. And the combustion rate of the entire gas generating agent in the second combustion chamber may decrease. On the other hand, the gas generating agent in the vicinity of the igniter is preferentially ignited in the second combustion chamber, so that the combustion product gas tends to pass intensively in the vicinity of the misaligned igniter. High-temperature combustion product gas is blown out, and the concentrated area of the filter is damaged, and there is a risk that the residue will blow out of the inflation overnight. Disclosure of the invention

The present invention has been made in order to solve such a conventional problem, and its object is to provide a dual-type single-frame type adopting a single-fill type structure in order to pursue simplicity and high productivity. To provide.

It is another object of the present invention to provide a dual-type inflator that can easily achieve ideal gas output performance by adjusting specifications.

It is another object of the present invention to provide a dual-type infra-red that can cope well with gas generating agents having various combustion characteristics.

Another object of the present invention is to provide a dual-type inflation system capable of cutting off the influence of the second combustion chamber from the first combustion chamber. Another object of the present invention is to provide a dual-type inflation system capable of reducing the amount of charge in the second combustion chamber and reducing the volume of the second combustion chamber. Another object of the present invention is to provide a partition cup that separates the first combustion chamber and the second combustion chamber with a nozzle, so that gas outflow from the second combustion chamber is controlled by the nozzle of the partition force, An object of the present invention is to provide a dual-type inflator capable of maintaining a predetermined combustion pressure and a predetermined gas generating agent combustion rate in two combustion chambers.

Another object of the present invention is to provide a nozzle on the entire bottom surface of a partition cup that separates the first combustion chamber and the second combustion chamber, thereby dispersing the gas blowing from the second combustion chamber and concentrating the generated gas. The purpose is to provide a dual-type inflation system that can prevent the problem.

Another object of the present invention is a dual type in which the height of the tank pressure output and the time to reach the maximum tank pressure output can be freely adjusted by adjusting the ignition delay time of the first combustion chamber and the second combustion chamber. To submit inflation overnight.

Another object of the present invention is to control the ignition of the gas generating agent and the flame propagation in the first combustion chamber, and to provide an S-shaped curve tank pressure output that is advantageous for airbag deployment (the sunset pressure becomes 1 at 20 ms after ignition). OOkPa or less).

Another object of the present invention is to prevent the damage of the filter by uniformly passing the circumference of the filter while controlling the flow of the gas generated in the combustion chamber, and to reduce the inflow due to the concentration of the gas flow. An object of the present invention is to provide a dual-type inflator that can suppress a single blow of gas from the airbag and improve the deployment characteristics of the airbag.

Another object of the present invention is to concentrate the initial ignition energy from the ignition cartridge to the gas generating agent around the ignition cartridge, thereby reducing the amount of ignition powder, inflation overnight output variation and inflation overnight output low temperature characteristics. The goal is to submit a dual-type inflation that can be expected to improve the economy.

Another object of the present invention is to provide an initial combustion control mechanism having a predetermined pressure holding capacity around an ignition cartridge and use the pressure holding characteristic to widely support the combustion characteristics of a gas generating agent. Is to submit a dual inflation overnight.

An object of the present invention is to provide an infinity chamber having a plurality of diffusers on a side wall, A partition force provided with a nozzle on the bottom surface, a first combustion chamber and a second combustion chamber formed in the inflation chamber by partitioning the inflation chamber in a vertical direction of the side wall by the partition cup; A sealing member provided on the first combustion chamber side of the bottom of the tip, a gas generating agent filled in the first combustion chamber and the second combustion chamber, and an ignition in the first combustion chamber located in the inflation chamber A first ignition means provided with an energy ejection section, a second ignition means provided in an infra-red chamber, and an ignition energy ejection section provided in a second combustion chamber, and a second ignition means provided in the first combustion chamber; Ignition energy ejected from one ignition means A combustion area of the gas generating agent due to one is formed around the first ignition means, and the combustion energy in the combustion area propagates to the gas generating agent in the first combustion chamber And stage, located Infu rate evening chamber, is achieved by providing a fill evening and which is disposed on the front side of the Difuyu monodentate.

