JPH0533821U - Filter for inflator of air bag device - Google Patents

Abstract

(57) [Summary] [Object] To easily form a filter for an inflator of an airbag device in a state having a gas passage hole of a desired size. [Structure] The filter 170 is a punching metal 172.
Are superposed on each other. Punching metal 1
72, a plurality of gas passage holes 174 are formed by punching, and the gas passage holes 174 of each punching metal 172 communicate with each other to form a gas passage. In the filter 170, the gas passage hole 174 having a desired size can be easily formed by punching without forming the gas passage hole by knitting.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a filter for an inflator of an airbag device.

[0002]

[Prior Art]

 The airbag system is equipped with an inflator that supplies the gas generated by burning the gas generating substance to the airbag bag when the vehicle rapidly decelerates, and the filter is placed between the gas generating substance and the airbag bag. Are arranged. In the inflator, this filter removes the burned dust contained in the gas and supplies it to the airbag bag.

By the way, in the airbag device, the inflation speed of the airbag bag and the amount of inflation to the occupant depend on the vehicle type because the distance between the airbag device and the occupant varies depending on the vehicle type and the mounting position. Must be set. Since the outflow rate and the outflow rate of the gas are changed according to this, it is necessary to prepare various filters having different gas passage hole sizes. Conventionally, the filter is in the form of a woven mesh, and the size of the gas passage hole is changed by changing the size of the stitches and weaving.

[0004]

[Problems to be solved by the device]

 However, in the conventional filter, since the size of the gas passage hole is changed by changing the size of the stitches and knitting, it is not easy to form the filter having the gas passage hole of a desired size. Further, when the filter is cut into a desired size, there is a problem that the cut portion is frayed.

In view of the above facts, the present invention has an object to easily form an inflator filter of an airbag device in a state having a gas passage hole of a desired size.

[0006]

[Means for Solving the Problems]

 A filter for an inflator of an airbag device according to the invention of claim 1 is a filter which is interposed between a gas generating substance of the inflator and a bag body of the airbag device and through which gas generated by combustion of the gas generating substance passes. A plate-shaped member formed with a plurality of parallel cuts and expanding the cuts in the plate thickness pressure direction and having a plurality of gas passage holes through which the gas passes, The feature is that it is constructed by stacking multiple gas flow directions.

In the filter for an inflator of an airbag device according to a second aspect of the present invention, a gas generated by combustion of the gas generating substance is interposed between a gas generating substance of the inflator and a bag body of the airbag device. A first plate-shaped member that is a filter that passes through and has a plurality of gas passage holes that are formed by punching and serve as gas passages, and a protrusion formed between the plurality of gas passage holes; By means of which a plurality of gas passage holes serving as gas passages are formed, and the protrusions are formed in the passage direction of the gas in a state where the gas passage holes are in communication with the gas passage holes of the first plate member. And a second plate-shaped member that is overlapped with the first plate-shaped member via the first plate-shaped member.

[0008]

[Action]

 According to the invention of claim 1, when forming a filter having a gas passage hole of a desired size, a plurality of cuts of a predetermined size are formed in the plate-shaped member, and the cuts are pushed and spread. A gas passage hole having a desired size is formed. A plurality of plate members are stacked in the gas passage direction to form a filter. Therefore, according to the present invention, according to the present invention, it is possible to adjust the cut amount and the spread amount without forming the gas passage hole of a desired size by changing the size of the stitches when weaving. Therefore, the inflator filter of the airbag device can be easily formed to have a gas passage hole of a desired size.

According to the second aspect of the invention, when forming the filter having the gas passage holes of a desired size, the gas passage holes of a desired size are formed in the first plate member by punching. Form a protrusion. Further, a gas passage hole having a desired size is formed in the second plate member by punching. Then, the second plate-shaped member is overlapped with the first plate-shaped member via the protrusion in the gas passage direction in a state of being communicated with the gas passage hole of the first plate-shaped member. Configure a filter.

[0010]

【Example】

 An inflator for an airbag device to which a filter according to an embodiment of the present invention is applied will be described below with reference to FIGS.

An airbag device 10 is shown in FIG. The arrow FR direction in the drawing indicates the front direction of the vehicle.

