JP2007001537A - Gas generator assembly for airbag - Google Patents

Abstract

The present invention provides a gas generator assembly with improved safety, a simple internal structure, and miniaturization.
When a gas generator assembly is formed by connecting a conduit to a gas generator, the discharge of gas from the conduit is substantially restricted only in the airbag deployment direction, and the airbag is rapidly deployed. Can be made. On the other hand, as a gas generator alone, one end is closed and a cup body having a peripheral wall surface is attached, and a gas generating agent is disposed therein. There is nothing in the cup body that restricts the flow of the gas generated by the combustion of the gas generant, and the cup body breaks evenly, so no thrust is generated.
[Selection] Figure 2

Description

  The present invention relates to a gas generator assembly suitable for a person restraining device such as an air bag system mounted on a motor vehicle.

  A gas generator incorporated in an airbag device that protects an occupant from an impact in the event of a vehicle collision usually has a gas exhaust port formed in any part of the housing, and the gas exhaust port is formed inside the airbag ( Alternatively, the gas is arranged inside the airbag module and the generated gas is guided into the airbag.

  If the airbag needs to be deployed quickly, the gas outlets are unevenly distributed so that the generated gas flows inside the airbag toward the airbag deployment direction (ie, the airbag deployment port direction). Oriented.

  The following are known as such conventional gas generators. In the gas generator of Patent Document 1, a plurality of gas discharge ports closed with a seal tape are formed in a part of a cylindrical housing. Specifically, the gas discharge port is formed only in the housing in the direction in which the airbag is deployed. When the combustion gas is discharged from the gas discharge port and flows into the bag, the airbag is immediately deployed from the module. is there.

   In this structure, since the gas emitted from the gas generator is discharged in one direction, thrust is generated when a malfunction occurs during storage or transportation of the gas generator alone.

  In order to prevent this, another member is connected to the gas discharge port portion to cancel the thrust (for example, to disperse the gas discharge direction). In some cases, it is not used when it is installed, but is discarded.

In view of the balance with the mounting portion of the vehicle, it is preferable that the gas generator has a small shape and that the internal structure is also simple.
JP 11-217054 A

    The present invention provides a gas generator assembly that is safe during transportation and storage, has a simple internal structure, and is easy to assemble.

In the present invention, an electric igniter that is ignited by an operating current is fixed to an igniter collar arranged around the electric igniter to form an igniter assembly. A cup-shaped member with an open end is attached, and a gas generator is sealed inside the cup-shaped member to form a gas generator,
Further, a tube-like conduit made of another member is attached to the gas generator, and at least a part of the conduit is disposed inside the airbag, and the gas exhaust for exhausting gas only in the direction in which the airbag is deployed. An exit is formed,
A gas generator assembly is provided in which the generated inflation gas is exhausted from the gas outlet through the conduit into the interior of the airbag.

  Since the igniter collar is attached around the electric igniter and performs a function of holding the electric igniter, the igniter collar is preferably made of metal or resin.

  The cup-shaped member contains a gas generating agent therein, and the gas generating agent is in direct contact with the inner surface of the peripheral wall portion of the cup-shaped member or the inner surface of the closed end portion, and is generated by combustion of the gas generating agent. It is preferable that the pressure is applied uniformly to the inner surface of the cup-shaped member. In other words, when the gas generating agent burns, there is no structure inside the cup that restricts the flow direction of the gas generating agent. Further, a sealing member can be disposed at the joint between the cup-shaped member and the igniter collar so that the gas generating agent inside the cup does not absorb moisture.

  Further, the tubular conduit is open at one end, and the opening is attached to the igniter collar. Preferably, the opening of the conduit is fixed by caulking against the collar. Alternatively, it can be detachably fixed by a screw or the like.

  When the conduit is attached to the airbag and the gas generator is attached to the opening of the conduit, at least a part of the conduit is present in the airbag, and even if the gas generator is outside the airbag, the air generator Although it may be arranged inside the bag, the gas outlet formed in the conduit is arranged inside the airbag so that the gas can be discharged in the direction in which the airbag is deployed. . That is, in the present invention, the gas generator assembly is formed by combining the conduit and the gas generator.

  Therefore, for example, when the gas generator is a single unit (the state before connecting the conduit), the thrust can be weakened even if a malfunction occurs, and at the same time, when the gas generator assembly is used for assembling the airbag, The gas can be quickly discharged in the direction in which it is desired to deploy. For this reason, it is desirable that the gas generator assembly is not connected to the conduit at the stage of storage, transportation, etc. before being incorporated into the airbag.

