Gas generator

Abstract

To provide a gas generator capable of acquiring proper output.SOLUTION: A gas generator includes: a housing; an igniter arranged in the housing; a gas generating agent stored in the housing, and for generating a combustion gas by activation of the igniter; a first discharge hole provided in the housing, and for discharging the combustion gas generated in the housing to the outside; a second discharge hole provided in the housing with the first discharge hole, and for discharging the combustion gas generated in the housing to the outside; and a closing member covering at least one first discharge hole and at least one second discharge hole together. In the closing member, a portion covering the first discharge hole is set to be cleaved by a first cleavage pressure, and a portion covering the second discharge hole is set to be cleaved by a second cleavage pressure which is higher than the first cleavage pressure. The closing member has, at least at a boundary portion between the first discharge hole and the second discharge hole, a breakage auxiliary part for lowering the strength of the closing member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas generator.

Background Art

[0002] Conventionally, a gas generator that fills a combustion chamber formed in a housing with a gas generating agent, burns the gas generating agent by an igniter to generate combustion gas, and discharges the combustion gas to the outside from a gas discharge hole provided in the housing has been widely used.

[0003] In the gas generator of Patent Document 1, the peripheral wall portion of the upper container has two types of gas discharge holes with different diameters, and a sealing tape closes these two types of gas discharge holes simultaneously. And the bursting pressure of the sealing tape that closes these two types of gas discharge holes is adjusted according to the opening diameter of the gas discharge hole. Thereby, it has been proposed to equalize the pressure (hereinafter referred to as "combustion internal pressure") in the housing when the gas generating means burns and stabilize the combustion performance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID=XXX]] When covering a large-diameter discharge hole (gas discharge hole) and a small-diameter discharge hole together with the same sealing tape and the pressure of combustion gas is applied in the shearing direction, the portion covering the large-diameter discharge hole cracks earlier than the portion covering the small-diameter discharge hole. That is, it is conceivable to configure so that only the portion covering the large-diameter discharge hole is cracked at the first cracking pressure, and the portion covering both discharge holes is cracked at the second cracking pressure higher than the first cracking pressure, thereby stabilizing the combustion performance. However, if a large-diameter discharge hole (gas discharge hole) and a small-diameter discharge hole are covered together with a single sealing tape, pressure will be applied to the portion covering the large-diameter discharge hole. When this tape ruptures, this force will be transmitted to the surrounding area, causing the sealing tape to shift or partially lift. As a result, the blockage of the small-diameter hole may be released at a pressure lower than the intended rupture pressure. In this case, some of the gas will be discharged through the small-diameter discharge hole. In other words, an unnecessary opening occurs when only the large-diameter discharge hole should be open, which may cause the output characteristics, such as the amount and pressure of combustion gas output from the gas generator, to not be as designed.

[0006] The technology disclosed herein has been developed in view of the circumstances described above, and its purpose is to provide a gas generator capable of obtaining an appropriate output. [Means for solving the problem]

[0007] To solve the above problems, the technology of this disclosure employs the following configuration. That is, the gas generator technology of this disclosure is Housing and An igniter located within the housing, A gas generating agent housed in the aforementioned housing generates combustion gas upon operation of the igniter, The housing is provided with a first discharge port for discharging the combustion gas generated within the housing to the outside, The housing is provided with the first discharge port, and a second discharge port is provided for discharging the combustion gas generated within the housing to the outside, A closing member that covers together at least one of the first discharge holes and at least one of the second discharge holes, Equipped with, The portion of the blocking member covering the first discharge hole is set to cleave at a first cleavage pressure, and the portion covering the second discharge hole is set to cleave at a second cleavage pressure that is higher than the first cleavage pressure. The blocking member is provided with a break-reducing portion at least at the boundary between the first discharge hole and the second discharge hole, which reduces the strength of the blocking member.

[0008] The opening area of ​​the first discharge hole may be set to be larger than the opening area of ​​the second discharge hole.

[0009] The fracture assist portion may be a weak portion provided in the closing member.

[0010] The blocking member is a sheet attached along the wall surface of the housing, which is provided with the first discharge hole and the second discharge hole. The rupture assist portion may be a part of the closing member in which the thickness dimension of the sheet is formed to be smaller than the thickness dimension of at least the portion covering the second discharge hole.

[0011] The blocking member is a sheet attached along the wall surface of the housing, which is provided with the first discharge hole and the second discharge hole. The break-relieving portion may be a linear portion in the closing member in which cut portions cut in the thickness direction of the sheet and uncut portions are arranged alternately.

[0012] The aforementioned blocking member is A sheet attached to the wall surface of the housing along the circumferential direction of the housing, In the circumferential direction, at the boundary between the portion covering the first discharge hole and the portion covering the second discharge hole, the closing member is provided with a cut portion in which the closing member is cut in such a way that the width of the closing member is narrowed along the width direction of the closing member. The fracture assist portion may be the part of the closing member whose width has been narrowed by the cut portion.

[0013] The blocking member is a sheet attached along the wall surface of the housing, which is provided with the first discharge hole and the second discharge hole. The break-relieving portion may be a projection formed at the boundary between the first discharge hole and the second discharge hole, and protruding from the wall surface of the housing toward the closing member.

[0014] The first discharge hole and the second discharge hole are arranged on the wall surface of the housing along the circumferential direction of the housing. The closing member is provided along the arrangement direction of the first discharge hole and the second discharge hole. The breaking assistance portion may be provided in a direction that divides a portion of the closing member covering the first discharge hole and a portion covering the second discharge hole.

[0015] The breaking assistance portion may be linearly formed so as to surround the first discharge hole or the second discharge hole.

Advantages of the Invention

[0016] According to the present disclosure, a gas generator capable of obtaining an appropriate output can be provided.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is an axial cross-sectional view schematically showing an internal structure along the central axis of a gas generator according to a first embodiment. [Figure 2] FIG. 2 is a view showing a part of a sealing tape covering the first discharge hole and the second discharge hole. [Figure 3] FIG. 3 is a view schematically showing a cross-section orthogonal to the central axis of an upper container to which a sealing tape is attached. [Figure 4] FIG. 4 is a view showing a configuration of a sealing tape according to Modification 1. [Figure 5] FIG. 5 is a view showing a configuration of the first discharge hole and the second discharge hole according to Modification 2. [Figure 6] FIG. 6 is a view showing a configuration of a sealing tape according to Modification 2. [Figure 7] FIG. 7 is a view showing an arrangement of the first discharge hole and the second discharge hole according to Modification 3. [Figure 8] FIG. 8 is a view showing a configuration of a sealing tape according to Modification 3. [Figure 9] FIG. 9 is a view showing an arrangement of the first discharge hole and the second discharge hole according to Modification 4. [Figure 10]Figure 10 shows the configuration of the sealing tape covering the first and second discharge holes in Figure 9. [Figure 11] Figure 11 shows the configuration of the sealing tape according to Modification 5. [Figure 12] Figure 12 shows the configuration of the first discharge hole, the second discharge hole, and the rupture assist part according to the second embodiment. [Figure 13] Figure 13 shows the sealing tape covering the first and second discharge holes. [Figure 14] Figure 14 is a cross-sectional view of AA in Figure 13. [Modes for carrying out the invention]

[0018] A gas generator according to an embodiment of this disclosure will be described below with reference to the drawings. Note that the configurations and combinations thereof in each embodiment are examples, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of the present invention. This disclosure is not limited by the embodiments, but is limited only by the claims.

[0019] <First Embodiment> [Overall structure] Figure 1 is an axial cross-sectional view schematically showing the internal structure of the gas generator 100 along its central axis C according to the first embodiment. Hereinafter, as shown in Figure 1, the cross-section obtained by cutting the gas generator 100 along its central axis C may be referred to as the "longitudinal cross-section" of the gas generator 100. Also, the direction along the central axis C of the gas generator 100 may be referred to as the "up and down direction" of the gas generator 100. Figure 1 shows the gas generator 100 in its state before operation. The gas generator 100 is, for example, an airbag gas generator that supplies gas to an airbag to inflate and deploy the airbag.

[0020] The gas generator 100 has a housing 3 formed by joining an upper container 1 having a gas discharge hole 26 and a lower container 2 that together with the upper container 1 form an internal storage space. Inside this housing 3, a substantially cylindrical inner cylinder member 4 is placed, with its outer surface forming the first combustion chamber 5A. The inner cylinder member 4 has a stepped cutout 6 on the inside of its peripheral wall so as to widen the inner diameter at the bottom, and a substantially flat circular partition wall 7 is arranged in the stepped cutout 6 along a plane perpendicular to the central axis C. This partition wall 7 divides the inside of the inner cylinder into two chambers, with the second combustion chamber 5B formed on the upper container side and the igniter storage chamber 8 formed on the lower container side. Therefore, in the gas generator 100, the first combustion chamber 5A and the second combustion chamber 5B are arranged concentrically within the housing 3 and are adjacent to each other in the radial direction of the housing 3.

[0021] The first and second combustion chambers contain gas generating agents 9 (9A, 9B) that generate combustion gas when ignited by the igniter 12, and the igniter 12, which is activated by impact, is housed in the igniter housing chamber 8. The inner cylinder member 4 that defines the first combustion chamber 5A and the second combustion chamber 5B is provided with a through hole 10, and this through hole 10 is sealed by the sealing tape 11 The seal tape 11 is sealed. However, this seal tape 11 will rupture when the gas generating agent 9B burns, generating combustion gas and increasing the pressure in the second combustion chamber 5B. Therefore, when the gas generating agent 9B burns, the two combustion chambers 5A and 5B are connected by the through hole 10. The material and thickness of this seal tape 11 are adjusted so that it ruptures only when the gas generating agent 9B in the second combustion chamber 5B burns. In this embodiment, a stainless steel seal tape with a thickness of 40 μm is used. The through hole 10 has a larger opening area than the second discharge hole 26B provided in the upper container 1.

[0022] The igniter 12 includes a first igniter 12A and a second igniter 12B, which are activated by an activation signal output based on an external sensor detecting an impact. The first igniter 12A and the second igniter 12B are mounted parallel to each other, with their heads protruding from the collar 13. In the gas generator 100 of this embodiment, for example, the igniter 12 can be easily fixed in a predetermined state by inserting the collar 13, which has the two igniters 12 (12A, 12B) attached, into the inner cylinder 4, and then crimping the lower end of the inner cylinder member 4 to fix the collar 13. Furthermore, the positional relationship, such as the orientation and spacing of the two igniters 12, can be easily controlled. Note that the configuration is not limited to the two igniters 12 being attached to one collar 13; the first igniter 12A and the second igniter 12B may each be attached to separate collars 13.

[0023] In this embodiment, a substantially cylindrical separation cylinder 14 is positioned in the space between the collar 13 and the partition wall 7 so as to surround one of the igniters 12 (hereinafter referred to as the second igniter 12B), defining a first explosive charge storage chamber 15A on the outside and a second explosive charge storage chamber 15B on the inside, and each storage chamber houses the igniter 12 and the explosive charges 16A and 16B that together with the igniter 12 constitute an ignition unit.

[0024] When the explosive charge 16A contained within the first explosive charge chamber 15A burns, the sealing tape 18 that closes the ignition hole 17 formed in the inner cylinder member 4 ruptures, opening it into communication with the first combustion chamber 5A. Similarly, when the explosive charge 16B contained within the second explosive charge chamber 15B burns, the sealing tape 20 that closes the ignition hole 19 formed in the partition wall 7 ruptures, opening it into communication with the second combustion chamber 5B. Therefore, when the gas generator 100 operates, the flame produced when the first igniter 12A ignites (operates) ignites and burns the explosive charge 16A in its chamber 15A, and this flame passes through the ignition hole 17 formed in the inner cylinder member 4, igniting and burning the gas generating agent 9A contained in the first combustion chamber 5A located radially to the chamber 15A.

[0025] The second igniter 12B ignites and burns the second propellant charge 16B in its containment chamber 15B, and the flame passes through the propellant hole 19 provided in the axial direction of the containment chamber 15B, igniting and burning the gas generating agent 9B contained in the second combustion chamber 5B located at the extension of the hole. In this embodiment, the shapes of the gas generating agents 9A and 9B are not limited, and known shapes can be used. The combustion gas generated in the second combustion chamber 5B flows into the first combustion chamber 5A through the through hole 10 provided on the upper container 1 side of the inner cylinder member 4.

[0026] In particular, in the gas generator 100 shown in Figure 1, the separation cylinder 14, which is positioned between the collar 13 and the partition wall 7, has a hole 21 on the lower surface of the partition wall 7 corresponding to the outer shape of the separation cylinder 14, and a similar hole 131 on the upper surface of the collar 13, with the upper or lower end of the separation cylinder 14 fitted into the respective holes 21 and 131.

[0027] By arranging the separation cylinder 14 in this manner, the flame of the ignition charge generated in one of the ignition charge containment chambers does not directly ignite the ignition charge in the other ignition charge containment chamber. Instead, the gas generating agents 9A and 9B contained in the two combustion chambers are ignited and burned by the flames of the ignition charges of different sections. In other words, there are no holes 21 and 131, and the separation cylinder 14 is simply separated from the partition wall 7 and the collar 13. When sandwiched between the partition wall 7 and the collar 13, if the propellant burns inside the separation cylinder 14 (i.e., inside the second propellant containment chamber), the pressure of the gas produced by the combustion will also act to expand the separation cylinder radially. However, in the configuration of this embodiment, the upper and lower ends of the separation cylinder 14 are supported by the holes 21 and 131, respectively, which can suppress the leakage of combustion gas and flame. However, the configuration is not limited to this, and there may be a configuration in which the separation cylinder 14 is sandwiched between the partition wall 7 and the collar 13 without the holes 21 and 131.

[0028] Furthermore, a coolant filter 22 is provided inside the housing 3 for purifying and cooling the combustion gases generated by the combustion of the gas generating agents 9A and 9B. The inner circumferential surface of the coolant filter 22 on the upper container 1 side is covered with a short-pass prevention member to prevent combustion gases from passing between the end face of the coolant filter 22 and the inner surface of the ceiling of the upper container 1. A gap 25 is formed on the outside of the coolant filter 22 so that the combustion gases can pass through the entire surface of the filter 22.

[0029] The peripheral wall portion 101 of the upper container 1 is provided with gas discharge holes 26 for discharging combustion gas generated in the housing 3 to the outside of the gas generator 100. The gas discharge holes 26 have first discharge holes 26A and second discharge holes 26B of different diameters. The first discharge holes 26A and second discharge holes 26B penetrate from the inside to the outside of the peripheral wall portion 101, and are formed so that the shape of the opening is circular. In addition, multiple first discharge holes 26A and second discharge holes 26B are provided along the circumferential direction of the upper container 1. The opening area per hole of the first discharge holes 26A is larger than that of the second discharge holes 26B. The number of holes is the same. For this reason, the total opening area of ​​multiple first discharge holes 26A is also larger than the total opening area of ​​multiple second discharge holes 26B. For example, the first discharge holes 26A may have a diameter of φ3.0 mm and 16 holes, and the second discharge holes 26B may have a diameter of φ2 mm and 16 holes. The shape, diameter, and number of each discharge port 26A, 26B are not particularly limited and can be arbitrarily set according to the required specifications of the gas generator 100. For example, the shape of each discharge port 26A, 26B is not limited to a circle, but may be elliptical or polygonal.

[0030] Furthermore, a sealing tape (closing member) 27 is attached to the inner surface of the peripheral wall portion 101 of the upper container 1, and the first discharge hole 26A and the second discharge hole 26B are covered and closed together by this sealing tape 27 (spanning both the first discharge hole 26A and the second discharge hole 26B).

[0031] Figure 2 shows a portion of the sealing tape 27 covering the first discharge hole 26A and the second discharge hole 26B, and Figure 3 shows a cross-section perpendicular to the central axis C of the upper container 1 to which the sealing tape 27 is attached. In this embodiment, as shown in Figure 2, a plurality of first discharge holes 26A are provided in a row along the circumferential direction of the upper container 1, and a plurality of second discharge holes 26B are provided in a row above these first discharge holes 26A along the circumferential direction of the upper container 1. That is, the row of first discharge holes 26A and the row of second discharge holes 26B are provided side by side in the direction of the central axis C.

[0032] The sealing tape 27 is a sheet-like member that, when applied to the peripheral wall portion 101, elongates in the circumferential direction. The sealing tape 27 has a width that allows for sufficient vertical clearance even when simultaneously sealing two types of gas discharge holes 26 aligned in the direction of the central axis C. For example, it is desirable to have a clearance of 2 to 3 mm from the upper end of each discharge hole 26A, 26B to the upper end of the sealing tape 27, or from the lower end of each discharge hole 26A, 26B to the lower end of the sealing tape. Furthermore, it is preferable that the sealing tape 27 comprises an aluminum sealing layer having a thickness of 20 μm to 200 μm and an adhesive layer or tack layer having a thickness of 5 to 100 μm, but the material and structure of the sealing tape 27 are not particularly limited as long as the desired effect is achieved.

[0033] In this embodiment, a sealing tape is used in which the aluminum sealing layer has a thickness of 50 μm and the adhesive layer or bonding layer has a thickness of 50 μm. In this embodiment, the diameter of each discharge hole 26A, 2 The row 6B is arranged adjacent to the central axis C of the gas generator 100, but this arrangement is not limited to this configuration.

[0034] The sealing tape 27 is arranged to cover at least one first discharge hole 26A and at least one second discharge hole 26B together. For example, if the sealing tape 27 is cut into small pieces and applied, it may lead to an increase in the number of parts and an increase in the manufacturing load. For this reason, it is desirable to cover many discharge holes 26A and 26B together. For example, one sealing tape 27 may be applied around the entire circumference of the inner wall surface of the upper container 1, covering all the discharge holes 26A and 26B. However, the configuration is not limited to this, and the discharge holes 26A and 26B may be covered with, for example, several pieces of sealing tape 27, as long as the manufacturing process is not complicated. In the example in Figure 3, the discharge holes 26A and 26B provided around the entire circumference of the inner wall surface of the upper container 1 are covered with four pieces of sealing tape 27. Similarly, the discharge holes 26A and 26B may be covered with two or three pieces of sealing tape 27.

[0035] Each of the first discharge holes 26A, which have a diameter of 3 mm, has an opening of 7.1 mm. 2 Each of the second discharge holes 26B, which have an area of ​​2 mm and a diameter of 2 mm, has an opening of 3.1 mm. 2 It has an area of ​​, and the ratio of the opening diameter of the first discharge hole 26A to the second discharge hole 26B is 1.5:1.0, and the ratio of the opening areas is 2.3:1.0.

[0036] As described above, in this embodiment, since two types of first discharge holes 26A and second discharge holes 26B with different opening areas are sealed with the same sealing tape 27, the pressure at which the portion of the sealing tape 27 covering the first discharge holes 26A and second discharge holes 26B breaks and the sealing of the first discharge holes 26A and second discharge holes 26B is released (hereinafter also referred to as the rupture pressure) is set in two stages. That is, the portion of the sealing tape 27 covering the first discharge hole 26A is set to rupture at the first rupture pressure, and the portion covering the second discharge hole 26B is set to rupture at the second rupture pressure, which is higher than the first rupture pressure. Depending on how the gas generator 100 operates, the timing at which the portion of the sealing tape 27 covering the second discharge hole 26B ruptures may be later than the timing at which the portion covering the first discharge hole 26A ruptures. Also, only the portion covering the first discharge hole 26A may rupture.

[0037] Furthermore, the sealing tape 27 is provided with a breaking aid portion 271 along the longitudinal direction of the sealing tape 27 at the center in the direction (width direction) where the first discharge hole 26A and the second discharge hole 26B are aligned. That is, when the sealing tape 27 is provided on the inner wall surface of the peripheral wall portion 101 so as to cover the first discharge hole 26A and the second discharge hole 26B, the breaking aid portion 271 is positioned at the boundary between the first discharge hole 26A and the second discharge hole 26B. Here, the boundary portion (hereinafter also referred to as the boundary portion) is, for example, the portion of the sealing tape 27 located between the first discharge hole 26A and the second discharge hole 26B, and is the boundary portion between the region around the first discharge hole that defines the first discharge hole 26A and the region around the second discharge hole that defines the second discharge hole 26B. In the example shown in Figure 2, the boundary portion is located in the center between the first discharge hole 26A and the second discharge hole 26B. However, the boundary portion is not limited to this arrangement and may be located either closer to the first discharge hole 26A or closer to the second discharge hole 26B.

[0038] The fracture assist portion 271 reduces the strength of at least the boundary portion of the seal tape 27 between the first discharge hole 26A and the second discharge hole 26B. In this embodiment, the fracture assist portion 271 is a weakly formed portion (weak part) in the seal tape 27 where the thickness of the seal layer is thinner than that of the first discharge hole 26A, the second discharge hole 26B, and the surrounding area. For example, the fracture assist portion 271 is formed by making an incision of a predetermined depth in the seal layer during the manufacturing of the seal tape 27. In this embodiment, the fracture assist portion 271 is a so-called half-cut, in which the incision is made so that the thickness dimension of the weak part is half the thickness dimension of the seal layer that is not a weak part. Therefore, as described later, the portion of the seal tape 27 covering the first discharge hole 26A ruptures, while the portion covering the second discharge hole 26B does not rupture. In this case, the rupture assist portion 271 will rupture, and only the portion covering the first discharge hole 26A will detach from the wall surface.

[0039] <Operation> In the gas generator 100 formed as described above, when the first igniter 12A, located inside the igniter housing chamber 8 and outside the separation cylinder 14, is activated, the propellant 16A housed in the first propellant housing chamber 15A ignites and burns, and its flame passes through the propellant hole 17 of the inner cylinder member 4, burning the first gas generating agent 9A housed in the first combustion chamber 5A. When the second igniter 12B, surrounded by the separation cylinder 14, is activated, the propellant 16B housed in the second propellant housing chamber 15B ignites and burns, and its flame ignites and burns the second gas generating agent 9B housed in the second combustion chamber 5B.

[0040] The flame in the second combustion chamber 5B then passes through the through-hole 10 and enters the first combustion chamber 5A. In this way, the combustion path differs depending on whether the first igniter 12A or the second igniter 12B is activated. Therefore, by changing the ignition timing of the igniters 12A and 12B—for example, by activating the second igniter 12B after the first igniter 12A, or by activating the first and second igniters 12A and 12B simultaneously—the timing of combustion of each gas generating agent 9A and 9B can be controlled, and the output form (operating performance) of the gas generator 100 can be adjusted as desired.

[0041] If the pressure inside the housing 3 exceeds the second rupture pressure, for example, by operating the first and second igniters 12A and 12B simultaneously, the sealing tape 27 covering the first discharge hole 26A and the second discharge hole 26B will rupture, and combustion gases will be discharged from both the first discharge hole 26A and the second discharge hole 26B.

[0042] On the other hand, if the pressure inside the housing 3 exceeds the first rupture pressure but does not exceed the second rupture pressure, for example by operating only the first igniter 12A, the portion of the sealing tape 27 covering the first discharge hole 26A will rupture, and combustion gas will be discharged only from the first discharge hole 26A. In this case, if the portion of the sealing tape 27 covering the first discharge hole 26A ruptures but the portion covering the second discharge hole 26B does not, and a rupture assist portion 271 is not provided as in the conventional design, the pressure of the combustion gas may cause a force that peels the portion covering the first discharge hole 26A away from the wall, pulling on the portion covering the adjacent second discharge hole 26B, which may cause the portion covering the second discharge hole 26B to rupture. In this case, the total opening area may become larger than the design value relative to the combustion surface area of ​​the gas generating agent 9A, and the desired output performance may not be obtained.

[0043] In contrast, in this embodiment, even if a force is applied by the combustion gas pressure that causes the portion covering the first discharge hole 26A to peel away from the wall surface, the rupture assist portion 271 ruptures and separates from the portion covering the second discharge hole 26B, thereby preventing the portion covering the second discharge hole 26B from rupturing at a pressure below the second rupture pressure. As a result, the gas generator 100 of this embodiment can obtain appropriate output, such as maintaining the amount of gas generated per unit time at the design value for a predetermined period after the start of operation of the gas generator 100.

[0044] <Example 1> Figure 4 shows the configuration of the sealing tape 27 according to Modification 1. In the first embodiment described above, the weak portion of the sealing tape 27 was half-cut, but in this modification, the weak portion is perforated. The other configurations are the same as in the embodiment described above, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0045] Figure 4(A) shows the sealing tape 27 as viewed from the surface, and (B) schematically shows a cross-section of the sealing tape 27. In this modified example, the sealing tape 27 is as described in the above embodiment. Similar to the breaking aid portion 271 in Figure 2, a breaking aid portion 272 is provided along the longitudinal direction at the center of the width direction of the sealing tape 27. That is, when the sealing tape 27 is provided on the inner wall surface of the peripheral wall portion 101 so as to cover the first discharge hole 26A and the second discharge hole 26B, the breaking aid portion 272 is positioned at the boundary between the first discharge hole and the second discharge hole.

[0046] As shown in Figure 4(B), the fracture assist portion 272 of this embodiment is a fragile portion formed alternately with cut portions 72A, which are cut in the thickness direction, and uncut portions 72B, extending from the adhesive layer 722 side (back side) of the seal layer 721 to the opposite side (front side) of the adhesive layer 722. The fracture assist portion 272 is a so-called perforation and, having partially cut portions 72A, is a fragile portion formed to be more fragile than other parts. Therefore, when the pressure inside the housing 3 exceeds the first fracture pressure without exceeding the second fracture pressure, and a force is applied to the portion of the seal tape 27 covering the first discharge hole 26A that peels away from the wall surface, the fracture assist portion 271 fractures, and the portion covering the first discharge hole 26A separates from the portion covering the second discharge hole 26B. This prevents the portion covering the second discharge hole 26B from rupturing at or below the second fracture pressure. As a result, the gas generator 100 of this modified example can obtain an appropriate output.

[0047] <Modification 2> Figure 5 shows the configuration of the first discharge hole 26A and the second discharge hole 26B according to Modification 2, and Figure 6 shows the configuration of the sealing tape 27 according to Modification 2. In the first embodiment described above, the first discharge hole 26A and the second discharge hole 26B are arranged in rows in the circumferential direction of the upper container 1. In contrast, in this modification, the first discharge hole 26A and the second discharge hole 26B are arranged in a mixed configuration in the circumferential direction of the upper container 1. Note that the other configurations are the same as in the embodiment described above, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0048] In this modified example, as shown in Figure 5, the first discharge hole 26A and the second discharge hole 26B are arranged alternately along the circumferential direction of the upper container 1, forming a single row. As shown in Figure 6, the sealing tape 27 is arranged along the direction of arrangement of the first discharge hole 26A and the second discharge hole 26B (circumferential direction of the upper container 1) so as to cover both the first discharge hole 26A and the second discharge hole 26B together. In this modified example, at the boundary between the first discharge hole 26A and the second discharge hole 26B, which are arranged in the circumferential direction of the upper container 1, a breaking aid portion 273 is provided in the direction that divides the sealing tape 27 into the first discharge hole 26A side and the second discharge hole 26B side, extending from the upper edge 711 to the lower edge 712 of the sealing tape 27.

[0049] In this modified example, the break-relieving portion 273 is a weakly formed portion (weak part) in the seal tape 27 where the thickness of the seal layer is at least thinner than the portion covering the first discharge hole 26A and the second discharge hole 26B and their surroundings, for example, it is half-cut. Note that the break-relieving portion 273 is not limited to half-cut, but may also be a weak part formed in a perforated manner, as in Modified Example 1.

[0050] The first discharge holes 26A and the second discharge holes 26B do not necessarily have to be arranged alternately. For example, at least one of the first discharge holes 26A and the second discharge holes 26B may be arranged in multiple consecutive rows in the arrangement direction (circumferential direction of the upper container 1). In this case, adjacent large holes (first discharge holes) and small holes (second discharge holes) of the same type in the circumferential direction of the upper container 1 may be grouped together, and a rupture assist portion 273 may be provided at the boundary of this group, i.e., at the position that divides the boundary portion between the first discharge hole 26A and the second discharge hole 26B. In this case, a rupture assist portion 273 does not need to be provided between discharge holes 26A and 26B of the same group.

[0051] According to this modified example, if the pressure inside the housing 3 exceeds the first rupture pressure but does not exceed the second rupture pressure, when a force is applied to the portion of the sealing tape 27 that covers the first discharge hole 26A that peels away from the wall surface, the rupture assist portion 273 ruptures and separates from the portion that covers the second discharge hole 26B. Therefore, the portion covering the second discharge port 26B is prevented from cleaving at a pressure below the second cleavage pressure. As a result, the gas generator 100 of this modified example can obtain an appropriate output.

[0052] <Variation 3> Figure 7 shows the arrangement of the first discharge hole 26A and the second discharge hole 26B in Modification 3, and Figure 8 shows the configuration of the sealing tape 27 in Modification 3. This modification differs from Modification 2 described above in the configuration of the sealing tape 27. The other components are the same as in Modification 2 described above, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0053] In this modified example, as shown in Figure 7, the first discharge hole 26A and the second discharge hole 26B are arranged together along the circumferential direction of the upper container 1, forming a single row. The sealing tape 27 is applied to the inner wall surface of the peripheral wall portion 101 along the circumferential direction of the upper container 1 so as to cover either the first discharge hole 26A or the second discharge hole 26B.

[0054] In this modified example, the rupture assist portion 274 is a weak point provided in the seal tape 27, and is provided in a linear shape at a position surrounding the second discharge hole 26B when the seal tape 27 is attached to the upper container 1. The rupture assist portion 274 may have a shape with cuts so that the thickness dimension of the seal layer is smaller (thinner) than the portion covering the first discharge hole 26A and the second discharge hole 26B, as in the first embodiment described above, or it may be perforated with alternating cut and uncut portions, as in Modified Example 1.

[0055] As shown in Figure 8(A), if a plurality of second discharge holes 26B are arranged consecutively in the circumferential direction of the upper container 1 and form a group (second discharge hole group) 26BG, the rupture assist portion 274 may surround these multiple second discharge holes 26B as the second discharge hole group 26BG. Alternatively, if the second discharge holes 26B are not consecutive and only one second discharge hole 26B-1 exists between two first discharge holes 26A, the rupture assist portion 274 may surround the second discharge hole 26B-1 by itself. Note that the rupture assist portion 274 is not limited to the configuration surrounding the second discharge holes 26B as shown in Figure 8(A), but may also be configured to surround the first discharge holes 26A as shown in Figure 8(B). Here, if a plurality of first discharge holes 26A are arranged consecutively in the circumferential direction of the upper container 1 to form a first discharge hole group 26AG, the rupture assist portion 274 may be configured to surround the consecutive plurality of first discharge holes 26A as the first discharge hole group 26AG. Alternatively, if the first discharge holes 26A are not consecutive and only one first discharge hole 26A-1 exists between two second discharge holes 26B, the rupture assist portion 274 may be configured to surround the first discharge hole 26A-1 individually.

[0056] According to this modified example, if the pressure inside the housing 3 exceeds the first rupture pressure but does not exceed the second rupture pressure, and a force is applied to the portion of the sealing tape 27 covering the first discharge hole 26A that peels away from the wall surface, the rupture assist portion 274 ruptures and separates from the portion covering the second discharge hole 26B. This prevents the portion covering the second discharge hole 26B from rupturing at or below the second rupture pressure. As a result, the gas generator 100 in this modified example can obtain an appropriate output.

[0057] <Modification 4> Figure 9 shows the arrangement of the first discharge hole 26A and the second discharge hole 26B according to Modification 4, and Figure 10 shows the configuration of the sealing tape 27 covering the first discharge hole 26A and the second discharge hole 26B in Figure 9. This modification differs from the previously described embodiment in the arrangement of the first discharge hole 26A and the second discharge hole 26B and the configuration of the sealing tape 27. Note that the other configurations are the same as in the previously described embodiment, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0058] In the example in Figure 9, similar to Figure 5, there is a row 261 where the first discharge port 26A and the second discharge port 26B are mixed, and a row 262 where only the second discharge port 26B is located. The sealing tape 27 is positioned to cover the first discharge hole 26A and the second discharge hole 26B, and a breaking aid portion 271 is provided in the center in the width direction, along the longitudinal direction of the sealing tape 27. Specifically, the breaking aid portion 271 is positioned between row 261, which includes the first discharge hole 26A, and row 262, where the second discharge hole 26B is located.

[0059] Furthermore, in the sealing tape 27, a breaking aid portion 273 is provided at the boundary between the first discharge hole 26A and the second discharge hole 26B, which are arranged in the circumferential direction of the upper container 1, in a direction that divides the sealing tape 27 into the first discharge hole 26A side and the second discharge hole 26B side, i.e., in the width direction of the sealing tape 27.

[0060] According to this modified example, if the pressure inside the housing 3 exceeds the first rupture pressure but does not exceed the second rupture pressure, when a force is applied to the portion of the sealing tape 27 covering the first discharge hole 26A that peels away from the wall surface, the rupture assist portions 271 and 273 rupture and separate from the portion covering the second discharge hole 26B. This prevents the portion covering the second discharge hole 26B from rupturing at or below the second rupture pressure. As a result, the gas generator 100 in this modified example can obtain an appropriate output.

[0061] <Modification 5> Figure 11 shows the configuration of the sealing tape 27 according to Modification 5. The configuration of the sealing tape 27 is different from that of Modification 2 described above. Note that the other components are the same as those of Modification 2 described above, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0062] In this modified example, as shown in Figure 5, the first discharge hole 26A and the second discharge hole 26B are arranged alternately along the circumferential direction of the upper container 1, forming a single row. As shown in Figure 11, the sealing tape 27 covers the first discharge hole 26A and the second discharge hole 26B, and at the boundary between the portion covering the first discharge hole 26A and the portion covering the second discharge hole 26B, there is a cut portion 260 that narrows the width of the sealing tape 27 along the width direction (direction along the central axis C), and this portion narrowed by the cut portion 260 is designated as a break-relieving portion 275. That is, the break-relieving portion 275 is a weak portion that is at least narrower in width than the portion covering the second discharge hole 26B and is formed to be fragile. In addition to being formed to be narrow in width, the break-relieving portion 275 may be a weak portion with cuts in the thickness direction as in the first embodiment, or it may be a perforated weak portion as in Modified Example 1. Furthermore, the cut portion 260 may not have width in the longitudinal direction of the sealing tape 27 (the left-right direction in Figure 11), but may be cut in a linear fashion.

[0063] According to this modified version, if the pressure inside the housing 3 exceeds the first rupture pressure but does not exceed the second rupture pressure, and a force is applied to the portion of the sealing tape 27 covering the first discharge hole 26A that peels away from the wall surface, the rupture assist portion 275 ruptures and separates from the portion covering the second discharge hole 26B. This prevents the portion covering the second discharge hole 26B from rupturing at or below the second rupture pressure. As a result, the gas generator 100 in this modified version can obtain an appropriate output.

[0064] <Second Embodiment> Figure 12 shows the configuration of the first discharge hole 26A and the second discharge hole 26B and the rupture assist portion 276 according to the second embodiment, Figure 13 shows the sealing tape 27 covering the first discharge hole 26A and the second discharge hole 26B, and Figure 14 is a cross-sectional view of AA in Figure 13. This embodiment differs from the aforementioned modified example 2 in that the rupture assist portion 276 is provided on the upper container 1. Note that the other configurations are the same as those of the aforementioned modified example 2, so the same elements are denoted by the same reference numerals, and further explanation is omitted.

[0065] The break-relief portion 276 in this embodiment is a projection that protrudes from the inner wall surface of the peripheral wall portion 101 of the upper container 1 toward the side to which the sealing tape 27 is applied, that is, toward the center of the housing 3. Furthermore, the breaking aid portion 276 is formed at the boundary between the adjacent first discharge hole 26A and the second discharge hole 26B. The breaking aid portion 276 has an acute-angled top so as to enable it to break the seal tape 27. In this embodiment, the breaking aid portion 276 is triangular prism-shaped and formed longitudinally along the direction of the central axis C. However, the shape of the breaking aid portion 276 is not limited to this, and any shape that can break the seal tape 27 is acceptable. The breaking aid portion 276 may be added to the inner wall surface of the upper container 1 by welding, brazing, bonding, etc., or it may be formed by cutting the part of the inner wall surface of the upper container 1 other than the breaking aid portion 276.

[0066] In this embodiment, as shown in Figures 13 and 14, the sealing tape 27 is applied so as to cover the first discharge hole 26A and the second discharge hole 26B and the breaking aid portion 276. At this time, the breaking aid portion 276 is formed to be longer than the width of the sealing tape 27 in the direction of the central axis C, and when the pressure inside the housing 3 increases and the sealing tape 27 is pressed against the breaking aid portion 276, the sealing tape 27 is divided from the upper side 711 to the lower side 712.

[0067] According to this embodiment, when the gas generator 100 operates and the pressure inside the housing 3 exceeds the first rupture pressure without exceeding the second rupture pressure, and a force is applied that causes the portion of the sealing tape 27 covering the first discharge hole 26A to rupture and peel away from the wall surface, the rupture assist portion 276 separates the portion covering the first discharge hole 26A from the portion covering the second discharge hole 26B. This prevents the portion covering the second discharge hole 26B from rupturing at a pressure below the second rupture pressure. As a result, the gas generator 100 of this embodiment can obtain an appropriate output.

[0068] In this embodiment, the arrangement of the rupture assist portion 276 is the same as in Modification 2, but even if the rupture assist portion 276 is provided between the first discharge hole 26A and the second discharge hole 26B which are arranged vertically as in the first embodiment, the rupture assist portion 276 may be arranged to surround the first discharge hole 26A or the second discharge hole 26B as in Modification 3.

[0069] Each of the embodiments disclosed herein can be combined with any other features disclosed herein. [Explanation of symbols]

[0070] 1: Upper container 10: Through hole 100: Gas generator 101: Peripheral wall part 11: Seal tape 12: Igniter 12A: First igniter 12B: Second igniter 13: Color 131: Hole 14: Separation tube 15A: First explosive containment chamber 15B: Second explosive containment chamber 16A,16B: Transfer gunpowder 17: Fire pit 18: Seal tape 19: Fire pit 2: Lower container 20: Seal tape 21: Hole 22: Coolant filter 26: Gas vent 260: Excision part 26A: First discharge hole 26B: Second discharge hole 27: Seal tape 271-276: Fracture support section 3: Housing 4: Inner cylinder member 5A: Combustion chamber 5B: Combustion chamber 7: Bulkhead 721: Sealing layer 722: Adhesive layer 72A: Cutting section 72B: Uncut part 8: Ignition device storage room 9: Gas generating agent 9A: Gas generating agent 9B: Gas generating agent 9B: Combustion chamber

Claims

1. Housing and an igniter disposed within the housing; a gas generating agent accommodated in the housing and configured to generate combustion gas upon activation of the igniter; a first exhaust hole provided in the housing for exhausting the combustion gas generated within the housing to the outside; a second exhaust hole provided in the housing together with the first exhaust hole, for exhausting the combustion gas generated within the housing to the outside; a blocking member that covers both the at least one first discharge hole and the at least one second discharge hole; Equipped with a portion of the blocking member covering the first discharge hole is set to rupture at a first rupture pressure, and a portion of the blocking member covering the second discharge hole is set to rupture at a second rupture pressure higher than the first rupture pressure, a breaking assisting portion for reducing strength of the closing member, the breaking assisting portion being located at least at a boundary portion between the first discharge hole and the second discharge hole of the closing member;

2. The gas generator according to claim 1 , wherein an opening area of ​​the first discharge hole is larger than an opening area of ​​the second discharge hole.

3. 2. The gas generator according to claim 1, wherein the breakage assisting portion is a weakened portion provided in the closing member.

4. 3. The gas generator according to claim 2, wherein the breakage assisting portion is a weakened portion provided in the closing member.

5. the blocking member is a sheet attached along a wall surface of the housing on which the first discharge hole and the second discharge hole are provided, 4. The gas generator according to claim 3, wherein the breakage assisting portion is a portion of the closing member where the thickness of the sheet is smaller than the thickness of at least a portion covering the second discharge hole.

6. the blocking member is a sheet attached along a wall surface of the housing on which the first discharge hole and the second discharge hole are provided, 4. The gas generator according to claim 3, wherein the breaking assisting portion is a linear portion in which cut portions cut in the thickness direction of the sheet in the closing member and uncut portions not cut are arranged alternately.

7. The blocking member is a sheet attached to a wall surface of the housing along a circumferential direction of the housing, a cutout portion formed by cutting out the blocking member so as to narrow the width of the blocking member along the width direction of the blocking member at a boundary portion between a portion covering the first discharge hole and a portion covering the second discharge hole in the circumferential direction, 4. The gas generator according to claim 3, wherein the breakage assisting portion is a portion of the blocking member whose width is narrowed by the cutout portion.

8. the blocking member is a sheet attached along a wall surface of the housing on which the first discharge hole and the second discharge hole are provided, The breaking assisting portion is formed at a boundary portion between the first discharge hole and the second discharge hole, and 2. The gas generator according to claim 1, wherein the projection projects from the wall surface of the housing toward the closing member.

9. the first discharge hole and the second discharge hole are arranged in the wall surface of the housing along the circumferential direction of the housing, the blocking member is provided along an arrangement direction of the first discharge hole and the second discharge hole, The gas generator according to any one of claims 1 to 8, wherein the breaking assist portion is provided in a direction separating a portion of the blocking member that covers the first discharge hole and a portion that covers the second discharge hole.

10. 7. The gas generator according to claim 1, wherein the rupture assisting portion is formed linearly so as to surround the first discharge hole or the second discharge hole.

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