JP2598814B2 - Combustion gas filtration device for gas generator for airbag deployment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an airbag used for deploying an airbag such as an air bag, a lifesaving bag, a rubber boat, and an escape chute for a collision safety device by using a combustion gas. The present invention relates to a deployment gas generator, and more particularly to a combustion gas filter for filtering combustion gas generated by combustion of a gas generating agent.

[Conventional technology]

Conventionally, in a passenger car, a collision safety device for protecting a driver from a shock at the time of the collision includes, for example, an airbag having a volume of 60 liters and an airbag deployment gas for deploying the airbag with gas. When a passenger car collides, a gas generating agent composed of explosives or a similar composition filled in the air bag deploying gas generating device is ignited and burned, and the air bag is generated by the generated gas. It deploys instantaneously to protect the driver from collisions and prevent serious injury to the driver.

FIG. 9 shows a conventional gas generator for deploying an air bag disclosed in Japanese Patent Application Laid-Open No. 55-110652. In the figure, reference numeral 11 denotes a large number of pellet-shaped gas generating agents 13. 2 shows a combustion chamber.

In the center of the combustion chamber 11, an igniter 15 and an ignition charge 17 for burning the gas generating agent 13 are arranged.
A combustion filter 19 is arranged along the inner periphery of the combustion chamber 11.

A charge chamber 21 that surrounds the combustion chamber 11 and in which the gas that has passed through the combustion chamber filter 19 flows is arranged in an annular shape.

In the charging chamber 21, a charging chamber filter 23 is accommodated, and in the charging chamber 21, a charging chamber filter 23 is provided.
A gas outlet 25 for discharging the gas passing through the airbag to the airbag is provided.

In such a gas generator for airbag deployment, when electricity is supplied to the igniter 15, the igniting agent 17 burns, and the combustion causes the gas generating agent 13 to burn. After flowing through the combustion chamber filter 19 arranged along the inner periphery of the combustion chamber 11 and flowing into the charging chamber 21, it is purified by the charging chamber filter 23 and flows into the airbag through the gas outlet 25. Then, for example, the airbag is sufficiently inflated in a short time of about 0.04 seconds.

[Problems to be solved by the invention]

However, in such a conventional airbag deployment gas generator, the high-velocity combustion gas that has passed through the combustion chamber filter 19 directly flows into the charging chamber filter 23. There is a problem in that the gas passes through the charging chamber filter 23 at a relatively high flow rate, and it is extremely difficult to reliably remove combustion residues in the charging chamber filter 23.

An object of the present invention is to solve the above-described problems and to provide a combustion gas filtering device for an airbag deployment gas generator capable of reliably filtering combustion gas. Means for Carrying Out] The combustion gas filtering device of the gas generator for deploying an air bag according to the present invention is formed by stacking a gas generating agent that is formed in an annular plate shape having a through hole in the center and that forms a chamfered portion on the outer and inner circumferences. Then, an annular wire mesh separator is disposed on the entire surface of the polymerization surface between the gas generating agents except for the chamfered portion of each gas generating agent, and the space formed by each central through hole is filled with an igniting agent. A combustion chamber, a combustion chamber filter disposed along an outer periphery of the combustion chamber, and a gas chamber surrounding the combustion chamber and the combustion chamber filter. Igniter for accommodating A sealed container formed with a portion, an igniter accommodated in a recess for accommodating an igniter of the sealed container, and an orifice which surrounds the sealed container and is annularly arranged to pass combustion gas passing through the combustion chamber filter. And a gas filtration filter which is disposed on the lower side of the upper filter via a partition plate and which is held by packing at the top and bottom, and A charging chamber filter housed in the charging chamber so as to guide the combustion gas passing through the upper filter to the gas filtering filter, and a combustion gas passing through the gas filtering filter of the charging chamber filter to the airbag. And a gas outlet for outflow.