  The direction of the gas discharge port formed in the conduit is formed so that the gas can be discharged in the direction in which the airbag is deployed (that is, the direction in which the airbag jumps out of the module). As long as it is the deployment direction, it may be formed deviating from that direction.For example, a discharge port having a large opening area is formed in the airbag deployment direction, and a discharge port having a smaller opening area is formed in the other direction. It may be formed toward.

  The gas generator used in this gas generator assembly basically consists of an electric igniter and a gas generating agent that is ignited and burned by the electric igniter, and has a simple structure and a small gas generator. Can be achieved. The electric igniter and the gas generating agent are preferably arranged in contact with each other, and the gas discharge port formed in the conduit is formed so as to discharge the gas in the direction in which the airbag is deployed. Therefore, it is suitable for the airbag system for side collision, which is preferable to inflate the airbag quickly at the same time as the impact detection.

  In addition, in the said invention, it is preferable that the burst pressure of the one end obstruction | occlusion part of the said cup-shaped member is higher than the burst pressure of a surrounding wall part.

  This is to make it easier to break the peripheral wall portion than the one-end closed portion of the cup-shaped member when operated when the gas generator is a single body, and to prevent thrust from being generated by only breaking the peripheral wall portion evenly. .

  In order to achieve this, it is possible to form weak parts (thin parts having a small thickness) at equal intervals on the peripheral wall part of the cup-shaped member.

  Of the peripheral wall portion of the cup-shaped member, for example, an outward flange is formed at the end on the opening side, and the annular portion formed on the collar is caulked against the flange so that both can be fixed However, the thickness of the flange portion can be increased so that the peripheral wall portion of the cup-shaped member does not reach the flange portion when the igniter is activated.

  Furthermore, in the above invention, when the opening formed at one end of the conduit is attached to the igniter, the outer surface of the peripheral wall portion of the cup-shaped member is in contact with or opposed to the inner peripheral surface of the conduit. Moreover, it is preferable that one end opening of the conduit is fixed to the igniter collar.

  That is, when the peripheral wall portion of the cup-shaped member and the conduit are opposed to or in contact with each other, the peripheral wall portion of the cup is not easily cleaved, and the one-end closed portion of the cup-shaped member is exclusively broken. In other words, when activated when the gas generator is in a single state (the state before being connected to the conduit), the peripheral wall portion of the cup-shaped member is broken and thrust cancellation is achieved, while it is connected to the conduit for incorporation into an airbag ( In the case of a gas generator assembly), one end closed part of the cup-shaped member will be cleaved, and a smooth flow of gas to the airbag is ensured, and the airbag can be deployed quickly. It becomes. Of course, the present invention is not limited to the one in which the peripheral wall portion of the cup-shaped member is not broken at all. As long as the main flow of the gas to the conduit is from the one-end closed portion of the cup-shaped member, the peripheral wall portion is small. It may be one that cleaves.

  Furthermore, in the gas generator assembly of the present invention, a filter can be placed in the conduit.

  The gas generator should be as small as possible. Therefore, only the components necessary for generating gas are arranged in the gas generator. However, since the inside of the conduit is hollow, this space can be used as a filter housing chamber. The entire gas generator assembly including the conduit can be reduced in size.

  The filter has a function of filtering the residue contained in the combustion gas from the gas generating agent and a function of cooling the combustion gas itself, and a multilayer laminate formed by knitting a wire mesh or a wire is used as a filter medium. It can be placed in a conduit.

  In addition to the method of disposing the filter inside the conduit, the filter may be formed such that a plurality of irregularities are formed in the conduit so that the combustion gas or residue easily contacts the irregularities and is easily collected. By providing irregularities, the gas passage in the conduit becomes zigzag, and the frequency with which the combustion gas or residue physically contacts the irregularities increases.

  Further, the plurality of irregularities are preferably formed so as to be resistant to the gas flow. Specifically, by providing irregularities at right angles to the gas flow direction, the above effect can be further enhanced. .

  The gas generating agent used in the gas generator assembly of the present invention is, for example, a fuel and an oxidizing agent or a fuel containing an oxidizing agent and a slag forming agent, mixed with a binder as necessary, and molded into a desired shape. Use things.