In the airbag device 10, the base plate 12 is supported substantially parallel to the hub 14 A of the steering wheel 14. An air bag body 16, an air bag cover 18, and an inflator 20 are attached to the base plate 12.

The airbag bag body 16 is arranged in a folded state on the occupant side (upper side in FIG. 4) of the base plate 12. The edge of the airbag bag body 16 on the opening side is attached to a substantially central portion of the base plate 12 via a ring plate 22. The ring plate 22 is fastened to the base plate 12 with a bolt (not shown), and the edge of the airbag bag body 16 on the opening side is pressed against the base plate 12.

The airbag cover 18 is arranged on the occupant side of the base plate 12 and stores the airbag bag body 16 between the airbag cover 18 and the base plate 12. A frame-shaped core metal (not shown) is embedded in the airbag cover 18 and is attached to the base plate 12 by a rivet or the like via the core metal. A thin portion 24 is formed at a portion of the airbag cover 18 facing the base plate 12, and is easily broken at this portion.

As shown in FIG. 1, accommodation chambers 50 to 56 are formed in the inflator 20. The accommodation chamber 50 accommodates a starter 32 and an ignition member unit 35, which will be described later, and the accommodation chamber 52 accommodates the gas generating substance 30. Further, the accommodation chamber 54 accommodates a coolant 36 for cooling the gas generated by the combustion of the gas generating substance 30, and the accommodation chamber 56 accommodates a filter 37 for removing burnt residue contained in the gas. Is housed.

The configuration of the main body of the inflator 20 will be described below. The main body of the inflator 20 is formed by joining press-molded stainless steel cylinders 58, 70, 84, 96, 112, respectively.

As shown in FIG. 1, the tubular body 58 has a bottom portion 60, and a flange 62 extends radially outward from the opening end portion. In the bottom portion 60, a central portion is bent toward the opening portion to form a circular concave portion 64 in a plan view. The outer wall surface 65A of the side wall forming the recess 64 and the inner wall surface 65B that is the back surface thereof are tapered surfaces that gradually become smaller in diameter in the axial direction of the main body of the inflator 20 (direction of arrow A in FIG. 1). .. The inner wall surface 65B is a welding surface with the tubular body 70. A part of the bottom of the recess 64 is bent to the side opposite to the opening of the tubular body 58, and is a circular groove 66 in a plan view. The wall portion forming the groove portion 66 has a substantially U-shaped cross section obtained by cutting the cylindrical body 58 along the axial direction. Further, a plurality of gas holes 63, which serve as gas passages, are formed in the side wall 58A of the cylindrical body 58 along the circumferential direction.

Inside the tubular body 58, a tubular body 70 having a bottom portion 72 is arranged. In this cylindrical body 70, a substantially central portion of a bottom portion 72 is bent toward the opening portion to form a circular recess 73. An inner wall surface 73A of the recess 73 viewed from the direction of the arrow A is a tapered surface whose diameter gradually decreases along the axial direction A of the main body of the inflator 20. Further, a circular groove portion 74 is formed in a plan view in a substantially central portion of the bottom of the recess 73, and the wall portion forming the groove portion 74 is a cross section obtained by cutting the tubular body 70 along the axial direction A. The shape is almost U-shaped. Further, as shown in FIG. 2, a plurality of locking pieces 78 are formed on the tubular body 70. The locking piece 78 includes a claw portion 82 formed by bending a tip of a base portion extending from the opening portion of the tubular body 70 in the axial direction at a substantially right angle in one circumferential direction of the tubular body 70. There is. Specifically, the claw portion 82 is formed by engraving the slit 78A on the locking piece 78. The locking piece 78 corresponds to the long hole 86 formed in the tubular body 84.

As shown in FIG. 1, the bottom portion 72 of the tubular body 70 is in contact with the bottom portion 60 of the tubular body 58, and the recess 64 and the groove portion 66 are in close contact with the recess portion 73 and the groove portion 74, respectively. Are joined by laser welding, whereby the tubular body 70 is fixed to the tubular body 58. The laser welding in this case is performed by irradiating the laser beam LB1 so as to be orthogonal to the outer wall surface 65A of the cylindrical body 58 to melt and solidify the contact portion.

