Gas generator

Abstract

To provide a gas generator that can efficiently remove residue that is contained in a gas.SOLUTION: A gas generator 100 includes: a cylindrical housing 10 including a peripheral wall part 11; a gas generating agent 70 accommodated in the housing 10 and generating a gas by being burned; an igniter 30 capable of igniting and burning the gas generating agent 70; and a filter 80 which is accommodated in the housing 10 and through which a gas passes. The peripheral wall part 11 includes: a plurality of protrusions 13 protruding toward the inside of the housing 10 in a space 15 through which the gas that has passed through the filter 80 flows; and a gas jetting port 14 for jetting the gas that flows through the space 15 to the outside of the housing 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas generator incorporated in an occupant protection device for protecting an occupant in the event of a vehicle collision, and more particularly to a gas generator incorporated in an airbag device mounted on an automobile or the like. [Background technology]

[0002] Airbag devices, which are passenger protection devices, have become widespread from the viewpoint of protecting passengers in automobiles, etc. Airbag devices are installed to protect passengers from impacts that occur during a vehicle collision, and the airbag instantly inflates and deploys during a vehicle collision, thereby acting as a cushion to support the passenger's body.

[0003] Gas generators have a variety of structures. For example, Patent Document 1 discloses a gas generator in which the inner wall surface of the housing has a recess that protrudes inward. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-184559 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, it is desired to efficiently remove residues contained in the gas generated by the gas generating agent.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a gas generator that can efficiently remove residue contained in gas. [Means for solving the problem]

[0007] (1) A gas generator of the present invention comprises a cylindrical housing having a peripheral wall portion, a gas generating agent contained in the housing and burning to generate gas, an igniter capable of igniting and burning the gas generating agent, and a filter contained in the housing and through which the gas passes, wherein the peripheral wall portion has one or more first convex portions that protrude toward the inside of the housing in a first space formed between the peripheral wall portion and the filter so that the gas that has passed through the filter flows, and a gas outlet that ejects the gas flowing in the first space to the outside of the housing.

[0008] (2) In the gas generator of (1) above, the one or more first protrusions preferably include a plurality of first protrusions aligned in the circumferential direction of the peripheral wall portion to form a first protrusion row.

[0009] (3) In the gas generator of (2) above, it is preferable that the one or more first protrusions form a plurality of first protrusion rows provided at different positions in the axial direction of the peripheral wall portion.

[0010] (4) In the gas generator of (3) above, it is preferable that two adjacent first convex portion rows among the plurality of first convex portion rows have the plurality of first convex portions at different positions in the circumferential direction of the peripheral wall portion.

[0011] (5) In the gas generators described above in (1) to (4), it is preferable that the one or more first protrusions contact the filter.

[0012] (6) In the gas generators of (1) to (4) above, it is preferable that the gas outlet is provided downstream of the one or more first convex portions in the axial direction of the peripheral wall portion when the gas flows in the first space during operation.

[0013] (7) In the gas generators of (1) to (4) above, it is preferable that the housing has a closing portion that closes an open end on one axial side of the peripheral wall portion, and that the closing portion has one or more second protrusions that protrude toward the inside of the housing in a second space through which the gas flows before passing through the filter.

[0014] (8) A gas generator of the present invention comprises a cylindrical housing having a peripheral wall portion and a closing portion that closes an open end on one axial side of the peripheral wall portion, a gas generating agent that is contained in the housing and generates gas by burning, an igniter that is capable of igniting and burning the gas generating agent, and a filter that is contained in the housing and through which the gas passes, wherein the closing portion has one or more convex portions that protrude toward the inside of the housing in a space through which the gas flows before passing through the filter, and the peripheral wall portion has a gas outlet that sprays the gas that has passed through the filter to the outside of the housing. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a gas generator that can efficiently remove residue contained in gas. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing a gas generator according to a first embodiment of the present invention. [Figure 2] 2 is a schematic enlarged cross-sectional view showing a part of the gas generator of FIG. 1. FIG. [Figure 3] FIG. 2 is a schematic end view showing the gas generator of FIG. 1. [Figure 4] FIG. 6 is a schematic enlarged cross-sectional view showing a part of a gas generator according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a schematic enlarged cross-sectional view showing a part of a gas generator according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a gas generator according to a fourth embodiment of the present invention. [Figure 7]FIG. 10 is a schematic enlarged cross-sectional view showing a part of a gas generator according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] First Embodiment A gas generator 100 according to a first embodiment of the present invention will now be described with reference to FIGS.

