GB2310482A

GB2310482A - Inflator

Info

Publication number: GB2310482A
Application number: GB9708516A
Authority: GB
Inventors: Osamu Fukawatase; Makoto Hamada
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 1995-12-08
Filing date: 1996-11-18
Publication date: 1997-08-27
Also published as: GB9708517D0; GB2310483A; GB9708516D0; GB2310483B

Abstract

An inflator eg. for a vehicle occupant restraint, comprising: a fixing member 134 which is provided to be removable from a bottom wall 14 of a gas or gas generating agent-accommodating portion which forms a housing of the inflator. Removal of the member 134 allows gas generating agent 28 to be removed from an inflator which has not been actuated. The member 134 may be removed by unscrewing it.

Description

INFLATOR AND DISCHARGING DEVICE BACKGROUND OF THE INVENTION Field of the Invention: The present invention relates to an inflator which is actuated to eject gas, and a discharging device for discharging gas ejecting means accommodated in the inflator outside the inflator.

Description of the Related Art: As a vehicle occupant protecting apparatus, for example, an air bag apparatus has come into wide use. An air bag apparatus of this type is provided with a sensor of a mechanical ignition type or an electrical ignition type, which detects a state of collision. When the sensor detects the state of collision, the inflator is actuated to eject gas and a bag body is thereby inflated.

The structure of an inflator of this type is described in Japanese Patent Application Laid-Open (JP-A) No. 5-213149. To be brief, as shown in Fig. 8, an inflator 200 includes an upper case 202 and a lower case 204 which are made of an aluminum alloy or the like. The upper case 202 and the lower case 204 are formed integrally with joining portions thereof being connected by welding.

A sensor 206 of the mechanical ignition type for detecting the state of collision is disposed in an axial portion of the inflator 200. A detonator 207 and a fire propagating agent 208 are disposed immediately above the sensor 206. The detonator 207 is ignited by being pierced by an unillustrated firing pin, and the fire propagating agent 208 is provided to propagate the flame from the detonator 207.

Further, a gas generating agent 210 is filled in around the sensor 206 and is provided to combust by the flame propagated by the fire propagating agent 208. When the gas generating agent 210 combusts, a large quantity of high-temperature gas is generated.

On the other hand, there has been demanded for reutilization of, for example, the upper case 202, the lower case 204, and the like in the above-described inflator 200. As an example of a method for reutilization, there exists a method in which, after an air bag apparatus mounted to a steering wheel is compressed together with a vehicle body, the compressed air bag apparatus is thrown into a shredder to be cut into shreds, and thereafter, a metal such as a reusable aluminum alloy is separated from other metals.

However, since the upper case 202 and the lower case 204 which form the outline of the above-described inflator 200 are formed of a relatively small and high-strength member, even if the inflator is thrown into the shredder, it is not almost damaged. For this reason, when the inflator 200 has not been actuated, the gas generating agent 210 is left untouched within the inflator 200, which, in turn, becomes a hindrance to an operation in a reutilization process including a melting process and the like.

SUMMARY OF THE INVENTION In view of the above-described circumstances, it is an object of the present invention to provide an inflator and a discharging device, in which reutilization of the inflator can be promoted by separating gas ejecting means such as a gas generating agent from the inflator.

The invention provides an inflator which is actuated to eject gas, comprising: a fixing member which is provided to be removable from a bottom wall of a gas or gas generating agent-accommodating portion which forms a housing of the inflator, and when the inflator is in an unactuated state, the fixing member causing gas or gas generating agent accommodated within the inflator to be discharged from the inflator.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal cross-sectional view showing an inflator of an air bag apparatus for a driver's seat according to a first embodiment of the present invention.

Fig. 2 is a longitudinal cross-sectional view showing an inflator of an air bag apparatus for a front passenger seat according to the first embodiment.

Fig. 3 is a longitudinal cross-sectional view showing an inflator of an air bag apparatus for a driver's seat according to a second embodiment of the present invention.

Fig. 4 is a longitudinal cross-sectional view showing an inflator of an air bag apparatus for a front passenger seat according to the second embodiment.