A tubular body 84 is locked to the tubular body 70. As shown in FIG. 2, the tubular body 84 has a bottom portion 88, and a flange 90 extends radially outward from the opening end portion. The flange 90 is formed with a gas hole 92 through which gas passes. Furthermore, a circular insertion hole 94 into which the cylindrical body 96 is inserted is formed in the bottom portion 88 in a substantially central portion thereof, and an elongated hole into which the locking piece 78 is inserted is formed in the outer periphery of the bottom portion 88. 86 is formed. The elongated hole 86 has a substantially arc shape, and a plurality of elongated holes 86 are formed along the circumferential direction of the bottom portion 88. When the locking piece 78 is inserted into the elongated hole 86 and then rotated, the claw portion 82 is engaged with the end portion of the elongated hole 86, that is, the peripheral edge of the elongated hole 86 enters the slit 78A, and the cylinder The body 84 is locked to the tubular body 70. As shown in FIG. 1, in this locked state, the outer peripheral surface 90A of the flange 90 is welded by laser welding to the vicinity of the opening on the inner surface of the side wall 58A of the tubular body 58, and the tubular body 58 and the tubular body 70 are joined together. A donut-shaped space, that is, a storage chamber 56 is formed therebetween.

The cylindrical body 96 inserted into the insertion hole 94 has a bottom portion 98, and has an axial length longer than that of the cylindrical bodies 58 and 70, and serves as a storage chamber 50 inside. The cylindrical body 96 has a flange 106 extending radially outward from the opening. A circular protrusion 100 is formed on the outer periphery of the bottom 98 in a plan view. The protrusion 100 has a substantially U-shaped cross section obtained by cutting the cylindrical body 96 along the axial direction of the main body of the inflator 20, and is in close contact with the groove 74. A plurality of through holes 104 are formed on the side wall 96A of the cylindrical body 96 on the bottom 98 side. A part of the flange 106 is bent toward the bottom 98, and is a circular groove 108 in a plan view. The wall portion forming the groove portion 108 has a substantially U-shaped cross-sectional shape obtained by cutting the tubular body 96 along the axial direction of the main body of the inflator 20. The protrusion 100 is joined to the inner surface 76A of the groove 74 of the cylindrical body 70 by laser welding. The laser welding in this case is performed by irradiating the projection 100 with the laser beam LB2 from the inside of the cylindrical body 96, whereby the boundary between the inner wall surface 76A and the projection 100 is melted and solidified. The boundary is joined by making it.

The cylindrical body 112 has a bottom 114, and a circular hole 116 is formed in a substantially central portion of the bottom 114. On the outside of the circular hole 116 of the bottom portion 114, a part is bent from the bottom portion 114 side toward the opening side to form a protrusion 118. The protrusion 118 has a substantially U-shaped cross section obtained by cutting the tubular body 112 along the axial direction of the main body of the inflator 20.

The protrusion 118 is in contact with the inner wall of the groove 108, and this contact portion is welded by laser welding. The laser welding in this case is performed by irradiating the side wall forming the protrusion 118 of the cylindrical body 112 with the laser beam LB3, whereby the boundary between the inner wall of the groove 108 and the protrusion 118 is melted and solidified. Are joined together. Further, the end of the side wall 112A of the tubular body 112 on the side of the opening is brought into contact with the end of the inner wall of the side wall 58A of the body 58 on the side of the opening, and this abutting portion is joined by laser welding. The side wall 112A is inclined at a predetermined angle θ with respect to the surface 67 orthogonal to the flange 62, whereby the distance between the side wall 112A and the flange 62 is widened, and the side wall 112A and the side wall 58A move toward each other. The laser beam is easy to irradiate. That is, the laser welding is performed by inserting a laser beam emitting portion (not shown) into the space between the flange 62 and the side wall 112A of the cylindrical body 112 and irradiating the laser beam LB4, whereby the end of the side wall 112A and the side wall 112A are irradiated. The contact portion of the 58A with the end portion is melted and solidified to join the cylindrical body 112 and the cylindrical body 58. The tubular body 112 forms the accommodation chamber 54 between the tubular body 84 and the tubular body 84. The accommodation chamber 54 is partitioned from the cylindrical body 50 by a side wall 96A on the inner side, and communicates with the accommodation chamber 52 through the insertion hole 94 and with the accommodation chamber 56 through the circular hole 92.