  For example, as a fuel, guanidine such as nitroguanidine (NQ), guanidine nitrate (GN), guanidine carbonate, aminonitroguanidine, aminoguanidine nitrate, aminoguanidine carbonate, diaminoguanidine nitrate, diaminoguanidine carbonate, triaminoguanidine nitrate, etc. There are those selected from derivatives and the like.

  On the other hand, as the oxidizing agent, one selected from strontium nitrate, potassium nitrate, ammonium nitrate, potassium perchlorate, copper oxide, iron oxide, basic copper nitrate, and the like can be used.

  Furthermore, as the slag forming agent, acidic clay, talc, bentonite, diatomaceous earth, kaolin, silica, alumina, sodium silicate, silicon nitride, silicon carbide, hydrotalcite can be used.

  As the binder, sodium salt of carboxymethyl cellulose, hydroxyethyl cellulose, starch, polyvinyl alcohol, guar gum, microcrystalline cellulose, polyacrylamide, calcium stearate and the like can be used.

  It is also possible to use a gas generating agent that does not generate a residue during combustion, or a gas generating agent that generates less residue. In this case, the filter disposed in the conduit or the unevenness formed in the conduit can be simplified, reduced in quantity, or omitted.

  Non-residue type gas generators using nitrocellulose, gas generators consisting of melamine / ammonium nitrate / potassium nitrate / polyacrylamide, or gas generation consisting of RDX / ammonium nitrate / potassium perchlorate / potassium nitrate / polyacrylamide There is an agent.

  Further, the low-residue gas generator includes a gas generator composed of nitroguanidine / potassium perchlorate / binder (carboxymethylcellulose), or melamine / ammonium nitrate / potassium nitrate / potassium perchlorate / polyacrylamide.

  According to the gas generator assembly of the present invention, in the state of being incorporated in an airbag, gas is mainly discharged in the deployment direction of the bag, and rapid airbag deployment is possible. Alternatively, when the gas generator is used alone (in a state before the conduit is connected) such as during storage, the thrust is suppressed even if a malfunction occurs. That is, it is a gas generator assembly that can simultaneously achieve the contradictory points of limiting the gas discharge direction and suppressing the thrust generated thereby, and further simplifying the structure itself It is excellent in that it is a generator assembly and can be applied to an existing airbag system.

  Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments of the present invention. FIG. 1 is an axial sectional view of only a gas generator in a gas generator assembly of the present invention. The gas generator 10 is formed by combining an igniter assembly and a cup body 20.

  The igniter assembly includes an igniter body 12 that is ignited by an ignition current, and a substantially cylindrical igniter collar 14 that encloses and holds the igniter body 12 from the outside. The igniter collar 14 can be formed of metal or resin.

  The igniter main body 12 has two conductive pins 13, and the top of the igniter body serves as an ignition part.

  The molten resin is poured into the gap between the igniter body 12 and the igniter collar 14 and solidified (resin portion 15), thereby joining the igniter body 12 and the collar 14.

  The cup body 20 has an opening on the igniter main body 12 side, has a flange portion 20a formed outward from the periphery of the opening, and is filled with a required amount of a gas generating agent 24 inside. . The cup body 20 can be formed of a metal such as aluminum. The cup body 20 and the collar 14 are joined by caulking the annular portion 11 formed on the collar 14 against the flange portion 20a. FIG. 1 shows a cross section after the annular portion 11 is caulked against the flange 20a.

  The cup body 20 has a fragile portion (not shown) on the peripheral wall surface 22. The fragile portion is formed so as to extend between the flange portion 20a and the bottom surface portion 21, and a thin portion is formed on the peripheral wall surface 22 at equal intervals. When the gas generator 10 is actuated, the cup body 20 is ruptured at the fragile portion, and the combustion gas is discharged from the rupture portion, whereby the gas is evenly discharged radially outward and the thrust is offset. The fragile portion is formed on the peripheral wall surface 22 in the axial direction.

  The gas generating agent 24 is in direct contact with the inner peripheral portion of the peripheral wall surface 22 and the inner peripheral portion of the bottom surface portion 21 of the cup body 20. In the cup body 20, there is no member that suppresses or regulates the flow direction of the gas generated from the gas generating agent 24. During operation of the gas generator 10, equal pressure is applied to the inner peripheral surface of the bottom surface portion 21 and the inner peripheral surface of the peripheral wall surface 22 of the cup body 20.