The combustion energy transmitting means is, for example, a partition surrounding the first igniting means and the second igniting means, an opening provided in the partition, and filled between the partition and the first igniting means and the second igniting means. And a gas generating agent.

The partition is, for example, a cylindrical fin, and an opening is provided on the partition cup side. If the ignition energies of the first ignition means and the second ignition means are clear, they respectively open toward the center of the infra-red chamber.

The nozzle provided on the bottom surface of the partition cup is provided, for example, on the entire bottom surface.

The volume of the first combustion chamber is larger than the volume of the second combustion chamber. The ratio is arbitrary and is determined by installing a partition cup.

The sealing member is peeled off from the partitioning force by the combustion gas pressure of the gas generating agent in the second combustion chamber.

The first ignition means and the second ignition means include, for example, an ignition cartridge provided with a nozzle, an ignition agent charged in the ignition cartridge, and an igniter activated by a signal from an external control device. .

On the nozzle provided on the bottom surface of the partition cup, for example, an annular heat absorbing material is arranged. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a vertical cross-sectional view of a dual-type inflator according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is an exploded perspective view of the filter used in FIG.

FIG. 4 is an exploded explanatory view of the partition cup used in FIG.

FIG. 5 is a graph showing the relationship between the airbag deployment pressure, the pressure in the combustion chamber, and the time in the dual-type inflator according to the present embodiment.

FIG. 6 is a graph showing the airbag deployment characteristics of the dual-type inflation system according to the present embodiment.

FIG. 7 is a graph showing a nozzle evaluation test of a partition cup according to the dual type inflation according to the present embodiment.

FIG. 8 is an explanatory diagram showing the arrangement of the fins of the present invention.

FIG. 9 is an explanatory diagram showing the nozzle positions of the fins in the first combustion chamber during the dual type inflation according to the present embodiment.

FIG. 10 is a graph showing the tank output characteristics during the dual inflation according to the present embodiment.

FIG. 11 is a graph showing output characteristics of the dual-type inflation system according to the present embodiment.

FIG. 12 is a graph showing a comparison of the amount of heat absorbing material during the dual type inflation according to the present embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described based on embodiments shown in the drawings.

1 and 2 show a dual-type inflation system A according to an embodiment of the present invention.

The inflation overnight chamber 1 is formed by combining, for example, cups 1 a and lb made of SUS304. The cup la is provided with a large number (eight in this example) of 03.5 mm diffusers 2 on the wall surface. The diffuser 2 is provided with a diffuser closure 3. Cup lb, first firing cartridge 20 and second firing powder Through holes 4 and 5 for mounting the cylinder 30 are provided.

In the inflation chamber 1, for example, a partition cup 10 made of an aluminum pressed product, a first ignition cartridge 20, a second ignition cartridge 30, a fin 70, and a filter Evening 40 is arranged.

An area defined by the partition cup 10, the cup 1 b of the inflation chamber 1, and the fill bowl 40 forms, for example, a first combustion chamber 100 of 59 mm and a height of 21 mm, The area defined by the partitioning force 10 and the cup 1a of the inflation chamber 1 forms, for example, a second combustion chamber 110 of 59 mm and a height of 9 mm.

The partition cup 10 has, for example, a cup shape with an outer diameter of 59 mm, an inner diameter of 55 mm, a height of 12 mm, a thickness of 3 mm and a bottom, and a second ignition cartridge 3 on the bottom surface 1 1 side. And a plurality (10 in this example) of nozzles 13 having a hole diameter of 3.5 mm for ejecting generated gas in the second combustion chamber 110. ing. The nozzles 13 are arranged at equal intervals on the same arc along the periphery of the bottom surface 11.

An annular heat absorbing material 50 is disposed on the partitioning force 10 so as to cover the nozzle 13. The heat absorbing material 50 is, for example, a pressed product of a knitted woven wire mesh (0.5 mm in wire diameter), and has a trapezoidal cross section in which the lower side is widened. The heat absorbing material 50 has, for example, a lower outer diameter of 55 mm, an inner diameter of 42 mm, an upper outer diameter of 55 mm, an inner diameter of 51.8 mm, a height of 9 mm, and a weight of 30 g.