The main body of the inflator 20 is configured as described above. As shown in FIG. 5, the ignition member housing unit 35 housed in the housing chamber 50 of the main body of the inflator 20 is composed of a housing case 122, an enhancer 124, and a detonator 45. The housing case 122 has a cylindrical shape with a bottom 126, and houses the enhancer 124 and the detonator 45 therein. Two detonators 45 are provided in the housing case 122, and an enhancer 124 is provided on the outer circumference of these detonators 45. Through holes 128 are formed in the bottom portion 126 at positions corresponding to the respective detonators 45. Around this through hole 128 is a step portion 128A, which accommodates the flange portion 45A of the detonator 45. Further, the bottom portion 126 is provided with a pair of positioning concave portions 130, and these positioning concave portions 130 are respectively formed at positions symmetrical to the central portion of the bottom portion 126 with respect to the central portion. As shown in FIG. 1, the positioning projections 33 of the starter 32 are fitted in these positioning recesses 130, whereby the tip of the ignition pin 43 corresponds to the through hole 128, and the ignition pin 43 collides with the detonator 45. It is located where possible.

Further, a plurality of through holes 134 are formed in the side wall of the housing case 122 along the circumferential direction so that sparks can pass through the respective through holes 134 when the enhancer 124 is ignited. Is becoming The through hole 134 communicates with the through hole 104 of the cylindrical body 96.

As shown in FIG. 3, the starting device 32 housed in the housing chamber 50 together with the ignition part member unit 35 is provided with a ball 42 that inertially moves when the vehicle suddenly decelerates. The ball 42 is housed in the cylinder 40, and one end of the drive shaft 44 is in contact therewith. A trigger portion 46 is formed at an intermediate portion of the drive shaft 44, and engages with the ignition pin 43 to hold it. During sudden deceleration of the vehicle, the ball 42 inertially moves to rotate the drive shaft 44, which unlocks the ignition pin by the trigger portion 46, moves the ignition pin 43, and collides with the detonator 45. It is like this.

The filter 37 is formed by stacking a plurality of expanded metals 150 shown in FIG. The expanded metal 150 has a plurality of gas passage holes 152 formed in a staggered arrangement. The gas passage hole 152 is formed by the cutter 158 shown in FIG.

The cutter 158 has an upper blade 154 and a lower blade 156. The upper blade 154 has a blade tip 154A formed at a predetermined pitch LW and has a saw-toothed tip. The lower blade 156 is arranged such that its longitudinal direction is parallel to the longitudinal direction of the upper blade 154 and is slightly offset in the direction orthogonal to the surface on which the cutting edge 154A of the upper blade 154 is formed.

When forming the gas passage hole 152, the metal plate 160 is arranged between the upper blade 154 and the lower blade 156, and the upper blade 154 is moved downward toward the lower blade 156 to move the upper blade 15 4 and the lower blade 156 form a cut in the metal plate 160, and the upper blade 154 is moved further downward to widen the cut portion. As a result, the corrugated portions 162 in which the concave portions are alternately formed at the pitch LW corresponding to the cutting edge 154A are formed on the metal plate 160. Next, the upper blade 154 is moved upward and further moved by 1/2 LW (1/2 of the pitch of the cutting edge 154A) in the longitudinal direction. Further, the metal plate 160 is horizontally conveyed by a predetermined amount in the direction of the upper blade 154, the upper blade 154 is moved downward, a cut is formed in the metal plate 160, and the upper blade 154 is moved further downward to cut the cut portion. Spread out. As a result, the concave portions are alternately formed at the pitch LW corresponding to the cutting edge 154A, and the corrugated portion 164 is formed in a state of being displaced from the corrugated portion 162 in the longitudinal direction by 1/2 LW. By repeating the above operation, the expanded metal 150 having the gas passage hole 154 is formed. In this case, the expanded metal 166, 168 having the gas passage holes 152 of different sizes (desired size) as shown in FIGS. 8 and 9 can be easily formed by changing the cut amount or the spread amount by the cutter 158. Can be formed into The filter 37 can be formed by simply stacking these expanded metals 166 and 168 on top of each other, so that the desired filter 37 required according to the vehicle type can be easily formed.