Fig. 5 is a longitudinal cross-sectional view showing an inflator of an air bag apparatus for a driver's seat according to a third embodiment of the present invention.

Fig. 6 is a longitudinal cross-sectional view showing a state in which an air bag apparatus for a driver's seat according to a fourth embodiment of the present invention is mounteito a steering wheel.

Fig. 7 is a longitudinal cross-sectional view showing an inflator of the air bag apparatus shown in Fig. 6.

Fig. 8 is a longitudinal cross-sectional view showing an inflator of a conventional air bag apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to Figs. 1 and 2, a description will be given of a first embodiment of the present invention.

Fig. 1 shows a longitudinal cross-sectional structure of an inflator 10 which is applied to an air bag apparatus for a drivers seat. As illustrated in this figure, the inflator 10 has an upper case 12 and a lower case 14 which are each formed in a substantially cylindrical shape with a bottom. The upper case 12 and the lower case 14 are each made of an aluminum alloy or the like.

The upper case 12 includes a bottom wall 12A, a sensor accommodating portion 12B, and a peripheral wall 12C. The sensor accommodating portion 12B is formed in a cylindrical shape to project from an axial portion of the bottom wall 12A toward the lower case 14, and the peripheral wall 12C is formed in the shape of a tube to project from an outer peripheral edge of the bottom wall 12A toward the lower case 14. The lower case 14 includes a bottom wall 14A and a peripheral wall 14B which is formed annularly to project from an outer peripheral edge of the bottom wall 14A toward the upper case 12. Further, a through hole 16 is formed in an axial portion of the bottom wall 14Aof the lower case 14 and the sensor accommodating portion 12B of the upper case 12 is fitted into the through hole 16. In this state, when the peripheral wall 12C of the upper case 12 and the peripheral wall 14B of the lower case 14 are welded together, the upper case 12 and the lower case 14 are formed integrally to form the outline of the inflator 10.

An annular retainer 18 having an L-shaped cross-sectional configuration is provided at an inner-peripheral corner portion in the above-described upper case 12. A filter 20, which removes crushed pieces produced after combustion of a gas generating agent 28 serving as a gas ejecting means (which will be described later), is provided in a space enclosed by the retainer 18 and the upper case 12. Meanwhile, the filter 20 is disposed to face a plurality of gas ejecting holes 22 formed on the peripheral wall 12C of the upper case 12. Further, a coolant 24 for cooling high-temperature gas generated by combustion of the gas generating agent 28 is disposed below the retainer 18, namely, disposed in such a manner as to be held between the retainer 18 and the lower case 14.

A plurality of gas generating agents 28 disposed in a laminated state and each having the shape of a ring plate is accommodated in a gas generating agent-accommodating chamber 26 which is annular and which is defined by the above-described retainer 18, the sensor accommodating portion 12B, and the lower case 14.

A fire propagating agent-accommodating chamber 30 is formed in a bottom portion of the sensor accommodating portion 12B of the upper case 12 and a fire propagating agent 32 is accommodated therein. The fire propagating agent-accommodating chamber 30 and the gas generating agent-accommodating chamber 26 communicate with each other via a communicating passage 34 which passes through a peripheral wall of the sensor accommodating portion 12B.

A retainer 36 is disposed on the side of the bottom portion of the sensor accommodating portion 12B of the upper case 12. A detonator 38 is accommodated in a bottom surface 36A of the retainer 36. Further, a substantially columnar sensor 40 is accommodated in an interior of the retainer 36. In this state, when a support ring 42 is mounted at an opening end portion of the sensor accommodating portion 12B, the sensor 40 is fixed to the sensor accommodating portion 12B.

As the above-described sensor 40, a sensor of a mechanical ignition type is used. Explaining briefly, provided within the sensor 40 are a ball which is accommodated in a cylinder, a trigger shaft, a bias pin, and a firing pin. The above-described ball inertially moves when a predetermined high load acts on a vehicle (i.e., at the time of a sudden deceleration of a vehicle). The trigger shaft is provided to swing due to the inertial movement of the ball, and the bias pin abuts against the trigger shaft by urging force to push the ball in a direction opposite to that of the inertial movement. The firing pin is engaged with the trigger shaft with the urging force applied thereto and moves away from the trigger shaft due to swinging of the trigger shaft to pierce the detonator.