(Operation)

In the combustion gas filtering device of the gas generator for deploying the air bag of the present invention, the annular wire mesh separator is disposed on the entire surface of the overlapping surface between the gas generating agents except for the chamfered portion of the gas generating agent to be laminated. Even during combustion, the gas generating agent is sandwiched between the annular wire mesh separators, so that stable combustion can be maintained even when the surface area of the gas generating agent changes due to combustion, and a combustion passage can be secured.

In addition, since the annular wire mesh separator has a wire mesh shape, it emphasizes a method of differentiating the flow of the combustion gas in the horizontal direction, the vertical direction, and the like, whereby the heat particles are dispersed and the combustion ignition is performed smoothly.

Further, since the wire mesh is used, the combustion gas can be cooled and the combustion residue can be removed.

Next, with respect to the chamfered portion, ignition from the igniting agent can be performed efficiently, and combustion can be improved.

In addition, since the igniting agent is arranged in the central through hole of the gas generating agent to be laminated and housed in a sealed container, the ignition from the igniter and the reliable ignition of the gas generating agent can be performed together with the moisture proof effect.

After passing through the combustion chamber filter, the combustion gas of the gas generating agent passes through the orifice and is guided to the upper filter. This upper filter scatters the combustion gas at a high flow rate, absorbs heat, and captures the combustion residue. After the flow velocity of the combustion gas is reduced, the combustion gas is guided to a gas filtration filter, and the combustion gas that has passed through the gas filtration filter flows out of the gas outlet to an air bag.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a gas generator for deploying an air bag provided with an embodiment of a combustion gas filtering device of the gas generator for deploying an air bag of the present invention.

In FIG. 1, reference numeral 41 denotes a combustion chamber in which a gas generating agent 43 is stored.

In the center of the combustion chamber 41, an igniter 45 and an ignition charge 47 for burning the gas generating agent 43 are arranged.
A combustion chamber filter 49 is arranged along the inner periphery of the combustion chamber 41.

A charge chamber 51 surrounding the combustion chamber 41 and into which gas that has passed through the combustion chamber filter 49 flows is arranged in an annular shape.

Further, in the charging chamber 51, a charging chamber filter including an upper filter 53 and a gas filtration filter 55 is accommodated. Further, in the charging chamber 51, a gas outlet 57 for discharging the gas that has passed through the gas filtration filter 55 to the airbag is disposed.

In this embodiment, the combustion chamber 41 is
It is formed by a bottomed cylindrical portion 61 of 59 and a lid member 65 that is electron beam welded 63 to this opening.

As shown in FIGS. 2 and 3, the housing body 59 has a bottomed cylindrical portion 61 and a flange portion 67 integrally formed outwardly with an opening of the bottomed cylindrical portion 61. From the outer periphery of the flange portion 67 to the bottom portion 69 of the housing body 59.
And an outer cylindrical portion 71 bent toward the side.

A second flange portion 73 is formed integrally at the tip of the outer cylindrical portion 71 toward the outside.
A mounting hole 75 for mounting an airbag is formed.

As shown in FIG. 1, the charging chamber 51 covers the outer cylindrical portion 71 and the bottomed cylindrical portion 61 of the housing main body 59 with the covering member 77 from the bottom surface portion 69 side of the housing main body 59, The cover member 77 is formed by welding and joining to the outer tubular portion 71 and the bottomed tubular portion 61 by welding 79, 80 such as an electron beam or a laser beam.

In this embodiment, the covering member 77 has an L-shaped cross section as shown in FIG. 4, one end of which is inserted inside the outer cylindrical portion 71 of the housing body 59 and the other end thereof. The inner periphery of the bent portion 81 formed on the housing body 59 is in contact with the outer periphery of the bottomed cylindrical portion 61 of the housing body 59.

The bottomed cylindrical portion 61 of the housing body 59 is formed with a predetermined angle, for example, 18 orifices 82 are formed, and the covering member 77 is formed with a predetermined angle, for example. , 18 gas outlets 57 are formed.