Furthermore, since the filter 37 of this embodiment is formed by a single metal plate, not by braiding, even if it is cut into a desired size, the cut portion does not fray. In the present embodiment, the main body of the inflator 20 is constituted by forming a plurality of cylindrical bodies 58, 70, 84, 96, 112 by press molding and joining them, so that the inflator is forged. Compared to the case of forming 20 main bodies, complicated post-processing such as cutting is unnecessary, and mass productivity is good. Further, in the present embodiment, the main body of the inflator 20 is joined to the plurality of tubular bodies 58, 70, 84, 96, 112 so that the main body of the inflator 20 can withstand the pressure received when the enhancer 124 is ignited. Since it is configured as described above, the wall thickness of each cylinder can be reduced and the cylinder is lightweight, and press molding is easy.

Although aluminum is conventionally used as the material of the main body of the inflator 20, aluminum has low strength and needs to be thick so as to withstand high pressure.

The operation of this embodiment will be described below. In the present embodiment, the expanded metal 150 having the gas passage hole 152 of a desired size is formed in consideration of the gas outflow rate generated by the gas generating substance 30, and the filter 37 is formed by stacking the expanded metal 150. The filter 37 is arranged in the storage chamber 56.

In a normal state, the activation device 32 does not operate and the airbag bag body 16 does not inflate.

On the other hand, during rapid deceleration of the vehicle, the ball 42 inertially moves, and the inertial movement disengages the ignition pin 43, causing the ignition pin 43 to move. The ignition pin 43 passes through the through hole 128 and collides with the detonator 45 to ignite the detonator 45, whereby the enhancer 124 burns. At this time, the flame propagates to the detonator 45 and the enhancer 124 in an extremely short time, and a large explosive force acts on the case main body. However, as described above, the bottom portion of the storage chamber 50 has the bottom portions 60, 72, 98. Since they are joined to form three layers and the strength of the case body in the axial direction is sufficiently secured, the case body can sufficiently withstand the explosive force. Further, since the tubular body 70 and the tubular body 84 are connected by the locking piece 78, they are not separated from each other in the axial direction of the case body.

When the enhancer 124 is ignited, the spark passes through the through hole 134 and further the through hole 104 to reach the gas generating substance 30, and the spark ignites the gas generating substance 30 to generate gas. In this case, the wall portion of the storage chamber 52 receives pressure when the gas generating substance 30 is burned, but as described above, the tubular body 70 and the tubular body 84 are connected to each other by the locking piece 78, and further, The side wall 84A of the cylindrical body 84 is arranged outside the side wall 70A of the cylindrical body 70, and the side wall 70A and the side wall 84A are configured to receive the pressure to the outside of the case main body in the radial direction. In addition, the strength to the outside in the radial direction is sufficiently secured. Further, since the bottom portion of the housing chamber 52 is a multilayer structure in which the bottom portion 60 of the tubular body 58 and the bottom portion 72 of the tubular body 70 are joined, a sufficient strength in the axial direction of the case body can be secured.

The gas generated by the combustion of the gas generating substance 30 passes through the circular hole 94 to reach the storage chamber 54, is cooled by the coolant 36, and then passes through the gas hole 92 to reach the storage chamber 56. .. The gas supplied into the storage chamber 56 passes through the gas holes 63 of the filter 37 through the gas holes 63 and is supplied into the airbag bag body 16 to inflate the airbag bag body 16. Due to this expansion, the airbag cover 18 is broken from the thin portion 24, and the airbag bag body 16 is expanded toward the occupant from the broken part. In this case, since the filter 37 is configured by the expanded metal 150 and the gas passage hole 152 is set to the optimum size in consideration of the gas outflow rate and the like, the state in which the burnt residue of the gas generating substance 30 is reliably removed. Then, the gas is supplied to the airbag body 16.