A nozzle blocking plate 60 made of, for example, SS and having a thickness of 0.3 mm is attached to the back surface 11 a of the bottom surface 11 of the partitioning force 10.

The second ignition cartridge 30 is inserted into the through hole 12 of the partition cup 10.

A nozzle closure 33 made of, for example, aluminum and having a thickness of 0.05 mm is attached to the nozzle 32 on the distal end side of the second ignition cartridge 30.

The first ignition cartridge 20 is in contact with the back surface 1 1a side of the bottom surface 11 of the partitioning force 10.

For example, a nozzle closure 23 made of aluminum and having a thickness of 0.5 mm is attached to the nozzle 22 on the distal end side of the first ignition cartridge 20.

For example, it is made of SUS so as to surround the first ignition cartridge 20 and the second ignition cartridge 30. A cylindrical fin 70 having a thickness of 0.3 mm, an outer diameter of 40 mm, and a height of 20 mm is provided. On the upper side of the fin 70, twelve semicircular nozzles 71 of <zi 4 to 5 mm are provided.

An annular filter 40 is provided between the partition cup 10 and the inflation chamber 1. Filler 40 is made of, for example, a punching metal 41 made of SUS 304 having an outer diameter of 72 mm, a height of 30 mm, a plate thickness of 0.4 mm, a hole diameter of 0.5 mm, and a pitch of 1 mm, and a knitted woven wire mesh (wire diameter of 0. It has a diameter of 71 mm, an inner diameter of 59 mm, a height of 33 mm, and a weight of 120 g.

The first ignition cartridge 20 is, for example, a SUS pressed product having a plate thickness of 1 mm. The nozzle 22 is 04 mm at 60 ° and 140 ° intervals at a position 5 mm below the back surface 11 a of the bottom surface 11 of the partitioning force gap 10 so as to open toward the second ignition cartridge 30. There are four holes. The ignition charge 24 is, for example, 1.3 g of potassium potassium nitrate. An igniter 25 made of, for example, a pin type igniter is attached to a position connected to the ignition charge 24.

The second ignition cartridge 30 is, for example, an aluminum pressed product in which the portion exposed to the second combustion chamber 110 has a plate thickness of 1 mm and the other portions have a plate thickness of 2 mm. The nozzle 32 is placed at a position 4.5 mm below the cup 1 a of the inflation chamber 1 at intervals of 60 ° and 140 ° so as to open toward the axis of the first ignition cartridge 20. There are four 3mm holes. The igniting charge 34 is, for example, 1.0 g of potassium potassium nitrate. An igniter 35 made of, for example, a pin type igniter is attached at a position following the ignition charge 34.

The first combustion chamber 100 is loaded with a gas generating agent 101 containing guanylaminotetrazole, an oxidizing agent, a coolant and a residue forming agent (for example, kaolin) as active ingredients. The second combustion chamber 110 is charged with a gas generating agent 111 containing guanylaminotetra-v-l, an oxidizing agent, a cooling agent and a residue forming agent (for example, kaolin) as active ingredients. The details of the gas generating agents 101 and 111 are disclosed in Japanese Patent Application No. 11-369913. Next, an assembling process of the dual type frame A according to the present embodiment will be described.

The igniter holder 26 of the first ignition cartridge 20 and the igniter holder 36 of the second ignition cartridge 30 are attached to the cup 1b through the through holes 4 and 5, and fixed by welding.

The nozzle closures 23, 33 are attached to the first ignition cartridge 20 and the second ignition cartridge 30, respectively.

After filling the ignition cartridges 20 and 30 with the ignition agents 24 and 34, press-fit them into the igniter holders 26 and 36.

As described above, the first ignition cartridge 20 and the second ignition cartridge 30 can be assembled to the cup 1b.

Next, as shown in FIG. 3, the knitting material 42 is press-fitted into the punching metal 41 to form the filling material 40, which is then disposed in the cup lb, and then the fin 70 is provided in the cup lb. Arrange.

Next, the gas generating agent 101 is filled into the cup 1b. Thereby, the charging of the gas generating agent 101 into the first combustion chamber 100 is completed.

Next, the second ignition cartridge 30 is passed through the through hole 12 of the partitioning force 10, and the first ignition cartridge 20 contacts the back surface 11 a side of the bottom surface 11.

At this time, as shown in FIG. 4, after attaching the nozzle blocking plate 60 to the back surface 11 a side of the bottom surface 11 of the partition cup 10, as shown in FIG. A gas seal 80 made of a SUS pressed product and having a thickness of 0.2 mm is attached around the through hole 12. The blocking plate 60 and the gas seal 80 can be integrated.

Next, the heat absorbing material 50 is placed on the partition cup 10.

Next, the gas generating agent 111 is filled on the partition cup 110. Thereby, the filling of the gas generating agent 111 into the second combustion chamber 110 is completed. A gap is formed between the partition 1 and the partition cup 10 due to the deformation of the cap 1a.In order to prevent gas from leaking from this gap, a 0.2 mm thick second combustion chamber gas seal 82 made of a SUS pressed product is used. Install.

Next, the cup 1a to which the diffuser closure 3 is attached is press-fitted into the force lip 1b, and the press-fit portion is welded.

Finally, attach the igniters 25 and 35 to the igniter holders 26 and 36, and crimp Fix it.

Next, the operation of the dual-type inflation system A according to the present embodiment configured as described above will be described.

When the ignition control device 130 determines that the impact is equal to or greater than a predetermined value for deploying the airbag 140 based on the acceleration signal from the acceleration sensor 120 during a vehicle collision, the ignition control device 130 ignites. A command is issued to activate the igniter 25 of the first ignition cartridge 20 and first ignite the gas generating agent 101 in the first combustion chamber 100. The airbag 140 is discharged from the diffuser 2 to the outside and supplied to the inside of the folded airbag 140. After a certain delay time (for example, 20 ms), the igniter 35 of the second ignition cartridge 30 is operated, and the gas generating agent 111 of the second combustion chamber 110 is ignited. After the gas generated in the second combustion chamber 110 flows into the first combustion chamber 100 through the nozzle 13 provided on the bottom surface 11 of the partitioning force 10 and then passes through the filter 40 The air is discharged from the diffuser 2 and supplied to the inside of the airbag 140. Since the generated gas flowing out of the second combustion chamber 110 is controlled by the nozzle 13 of the partition cup 10, a predetermined combustion pressure can be maintained, and the combustion of the gas generating agent 101 is performed for a predetermined time. Can be terminated within The result is shown in FIG.

In the figure, the pressure X for inflating the airbag 140 is provided by the pressure Y in the first combustion chamber 100 and the pressure Z in the second combustion chamber 110. At present, the in-floor evenings on vehicles are almost single-infrared evenings with a single combustion chamber. The dual-type inflation system of the present invention can operate in the first combustion chamber 100 alone. When the first combustion chamber 100 operates alone, the tank pressure output reaches the maximum value of 180 kPa in about 70 ms as in the case of the single type inflation. When the second combustion chamber 110 is operated with a delay time of, for example, 20 ms following the operation of the first combustion chamber 100, the gas flows in from the second combustion chamber 110 for 20 ms. The pressure in the first combustion chamber 100, which started to decrease before, rises again. Thereafter, the pressure decreases in proportion to the pressure Z of the second combustion chamber 110. With the additional supply of the generated gas in the second combustion chamber 110, it is possible to increase the maximum tank pressure output to 230 kPa.

In the present embodiment, the tank pressure output characteristics that draw an S-shaped curve can be achieved. Here, the reason why the s-shaped curve is necessary will be described.

The airbag device is designed to protect the occupants by deploying the airbag in an emergency such as a vehicle collision. In this airbag device, a vehicle collision or the like is detected by a sensor, the gas generator over the inflation installed in the steering wheel is burned, and the combustion product gas is converted into an airbag folded in the steering wheel. Supplied, this airbag is instantly deployed. This protects the seat occupant from colliding with vehicle interior parts such as steering wheels.

As shown in FIG. 5 of Japanese Patent Application Laid-Open No. H08-332129, for example, the airbag device includes a circular cover 1 having a notch 2 at the center, and a folded airbag. And a gas generator provided with an electric igniter 5.

Then, when the airbag 3 is inflated, the notch 2 at the center of the cover 1 is cut first, the cover 1 is broken and opened, and the airbag 3 is configured to jump out of the cover 1.

