JP4625735B2 - Gas generator for airbag - Google Patents

Description

  The present invention relates to a gas generator for an air bag and an air bag apparatus using the same.

  2. Description of the Related Art As a gas generator for an air bag used in a vehicle air bag system, there is a dual type that can inflate and deploy an air bag in two stages in order to improve occupant protection performance.

  When the vehicle collides during high-speed driving, the airbag is inflated in one step from the viewpoint of occupant protection. However, if the vehicle collides during medium-speed driving, the airbag is inflated in one step. And children may be injured by the inflation pressure of the airbag.

Therefore, the airbag is inflated in two stages, and the maximum inflating is performed in the second stage, thereby improving the protection performance of the occupant.
US2005-35582A

  Since the airbag is inflated in front of the occupant when the device is in operation (that is, the airbag is inflated toward the occupant), the occupant is apt to receive an impact due to the inflation of the airbag. Become. For this reason, even when the airbag is inflated in two stages, it may be desirable for some occupants to further reduce the impact received by the inflation of the airbag.

  Therefore, according to the present invention, when the airbag is inflated in two stages, the impact received by the occupant due to the inflation of the airbag is mitigated by controlling the direction of inflation of the airbag during the first stage of inflation. It is an object of the present invention to provide a gas generator for an air bag having a further improved air quality.

As a means for solving the problems, the present invention
A housing having a gas discharge port; a first combustion chamber and a second combustion chamber which are provided in the housing and filled with a gas generating agent; and a first ignition means and a second ignition chamber arranged for each of the two combustion chambers. An air bag gas generator having ignition means;
The second ignition means includes an electric igniter, a piston, and an enhancer agent having a detonator arranged to face the tip of the piston,
A tether is connected to the rear end portion of the piston, and the opposite end side of the tether is wound around the airbag when accommodated in an airbag module,
When the first ignition means is activated, the tether acts to tighten the inflating airbag and control the inflation direction of the airbag. When the second ignition means is activated, the piston Provided is a gas generator for an air bag which is pulled and cut by movement of the air bag.

  In the present invention, when the airbag is inflated in two stages, the inflation direction of the airbag in the first stage is controlled in the lateral direction (width direction of the occupant body).

  In the case of a driver's seat or a passenger seat, an air bag module containing an air bag gas generator and an air bag is attached to the front of the occupant (for example, a handlebar for a driver seat and a dashboard for a passenger seat). . For this reason, an airbag will expand | swell toward a passenger | crew.

  Therefore, according to the present invention, when the occupant's body is used as a reference, means for inflating the airbag mainly in the width direction of the body (that is, suppressing the airbag from inflating forward toward the occupant) (control of the inflation direction) By means), the protection performance of the occupant is further enhanced.

  When the airbag is inflated in the second stage, the tether wound around the airbag is cut, and the airbag is inflated mainly toward the occupant.

  The piston moves linearly in response to pressure (shock wave or pressure increase due to gas generation) due to the operation of the electric igniter. The piston is made of metal such as aluminum or iron. The shape of the piston is not particularly limited as long as it is rod-shaped, but the tip is preferably arrowhead-shaped to collide with the detonator during operation, and the rear end is non-arrowhead-shaped (for example, cylindrical) ). A groove, a protrusion, or the like for connecting the tether may be formed at the rear end.

  Since the tether is wound around the airbag, the tether is preferably made of a synthetic resin string so as not to damage the airbag, and more preferably made of the same material as the airbag (for example, nylon).

  One tether may be used, but two or more tethers may be used, and one tether may be branched into two or more from the middle.

  The tether is wound around the airbag folded in the module at least once (one turn), and the end is fixed to the airbag module or the like. When the airbag is inflated, the tether is preferably wound at least twice so that the airbag when inflated can be divided into approximately three equal parts in the length direction. When the airbag is inflated in a state of being equally divided into three in this way, it is preferable that the airbag is restrained from inflating forward toward the occupant and inflated mainly in the lateral direction.

  The thickness (strength) of the tether is adjusted so that it is not cut when the airbag is inflated at the first stage and is cut when the airbag is inflated at the second stage (at the time of maximum inflation). Note that the cutting of the tether includes not only the case where the tether is cut from the middle, the case where the tether is cut from the knot, but also the case where the knot of the tether can be broken.

  According to another aspect of the present invention, the housing has a cylindrical shape, a gas discharge port is provided near the center, and two combustion chambers are disposed on both ends. An air bag gas generator according to Item 1, is provided.

  Thus, since the outer shape is cylindrical, it is particularly suitable as a gas generator for an airbag for a passenger seat.

  The present invention provides, as another means for solving the problems, an airbag device in which the gas generator and the airbag according to claim 1 or 2 are accommodated in an airbag module.

  The gas generator and the air bag apparatus for an air bag of the present invention are particularly suitable for a driver seat and a passenger seat, but are not limited to these, and the known gas generator and air bag apparatus for an air bag are used. Can also be used.