FIG. 10 shows another embodiment of the filter. The filter 170 shown in FIG. 10 is configured by stacking three punching metals 172. The punching metal 172 has a plurality of gas passage holes 174 formed by punching, and a protrusion 176 is formed between the gas passage holes 174 by embossing. The protrusion 176 may be formed in a protrusion shape extending in the direction orthogonal to the paper surface, or may be protrusions formed at intervals in the direction orthogonal to the paper surface. The punching metals 172 are superposed on each other in the gas passage direction (direction of arrow B in FIGS. 1 and 10) via the protrusion 176. As a result, the gas passage holes 174 of each punching metal 172 communicate with each other to form a passage through which gas passes.

In this embodiment, punching metal 172 having gas passage holes 174 of various sizes can be easily formed by punching. The filter 170 can be formed by simply stacking these expanded metals 166, 168 on top of each other, so that the desired filter 37 required according to the vehicle type can be easily formed. Further, as in the case of the filter 37, even if it is cut into a desired size, the cut portion is not frayed because it is formed by a single metal plate instead of braiding.

FIG. 11 shows another embodiment of the filter. This embodiment is different from the embodiment shown in FIG. 11 in that the protrusion 176 is not formed on the second layer punching metal 175. That is, the punching metal 175 of this embodiment has a flat plate shape, and as shown in FIG. 2, the gas passage holes 174 formed in the punching metal 175 are formed on the punching metal 175. It is in communication with the gas passage hole 174 of the metal 172 and serves as a passage through which gas passes.

[0040]

[Effect of the device]

 With the above-described structure, the present invention has an excellent effect that the inflator filter of the airbag device can be easily formed with the gas passage hole having a desired size.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an inflator for an airbag device to which a filter according to an embodiment of the present invention is applied.

FIG. 2 is an exploded perspective view showing a locked state of a cylinder forming a case body of an inflator for an airbag device to which a filter according to an embodiment of the present invention is applied.

FIG. 3 is an exploded perspective view showing the arrangement of components that form the activation device.

FIG. 4 is a cross-sectional view showing a state where an inflator for an airbag device to which a filter according to an embodiment of the present invention is applied is attached to a steering wheel.

FIG. 5 is an exploded perspective view of an ignition member unit.

FIG. 6 is a perspective view of a cutter for manufacturing a filter according to an embodiment of the present invention.

FIG. 7 is a plan view of an expanded metal forming a filter according to an embodiment of the present invention.

FIG. 8 is a plan view of an expanded metal forming a filter according to another embodiment of the present invention.

FIG. 9 is a plan view of an expanded metal forming a filter according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view of a filter according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view of a filter according to another embodiment of the present invention.

[Explanation of symbols]

 16 Airbag Bag 20 Inflator 30 Gas Generating Material 32 Starter 37 Filter 45 Detonator 150 Expanded Metal (Plate Member)

Front page continued (72) Kozo Kono, No. 1 Noda, Oita-machi, Oguchi-machi, Niwa-gun, Aichi Prefecture Toda Rika Denki Seisakusho Co., Ltd. Tokai Rika Electric Co., Ltd. (72) Creator Yoshihide Sakaguchi No. 1 Noda, Ota-cho, Oguchi-machi, Niwa-gun, Aichi Prefecture Tokai Rika Electric Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A filter, which is interposed between a gas generating substance of an inflator and a bag body of an airbag device, and through which gas generated by combustion of the gas generating substance passes, wherein a plurality of parallel cuts are formed. A plurality of plate-like members, which are formed by expanding the notches in the plate thickness pressure direction and formed with a plurality of gas passage holes through which the gas passes, are formed by stacking a plurality of plate members in the gas passage direction. A filter for an inflator of an airbag device. 2. A filter, which is interposed between a gas generating substance of an inflator and a bag body of an airbag device, and through which a gas generated by combustion of the gas generating substance passes, the gas passage being formed by punching. A first plate-shaped member having a plurality of gas passage holes and a protrusion formed between the plurality of gas passage holes, and a plurality of gas passage holes serving as passages for the gas are formed by punching. A second plate superposed on the first plate-shaped member via the protrusion in the gas passage direction in a state where the gas passage hole is in communication with the gas passage hole of the first plate-shaped member -Shaped member,
A filter for an inflator of an airbag device, comprising: