JP5528962B2 - Inflator - Google Patents

Description

  The present invention relates to an inflator that generates gas during operation, and more particularly to a disk type inflator.

An inflator is disclosed in which an annular metal cooling filter is disposed between an inner baffle (outer cylinder member) constituting an outer peripheral wall of a combustion chamber whose one end is fixed to a closure, and an outer baffle provided on the outer periphery thereof. (See Patent Document 1).
US Pat. No. 7,267,365

  In the case of an inflator of the type that generates gas by burning a gas generating agent as in the conventional example described above, combustion residue (hereinafter referred to as “mist”) when the gas generating agent burns is removed. In order to cool the high-temperature gas, an annularly wound cooling and filtering filter is disposed on the inner peripheral portion of the upper case. This filter increases the size of the inflator in the radial direction and increases the weight of the inflator. Therefore, it is desirable to eliminate the filter in order to reduce the size and weight of the inflator.

  However, in the above-described conventional example, when the cooling and filtering filter is abolished, the inner baffle (outer cylinder member) is deformed to the outside when the internal pressure of the combustion chamber rapidly rises immediately after ignition of the gas generating agent, There is concern about the narrowing of the gas flow path from the combustion chamber to the gas ejection hole of the upper case, and some measures are considered necessary.

  In consideration of the above-mentioned fact, the present invention eliminates the cooling and filtering filters and enables the inflator to be reduced in size and weight, and to ensure the speed of gas ejection from the gas ejection holes during operation. With the goal.

The invention of claim 1 comprises a bottomed cylindrical upper case and a bottomed cylindrical lower case that closes an opening at an end of the upper case, and a plurality of gas ejection holes in the peripheral wall portion on the upper case side Formed in the inflator case, an inner cylinder member that accommodates and holds the transfer charge, and an ignition that is provided in the inner cylinder member and ignites the transfer charge In the apparatus and the inflator case, one end is disposed and closed on one side in the axial direction of the inflator case, the other end is disposed on the other side in the axial direction of the inflator case, and combustion of the transfer charge is performed. A gas generating agent that burns and generates gas by propagating is provided between an outer cylinder member that houses and holds around the inner cylinder member, and the outer cylinder member and the inner cylinder member. A combustion chamber located on the one end side of the member and containing the gas generating agent is partitioned from a cooling space located on the other end side of the outer cylindrical member, and the cooling chamber is separated from the combustion chamber side. A partition wall provided with a plurality of communication holes allowing the flow of the gas to the space side, and the other end of the outer cylinder member inside the inflator case and outside the outer cylinder member A gas flow path communicating with the cooling space on the side and communicating with the gas ejection hole of the upper case is formed, and the gas generated in the combustion chamber passes through the communication hole of the partition wall to form the cooling A filter for cooling and filtering the gas by flowing into the gas space and directly contacting the bottom wall of the inflator case facing the cooling space and then flowing into the gas flow path It is configured without using a further, before The other end of the outer cylinder member, the inner surface of the corner portion of the circular arc cross sectional shape continuing to the peripheral wall portion from said bottom wall portion of the upper case, is constructed in contact without blocking the gas flow path, of the gas Deformation suppression means is provided for inhibiting the other end of the outer cylinder member from deforming outward due to an increase in pressure in the outer cylinder member at the time of occurrence.

  In the inflator according to claim 1, when the ignition device is actuated to ignite the transfer charge in the inner cylinder member, and the combustion of the transfer charge propagates into the combustion chamber of the outer cylinder member, it is stored and held in the combustion chamber. The gas generating agent is burned and high temperature and high pressure gas is generated. This gas enters the cooling space through the communication hole formed in the partition wall, hits the bottom wall portion of the inflator case and then flows into the gas flow path, and the gas ejection hole formed in the peripheral wall portion on the upper case side From outside the inflator. For this reason, heat exchange performed between the high-temperature gas generated in the combustion chamber and the inflator case is promoted, and the gas is efficiently cooled.

  Also, the mist contained in the gas generated in the combustion chamber adheres to the bottom wall portion of the inflator case, the inner surface of the peripheral wall portion, etc. due to the flow resistance when passing through the cooling space and the gas flow path, It is efficiently removed before reaching the gas ejection holes. Thereby, the conventional filter for cooling and filtration is abolished, and the inflator can be reduced in size and weight.

  In the inflator according to claim 1, the deformation suppressing means suppresses deformation of the other end of the outer cylinder member to the outside when the internal pressure of the outer cylinder member increases due to the generation of gas. Can be suppressed. For this reason, the quickness of the ejection of the gas from the gas ejection hole during the operation of the inflator can be ensured.

Furthermore , when the internal pressure of the outer cylinder member increases due to the generation of gas, the other end of the outer cylinder member does not block the gas flow path, and the corner of the arc-shaped cross section that continues from the bottom wall portion of the upper case to the peripheral wall portion is provided. Abuts the inner surface . Thereby, it is suppressed that this other end deform | transforms outside. For this reason, with a simple configuration, it is possible to ensure the speed of gas ejection from the gas ejection holes during operation of the inflator.

According to a second aspect of the present invention, in the inflator according to the first aspect, the deformation suppressing means includes an overhanging portion that is provided at the other end of the outer cylindrical member and projects outward from the outer cylindrical member. It is the structure which contact | abuts or adjoins to the inner surface of the corner part continued from the said bottom wall part to the said surrounding wall part.

In the inflator according to claim 2 , when the internal pressure of the outer cylinder member rises due to the generation of gas, the projecting portion at the other end of the outer cylinder member is a corner having a circular arc shape that extends from the bottom wall portion to the peripheral wall portion in the upper case. By coming into contact with the portion, the other end is prevented from being deformed outward. As described above, in the inflator according to claim 3, by providing the overhanging portion at the other end of the outer cylinder member, the rigidity of the other end is increased, and the ejection of the gas from the gas ejection hole during the operation of the inflator is increased. Rapidity can be ensured.

  As described above, according to the inflator of the first aspect of the present invention, the cooling and filtering filter can be eliminated to reduce the size and weight of the inflator, and from the gas ejection hole during operation. An excellent effect is obtained that the speed of gas ejection can be ensured.

According to the inflator of the second aspect , it is possible to obtain an excellent effect that the rigidity of the other end of the outer cylinder member is increased and the speed of gas ejection from the gas ejection hole during operation can be ensured. It is done.

1 to 3 relate to a first embodiment, and FIG. 1 is a cross-sectional view showing an inflator. It is a disassembled perspective view which shows an inflator. It is a principal part expanded sectional view which shows the internal structure of an inflator. 4 and 5 relate to the second embodiment, and FIG. 4 is an enlarged cross-sectional view of a main part showing the internal structure of the inflator. It is a perspective view which shows an outer cylinder member. 6 and 7 relate to Reference Example 1 , and FIG. 6 is an enlarged cross-sectional view of a main part showing the internal structure of the inflator. It is a perspective view which shows an outer cylinder member. 8 to 11 relate to Reference Example 2 , and FIG. 8 is a cross-sectional view showing an inflator. It is a principal part expanded sectional view which shows the internal structure of an inflator. It is a principal part perspective view which shows an example of an outer cylinder member. It is a principal part perspective view which shows the other example of an outer cylinder member. 10 is a half cross-sectional view showing an internal structure of an inflator according to Reference Example 3. FIG.

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

[First Embodiment]
1 to 3, an inflator 10 according to the present embodiment is a gas generation source for supplying inflation gas to an airbag or the like (not shown), and includes an inflator case 12 and an inner cylinder member 14. And an ignition device 16, an outer cylinder member 18, a partition wall 22, and deformation suppression means 24.

  The inflator case 12 includes a bottomed cylindrical upper case 26 and a bottomed cylindrical lower case 28 that closes an opening 26A at a lower end (end) of the upper case 26, and a peripheral wall portion 26B on the upper case 26 side. A plurality of gas ejection holes 26C are formed. The gas ejection holes 26C of the upper case 26 are closed from the inside with, for example, aluminum tape for moisture prevention.

  The upper case 26 and the lower case 28 are each made of metal, and are fixed to each other by welding, for example. The outer diameter of the peripheral wall portion 28B of the lower case 28 is equal to the inner diameter of the peripheral wall portion 26B of the upper case 26, and a part of the peripheral wall portion 28B of the lower case 28 is inserted inside the peripheral wall portion 26B of the upper case 26. It is in a fitted state. As a result, a step 32 is formed at the position of the upper end of the peripheral wall 28 </ b> B in the lower case 28.

  A flange 26E is formed at the lower end of the upper case 26 so as to project radially outward along the circumferential direction. For example, mounting flanges 26F projecting further outward in the radial direction are formed at four locations of the flange 26E. The mounting flange 26F is formed with through holes 26G through which bolts and the like pass when the inflator 10 is mounted at a predetermined position.