Meanwhile,. in this embodiment, the sensor 40 of a mechanical ignition type is used, but a sensor of an electrical ignition type may also be used. Further, a tablet-shaped gas generating agent may be used in place of the gas generating agent 28 having the shape of a ring plate.

Notches 44 are respectively formed at predetermined positions on the bottom wall 12A of the upper case 12 and on the lower wall 14A of the lower case 14 (i.e., the positions immediately above and immediately below the gas generating agent-accommodating chamber 26). The depth of each notch 44 is set so as not to be broken by a load (gas pressure) acting during actuation of the inflator 10, and in this embodiment, the depth is set at a value which is half or less the plate thickness of the upper case 12 and the lower case 14. By forming these notches 44, the rigidity of each of the portions of the bottom wall 12A of the upper case 12 and the bottom wall 14A of the lower case 14, where the notches are formed, is decreased so that the upper case 12 and the lower case 14 are made weak.

Next, an operation and an effect of this embodiment will be described.

When the predetermined high load acts on the vehicle, i.e., at the time of a sudden deceleration of the vehicle, the ball within the sensor 40 inertially moves against the urging force for pressing and urging the bias pin. For this reason, the trigger shaft swings and the firing pin is separated from the trigger shaft. Accordingly, the firing pin moves due to the urging force and pierces the detonator 38. As a result, the generated flame causes the gas generating agents 28 to combust via the fire propagating agent 32, and a large quantity of high-temperature gas is generated. After the generated gas is cooled by the coolant 24 and crushed pieces are removed by the filter 20, the gas is ejected from the gas ejecting holes 22 and flows into a bag body of an unillustrated air bag apparatus. As a result, a pad of the air bag apparatus expands and the bag body is thereby inflated toward an occupant seated in a driver's seat.

Here, when a vehicle body is scrapped in a state in which the air bag apparatus is mounted to the steering wheel without being actuated, the air bag apparatus is compressed together with the vehicle body, and thereafter, is thrown into a shredder to be crushed. At this time, the upper case 12 and the lower case 14 of the inflator 10 are subjected to crushing load and are thereby broken off at the weakened portions where the notches 44 are formed. Since the notches 44 are respectively formed immediately above and immediately below the gas generating agentaccommodating chamber 26, when the upper case 12 and the lower case 14 are respectively broken off at the portions where the notches 44 are formed, the gas generating agent-accommodating chamber 26 communicates with the outside of the inflator 10. Accordingly, a considerable amount or all the amount of the gas generating agents 28 accommodated in the gas generating agent-accommodating chamber 26 is discharged from the inflator 10. Namely, the gas generating agents 28 are separated from the inflator 10.

The inflator 10, which has been crushed into pieces with the gas generating agents 28 being separated therefrom in the above-described manner , is sorted out together with other reusable metals and is transferred to the reutilization process.

As described above, in this embodiment, the upper case 12 and the lower case 14 of the inflator 10 are made weak by forming the notches 44 at the respective predetermined locations of the upper case 12 and the lower case 14. For this reason, prior to the reutilization process, the gas generating agents 28 can be separated from the inflator 10. As a result, the reutilization of the inflator 10 can be promoted.

Further, the structure provided in this embodiment is such that the upper case 12 and the lower case 14 of the inflator 10 are made weak by forming the notches 44 at the predetermined locations thereof.

Accordingly, it is not necessary to use any additional parts, which makes it possible to achieve reduction in cost.

Meanwhile, in this embodiment, the present invention is applied to the inflator 10 of the air bag apparatus for a driver's seat, but is not limited to the same. The present invention may also be applied to an inflator of an air bag apparatus for a front passenger seat and an example thereof is described below.