When the airbag 3 is inflated, the cover 11 is first broken. From the high-speed video footage, the cover 1 is destroyed and the nogg starts to pop out about 5 ms after ignition. When the inflation output is to the 60-litre tank, the tank pressure reaches the maximum value at about 7 O ms. This means that the combustion of the gas generant ends about 70 ms after ignition and the gas supply to the tank stops. Immediately after the operation of the inflation, two vent holes (Vent Holes) are constantly opened on the rear surface of the airbag to release the occupants immediately from the restraint of the airbag. With venting from the vent hole, the pressure in the bag reaches the maximum bag pressure in about 45 ms, faster than the maximum tank pressure of 70 ms. Immediately after the cover 1 is destroyed by the bag popping out, the pressure in the bag becomes a negative pressure, and changes to a positive pressure in about 20 ms. Later, it became necessary to supply a large amount of gas to the bag. Therefore, the tank pressure output of the so-called S-shaped carp, which suppresses the combustion speed of the gas generating agent at the stage of destruction of the cover and jumps out of the bag, accelerates the combustion speed of the gas generating agent after the bag starts to inflate, This is considered advantageous for bag development.

This phenomenon will be described with reference to the airbag deployment characteristics shown in FIG.

The graph of the airbag deployment characteristics shows the inside of the airbag when the airbag is inflated. The change in pressure over time is shown.

In Fig. 6, part H shows the pressure when the cover is broken, part I is the pressure when the airbag is deployed, and a lot of energy is released when the cover of part H is broken. Indicates that it is being consumed.

This means that since the gas generating agent is formed into tablets, the surface area during combustion tends to be maximum at the start of combustion, and to decrease as the fuel burns. Due to the large amount of energy generated at the beginning of combustion.

If the energy consumption in section H is too high, the energy for deploying the airbag will decrease and the pressure of J will occur, causing insufficient deployment.

For this reason, by controlling the combustion rate of the gas generating agent for the initial 20 ms of the gas generating agent combustion time of the gas generator, the energy loss consumed before the airbag jumps out of the cover is minimized. Then, it becomes possible to turn to the deployment energy of the airbag.

As described above, this embodiment does not require two filters as in the conventional dual-type inflation system, and can be configured with one filter 40. Therefore, the structure is simple and it is possible to increase productivity.

Further, in the present embodiment, the second combustion chamber 110 is completely thermally and pressure-controlled in order to shut off all the influence from the first combustion chamber 100 before the second combustion chamber 110 operates. Can be isolated.

In the present embodiment, a partition cup 10 is used in place of the conventional dual-type disk-shaped partition plate. Therefore, the generated gas in the second combustion chamber 110 enters the first combustion chamber 100 from the nozzle 13 provided on the bottom surface 11 of the partition cup 10 once, and then from the diffuser 2 through the filter 40. Is discharged.

Further, in the present embodiment, the amount of charge in the second combustion chamber 110 is smaller than in the first combustion chamber 100, and the volume of the second combustion chamber 110 is smaller. The ratio of the first combustion chamber 100 to the second combustion chamber 110 can be from 6: 4 to 8: 2. In addition, the target value of the tank pressure (when the primary combustion chamber operates alone, and when the two combustion chambers operate with a time difference and simultaneous operation) can support a maximum output of 180 kPa to 240 kPa . 12 Compared to the first combustion chamber 100, the amount of charge in the second combustion chamber 110 is smaller, the combustion chamber is flat and the heat loss is large, so the gas generating agent in the second combustion chamber 110 It is predicted that the combustion rate of 1 1 1 will decrease. It is necessary to maintain the high combustion rate of the gas generator 111 in the second combustion chamber 110 in order to prevent the gas after-blowing problem.

In the present embodiment, by adjusting the opening area of the nozzle 13 of the bottom surface 11 of the partition cup 10, gas outflow from the second combustion chamber 11 ◦ is controlled, and a constant The method of maintaining the burning pressure and burning speed was adopted.