Further, in this embodiment, the housing body 59, the lid member 65
The cover member 77 is formed of stainless steel.

Five gas generating agents 43 are arranged outside the igniter 45 and the igniting agent 47 in the combustion chamber 41, and in this embodiment, each gas generating agent 43 has a through hole formed in the center. It is formed in an annular plate shape.

In order to improve the ignitability of each gas generating agent 43, it is desirable that both ends are thin and the center is thick drum-shaped, or that both ends are chamfered, and that the center is flat, and if necessary, May be divided into two to four at a predetermined angle from the center.

The gas generating agent 43 is, for example,
It contains 28% by weight of iron oxide, 28% by weight of iron oxide, 8% by weight of potassium perchlorate, and 2% by weight of solder glass. And press-molded at a pressure of 40-60 tons.

These gas generating agents 43 are stacked, and an igniter 45 and an igniter 47 are arranged in a through hole formed in the center.

Further, a separator 83 is arranged between the gas generating agents 43.

These separators 83 are, for example, stainless steel 10
It is made of an annular wire mesh using # 30 wire, which improves the ignitability of the gas generating agent 43 and enables the gas generating agent 43 to have an exhaust passage.

In this embodiment, these gas generating agent 43, separator 8
3. The igniting agent 47 and the combustion chamber filter 49 are surrounded by a sealed container 85 in order to prevent the gas generating agent 43 and the igniting agent 47 from absorbing moisture.

This sealed container 85 is made of flame-retardant thermoplastic,
For example, polypropylene, nylon with glass fiber, polycarbonate, polyacetal, polysulfone, polyethylene terephthalate, etc. and flame-retardant thermosetting resin,
For example, it is made of epoxy, phenolic resin, polyphenyl sulfide or aluminum.
Sealed by ultrasonic bonding or hot melt welding in the state of being inserted into 87. In this case, the aluminum is sealed by winding, bonding or electron beam welding.

At the center of the upper lid 86 of the sealed container 85, a concave portion 88 which is depressed toward the through hole of the gas generating agent 43 and accommodates the igniter 45 is formed.

The center of the gas generating agent 43 is filled with an igniting agent 47. In this embodiment, the igniting agent 47 is obtained by coagulating magnesium and ethylene tetrafluoride with a binder of ethylene trifluoride chloride. Is formed.

The igniting powder 47 is, for example, 60% by weight of magnesium and 40% by weight of ethylene tetrafluoride.
It is a flocculent igniting agent composed of 5% by weight. For example, when 1.1 g of igniting agent is used, the calorific value is 1940 calories / g, the gas generation amount is 40 cc / g, and the conventional boron-potassium sulfate igniting agent is used. The calorific value is 1790 calories / g and the gas generation amount is 79cc / g.
43 can be obtained without cracking and with no time delay.

The ignition charge 47 is manufactured as described below.

That is, for example, in order to obtain four igniting agents having a weight of 300 g, 180 g of magnesium was added to 14.2 g of trifluoroene chloride dissolved in toluene, and this magnesium was sufficiently wetted. , Ethylene tetrafluoride
120 g is mixed and then passed through a 12-mesh sieve and dried twice, and after this drying, the mixture is stirred with a mixer to obtain a flocculent ignition powder.

That is, in this embodiment, since the gas generating agent 43 has a ring shape, if the same ignition method as that of the conventional air bag developing gas generating device shown in FIG.
Is destroyed, it is easy to cause abnormal combustion, and even when it does not lead to destruction, the ignitability varied, but in this example, magnesium was directly coagulated with Teflon at the center of the gas generating agent 43. Since the formed ignition charge 47 is filled, the risk of destruction of the gas generating agent 43 can be reliably eliminated.

Thus, in this embodiment, a combustion chamber filter (first filter) 49 that constitutes a part of the combustion gas filtering device is disposed in the sealed container 85 so as to surround the gas generating agent 43.

As shown in FIG. 5, this combustion chamber filter 49 is made of a stainless steel wire mesh having a mesh size of 10 to 35 by using a gas generating agent.
It is wound around 43 and has the functions described below.

A function of lowering the combustion gas temperature of the gas generating agent 43 and facilitating capture of combustion products by a filter.

A function that acts as a buffer against vibration and shock. That is, if the gas generating agent 43 is cracked, the surface area of the gas generating agent 43 increases, and abnormal combustion occurs.However, this combustion chamber filter 49 is used until the gas generating device for deploying an air bag is incorporated into a passenger car or the like. In this case, the gas generating agent 43 is prevented from being cracked due to a fall accident at or in a long-term vibration after being mounted on a passenger car.

Capture function of combustion products.

The function of retaining the gas generating agent 43 and securing the discharge path of the combustion gas. If there is no discharge path, the inside of the housing will be at a high pressure and may be broken.

The inside of the air charge chamber 51 is vertically divided by a partition plate 89, and an upper filter (second filter) 53 is provided above the partition plate 89, and a gas filtration filter (third filter) 55 is provided below the partition plate 89. Are located.

That is, the partition plate 89 is made of, for example, a member such as stainless steel or aluminum, and is pressed into the inner peripheral surface of the covering member 77. As shown by arrows in FIG. 1, the partition plate 89 allows the combustion gas that has passed through the combustion chamber filter 49 and flowed into the charging chamber 51 to flow into the upper filter 53, and then, It acts to change the flow and guide it to the gas filtration filter 55.

The upper filter 53 is disposed at a predetermined distance from an orifice 82 formed in the housing body 59, and for example, as shown in FIG. 6, a stainless steel demister wire mesh is press-formed by a ring mold. It is formed.

The upper filter 53 has a function of causing high-velocity combustion gas ejected from the orifice 82 to collide with the upper filter 53, thereby causing the high-velocity combustion gas to become a turbulent flow and causing a combustion gas residue to adhere to the wire mesh.

The gas filtration filter 55 has a function of cooling the combustion gas to such an extent that the airbag does not burn out, removing combustion residues contained in the combustion gas, and supplying only harmless nitrogen gas to the airbag. .

As shown in FIGS. 7 and 8, the gas filtration filter 55 includes a fine wire mesh A1, a metal fiber sintered cloth C1, an inorganic fiber sheet D1, a metal fiber sintered cloth C2, a fold weave, in this order from the inside. The wire mesh B2 and the fine wire mesh A2 are formed by layering and winding.

That is, the gas filtration filter 55, for example, winds the fine wire meshes A1 and A2 outward in order from the inside, and a certain length, for example, at a position 3 m from the innermost end face of the fine wire meshes A1 and A2, The folding woven wire mesh B1 is spot-welded in advance, and winding is performed by winding the inorganic fiber sheet D1 sandwiched between the metal fiber sintered cloths C1 and C2. At this time, the end of the fine wire mesh A2 at the outermost periphery is spotted. It is joined by welding at 2 to 10 places, and is wound and wound around 2 to 4 times to increase the strength of the filter.

Here, the fine metal meshes A1 and A2 are configured by winding a stainless steel mesh of No. 10 to 30 multiple times into a cylindrical shape, for example, and cooling the combustion gas to appropriately expand the airbag. It functions to adjust the amount of gas necessary for the purpose.

The fold woven wire mesh B2 is made of, for example, a stainless steel wire mesh, is wound around the outer periphery of the metal fiber sintered cloth C1, improves the backup and filter strength of the metal fiber sintered cloth C1, and further disperses the gas into a turbulent flow. To act.

The inorganic fiber sheet D1 is wound around the inner circumference of the woven wire mesh B1 through the metal fiber sintered cloth C1, and filters fine powder of sodium oxide and metal sodium contained in the gas and causing a pungent odor. To act.

Sintered metal fiber cloths C1 and C2 are wound adjacent to the inside and outside of the inorganic fiber sheet D1, and the sintered metal fiber cloths C1 and C2 and the woven wire mesh B2 are formed of the inorganic fiber sheet D1. Acts to prevent destruction by the gas flow.

Outside the inorganic fiber sheet D1, a metal fiber sintered cloth C2, a woven woven wire mesh B2, and a fine wire mesh A2 are wound respectively.

The metal fiber sintered cloths C1 and C2 have a wire diameter of 4 to 8, for example.
It is formed by compressing and sintering a stainless steel filament of micron meter at 500 g / m ² to a thickness of 0.2 to 1.0 mm, and has a porosity of 65 to 90%.

Further, packings 91 are arranged above and below the gas filtration filter 55 in order to prevent gas leakage from the gas filtration filter 55.

The packing 91 is made of a heat-resistant and flame-retardant material such as silicon rubber to prevent burning, and has a thickness of 0.6 to 2.0 mm.

The igniter 45 is supported by a plug 93 screwed into a through hole formed in the center of the lid member 65, and the center of the plug 93 is filled with a seal member 95.

In the airbag deployment gas generator configured as described above, when electricity is supplied to the igniter 45, the igniter 47 burns, and by this combustion, the gas generating agent 43 burns. The gas of 43 passes through a combustion chamber filter 49 arranged along the inner periphery of the combustion chamber 41, and flows into the charging chamber 51.
After flowing into the upper filter 53, colliding with the partition plate 89 and inverting, the gas is filtered by the gas filtration filter 55, and the gas outlet 57
And flows into the airbag, and the airbag is sufficiently inflated in a short time of, for example, about 0.04 seconds.

Thus, in the combustion gas filtering device of the air bag developing gas generator configured as described above, the charging chamber filter is connected to the upper filter 53 disposed beside the orifice 82.
And a gas filtration filter 55 disposed below the upper filter 53 via a partition plate 89. The combustion gas passing through the upper filter 53 is
The combustion gas passed through the gas filtration filter 55 was caused to flow out of the gas outlet 57 into the airbag, so that the combustion gas of the gas generating agent 43 passed through the combustion chamber filter 49, and then passed through the orifice 82. As a result, the gas is guided to the upper filter 53, which scatters the high-velocity combustion gas, absorbs heat, and captures the heat-burning residue, and reduces the flow velocity of the combustion gas. The combustion gas that has passed through the gas filter 55 flows out of the gas outlet 57 into the airbag.

That is, in the combustion gas filtering device of the air bag deployment gas generator configured as described above, the upper filter 53
As a result, high-velocity combustion gas is scattered, heat is absorbed and combustion residues are captured, and the combustion gas is guided to the gas filtration filter 55 after the flow rate of the combustion gas is reduced by the upper filter 53. In addition, the trapping performance of the combustion residue in the gas filtration filter 55 can be greatly improved as compared with the related art, so that the combustion residue in the combustion gas can be reliably removed.

Further, in the combustion gas filtering device of the air bag developing gas generator configured as described above, the combustion gas flowing into the upper filter 53 collides with the partition plate 89 as shown by the arrow in FIG. After that, it is turned to the opposite side and passes through the upper filter 53 again, so that it is possible to sufficiently reduce the flow velocity of the combustion gas and to sufficiently capture the combustion residue. It becomes possible.

〔The invention's effect〕

As described above, according to the present invention, a gas generating agent that forms a circular plate having a through hole at the center and forms a chamfered portion on the outer periphery and the inner periphery is laminated, and the chamfered portion of each gas generating agent is removed. A combustion chamber in which an annular wire net-like separator is arranged on the entire surface of the polymerization between the gas generating agents, and a space formed by each central through hole is filled with an igniting agent, and an outer periphery of the combustion chamber A combustion chamber filter disposed along the combustion chamber and the combustion chamber filter, and forming a recess for accommodating an igniter that is immersed in the through hole of the gas generating agent facing the ignition powder. A sealed gas container, an igniter accommodated in a recess for accommodating an igniter of the sealed container, and a combustion gas passing through the combustion chamber filter which is annularly arranged so as to surround the sealed container and flows through an orifice. The charging chamber and the orifice And a gas filtration filter disposed below the upper filter via a partition plate and held up and down by a packing, and the combustion gas passing through the upper filter is removed by the gas filtration filter. And a gas outlet for discharging the combustion gas that has passed through the gas filtration filter of the air charge chamber filter to the airbag. From, by an annular wire mesh separator placed between the gas generating agent,
It is possible to sufficiently secure the ignitability of the gas generating agent and the exhaust passage of the combustion gas, and the combustion gas can be cooled and the combustion residue can be removed by the annular wire mesh separator.

Further, since the combustion chamber and the combustion chamber filter are surrounded by the sealed container, the gas generating agent and the igniting agent can be securely sealed with a simple structure.

In addition, since the concave portion is formed in the sealed container for accommodating the igniter, the igniter can be easily and surely arranged adjacent to the ignition charge.

Further, the charging chamber filter is constituted by an upper filter disposed on the side of the orifice and a gas filtration filter disposed below the upper filter via a partition plate, and the combustion gas passing through the upper filter is formed. Is led to a gas filtration filter, and the combustion gas that has passed through the gas filtration filter is caused to flow out of the gas outlet to the airbag, so that there is an advantage that combustion residues in the combustion gas can be reliably removed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an airbag developing gas generator having one embodiment of a combustion gas filtering device of the airbag developing gas generator of the present invention. FIG. 2 is a longitudinal sectional view showing the housing body of FIG. FIG. 3 is a top view of the housing body of FIG. FIG. 4 is a longitudinal sectional view showing the covering member of FIG. FIG. 5 is a longitudinal sectional view showing the combustion chamber filter of FIG. FIG. 6 is a longitudinal sectional view of the upper filter of FIG. FIG. 7 is a longitudinal sectional view showing the gas filtration filter of FIG. FIG. 8 is a top view of the gas filtration filter of FIG. FIG. 9 is a longitudinal sectional view showing a conventional gas generator for deploying an air bag. [Description of Signs of Main Parts] 41: Combustion chamber 43: Gas generating agent 45: Igniter 47: Igniter 49: Combustion chamber filter 51: Charging chamber 53: Upper filter 55: Gas Filtration filter 57 Gas outlet 59 Housing body 77 Cover member 89 Partition plate.

Continuation of front page (56) References JP-A-55-110642 (JP, A) JP-A-52-121242 (JP, A) JP-A-2-24212 (JP, A) JP-A 1-145867 (JP) , U)

Claims (1)

(57) [Claims] 1. A gas-generating agent which is formed in an annular plate shape having a through hole in the center and which forms a chamfered portion on the outer and inner peripheries, and which is formed between the gas generating agents excluding the chamfered portion of each gas generating agent. A combustion chamber in which an annular wire mesh separator is disposed on the entire surface, and a space formed by each central through-hole is filled with an igniting agent; and combustion disposed along the outer periphery of the combustion chamber. A sealed container that surrounds the combustion chamber and the combustion chamber filter and forms a recess for accommodating an igniter that is immersed in a through hole of the gas generating agent facing the ignition agent; An igniter accommodated in a concave portion for accommodating an igniter of the sealed container; an air charge chamber surrounding the sealed container and annularly disposed to flow combustion gas passing through the combustion chamber filter through an orifice; Located on the side of the orifice And a gas filter which is disposed below the upper filter via a partition plate and held up and down by a packing, and wherein the combustion gas passing through the upper filter is guided to the gas filter. An airbag deployment, comprising: a charging chamber filter housed in a charging chamber; and a gas outlet for flowing combustion gas that has passed through a gas filtration filter of the charging chamber filter to an airbag. Gas filter of combustion gas generator.