  A cylindrical portion 28A that protrudes toward the upper case 26 is integrally formed at the center of the lower case 28, for example. An inward flange 28C facing inward in the radial direction is formed at, for example, the upper end of the cylindrical portion 28A. The cylindrical portion 28 </ b> A and the flange 28 </ b> C serve as a mounting portion for the ignition device 16.

  The inner cylinder member 14 is a bottomed cylindrical member that is disposed inside the inflator case 12 and accommodates and holds the transfer charge 15. An inner diameter of the peripheral wall portion 14B of the inner cylindrical member 14 is set slightly smaller than an outer diameter of the cylindrical portion 28A of the lower case 28, and the inner cylindrical member 14 is press-fitted in a state of being covered with the cylindrical portion 28A. ing. The bottom wall portion 14D of the inner cylindrical member 14 is in contact with or close to the bottom wall portion 26D of the upper case 26. The method of fixing the inner cylinder member 14 to the lower case 28 is not limited to press-fitting to the cylindrical portion 28A, and may be by caulking or the like.

  As shown in FIGS. 1 and 2, an annular enlarged portion 14 </ b> A having an outer diameter and an inner diameter larger than those of the peripheral wall portion 14 </ b> B is provided at an end portion of the inner casing member 14 on the bottom wall portion 28 </ b> D side of the lower case 28. For example, it is formed over the entire circumference. For example, rectangular notches 14C are formed at a plurality of positions in the circumferential direction of the annular enlarged diameter portion 14A. The cutout portion 14 </ b> C and the bottom wall portion 28 </ b> D of the lower case 28 form a ventilation portion 34 that communicates solely with the inside and outside of the inner cylinder member 14.

  In the inner cylinder member 14, at least a portion surrounding the cylindrical portion 28 </ b> A of the lower case 28, a groove-shaped enlarged portion extending along the axial direction of the inner cylinder member 14 and having a larger outer diameter and inner diameter than the peripheral wall portion 14 </ b> B. 14E is formed. The lower end of the groove-shaped enlarged diameter portion 14E is connected to the annular enlarged diameter portion 14A. Further, the groove-shaped enlarged diameter portion 14E is formed at a plurality of positions in the circumferential direction of the inner cylinder member 14 at angular positions avoiding the notches 14C of the annular enlarged diameter portion 14A. As a result, the combustion of the explosive 15 in the inner cylinder member 14 propagates along the inner side of the groove-shaped enlarged portion 14E to the annular enlarged portion 14A located on the bottom wall portion 28D side of the lower case 28, and further It spreads in the outer cylinder member 18 through the ventilation portion 34 while spreading in the circumferential direction along the annular enlarged diameter portion 14A.

  The ignition device 16 is a device that is disposed inside the inner cylindrical member 14 and ignites the transfer charge 15. For example, the ignition device 16 is attached to the lower case 28 through the synthetic resin 36 (the cylindrical portion 28 </ b> A and the flange 28 </ b> C). ). The terminal 16A of the ignition device 16 penetrates the synthetic resin 36 and is exposed to the inside of the cylindrical portion 28A of the lower case 28, and a wire harness (not shown) is connected to the terminal 16A. This wire harness is connected to an ECU (not shown) so that an ignition current flows to the ignition device 16 in a predetermined case.

  In the inflator case 12, one end 18 </ b> A is disposed on the bottom wall portion 28 </ b> D side (one side in the axial direction of the inflator case 12) of the lower case 28 and the other end 18 </ b> B is closed on the outer case member 18. It is arranged on the bottom wall portion 26D side (the other side in the axial direction of the inflator case 12). The outer cylinder member 18 accommodates and holds in the combustion chamber 42 around the inner cylinder member 14 a gas generating agent 38 that burns and generates gas as the combustion of the transfer charge 15 propagates.

  The outer cylinder member 18 is fitted inside the peripheral wall portion 28 </ b> B in the lower case 28. One end 18 </ b> A of the outer cylinder member 18 has an inward flange shape, and is in contact with the bottom wall portion 28 </ b> D of the lower case 28 in a fitted state with the lower case 28. That is, the one end 18 </ b> A of the outer cylinder member 18 is closed by the bottom wall portion 28 </ b> D of the lower case 28.

  The other end 18B of the outer cylinder member 18 is in contact with or close to the bottom wall portion 26D of the upper case 26, and, for example, rectangular notches 18C are formed at a plurality of locations in the circumferential direction of the other end 18B. ing. More specifically, as shown in FIG. 3, the other end 18B of the outer cylindrical member 18 is in contact with the inner surface of a corner portion 26H having a circular arc shape, for example, that extends from the bottom wall portion 26D of the upper case 26 to the peripheral wall portion 26B. Close or close. Specifically, the other end 18B of the outer cylinder member 18 is in contact with or close to a terminal portion on the upper side of the corner portion 26H, that is, a boundary portion between the corner portion 26H and the bottom wall portion 26D. In the present embodiment, such an arrangement of the other end 18 </ b> B of the outer cylinder member 18 constitutes the deformation suppressing means 24.

  The deformation suppressing means 24 suppresses the other end 18B from being deformed to the outside due to an increase in pressure in the outer cylinder member 18 when gas is generated, and further prevents a gas flow path 48 described later from being blocked. It is supposed to be. Note that the other end 18B of the outer cylinder member 18 may be configured to contact or approach an intermediate portion of the corner portion 26H on the condition that the gas flow path 48 is not blocked.

  In FIG. 1, a partition wall 22 is provided between the outer cylinder member 18 and the inner cylinder member 14 by, for example, press-fitting, and is located on one end 18 </ b> A side of the outer cylinder member 18 and accommodates a gas generating agent 38. 42 and a cooling space 44 located on the other end 18B side of the outer cylinder member 18 are partitioned. The partition wall 22 is provided with a plurality of communication holes 22A that allow gas flow from the combustion chamber 42 side to the cooling space 44 side.

  An inner annular wall portion 22 </ b> D that fits to the outer surface of the peripheral wall portion 14 </ b> B of the inner cylinder member 14 is formed on the inner peripheral edge of the partition wall 22. An outer annular wall portion 22 </ b> E that fits with the inner surface of the outer cylinder member 18 is formed on the outer peripheral edge of the partition wall 22. A notch 22C corresponding to the notch 18C of the outer cylindrical member 18 is formed at the end 22B of the outer annular wall 22E. As shown in FIG. 3, the notches 18C and 22C have the same angular position and size in the circumferential direction, and the notches 18C and 22C and the bottom wall 26D of the upper case 26 A ventilation portion 46 communicating with the inside and outside of the outer cylinder member 18 is formed.

  A gas flow path 48 communicating with the gas ejection hole 26 </ b> C of the upper case 26 is formed inside the peripheral wall portion 26 </ b> B of the upper case 26 and outside the outer cylinder member 18. In the present embodiment, a step 32 is formed at the position of the upper end of the lower case 28 that is inserted inside the peripheral wall portion 26 </ b> B of the upper case 26. Therefore, the gas flow path 48 is formed in an annular shape between the peripheral wall portion 26 </ b> B of the upper case 26, the outer cylinder member 18, and the step 32. Further, the gas flow path 48 communicates with the cooling space 44 at, for example, the ventilation portion 46 on the other end 18 </ b> B side of the outer cylinder member 18.

  In the inflator 10 according to the present embodiment, the gas generated in the combustion chamber 42 flows into the cooling space 44 through the communication hole 22 </ b> A of the partition wall 22, and the bottom of the upper case 26 facing the cooling space 44. By directly contacting the wall 26D and then flowing into the gas flow path 48 through the vent 46, a filter (not shown) for cooling and filtering the gas is not used.

  The transfer agent 15 and the gas generating agent 38 are not necessarily different from each other, and the gas generating agent 38 can be used as the transfer agent 15.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. In FIG. 1, in the inflator 10 according to the present embodiment, the ignition charge 16 in the inner cylinder member 14 is ignited by operating the ignition device 16 when receiving an operating current from the ECU. When the combustion of the transfer charge 15 propagates into the combustion chamber 42 of the outer cylinder member 18 through the ventilation portion 34 provided at the end of the inner casing member 14 on the bottom wall portion 28D side of the lower case 28, the combustion chamber The gas generating agent 38 accommodated and held in 42 burns, and high-temperature and high-pressure gas is generated.

  This gas passes through the communication hole 22A formed in the partition wall 22 and enters the cooling space 44 (in the direction of arrow A), hits the bottom wall portion 26D of the upper case 26, and then passes through the ventilation portion 46 to pass through the gas flow path 48. To the outside of the inflator 10 (arrow C direction) from the gas jet holes 26C formed in the peripheral wall portion 26B on the upper case 26 side. A ventilation portion 34 for propagating the combustion of the charge transfer agent 15 to the gas generating agent 38 and a communication hole 22A for flowing the generated gas to the cooling space 44 are opposite to each other in the axial direction of the inflator case 12. Therefore, the gas generating agent 38 can be burned efficiently.

  Even in a configuration that does not use a conventional cooling and filtering filter, the gas is caused to flow between the high-temperature gas generated in the combustion chamber 42 and the inflator case 12 by flowing the gas through the above-described path. Heat exchange can be promoted to cool the gas efficiently. In particular, in the present embodiment, since the mounting flange 26F is formed on the upper case 26 side where high temperature gas hits, heat of the inflator case 12 is efficiently transmitted to a predetermined mounting position where the inflator 10 is mounted. The Thereby, the temperature of the gas ejected from the gas ejection hole 26C can be cooled more efficiently.

  When gas flows in such a path, when the internal pressure of the outer cylinder member 18 increases due to the generation of gas, the gas flows from the cooling space 44 to the gas flow path 48 in the outer cylinder member 18. A strong pressure radially outward acts on the end 18B. However, in the present embodiment, the deformation suppressing means 24 can suppress the other end 18B of the outer cylinder member 18 from being deformed so as to fall outward.

  Specifically, when the internal pressure of the outer cylinder member 18 increases due to the generation of gas, the other end 18B of the outer cylinder member 18 is a corner having an arcuate cross section that continues from the bottom wall portion 26D of the upper case 26 to the peripheral wall portion 26B. It contacts the inner surface of 26H. Therefore, the gas channel 48 is prevented from being narrowed due to the outer end 18B of the outer cylinder member 18 being deformed outward. For this reason, even if it is the structure which does not use the filter for cooling and filtration like the conventional, the gas flow path 48 in the inflator case 12 is ensured appropriately, and the gas ejection hole 26C at the time of the operation of the inflator 10 The speed of gas ejection can be ensured.

  Also, mist (not shown) contained in the gas generated in the combustion chamber 42 flows into the bottom wall portion 26 </ b> D of the upper case 26 due to flow resistance when passing through the cooling space 44 and the gas flow path 48. Since it adheres to the inner surface and the like of the peripheral wall portion 26B, it is efficiently removed before reaching the gas ejection hole 26C. Thereby, the conventional filter for cooling and filtration is abolished, and the inflator 10 can be reduced in size and weight.

[Second Embodiment]
4 and 5, in the inflator 20 according to the present embodiment, the overhanging portion 18 </ b> F, in which the deformation suppressing means 24 is provided at the other end 18 </ b> B of the outer cylinder member 18 and protrudes to the outside of the outer cylinder member 18, The case 26 is configured to come into contact with or close to the inner surface of the corner portion 26H. Since the corner portion 26H of the upper case 26 is a portion having a circular arc shape that continues from the bottom wall portion 26D to the peripheral wall portion 26B, the cross-sectional shape of the overhang portion 18F is also a cross-sectional arc shape that follows the curvature of the corner portion 26H. It has become.

  The overhang portion 18F is formed integrally with the outer cylinder member 18 by providing an extension portion at the other end 18B of the outer cylinder member 18 and bending the extension portion. Moreover, the overhang | projection part 18F is each formed in each other end 18B located between each notch part 18C.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. 4, in the inflator 20 according to the present embodiment, when the internal pressure of the outer cylinder member 18 increases due to the generation of gas in the combustion chamber 42, the overhanging portion 18F of the other end 18B of the outer cylinder member 18 is 26, the other end 18B is prevented from being deformed outward by contacting the inner surface of the corner 26H having a circular arc shape that continues from the bottom wall 26D to the peripheral wall 26B. Since the overhanging portion 18F is formed at each of the other end 18B located between the notch portions 18C, the other end 18B can be uniformly suppressed from being deformed outward. As a result, the rigidity of the other end 18B of the outer cylinder member 18 can be increased, and the speed of gas ejection from the gas ejection hole 26C during operation of the inflator 20 can be ensured. Further, the gas can be ejected evenly from the plurality of gas ejection holes 26C.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[ Reference Example 1 ]
6 and 7, in the inflator 30 according to the present reference example , the deformation suppressing means 24 is arranged as the other end 18B of the outer cylindrical member 18 with respect to the corner portion 26H of the upper case 26 as described in the first embodiment. In addition, the outer cylinder member 18 has a reinforcing portion 18D provided on the peripheral wall portion on the other end 18B side.

  This reinforcement part 18D is comprised by making the surrounding wall part of the outer cylinder member 18 into a cross-sectional uneven | corrugated shape, and the cross-section coefficient is large compared with a mere cylindrical surface. The uneven shape of the cross section is, for example, a zigzag shape, and protrudes only inside the peripheral wall portion of the outer cylindrical member 18 and does not protrude outside the peripheral wall portion on the gas flow path 48 side. Thereby, the smooth flow of the gas in the gas channel 48 can be secured without narrowing the gas channel 48.

Since the reinforcing portion 18D protrudes in this way, the partition wall 22 is provided to avoid the reinforcing portion 18D. Specifically, the upper end of the reinforcing portion 18D (the end portion on the bottom wall portion 26D side of the upper case 26) is located below (the lower case 28 side) the attachment position of the partition wall 22. In the present reference example , the upper end of the reinforcing portion 18D corresponds to the lower end of the mounting position of the partition wall 22, and the partition wall 22 can be positioned when the partition wall 22 is mounted between the outer cylinder member 18 and the ignition device 16. It is like that.

(Function)
This reference example is configured as described above, and the operation thereof will be described below. In FIG. 6, in the inflator 30 according to the present reference example , as the deformation suppressing means 24, the reinforcing portion 18 </ b> D is provided on the peripheral wall portion on the other end 18 </ b> B side of the outer cylindrical member 18. When the internal pressure of 18 increases, the other end 18B of the outer cylinder member 18 is prevented from being deformed outward. Since this reinforcement part 18D is comprised by making the surrounding wall part of the outer cylinder member 18 into a cross-sectional uneven | corrugated shape, it reinforces the surrounding wall part by the side of the other end 18B of the outer cylinder member 18 without increasing a number of parts. The rigidity of the other end 18B can be improved.

  The concavo-convex shape of the reinforcing portion 18D protrudes only to the inside of the peripheral wall portion of the outer cylindrical member 18, and does not protrude to the outside of the peripheral wall portion on the gas flow channel 48 side. Therefore, a smooth flow of gas in the gas flow path 48 can be ensured.

Thus, in the inflator 20 according to the present reference example , by providing the reinforcing portion 18D on the peripheral wall portion on the other end 18B side of the outer cylinder member 18, the speed of gas ejection from the gas ejection hole 26C during operation can be increased. Can be secured.

In this reference example , as the deformation suppressing means 24, the arrangement of the other end 18B of the outer cylinder member 18 with respect to the corner portion 26H of the upper case 26 and the reinforcing portion 18D provided on the peripheral wall portion of the outer cylinder member 18 are cited. However, the present invention is not limited to this. For example, the deformation suppressing means 24 may be configured only by the reinforcing portion 18D. The shape of the reinforcing portion 18D is not limited to the zigzag shape, and may be a bead shape extending in the circumferential direction or the axial direction of the outer cylinder member 18.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[ Reference Example 2 ]
8 and 9, in the inflator 40 according to this reference example , the deformation suppressing means 24 is provided at the other end 18 </ b> B of the outer cylinder member 18, and an overhanging portion 18 </ b> G projecting to the outside of the outer cylinder member 18 includes an upper case. 26 is in contact with or close to the inner surface of the peripheral wall portion 26B. As shown in FIG. 10, the overhanging portion 18G is formed, for example, by bending so as to protrude from the longitudinal edge portions 18V on both sides in the circumferential direction of the notch portion 18C to the outside in the radial direction of the outer cylinder member 18. Yes. That is, a pair of overhanging portions 18G are formed separately in the circumferential direction of the outer cylinder member 18 for one notch portion 18C.

  The upper end position of the overhang portion 18G is located in the vicinity of the boundary portion between the corner portion 26H of the upper case 26 and the peripheral wall portion 26B. By avoiding the corner portion 26H of the upper case 26, it becomes unnecessary to shape the overhanging portion 18G in accordance with the cross-sectional shape of the corner portion 26H, thereby suppressing an increase in cost and reducing the internal pressure of the outer cylinder member 18. This is because the pressure acting on the other end 18B is efficiently dispersed from the overhanging portion 18G to the peripheral wall portion 26B of the upper case 26 when ascending.

  Note that the configuration of the overhanging portion 18G is not limited to that provided in the vertical edge portion 18V of the notch portion 18C as shown in FIG. 10, and further, as shown in FIG. 11, the lateral edge portion of the notch portion 18C. It may be provided at 18H. In the example shown in FIG. 11, a pair of overhang portions 18G are formed in an L shape from one vertical edge portion 18V to the horizontal edge portion 18H per cutout portion 18C. Thereby, the rigidity of the deformation | transformation suppression means 24 in the outer cylinder member 18 can further be improved. In each cutout portion 18C, the pair of overhang portions 18G are separated in the circumferential direction of the outer cylinder member 18, and the ventilation portion 46 of the outer cylinder member 18 and the gas flow path 48 communicate with each other. ing.

(Function)
This reference example is configured as described above, and the operation thereof will be described below. In FIG. 9, in the inflator 40 according to the present reference example , the rigidity of the other end 18B is increased by the overhanging portion 18G (deformation suppressing means 24) formed on the other end 18B of the outer cylinder member 18, and gas is generated. When the internal pressure of the outer cylinder member 18 rises due to the above, the overhanging portion 18G comes into contact with the inner surface of the peripheral wall portion 26B in the upper case 26, so that the other end 18B is prevented from being deformed outward.

  As shown in FIGS. 10 and 11, a pair of overhang portions 18G are formed for each notch portion 18C. The pair of overhang portions 18G are separated from each other in the circumferential direction of the outer cylinder member 18. Therefore, the ventilation portion 46 and the gas flow path 48 of the outer cylinder member 18 are in communication. Accordingly, it is possible to ensure the speed of gas ejection from the gas ejection holes 26C during the operation of the inflator 40.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[ Reference Example 3 ]
12, in the inflator 50 according to this reference example , the combustion chamber 42 is disposed on the bottom wall portion 26D side of the upper case 26, while the cooling space 44 is disposed on the bottom wall portion 28D side of the lower case 28. Yes. Along with this, the ventilation portion 46 that leads from the cooling space 44 to the gas flow path 48 and the partition wall 22 that partitions the cooling space 44 and the combustion chamber 42 are disposed on the bottom wall portion 28D side of the lower case 28. ing.

  A flange 26E is formed at the lower end of the upper case 26 so as to project radially outward along the circumferential direction. The upper case 26 and the lower case 28 are joined by, for example, welding at the flanges 26E and 28E. A mounting flange 28F for mounting the inflator 50 at a predetermined mounting position is provided on the lower case 28 side.

  The inner diameters of the peripheral wall portions 26B and 28B in the upper case 26 and the lower case 28 are equal to each other, and the outer diameter of the outer cylinder member 18 is set smaller than the inner diameters of the peripheral wall portions 26B and 28B. As a result, the gas flow path 48 passes from between the peripheral wall portion 28B of the lower case 28 and the outer cylindrical member 18 to between the peripheral wall portion 26B of the upper case 26 and the outer cylindrical member 18, and gas is discharged from the peripheral wall portion 26B. It communicates with the hole 26C.

Further, in the inflator 50 according to the present reference example , as the deformation suppressing means 24, the other end 18B of the outer cylindrical member 18 is connected to the lower end portion of the lower case 28, for example, the corner 28H having a circular arc shape, that is, the corner 28H. It has a configuration in contact with or close to the boundary with the bottom wall 28D. Therefore, the outer diameter at the position of the other end 18 </ b> B of the outer cylinder member 18 corresponds to the outermost diameter of the bottom wall portion 28 </ b> D of the lower case 28.

(Function)
This reference example is configured as described above, and the operation thereof will be described below. In FIG. 12, in the inflator 50 according to the present reference example , the ignition charge 16 in the inner cylinder member 14 is ignited by operating the ignition device 16 when receiving an operating current from the ECU. When the combustion of the transfer charge 15 propagates into the combustion chamber 42 of the outer cylinder member 18 through the ventilation portion 34 provided on the bottom wall portion 26D side of the upper case 26 in the inner cylinder member 14, The gas generating agent 38 contained and held in the cylinder burns, and high-temperature and high-pressure gas is generated.

  This gas passes through the communication hole 22A formed in the partition wall 22 and enters the cooling space 44 (in the direction of arrow A), hits the bottom wall portion 28D of the lower case 28, and then enters the gas flow path 48 through the ventilation portion 46. Flow (in the direction of arrow B) is ejected from the gas ejection holes 26C formed in the peripheral wall portion 26B on the upper case 26 side (in the direction of arrow C). A ventilation portion 34 for propagating the combustion of the charge transfer agent 15 to the gas generating agent 38 and a communication hole 22A for flowing the generated gas to the cooling space 44 are opposite to each other in the axial direction of the inflator case 12. Therefore, the gas generating agent 38 can be burned efficiently.