Here, a method of maintaining the combustion pressure by the nozzle 13 on the bottom surface 11 will be described. As shown in FIG. 7, the outflow of gas from the second combustion chamber 110 is controlled by changing the opening area of the nozzle 13 on the bottom surface 11. If the nozzle 13 on the bottom surface 11 is throttled, the combustion pressure in the second combustion chamber 110 is increased, and the combustion of the gas generating agent 111 is promoted.

Table 1 shows the results of the nozzle evaluation test shown in FIG. table 1

In the present embodiment, when the first combustion chamber 100 is operated, in order to prevent reverse flow of gas into the second combustion chamber 110 through the nozzle 13 of the bottom surface 11 of the partitioning force 10, The nozzle blocking plate 60 of the bottom surface 11 of the partition cup 10 was used.

In the present embodiment, when the first combustion chamber 100 operates, it is possible to suppress one-shot blowing of the generated gas.

As a result, it was possible to prevent damage to the vehicle and improve the airbag deployment characteristics.

Next, measures for preventing damage to the fill due to one-shot blowing of generated gas will be described in detail. In this embodiment, the shape of the ignition system was first changed as follows in order to solve the problem of damage to the filter due to a single blow.

The angle range of the nozzles 22 and 32 was set to 60 ° and 140 ° so as to open toward the first ignition cartridge 20 and the second ignition cartridge 30 toward each other. Experiments have confirmed that there is no problem if this angle is less than 140 °.

Further, a cylindrical fin 70 was provided to completely eliminate one-sided blowing.

By installing the fin 70, it is possible to control the flow of the generated gas and eliminate one-sided spraying completely. The reason will be described below.

Since the first ignition cartridge 20 of the first combustion chamber 100 is far from the center of the first combustion chamber 100, the ignition nozzles are equally spaced around the circumference of the ignition cartridge as in a single type inflation. When opened, the gas generating agent near the ignition cartridge is preferentially ignited, and the combustion product gas tends to pass intensively near the misaligned ignition cartridge. By opening two nozzles at an angle of 70 ° toward the central axis of inflation overnight, or by clogging four nozzles 20 at intervals of 60 ° and 140 °, the first combustion chamber Although there was a certain effect in reducing the non-uniformity of ignition in 100 and suppressing the one-sided blowing of the generated gas, the one-sided blowing problem was not fundamentally solved. In addition, the spatial non-uniformity of the charge in the first combustion chamber 100 is also considered to be one of the causes of the one-shot blowing of the generated gas. The installation of fins 70 was considered in order to completely resolve one-sided gas blowing. After the fins 70 have been installed, the generated gas inside the fins 70 is controlled by the nozzles 71 of the fins 70 to flow outward in the radial direction evenly around the fins 70. become. On the other hand, the gas generating agent outside the fin 70 is evenly ignited from the nozzle 71 portion of the fin 70, and the combustion product gas immediately passes through the filter 40 along the radial direction and out. Is discharged to In this way, it is possible to blow out gas from the inflation overnight diffuser uniformly.

It is necessary to delay ignition of the gas generating agent 101 as much as possible so that the tank pressure output of the first combustion chamber 100 becomes an S-shaped curve. When the gas generating agent 101 had good flammability, a structure in which the first combustion chamber ignition cartridge nozzle was provided at the end of the first combustion chamber 100 was adopted. Further, as a measure for outputting the tank pressure output of the S-shaped curve, in the present embodiment, the nozzle 71 of the fin 70 is installed at the extreme end, and has a semicircular shape. As a result, it is possible to control the flow of generated gas and delay the propagation of the flame.

Figure 8 illustrates the fin installation.

As shown in the figure, the flow of the generated gas is controlled by the nozzles 71 of the fins 70 provided at the ends of the circumference evenly, which is useful for eliminating gas blowing and realizing pressure output of the S-shaped curve tank.

The position of the hole 71 of the fin 70 will be described.

It is considered that the tank pressure output of the S-shaped curve is most easily obtained by locating the hole 71 at the end.

When the hole 71 is at the top, first, as shown in FIG. 9 (a), the ignition to the gas generating agent 24 propagates from top to bottom. Thereafter, as shown in FIG. 9 (b), gas is jetted from the nozzle 71 of the fin 70 to the first combustion chamber 100 outside.