[0018] Fig. 1 is a schematic cross-sectional view showing gas generator 100 according to a first embodiment of the present invention. Fig. 2 is a schematic enlarged cross-sectional view showing a portion of gas generator 100 of Fig. 1. Fig. 3 is a schematic end view showing gas generator 100 of Fig. 1. Fig. 3(a) shows the end face of gas generator 100 at the position of line AA in Fig. 1, and Fig. 3(b) shows the end face of gas generator 100 at the position of line BB in Fig. 1.

[0019] As shown in Figures 1 to 3, gas generator 100 is a cylinder-type gas generator having a long, approximately cylindrical outer shape, and includes a housing 10, a holder 20, an igniter 30, a cup-shaped member 40, a flow path forming member 50, a plate-shaped member 60, a gas generating agent 70, a filter 80, and a sealing tape 90.

[0020] The housing 10 is cylindrical and has a peripheral wall portion 11 and a closing portion 12, and contains an igniter 30, a cup-shaped member 40, a flow path forming member 50, a plate-shaped member 60, a gas generating agent 70, a filter 80, and a sealing tape 90, etc.

[0021] The peripheral wall portion 11 is a long cylindrical shape having openings at both ends in the axial direction. Note that, hereinafter, the axial direction of the peripheral wall portion 11 may be simply referred to as the axial direction. Also, the radial direction of the peripheral wall portion 11 may be simply referred to as the radial direction. Also, the circumferential direction of the peripheral wall portion 11 may be simply referred to as the circumferential direction. The peripheral wall portion 11 has a plurality of protrusions 13 and a plurality of gas ejection ports 14.

[0022] The multiple protrusions 13 are provided to remove residue contained in the gas generated by the combustion of the gas generating agent 70. The multiple protrusions 13 protrude toward the inside of the housing 10 in a space 15 through which the gas that has passed through the filter 80 flows. In this embodiment, the outer peripheral surface of the peripheral wall portion 11 is recessed toward the inside, causing the inner peripheral surface of the peripheral wall portion 11 to protrude toward the inside, thereby forming the protrusions 13. The space 15 is a space sandwiched between the peripheral wall portion 11 and the filter 80 in the radial direction. The protrusions 13 are an example of a first protrusion, and the space 15 is an example of a first space. The protrusions 13 may be formed by increasing the surface roughness of the inner peripheral surface of the peripheral wall portion 11.

[0023] The plurality of protrusions 13 includes a plurality of protrusions 13 arranged in the circumferential direction and constituting protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g. That is, the plurality of protrusions 13 include a plurality of protrusions 13 constituting protrusion row 13a, a plurality of protrusions 13 (not shown) constituting protrusion row 13b, a plurality of protrusions 13 constituting protrusion row 13c, a plurality of protrusions 13 constituting protrusion row 13d, a plurality of protrusions 13 constituting protrusion row 13e, a plurality of protrusions 13 (not shown) constituting protrusion row 13f, and a plurality of protrusions 13 constituting protrusion row 13g. Protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g are an example of a first protrusion row.

[0024] The plurality of protrusions 13 constitute a plurality of protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g that are provided at different positions in the axial direction. That is, the plurality of protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g are provided at mutually different axial positions. In this embodiment, the plurality of protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g are provided at equal intervals in this order from the igniter 30 side toward the blocking portion 12 side in the axial direction.

[0025] Among the multiple protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, and 13g, the positions of the multiple protrusions 13 in the circumferential direction of any two adjacent protrusion rows 13a, 13b are different from each other. That is, among the two adjacent protrusion rows 13a, 13b, the circumferential positions of the multiple protrusions 13 constituting protrusion row 13a are different (shifted) from each other. The same is true for the two adjacent protrusion rows 13b, 13c, the two adjacent protrusion rows 13c, 13d, the two adjacent protrusion rows 13d, 13e, the two adjacent protrusion rows 13e, 13f, and the two adjacent protrusion rows 13f, 13g. In this embodiment, the positions of the protrusions 13 in the multiple protrusion rows 13a, 13c, 13e, and 13g are the same (not shifted) as each other in the circumferential direction. Also, the positions of the protrusions 13 in the multiple protrusion rows 13b, 13d, and 13f are the same (not shifted) as each other in the circumferential direction.

[0026] The plurality of protrusions 13 face the filter 80 in the radial direction. In this embodiment, the plurality of protrusions 13 are not in contact with the filter 80, and gaps are formed between the plurality of protrusions 13 and the filter 80 in the radial direction.

[0027] Gas outlets 14 are holes for ejecting gas generated inside gas generator 100 to the outside, and a plurality of gas outlets 14 are provided along the circumferential and axial directions. The plurality of gas outlets 14 eject gas flowing through space 15 to the outside of housing 10. In other words, the gas flowing through space 15 is ejected from gas outlets 14 to the outside of housing 10.

[0028] The gas outlets 14 are opposed to the filter 80 in the radial direction. In this embodiment, the gas outlets 14 are opposed to the filter 80 with the seal tape 90 sandwiched therebetween.

[0029] The plurality of gas outlets 14 are provided on one side of the plurality of protrusions 13 in the axial direction. In this embodiment, the plurality of gas outlets 14 are provided on the opposite side of the plurality of protrusions 13 from the igniter 30 in the axial direction. In other words, the plurality of protrusions 13 are provided on the igniter 30 side of the plurality of gas outlets 14 in the axial direction.

[0030] The closing portion 12 is attached to an open end portion on one axial side of the peripheral wall portion 11 and closes the open end portion. A seal member 16 is provided between the peripheral wall portion 11 and the closing portion 12 to prevent gas from leaking between the peripheral wall portion 11 and the closing portion 12. For example, the closing portion 12 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy.

[0031] Holder 20 is attached to the other open end of peripheral wall 11 in the axial direction and closes the open end. A seal member 17 is provided between peripheral wall 11 and holder 20 to prevent gas from leaking between peripheral wall 11 and holder 20. Holder 20 holds igniter 30. For example, holder 20 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy.

[0032] The igniter 30 is capable of igniting a transfer charge (not shown) in the cup-shaped member 40. Specifically, the igniter 30 is disposed at the other axial end of the housing 10 (i.e., the portion closer to the holder 20) as ignition means for igniting and burning the gas generating agent 70 via the ignited transfer charge (not shown). The igniter 30 and the holder 20 that fixes the igniter 30 function as ignition means for generating a flame for burning the granular gas generating agent 70, which will be described later.

[0033] More specifically, the igniter 30 includes a base frame for inserting and holding a pair of terminal pins 32, and a squib cup 31 attached to the base frame. A resistor (bridge wire) is attached to connect the tips of the terminal pins 32 inserted into the squib cup 31, and an ignition charge is filled in the squib cup 31 so as to surround or contact the resistor. Nichrome wire or the like is typically used as the resistor, and ZPP (zirconium, potassium perchlorate), ZWPP (zirconium, tungsten, potassium perchlorate), lead tricinate, or the like is typically used as the ignition charge. Note that a transfer charge may be filled in the squib cup 31 in addition to the ignition charge. Examples of transfer charges that can be placed simultaneously with the ignition charge include a composition consisting of a metal / oxidizer, such as boron / potassium nitrate, a composition consisting of titanium hydride / potassium perchlorate, or a composition consisting of boron / 5-aminotetrazole / potassium nitrate / molybdenum trioxide. For example, the squib cup 31 is generally made of metal or resin.

[0034] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 32. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and this heat causes the ignition charge to start burning. The high-temperature flame generated by the combustion ruptures the squib cup 31 containing the ignition charge. If nichrome wire is used for the resistor, the time from when the current flows through the resistor to when the igniter 30 is activated is 2 milliseconds or less.

[0035] The cup-shaped member 40 has a generally cylindrical shape with a bottom and an open end on the other axial side, and includes a space (also called a transfer chamber, which is a space surrounded by the inner wall of the cup-shaped member 40, the igniter 30, and the holder 20) for accommodating a transfer charge (not shown). The cup-shaped member 40 is attached to the holder 20 so that the space provided therein faces the igniter 30. The cup-shaped member 40 has no openings in either the side wall or the top wall, and surrounds the space provided therein. When the igniter 30 is activated and the transfer charge in the transfer chamber is ignited, the cup-shaped member 40 bursts, deforms, or melts due to an increase in pressure in the internal space and the conduction of the generated heat.

[0036] Suitable materials for the cup-shaped member 40 include metal members such as stainless steel, steel, aluminum, aluminum alloy, stainless steel, stainless steel alloy, etc., and resin members such as thermosetting resins typified by epoxy resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (e.g., nylon 6, nylon 66, etc.), polypropylene sulfide resin, polypropylene oxide resin, etc. In particular, aluminum alloys or iron-based metal materials such as stainless steel and steel, which have relatively higher mechanical strength than aluminum, are preferred.

[0037] The flow path forming member 50 has a first cylindrical portion 51, a second cylindrical portion 52, and a third cylindrical portion 53. The first cylindrical portion 51 is annular along the circumferential direction and is attached to the holder 20 so as to surround the cup-shaped member 40. The first cylindrical portion 51 contacts the other end of the filter 80 in the axial direction and supports the filter 80 in the axial direction. The second cylindrical portion 52 is annular along the circumferential direction and connected to one end of the first cylindrical portion 51 in the axial direction. The second cylindrical portion 52 has a smaller outer diameter than the first cylindrical portion 51 in the radial direction and contacts the inner circumferential surface of the filter 80 in the radial direction and supports the filter 80 in the radial direction. The third cylindrical portion 53 is annular along the circumferential direction and connected to one end of the second cylindrical portion 52 in the axial direction. The third cylindrical portion 53 has a smaller outer diameter than the second cylindrical portion 52 in the radial direction and is elongated in the axial direction. One end of the third cylindrical portion 53 in the axial direction is in contact with the blocking portion 12. The third cylindrical portion 53 has a plurality of through holes 54. The flame generated when the transfer charge (not shown) in the cup-shaped member 40 is ignited by the igniter 30 melts and ruptures the cup-shaped member 40, and then ejects from the cup-shaped member 40, passing through the insides of the first cylindrical portion 51, the second cylindrical portion 52, and the third cylindrical portion 53, and ejected from the through holes 54, igniting and burning the gas generating agent 70.

[0038] The plate-like member 60 is annular in the circumferential direction and is attached to the blocking portion 12. The plate-like member 60 is in contact with the inner peripheral surface of the filter 80 in the radial direction, and supports the filter 80 in the radial direction. The plate-like member 60 is in contact with the outer peripheral surface of the third cylindrical portion 53 in the radial direction, and supports the third cylindrical portion 53 in the radial direction.

[0039] The gas generating agent 70 is accommodated in the housing 10 and generates gas by burning. Specifically, the gas generating agent 70 is accommodated radially inside the filter 80, between the filter 80 and the third cylindrical portion 53. The gas generating agent 70 is an integrally molded product that is ignited by a flame generated by ignition by the igniter 30 and burns to generate gas. The gas generating agent 70 is generally formed as a molded product containing a fuel, an oxidizer, and an additive. Examples of fuels that can be used include triazole derivatives, tetrazole derivatives, guanidine derivatives, azodicarbonamide derivatives, hydrazine derivatives, and combinations thereof. Specifically, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, and the like are preferably used. Examples of oxidizing agents include basic metal nitrates such as basic copper nitrate, basic metal carbonates such as basic copper carbonate, perchlorates such as ammonium perchlorate or potassium perchlorate, and nitrates containing cations selected from alkali metals, alkaline earth metals, transition metals, and ammonia. Nitrates such as sodium nitrate and potassium nitrate are preferred. Examples of additives include binders, slag formers, and combustion modifiers. Examples of binders that can be used include organic binders such as cellulose derivatives such as hydroxypropylene methylcellulose, metal salts of carboxymethylcellulose, and stearates, as well as inorganic binders such as synthetic hydroxytalcite and acid clay. Examples of slag formers that can be used include silicon nitride, silica, and acid clay. Examples of combustion modifiers that can be used include metal oxides, ferrosilicon, activated carbon, and graphite.

[0040] The filter 80 is passed through by the gas generated by the combustion of the gas generating agent 70. The filter 80 is annular in the circumferential direction and is provided so that the gas passes through from the inside to the outside in the radial direction. The filter 80 is elongated in the axial direction. One end of the filter 80 in the axial direction is supported by the blocking portion 12 and the plate-like member 60, and the other end of the filter 80 in the axial direction is supported by the first cylindrical portion 51 and the second cylindrical portion 52.

[0041] The filter 80 is a cylindrical member with a generally cylindrical hollow center. Using the filter 80 made of the cylindrical member reduces the flow resistance of the working gas during operation, allowing for efficient gas flow. The filter 80 may be made of wire material made of metal, such as stainless steel or steel, or a wound or pressed mesh material. Specifically, a knitted wire mesh, a plain weave wire mesh, or an assembly of crimped metal wires may be used. The filter 80 functions as a cooling means for cooling the gas generated in the housing 10 by removing the high-temperature heat of the gas as it passes through the filter 80, and also as a removal means for removing slag and other contaminants contained in the gas. As a variation of the filter 80, a filter with a labyrinth-like flow path formed by combining generally cylindrical or cone-shaped metal components may be used. This allows the path of the working gas to be diverted in various directions, thereby cooling the gas and removing slag.

[0042] Furthermore, while the filter 80 has been illustrated as being made of a so-called knitted wire mesh, it is also possible to use a filter made by winding punched metal or expanded metal instead. Here, punched metal refers to a metal plate in which only openings are provided (i.e., no protrusions are provided around the edges of the openings), and expanded metal refers to a metal plate in which openings are provided in the plate metal member by, for example, making staggered cuts and then expanding the cuts to form a mesh-like structure. Even when such punched metal or expanded metal is used in place of the knitted wire mesh described above, the same effects as those described in the above-described embodiments of the present invention can be obtained.