Fig. 2 shows a longitudinal cross-sectional structure of an inflator 46 of an air bag apparatus for a front passenger seat. Note that this inflator 46 is of a high-pressure gas filling type. The inflator 46 has a cylindershaped pressure container 50. A tube-shaped housing 54 in which a plurality of gas ejecting holes 52 are formed is fixed by welding to one end portion of the pressure container 50. An opening end portion of the housing 54 is closed by a pressure partition wall 56. Further, a tubeshaped housing 58 is fixed by welding at an inner side of the housing 54.

As a result, a gas outlet 59 is formed between the housing 54 and the housing 58. A substantially columnar holding body 60 is held on the side of the bottom portion of the housing 58 and a gas heating agent (namely, detonator) 62 is provided at the intermediate portion of the housing 58. A squib 64 is provided in an axial portion of the holding body 60 and an igniting agent 66 is provided between the squib 64 and the gas heating agent 62. Moreover, a piercing member 68 moving due to the force of ignition of the gas heating agent 62 is provided at an end portion of the housing 58.

Further, a hemispherical closing member 70 is fixed by welding to another end portion of the pressure container 50. An internal space 72 of the pressure container 50 formed between the closing member 70 and the housing 54 is sealingly filled with a mixed gas of argon and helium in a pressurized state.

Here, a notch 80 formed in a manner similar to the abovedescribed notch 44 is formed at a predetermined position of the abovedescribed pressure container 50 (specifically, a position corresponding to a longitudinal-direction intermediate portion or thereabouts of the internal space 72). The rigidity of the position of the pressure container 50 where the notch is formed is decreased by forming the notch 80 therein so that the container 50 is made weak.

With the above-described structure, when the predetermined high load acts on the vehicle (i.e., at the time of a sudden deceleration of the vehicle), a predetermined electric current flows in the squib 64 and the gas heating agent 62 is heated via the igniting agent 66. For this reason, the gas heating agent 62 is ignited and the force of ignition causes air within the housing 54 to be pressurized. Accordingly, the pressurized air acts on the piercing member 68 and the piercing member 68 moves to the position indicated by the two-dot chain line in Fig. 2. As a result, the pressure partition wall 56 is broken and the mixed gas within the internal space 72 is ejected from the gas ejecting holes 52 via the gas outlet 59.

Here, when the vehicle body is scrapped in a state in which the air bag apparatus is mounted to an instrument panel without being actuated, the air bag apparatus is compressed together with the vehicle body, and thereafter is thrown in the shredder to be crushed. At this time, the pressure container 50 of the inflator 46 is subjected to crushing load and the pressure container 50 is broken off at the weakened portion in which the notch 80 is formed. Since the notch 80 is formed at the longitudinaldirection intermediate portion or thereabouts of the internal space 72 in which the mixed gas of argon and helium is sealingly filled in a pressurized state, when the pressure container 50 is broken off at a position where the notch 80 is formed, the internal space 72 is provided to communicate with the outside of the inflator 46. Accordingly, all the amount of high-pressure gas accommodated within the internal space 72 is discharged from the inflator 46. Namely, the high-pressure gas is separated from the inflator 46.

Meanwhile, the inflator 46, which has been crushed with the high-pressure gas being separated from in the above-described manner is sorted out together with other reusable metals, and then is transferred to the reutilization process.

As described above, this embodiment is constructed in that the notch 80 is formed at the predetermined position of the pressure container 50 of the inflator 46 and the pressure container 50 is thereby made weak.

For this reason, it is possible to separate the high-pressure gas from the inflator 46 prior to the reutilization process. As a result, the reutilization of the inflator 46 can be promoted.

Meanwhile, in the above-described embodiment, the present invention is applied to the inflator 10 of the air bag apparatus for a driver's seat and the inflator 46 of the air bag apparatus for a front passenger seat.

However, the present invention is not limited to the same, and can also be applied to an air bag apparatus for countering a side impact In addition, if the shape and the like of the inflator are altered, the present invention can also be applied to a pretensioner for quickly retracting a buckle device during a collision or quickly rotating a winding shaft of a webbing retractor in the direction of the webbing being wound. Meanwhile, these applications of the present invention could be similarly obtained in the second and subsequent embodiments.

Next, the second embodiment of the present invention will be described with reference to Figs. 3 and 4. It should be noted that the same members as those of the first embodiment will be denoted by the same reference numerals, and a description thereof will be omitted.