Conversely, if the position of the hole 71 is in the middle, the gas generating agent 101 is ignited from the middle, and the flame moves up and down, so that the combustion time is shortened and the effect of the S-shape is deteriorated.

When the position of the hole 71 is below, since the direction of flame propagation coincides with the direction of gas flow, the effect of preheating the unburned portion on the gas generant pellet is increased, and the speed of flame propagation is increased. It will be further accelerated. It is thought that the burning rate of the gas generating agent as a whole is the fastest and the burning time is the shortest.

Therefore, the position of the hole 71 is optimal on the upper end surface. At other positions, it may be set appropriately according to the degree of the burning rate of the gas generating agent 101 and the required degree of S-shape.

Also, by reducing the amount of igniting agent, the supply of thermal energy to the gas generating agent can be reduced.

By increasing the opening area of the nozzle 32 on the distal end side of the first ignition cartridge 30, the pressure inside the first ignition cartridge 30 can be reduced.

By reducing the thickness of the diffuser closure 3, it is possible to moderate the initial rise in the primary combustion chamber pressure.

In order to eliminate the effect on the second combustion chamber 110 when the first combustion chamber 100 operates, The following structure is valid:

Prevention of deformation of the partition force 10:

To prevent the deformation of the partition cup 10 from affecting the second combustion chamber 110, use a material with a plate thickness of 3 mm or more for the bottom surface 11 of the partition cup 10. Experiments have confirmed that a thickness of 3 mm is sufficient.

Prevent gas leaks:

a. Prevent gas leakage through nozzle 13 of partition cup 10

In order to shut off the nozzle 13 of the partition cup 10, a 0.3 mm-thick stainless plate-shaped nozzle shut-off plate 60 is attached to the bottom surface 11 of the partition cup 10.

It was confirmed that there was no breakage of the nozzle blocking plate 60 at the stage when the first combustion chamber 100 was operated. Subsequently, the second combustion chamber 110 is actuated, and the nozzle blocking plate 60 is peeled off from the bottom surface 11, so that the gas generated in the second combustion chamber 110 can pass through the nozzle 13 on the bottom surface 11. You.

The nozzle blocking plate 60 is not broken by the operating pressure of the first combustion chamber 100. At the operating pressure of the second combustion chamber 110, the nozzle blocking plate 60 is peeled off from the bonding surface of the partitioning force 10 and moves to the fin 70 (the distance between the partitioning force 10 and the fin 70 is After a slight gap), it is bent downward (towards the igniters 25 and 35) with the fin 70 as a fulcrum.

b. Prevent gas flow through the gap between the partition cup 10 and the cup 1a

When the first combustion chamber 100 operates, an upward force is applied to the bottom surface 11 of the partition cup 10 due to an increase in pressure. It was confirmed by experiments that the upper part of the partitioning force 10 became in close contact with the inside of the infra-red chamber with such a force, and gas leakage was completely prevented. However, when the second combustion chamber 110 is operated, it is expected that the gap becomes larger due to the deformation of the cup 1a. In order to prevent gas leakage from the gap, a gas seal 82 of the second combustion chamber 110, which can completely block the movement of gas from the inside to the outside, was decided. c. Prevention of gas flow through the gap between partition force 10 and fill 40

The gap between the side of the partition cup 10 and the fill 40 is long, making it difficult for flame and gas to pass through. Even after passing a little, enter the second combustion chamber 110 from the upper end of the partition cup 110 The experiment confirmed that the gas generant 1 1 1 did not ignite.

Combustion of the gas generating agent 101 in the first combustion chamber 100 is mainly controlled by the diffuser 2.

d. Prevention of gas leakage through the gap between the second ignition cartridge 30 and the bottom surface 11 of the partition 10

The use of a gas seal 80 is effective to prevent gas leakage through a gap between the second ignition cartridge 30 and the bottom surface 11 of the partition cup 10.