Even in a configuration that does not use a conventional cooling and filtering filter, the gas is caused to flow between the high-temperature gas generated in the combustion chamber 42 and the inflator case 12 by flowing the gas through the above-described path. Heat exchange can be promoted to cool the gas efficiently. In particular, in this reference example , the mounting flange 28F is formed on the lower case 28 side where the high-temperature gas hits. Therefore, heat of the inflator case 12 is efficiently transmitted to a predetermined mounting position where the inflator 50 is mounted. . Thereby, the temperature of the gas ejected from the gas ejection hole 26C can be cooled more efficiently.

  When the internal pressure of the outer cylinder member 18 increases due to the generation of gas in the combustion chamber 42, the other end 18B of the outer cylinder member 18 is a corner having an arcuate cross section that continues from the bottom wall portion 28D of the lower case 28 to the peripheral wall portion 28B. It contacts the inner surface of 28H. Therefore, the gas channel 48 is prevented from being narrowed due to the outer end 18B of the outer cylinder member 18 being deformed outward. For this reason, with a simple configuration, it is possible to ensure the speed of gas ejection from the gas ejection holes 26 </ b> C during operation of the inflator 50.

  Since other parts are the same as those in the first embodiment, the same parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

In each embodiment, the corner portion 26H of the upper case 26 and the corner portion 28H of the lower case 28 are each arc-shaped in cross section, but the shape of the corner portions 26H and 28H in each reference example is limited to this. Instead, it may be a cross-sectional chamfered (corner cut) linear shape, a combination of a linear shape and an arc shape, or the like.

DESCRIPTION OF SYMBOLS 10 Inflator 12 Inflator case 14 Inner cylinder member 15 Transfer agent 16 Ignition device 18 Outer cylinder member 18B Other end 18D Reinforcement part
18F Overhang portion 20 Inflator 22 Partition 22A Communication hole 24 Deformation suppression means 26 Upper case 26A Opening 26B Perimeter wall portion 26C Gas ejection hole 26D Bottom wall portion 26H Corner portion 28 Lower case 28B Perimeter wall portion 28D Bottom wall portion 28H Corner portion 30 Inflator 38 Inflator 38 Agent 40 Inflator 42 Combustion chamber 44 Cooling space 48 Gas flow path 50 Inflator

Claims (2)

An inflator case comprising a bottomed cylindrical upper case, and a bottomed cylindrical lower case that closes an opening at an end of the upper case, and a plurality of gas ejection holes formed in a peripheral wall portion on the upper case side; ,
An inner cylinder member that is disposed inside the inflator case, and stores and holds a charge transfer agent;
An ignition device disposed in the inner cylinder member for igniting the transfer charge;
Inside the inflator case, one end is arranged on one side in the axial direction of the inflator case and closed, and the other end is arranged on the other side in the axial direction of the inflator case, and the combustion of the transfer charge propagates. An outer cylinder member that houses and holds a gas generating agent that burns and generates gas around the inner cylinder member;
A combustion chamber provided between the outer cylinder member and the inner cylinder member, located on the one end side of the outer cylinder member and containing the gas generating agent, and located on the other end side of the outer cylinder member And a partition wall provided with a plurality of communication holes that allow the flow of the gas from the combustion chamber side to the cooling space side.
A gas flow path that communicates with the cooling space on the other end side of the outer cylinder member and communicates with the gas ejection hole of the upper case inside the inflator case and outside the outer cylinder member. Formed,
The gas generated in the combustion chamber flows into the cooling space through the communication hole of the partition wall and directly hits the bottom wall portion of the inflator case facing the cooling space. By making it flow into the flow path, it is configured not to use a filter for cooling and filtering the gas,
Further, the other end of the outer cylinder member is configured to abut on the inner surface of a corner portion having a circular arc shape that is continuous from the bottom wall portion of the upper case to the peripheral wall portion without blocking the gas flow path, The inflator which has a deformation | transformation suppression means which suppresses that the said other end of this outer cylinder member deform | transforms outside by the raise of the pressure in the said outer cylinder member at the time of the said gas generation | occurrence | production. The deformation suppressing means projecting portion which projects to the outside of the provided outer cylindrical member to the other end of the outer cylinder member, an inflator according to claim 1 is configured to abut an inner surface of the corner portion.

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