Fig. 3 shows a longitudinal cross-sectional structure of an inflator 100 applied to an air bag apparatus for a driver's seat. As illustrated in this figure, in this embodiment, in place of the above-described notches 44, stepped portions 102, 104 are respectively formed in the bottom wall 12A of the upper case 12 and in the bottom wall 14A of the lower case 14 at respective outer peripheries of these cases. Meanwhile, each depth of the stepped portions 102, 104 is set such that the upper case 12 and the lower case 14 are not broken by load acting during actuation of the inflator 100 (i.e., gas pressure), and in this embodiment, each depth of these stepped portions is set at a value which is half or less the plate thickness of the upper case 12 and the lower case 14. By forming the stepped portions 102, 104, the rigidity of each of the bottom walls 12A, 14A where the stepped portions are formed is decreased and the upper case 12 and the lower case 14 are thereby made weak.

According to the above-described structure, when the vehicle body is scrapped in the state in which the air bag apparatus is mounted to a steering wheel, after the air bag apparatus has been compressed together with the vehicle body, the compressed air bag apparatus is thrown into the shredder to be crushed. In this case, the upper case 12 and the lower case 14 of the inflator 100 are subjected to crushing load and are thereby broken off at the respective weakened portions where the stepped portions 102, 104 are formed. Since the stepped portions 102, 104 are respectively disposed immediately above and immediately below the gas generating agent-accommodating chamber 26, when the upper case 12 and the lower case 14 are broken off at the positions where the stepped portions 102, 104 are formed, the gas generating agent-accommodating chamber 26 communicates with the outside of the inflator 100. Accordingly, a considerable amount or all the amount of the gas generating agents 28 accommodated in the gas generating agent-accommodating chamber 26 is discharged from the inflator 100. Namely, the gas generating agents 28 are separated from the inflator 100.

As described above, this embodiment is constructed in that the stepped portions 102, 104 are respectively formed at the predetermined positions on the upper case 12 and the lower case 14 of the inflator 100 so that these cases are made weak. For this reason, prior to the reutilization process, the gas generating agents 28 can be separated from the inflator 100. As a result, the reutilization of the inflator 100 can be promoted.

Further, since this embodiment is constructed in that the stepped portions 102, 104 are formed at the predetermined positions on the upper case 12 and the lower case 14 of the inflator 100 so that these cases are made weak, in the same way as in the first embodiment, reduction in cost can be achieved without using any additional parts.

Meanwhile, in this embodiment, the present invention is applied to the inflator 100 of the air bag apparatus for a driver's seat, but is not limited to the same. The present invention can also be applied to an inflator of an air bag apparatus for a front passenger seat and an example thereof is described below.

Fig. 4 shows a longitudinal cross-sectional structure of an inflator 106 of a gas generating agent-type which is used in an air bag apparatus for a front passenger seat. As illustrated in this figure, the inflator 106 has a cylinder-shaped inflator case 108 having a bottom. A plug body 112 in which a squib 110 is provided in an axial portion thereof is fitted into an opening end portion of the inflator case 108. Further, a cylinder-shaped filter 114 is provided in an inner side of the inflator case 108 and an interior of the filter 114 is sealingly filled with a plurality of ring plate-shaped gas generating agents 116, which are arranged in series, for generating nitrogen gas. A plurality of gas ejecting holes 118 are formed on the peripheral wall of the above-described inflator 108. A stepped portion 120 is formed in the peripheral wall of the inflator case 108 at the axial direction intermediate portion. For this reason, the thickness of the peripheral wall of the inflator case 108 from its axial-direction intermediate portion to its bottom portion is made smaller than that of the peripheral wall of the inflator case 108 from its opening end portion to its axialdirection intermediate portion. Accordingly, the rigidity of the portion of the inflator case 108 where the stepped portion is formed is decreased and the inflator case 108 is thereby made weak.