  According to the gas generator for an air bag and the air bag device of the present invention, the pressure on the occupant when the airbag is inflated in the first stage is relieved, and sufficient occupant protection can be achieved during maximum inflation.

  The airbag gas generator 10 and the airbag apparatus of the present invention will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a vertical end view of a gas generator for an air bag, and FIGS. 2 and 3 are diagrams for explaining operations of the gas generator for an air bag and the air bag device.

  The gas generator 10 is divided into three parts, a first combustion chamber 20, a second combustion chamber 30, and a filter chamber 50, and an outer shell is formed by separate housings. It can also be made of stainless steel or aluminum.

  The first combustion chamber 20 has an outer shell formed by a cup-shaped first combustion chamber housing 21, and the opening is closed by a boss 22. The connecting portion between the first combustion chamber housing 21 and the boss 22 is fixed by welding.

  A first igniter 23 is fitted in a hole provided in the center of the boss 22, and the first igniter 23 is fixed by caulking a peripheral edge portion 26 of the hole. A connector 24 is fitted into the first igniter 23, and the lead wire 25 is connected to a power source (vehicle battery).

  The first combustion chamber 20 is filled with a required amount of a gas generating agent 27 (which is cylindrical in FIG. 1, but the shape is not limited).

  An enhancer cup 28 is disposed in the first combustion chamber 20, and is fixed by being press-fitted into the first combustion chamber 20 by a flange portion 28a. A plurality of first heat transfer holes 28 b are provided on the peripheral surface of the enhancer cup 28, and a known first enhancer agent 29 is filled therein.

  The second combustion chamber 30 has an outer shell formed by a cup-shaped second combustion chamber housing 31, and the opening is closed by a boss 32. The connecting portion between the second combustion chamber housing 31 and the boss 32 is fixed by welding.

  A second igniter 33 is fitted into a hole provided in the center of the boss 32, and the second igniter 33 is fixed by caulking the peripheral edge 36 of the hole. A connector 34 is fitted into the second igniter 33, and the lead wire 35 is connected to a power source (vehicle battery).

  The second combustion chamber 30 is filled with a required amount of a gas generating agent 37 (which is cylindrical in FIG. 1 but the shape is not limited).

  An enhancer cup 38 is disposed in the second combustion chamber 30, and is fixed by being press-fitted into the second combustion chamber 30 by a flange portion 38a. A plurality of second heat transfer holes 38b are provided on the peripheral surface of the enhancer cup 38, and a known second enhancer agent 39 is filled therein and a detonator 40 is disposed.

  The boss 32 is provided with a space 43 facing the ignition portion (tip portion) of the second igniter 33 and the detonator 40, and the boss bottom surface 32 a side of the space 43 is opened. The piston 41 is inserted into the space 43 from the opening. The piston 41 has a tip end portion 41a having an arrowhead shape and a rear end portion 41b having a cylindrical shape. The tip end portion 41a is located in the space 43, and the rear end portion 41b is projected outward from the opening. ing.

  The front end portion 41a of the piston 41 faces the detonator 40 with a gap in the space 43, and a tether 42 made of nylon 6, 66, 11, 12, 610 or the like is connected and fixed to the rear end portion 41b. Has been.

  The tether 42 extended from the piston 41 is wound around the airbag when the airbag gas generator 10 is accommodated in the module together with the airbag, and the end is fixed to the module.

  The filter chamber 50 has an outer shell formed by a filter chamber housing 51, and a cylindrical coolant / filter 52 is disposed therein. Both end surfaces of the coolant / filter 52 are in contact with the ceiling surface 21a of the first combustion chamber housing 21 and the ceiling surface 31a of the second combustion chamber housing 31, and are pressed and fixed on both ceiling surfaces.

  The filter chamber 50 and the first combustion chamber 20 communicate with each other through a first communication hole 53 provided in the ceiling surface 21a, and the filter chamber 50 and the second combustion chamber 30 communicate with a second communication provided in the ceiling surface 31a. The holes 54 communicate with each other. The second communication hole 54 is covered from the filter chamber 50 side by a table-like fire spread prevention member 55 having an opening on the peripheral surface.

  The filter chamber housing 51 is provided with a plurality of gas discharge ports 56 and is closed from the inside with aluminum tape (not shown) for moisture prevention. An annular gap is provided between the gas discharge port 56 and the outer peripheral surface of the coolant / filter 52.

  Next, the operation of the airbag apparatus including the airbag gas generator 10 will be described with reference to FIGS. 1, 2, and 3. 2 and 3, the module is not shown. In the following, a case will be described in which the first igniter 23 is operated first and the second igniter 33 is operated with a slight delay.

  When the automobile collides and receives an impact, the operation signal is received from the control unit, the first igniter 23 is activated and ignited, and the first enhancer agent 29 is ignited and burned. The flame and high-temperature gas generated by the combustion of the first enhancer agent 29 are ejected into the first combustion chamber 20 from the first transfer hole 28b, and the first gas generating agent 27 is ignited and burned to generate high-temperature gas.