Prevention of heat conduction:

a. Prevention of heat conduction through bottom 1 1 of partition cup 10

To prevent heat conduction through the bottom surface 11 of the partition cup 10, use of a thick material is conceivable. If a stainless steel material of 3 mm is used for the bottom surface 11 of the partition cup 10, the gas generating agent 1 1 1 in the second combustion chamber 110 will not ignite when the first combustion chamber 100 operates. It was confirmed.

b. Prevention of spontaneous ignition of ignition powder by heat conduction through the wall of the second ignition cartridge 30

When the first combustion chamber 100 is operated, it is necessary to prevent spontaneous ignition of the ignition agent 34 contained in the second ignition cartridge 30. To block heat conduction through the wall of the second ignition cartridge 30, a thicker material could be used. By using a stainless steel material of 2 mm for the second igniter cylinder 30, it was confirmed that there was no ignition of the igniter 35 and the igniter 34 at the stage where the first combustion chamber 100 was operated.

The ignition of the first ignition cartridge 20 and the second ignition cartridge 30 can have a width of about 40 ms delay from the simultaneous ignition as shown in Fig. 10 and Fig. 11. is there.

Tables 2 and 3 show the results. Table 2

Delay Time Pt actual value Pt aim ffi i

(kPa) (ms) (kPa) (ms)

0 260.3 53.5 230

20 231 .9 61 .5 70

40 214 74 240 Table 3

Further, as shown in FIG. 12, the tank pressure and the combustion chamber pressure can be controlled also by the heat absorbing material 50 installed in the second combustion chamber 110.

The results are shown in Table 4. Table 4

Industrial applicability

According to the present invention according to the present invention, it is possible to obtain a dual-type inflator having a simple structure and high productivity. Due to the effects of the first combustion chamber (heat, pressure and gas flow), the second combustion chamber can be completely isolated. There are advantages such as easy adjustment of gas output and correspondence with combustion characteristics of gas generating agents.

Claims

The scope of the claims

(1) an infra-red chamber with a plurality of diffusers on the side wall,

A partitioning power cup with a nozzle on the bottom,

A first combustion chamber and a second combustion chamber formed in the inflation chamber by partitioning the inside of the inflation chamber in the vertical direction of the side wall with a partition cup;

A sealing member provided on the first combustion chamber side of the bottom surface of the partitioning force,

A gas generating agent filled in the first combustion chamber and the second combustion chamber,

A first ignition means which is located in the infinity chamber and has an ignition energy ejection section in the first combustion chamber;

A second ignition means located in the inflation overnight chamber and having an ignition energy ejection section in the second combustion chamber;

A combustion region for the gas generating agent, which is located in the first combustion chamber and is ignited by the ignition energy ejected from the first ignition means, is formed around the first ignition means, and the heat energy in the combustion region is converted to the gas generating agent in the first combustion chamber. Means for propagating combustion energy to the

A dual-type infra-red evening, which is located in the inflation evening chamber and includes a fill-in evening disposed in front of the diffuser.

(2) ^ In the scope of claim 1, the dual type infra

The combustion energy propagating means includes a partition surrounding the first ignition means and the second ignition means, an opening provided in the partition, and gas filled between the partition and the first ignition means and the second ignition means. Consisting of a generator

Dual-type inflation overnight.

(3) In the dual-type infra-frame set forth in claim 1,

The partition is a cylindrical fin with an opening on the side of the partition

Dual-type inflation overnight.

(4) In the dual type inflation described in claim 1,

The ignition energy jets of the first ignition means and the second ignition means open toward the center of the inflation chamber, respectively. This is a dual-type infra evening.

(5) In the dual-type infra-frame set forth in claim 1,

Nozzles provided on the bottom of the partitioning tap are provided on the entire bottom

This is a dual-type infra evening.

(6) In the dual type inflation described in claim 1,

The volume of the first combustion chamber is larger than the volume of the second combustion chamber

This is a dual-type infra evening.

(7) In the dual type inflation described in claim 1,

A dual-type inflator, wherein the sealing member is separated from the partitioning force by a combustion gas pressure of the gas generating agent in the second combustion chamber.

(8) In the dual type infra-frame set forth in claim 1,

The first ignition means and the second ignition means are characterized by comprising an ignition cartridge provided with a nozzle, an ignition charge filled in the ignition cartridge, and an igniter activated by a signal from an external control device. And dual-type infra evening.

(9) Scope of request

An annular heat-absorbing material is arranged on the nozzle provided on the bottom surface of the partition.