  The gas generating agent 24 includes, for example, 34% by mass of nitroguanidine as a fuel, 56% by mass of strontium nitrate as an oxidizing agent, and 10% by weight of sodium carboxymethylcellulose as a binder (exhaust gas temperature 700 to 1630 ° C.). Is used. In the embodiment of FIG. 1, 2-16 g of the gas generating agent 24 is filled in the cup body 20.

  FIG. 2 shows a case where the gas generator 10 of FIG. 1 is connected to a conduit 30 to form a gas generator assembly 50, and a part of the conduit is assembled in a side impact airbag 40 (or airbag module 40a). An example of

  The conduit 30 includes an open end 31 to which the gas generator 10 is attached, and a closed end 32 disposed in the airbag 40. In the airbag 40, a first is disposed along the length of the bag. Part 33 and a second part 34 extending perpendicularly from the first part 33, the second part 34 extends to the outside of the airbag 40 (or the airbag module 40 a) over the open end 31. positioned.

  The first portion 33 is located at the bottom 40b of the airbag 40. In FIG. 1, the airbag is deployed on the right side. A plurality of gas discharge ports 36 are formed in the peripheral wall portion 35 of the first portion 33 in the direction in which the airbag is deployed (that is, on the right side in FIG. 1). A plurality of gas discharge ports 36 are formed in the axial direction of the first portion 33. If the main gas ejection direction is the same as the airbag deployment direction, a plurality of gas discharge ports 36 are also provided in the circumferential direction of the peripheral wall portion 35. It may be formed.

  Further, a stud bolt 37 is attached to the peripheral wall portion 35 of the first portion 33 on the substantially opposite side to the gas discharge port 36. The stud bolt 37 fixes the airbag 40 (or module 40a) and the conduit 30 to a desired location of the vehicle, and the airbag 40 (or module 40a) has a hole in a portion corresponding to the stud bolt 37. The stud bolt hole of the airbag can be closed by passing the stud bolt 37 through and tightening with the nut. A seal member may be interposed.

  On the other hand, the second portion 34 of the conduit 30 protrudes from a hole 51 formed in the side surface of the airbag 40 and extends in a direction perpendicular to the first portion 33. The direction in which the second portion 34 extends is not particularly limited, and the second portion 34 may extend on the extension line of the first portion 33. The gas generator 10 is attached to the open end 31 of the tip. The distal end portion of the second portion 34 is formed with an inflating portion 38 in which the cup body 20 of the igniter 10 is accommodated, and a protruding portion 39 formed subsequently thereto, and between the protruding portion 39 and the inflating portion 38. The collar 14 is brought into contact with the stepped portion 41, and the open end 31 is caulked against the collar 14 to fix the gas generator 10.

  The inner peripheral surface of the inflating part 38 is in contact with the outer peripheral surface of the cup body 20.

  The hole 51 formed in the side surface of the airbag 40 (or the module 40a) is a hole having a size that allows the conduit 30 (mainly the first portion 33) and the stud bolt 37 to pass therethrough, and the conduit 30 is inserted into the airbag 40. After that, the airbag 40 can be sealed by binding the bag in the hole 51 portion to the conduit 30 with a string-like member or a band.

  Further, a filter 52 that cools and purifies the gas from the gas generator 10 is disposed in the second portion 34. The filter 52 is fixed at a predetermined position by an emboss 53 formed in the second portion 34, and a filter formed by overlapping a plurality of metal meshes is used.

  Next, the operation mode when the gas generator assembly of FIG. 2 operates will be described. When the ignition signal is transmitted to the igniter body 12 in response to the collision impact, the gas generator 10 is ignited and transmitted to the gas generating agent 24. At this time, high-temperature combustion gas is generated from the gas generating agent 24, and the pressure inside the cup body 20 is increased. At this time, although the weakened portion is formed on the peripheral wall surface 22, the peripheral wall surface 22 is in contact with the expanding portion 38. It is transmitted to the first portion 33 and is discharged into the airbag 40 from the gas discharge port 36.

  Although the airbag 40 is initially folded, the inflation gas from the gas discharge port 36 formed in the deployment direction can quickly inflate the bag in the deployment direction, and the airbag 40 can be inflated in a short time. Is completed.