  The high-temperature gas generated by the combustion of the first gas generating agent 27 flows into the filter chamber 50 from the first communication hole 53, but due to the action of the fire spread prevention member 55, the second communication hole 54 enters the second combustion chamber 30. And the second gas generating agent 37 is prevented from igniting and burning. The hot gas is filtered and cooled by the coolant / filter 52 and then discharged from the gas discharge port 56 to inflate the airbag 60 made of nylon 6, 66, 11, 12, 610 or the like.

  At this time, due to the tightening action of the tether 42 that has been wound around the airbag 60 in advance, as shown in FIG. 2, the airbag 60 expands in the lateral direction, and the expansion in the forward direction in which the occupant sits is suppressed. Further, by wrapping the tether 42 so that the airbag 60 is divided into approximately three equal parts (the airbag portions 61, 62, 63) when inflated, the effect of suppressing the expansion in the forward direction in which the occupant is sitting is further enhanced. .

  By inflating the airbag in the first stage in this way, it is possible to receive and protect the occupant over a wider area, and it is possible to prevent the occupant from being given excessive pressure due to the inflation of the airbag.

Subsequently, the second igniter 33 is activated and ignited, and the pressure in the space 43 is increased, whereby the piston 41 is pushed and collides with the detonator 40, the detonator 40 is ignited, and the second enhancer agent 39 is Ignite and burn. The flame and high-temperature gas generated by the combustion of the second enhancer agent 39 are ejected into the second combustion chamber 30 from the second transmission hole 38b, and the second gas generating agent 37 is ignited and burned to generate high-temperature gas.

  The high temperature gas generated by the combustion of the second gas generating agent 37 flows into the filter chamber 50 through the second communication hole 54, is filtered and cooled by the coolant / filter 52, is discharged from the gas discharge port 56, and is air The bag 60 is further inflated.

  At this time, as shown in FIG. 3, the tether 42 wound around the airbag 60 is cut by the inflation pressure of the airbag 60 in the second stage, so that the airbag 60 is mainly in front of the occupant sitting. Inflated.

  When only the first igniter 23 is operated due to the collision state of the vehicle, the expanded state of FIG. 2 is obtained, and when both the first igniter 23 and the second igniter 33 are simultaneously operated, the expanded state of FIG. In all cases, the passengers are well protected.

The longitudinal cross-sectional view of the gas generator for airbags. Description of the operation of the airbag device using the gas generator for the airbag. Description of the operation of the airbag device using the gas generator for the airbag.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas generator for airbags 20 1st combustion chamber 21 1st combustion chamber housing 23 1st igniter 27 1st gas generating agent 30 2nd combustion chamber 31 2nd combustion chamber housing 33 2nd igniter 37 2nd gas generation Agent 41 Piston 42 Tether 50 Filter chamber 52 Coolant filter 56 Gas outlet 60 Air bag

Claims (3)

A housing having a gas discharge port; a first combustion chamber and a second combustion chamber which are provided in the housing and filled with a gas generating agent; and a first ignition means and a second ignition chamber arranged for each of the two combustion chambers. An air bag gas generator having ignition means;
The second ignition means includes an electric igniter, a piston, and an enhancer agent having a detonator arranged to face the tip of the piston,
The piston is positioned such that the front end portion faces the detonator in the housing, and the rear end portion protrudes to the outside of the housing;
Wherein a rear end portion of the piston tether is connected, the opposite end portions of said tether is wrapped airbag when it is housed in the airbag module, end be shall be fixed to the air bag module ,
When the first ignition means is actuated, the tether tightens the inflating airbag to control the inflation direction of the airbag so as to suppress the inflation in the forward direction in which an occupant is sitting and to expand laterally. It works like
When the electric igniter of the second ignition means is actuated, the piston is pushed and moves, collides with the detonator to ignite the detonator, ignites and burns the enhancer agent by ignition of the detonator, and further ignites and burns the enhancer agent In the process of igniting and burning the gas generating agent in the second combustion chamber and generating a high-temperature gas to inflate the airbag,
The tether connected to the rear end of the piston is pulled and cut by the movement of the piston , and the opposite end of the tether is cut by inflation of the airbag, so that the airbag sits forward a shall be expanded in the direction, a gas generator for an air bag.   The gas generator for an air bag according to claim 1, wherein the housing is cylindrical, a gas discharge port is provided in the vicinity of a central portion, and two combustion chambers are disposed on both ends. An air bag device in which the gas generator and the air bag according to claim 1 or 2 are accommodated in an air bag module ,
One end of the tether is connected to the rear end of the piston of the gas generator for the air bag, the other end is wound around the air bag accommodated in the air bag module, and the end is fixed to the module. An airbag device for a driver seat and a passenger seat.

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