According to the above-described structure, when the vehicle body is scrapped in a state in which the air bag apparatus is mounted to the instrument panel without being actuated, after the air bag apparatus has been compressed together with the vehicle body, the compressed air bag apparatus is thrown into the shredder to crushed. In this case, the inflator case 108 of the inflator 106 is subjected to crushing load and is broken off at the weakened portion where the stepped portion 120 is formed. For this reason, a considerable amount or all the amount of the gas generating agent 116 is discharged from the inflator 106. Namely, the gas generating agents 116 are separated from the inflator 106.

As described above, since this embodiment is constructed in that the inflator case 108 of the inflator 106 is made weak by the stepped portion being formed at the predetermined position thereon, it is possible to separate the gas generating agents 116 from the inflator 106 prior to the reutilization process. As b result, the reutilization process of the inflator 106 can be promoted.

Next, a third embodiment of the present invention will be described with reference to Fig. 5. It should be noted that the same members as those of the first embodiment will be denoted by the same reference numerals, and a description thereof will be omitted.

Fig. 5 shows a longitudinal cross-sectional structure of an inflator 130 applied to an air bag apparatus for a driver's seat. As illustrated in this figure, in this embodiment, a through hole 132 in which a female screw is formed in an inner peripheral surface thereof is provided in the bottom wall 14A of the lower case 14 of the inflator 130 in the vicinity of the axial portion thereof. A ring plate-shaped fixing ring 134 serving as a fixing member, in which a male screw is formed on an outer peripheral surface thereof, is engaged with the female screw of the through hole 132. A plurality of rectangle-shaped projections 136 are integrally formed on a lower surface of the fixing ring 134 at, for example, positions which divides the fixing ring 134 into four equal portions in the circumferential direction thereof.

In addition, annular grooves 138, 140 facing each other are formed above the position with the female screw of the through hole 132 is formed, on the inner peripheral surface of the through hole 132 and on the outer peripheral surface of the sensor accommodating portion 12B of the upper case 12, respectively. A cover 142 serving as a fixing member, which is formed into a thin-walled ring plate of resin or the like, is fitted into these grooves 138, 140. Meanwhile, the cover 142 is mounted in the grooves 138, 140 in a state of being elastically deformed.

According to the above-described structure, first, a pad to which the air bag apparatus is mounted is removed from the steering wheel. Next, with operator's fingers being put at the projections 136 of the fixing ring 134, the fixing ring 134 is rotated to be removed from the lower case 14.

Meanwhile, an operation of removing the fixing ring 134 may be effected after the inflator 130 has been removed from a main body of the air bag apparatus or in a state in which the inflator 130 is mounted to the main body of the air bag apparatus.

When the fixing ring 134 is removed from the lower case 14, the cover 142 is uncovered and is then removed from the grooves 138, 140 in a state of being elastically deformed. As a result, the gas generating agents 28 can be pulled out and separated from the inflator 130. Meanwhile, the cover 142 may not be provided in this embodiment.

As described above, since this embodiment is constructed in that the fixing ring 134 which is removable in a screwing manner is provided in the bottom wall 14A of the lower case 14 of the inflator 130, the gas generating agents 28 can be separated from the inflator 130 prior to the reutilization process. As a result, the reutilization of the inflator 130 can be promoted.

Next, a fourth embodiment of the present invention will be described with reference to Figs. 6 and 7. It should be noted that the same members as those of the first and third embodiments will be denoted by the same reference numerals, and a description thereof will be omitted.

Fig. 6 shows a longitudinal cross-sectional structure of an air bag apparatus 150 for a driver's seat and Fig. 7 shows a longitudinal crosssectional structure of an inflator 152 provided in the air bag apparatus 150. As illustrated in these figures, a through hole 154 whose inner peripheral surface is made flat is formed in the bottom wall 14A of the lower case 14 of the inflator 152 in the vicinity of the axial portion thereof. The above-described grooves 138, 140 are respectively formed on the inner peripheral surface of the through hole 154 and on the outer peripheral surface of the sensor accommodating portion 12B of the upper case 12.

The cover 142 formed into a thin-walled ring plate is fitted into these grooves 138, 140. Meanwhile, the cover 142 is mounted in the grooves 138, 140 in a state of being elastically deformed.