  In addition, the gas generator assembly of a present Example will have the weak part formed in the cup surrounding wall surface 22 at equal intervals if it will be in the state of the gas generator of FIG. Therefore, in the unlikely event of a malfunction, the gas is evenly discharged radially outward and no thrust is generated. And it connects with a conduit | pipe when incorporating in an airbag. Therefore, a simple method for connecting the gas generator 10 to the conduit is preferable. Besides the caulking shown in FIG. 2, the gas generator 10 is screwed into the opening 31 of the conduit 30 or a third part is attached. A method of fixing the gas generator 10 by screwing into the opening 31 of the conduit 30 is also possible.

  FIG. 3 shows another embodiment of the first portion 33 of the conduit 30 of FIG. 2, and the first portion 33 is uneven so that the inside of the conduit becomes a zigzag gas passage.

  While the combustion gas passes through the uneven portion, the residue contained in the gas collides with the protruding portion 54, so that the residue is accumulated in this portion. In addition, the contact frequency between the gas and the conduit is increased, heat is transferred from the gas to the conduit, and cooling of the gas is achieved. In addition, a similar effect can be obtained by providing a plurality of protrusions inside the conduit 30.

  Further, not only the first portion 33 but also the second portion 34 can be provided with similar irregularities and a plurality of protrusions. The filter 52 may be used in combination with protrusions or irregularities, or the protrusions or irregularities may be used in place of the filter 52.

  FIG. 4 is a view showing another embodiment of the gas generator assembly 70 of the present invention, and shows a case where the gas generator assembly 70 is incorporated in a system for side collision as in FIG. In the embodiment of FIG. 4, the gas generator 10 is inserted into a conduit 60, which is disposed entirely within the airbag 40.

  In FIG. 4, the conduit 60 abuts the flange 14 of the gas generator 10 against the stepped portion 62 formed in the one end opening 61, and fixes the end by caulking. The opposite end 63 is closed. A plurality of gas discharge ports 64 are formed in the peripheral wall portion 66 so as to generate gas when the airbag 40 is deployed (on the right side in FIG. 4).

  The arrangement of the gas outlets 64 is the same as that of the gas outlets 36 shown in FIG. In the gas generator assembly 70 of FIG. 4, as in FIG. 2, the stud bolt 37 formed on the side surface portion of the conduit 60 passes through the hole formed in the bag bottom surface portion 65. is doing. A lead wire for sending an ignition current to the gas generator 10 extends from the hole into the airbag and is connected to the gas generator 10.

As in the embodiment of FIG. 2, a filter may be used inside the conduit 60, and the conduit 60 itself may be formed with irregularities and a plurality of protrusions on the inner surface.
The gas generator assembly of the present invention is mainly applied to a side impact airbag system. However, the present invention is not limited to these embodiments, and other airbag systems (for example, the air bolster of a knee bolster). It can also be used for bags and air bags for curtains).

  Further, the method for fixing the conduit and the gas generator is not limited to this embodiment, and a known technique may be used.

Sectional drawing of the gas generator incorporated in a gas generator assembly. Sectional drawing of the gas generator assembly of this invention. FIG. 3 is a partial cross-sectional view of a conduit in a gas generator assembly. Sectional drawing which shows another Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas generator 30 Conduit 34 2nd part of conduit 35 1st part of conduit 36 Gas exhaust port 38 Expansion part 37 Stud bolt 39 Projection part 40 Air bag

Claims (5)

An electric igniter that is ignited by an operating current is fixed to an igniter collar disposed around the electric igniter to form an igniter assembly. Further, one end of the igniter assembly is closed and the opposite end is opened. A cup-shaped member is attached, and a gas generating agent is sealed inside the cup-shaped member to form a gas generator,
Further, a tube-like conduit made of another member is attached to the gas generator, and at least a part of the conduit is disposed inside the airbag, and the gas exhaust for exhausting gas only in the direction in which the airbag is deployed. An exit is formed,
A gas generator assembly in which inflation gas generated from the gas generator is discharged from the gas discharge port into the airbag through the conduit.   The gas generator assembly according to claim 1, wherein the cup-shaped member has a burst pressure at the one end closed portion higher than a burst pressure at the peripheral wall portion.   When the opening formed at one end of the conduit is attached to the igniter, one end of the conduit is arranged such that the outer surface of the peripheral wall portion of the cup-shaped member is in contact with or opposed to the inner peripheral surface of the conduit. The gas generator assembly of claim 2, wherein an opening is secured to the igniter collar.     The gas generator assembly according to any one of claims 1 to 3, wherein a filter is disposed in the conduit.     The gas generator assembly according to any one of claims 1 to 3, wherein a plurality of irregularities are formed inside the conduit.

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