A discharging device 158 is provided at a hub 156A of a steering wheel 156 to which the air bag apparatus 150 is mounted. The discharging device 158 is formed by a supporting body 160 having a substantially drum-shaped configuration, and a ring plate-shaped closing ring 162 serving as a closing member, which is fixed to an upper flange portion 160A of the supporting body 160. A lower flange portion 160B of the supporting body 160 is fixed to the hub 156A by screws 164. Meanwhile, the air bag apparatus 150 is not of a center-phone type in which a phone is actuated with a pad 166 being entirely moved toward the hub 156A, and is of a switch-phone type in which the phone is actuated base plate 170 and the pad 166. A ring plate 176 is disposed at an inner peripheral edge of.an opening portion of the bag body 174 and the opening portion of the bag body 174 is nipped between the ring plate 176 and the base plate 170 with the ring plate 176 being fixed to the base plate 170.

The Hator 152 is fixed to the central portion in the vicinity of the axial portion of the base plate 170 with the upper case 12 disposed to pass through the opening portion of the bag body 174.

With above-described structure, when the pad 166 to which the air bag apparatus 150 is mounted is fixed to the hub 156A of the steering wheel 156, there is no possibility that the gas generating agents 28 are inadvertently discharged from the inflator 152 by the reason that the cover 142 is fitted in the grooves 138, 140. Meanwhile, by the pad 166 being fixed to the hub 156A, the closing ring 162 of the discharging device 158 is fitted in the through hole 154 of the lower case 14. In the state in which the closing ring 162 is fitted in the through hole 154, even if the air bag apparatus 150 is actuated when the predetermined high load acts on the vehicle body, the gas pressure is transmitted to the hub 156A via the closing ring 162 and the supporting body 160. For this reason, any trouble is not caused at the time of actuation of the air bag apparatus 150.

On the other hand, at the time of scrapping, first, the pad 166 to which the air bag apparatus 150 is mounted is removed from the steering wheel 156. At this time, since the through hole 154 of the lower case 14 of the inflator 152 is merely closed by the closing ring 162 of the discharging device 158, the through hole 154 is opened synchronously with removal of the pad 166. As a result, the gas generating agents 28 can be discharged from the inflator 152. Accordingly, as described above, the gas generating agents 28 are separated from the inflator 152 in such a manner that the cover 142 is removed from the grooves 138, 140 by being elastically deformed and the gas generating agents 28 are pulled out.

Meanwhile, in this embodiment, the cover 142 is provided so as to solve a troublesome matter in which an operator carefully operates so that the gas generating agents 28 are not discharged at the time of mounting the pad 166 to the steering wheel 156. However, so long as the gas generating agents 28 may be held by a different structure having no cover 142, the gas generating agents 28 can be discharged synchronously with the removal of the pad 166.

As described above, the structure provided in this embodiment is such that the discharging device 158 is provided at the hub 156A of the steering wheel 156 and the gas generating agents 28 can be discharged by removal of the pad 166. For this reason, the gas generating agent 28 can be separated from the inflator 152 prior to the reutilization process. As a result, the reutilization of the inflator 152 can be promoted.

Moreover, this embodiment allows the gas generating agents 28 to be discharged from the inflator 152 due to the removal operation of the pad 166 from the steering wheel 156 (as described above, when the cover 142 is not provided, the gas generating agents 28 are automatically discharged from the inflator 152) and an improvement in convenience can be made accordingly.

Claims

1. An inflator which is actuated to eject gas, comprising: a fixing member which is provided to be removable from a bottom wall of a gas or gas generating agent-accommodating portion which forms a housing of the inflator, and when the inflator is in an unactuated state, the fixing member causing gas or gas generating agent accommodated within the inflator to be discharged from the inflator.

2. An inflator according to Claim 1, wherein said fixing member includes a plate-shaped member which is mounted by being screwed to the housing.

3. An inflator according to Claim 2, wherein said fixing member includes a cover provided between the gas or gas generating agent accommodated within the inflator and said plate-shaped member.

4. An inflator substantially as hereinbefore described with reference to Fig. 5 of the accompanying drawings.