[0043] Furthermore, in the above-described perforated metal and expanded metal, the filter is formed as a laminate by winding a single metal plate-like member, but the configuration of the filter is not limited to this. That is, the filter may be formed as a laminate by combining different metal plate-like members each having different layers, or the filter may be formed as a laminate by combining a plurality of layers in which some layers are formed as a single metal plate-like member and the remaining layers are formed as a different single metal plate-like member.

[0044] The sealing tape 90 is attached as a sealing member to the inner peripheral surface of the peripheral wall portion 11 so as to close the plurality of gas outlets 14. For example, the sealing tape 90 is made of metal. Aluminum foil with an adhesive material applied to one side can be suitably used as the sealing tape 90, and the sealing tape 90 ensures the airtightness of the combustion chamber inside the housing 10.

[0045] Next, the operation of gas generator 100 during activation described above will be described. When a vehicle equipped with an airbag device incorporating gas generator 100 in the present embodiment collides, the collision is detected by collision detection means separately provided in the vehicle, and igniter 30 is activated based on this detection. When igniter 30 is activated, the pressure inside igniter 30 increases due to combustion of the ignition charge, causing the tip of squib cup 31 of igniter 30 to rupture, and a flame flows from the tip of squib cup 31 of igniter 30 into a transfer chamber inside cup-shaped member 40. The flame that flows into the transfer chamber ignites the transfer charge inside the transfer chamber, and ruptures, deforms, or melts the tip of cup-shaped member 40 along with the pressure increase in the internal space and the conduction of the generated heat. Thereafter, the flame caused by the ignited transfer charge flows through the ruptured, deformed, or melted tip of cup-shaped member 40, through flow path forming member 50, and toward gas generating agent 70.

[0046] The flame flowing in in this manner ignites and burns the gas generating agent 70, generating a large amount of gas. This combustion of the gas generating agent 70 increases the pressure within the housing 10, and the generated gas passes through the filter 80 and flows into the space 15. In the space 15, it collides with the protrusions 13 and flows toward the gas outlets 14 (see the thick arrows in FIG. 2 ). After rupturing the sealing tape 90, it is ejected from the gas outlets 14 to the outside of the housing 10. The gas ejected from the gas outlets 14 is then guided into the interior of the airbag, inflating and deploying the airbag. Note that because the pressure inside the filter 80 is greater than that in the space 15, the gas that passes through the filter 80 and flows into the space 15 can flow through the space 15 without returning to the inside of the filter 80. Furthermore, because the gas passes through the filter 80 and comes into contact with the protrusions 13 before being ejected from the gas outlets 14, residue contained in the gas can be efficiently removed and the gas can be cooled to a predetermined temperature. In this way, by providing the convex portion 13, the amount of residue that can be removed can be increased without increasing the size of the filter 80, and the gas can be cooled, so that increases in weight and cost due to an increase in the size of the filter 80 can be suppressed.

[0047] As explained above, gas generator 100 in the first embodiment of the present invention described above comprises cylindrical housing 10 having a peripheral wall portion 11, gas generating agent 70 that is contained in housing 10 and generates gas by combustion, igniter 30 that is capable of igniting and burning gas generating agent 70, and filter 80 that is contained in housing 10 and through which gas passes, and peripheral wall portion 11 has a plurality of protrusions 13 that protrude toward the inside of housing 10 in space 15 through which gas that has passed through filter 80 flows, and gas outlet 14 that ejects gas flowing in space 15 to the outside of housing 10.

[0048] According to this, the gas generated by the gas generating agent 70 passes through the filter 80, and residue contained in the gas can be removed by the filter 80. Furthermore, by providing the convex portions 13, the area with which the gas comes into contact on the peripheral wall portion 11 is increased, and by bringing the gas into contact with the convex portions 13, residue contained in the gas can be attached to the convex portions 13, and therefore residue contained in the gas can be removed by the convex portions 13. In this way, residue contained in the gas can be efficiently removed.

[0049] Furthermore, as explained above, in gas generator 100 in the first embodiment of the present invention described above, the plurality of protrusions 13 include a plurality of protrusions 13 that are aligned circumferentially around peripheral wall portion 11 and form protrusion row 13a (13b, 13c, 13d, 13e, 13f, 13g).

[0050] This further increases the area of ​​the peripheral wall 11 that the gas comes into contact with, making it easier for the gas to come into contact with the protrusions 13, so that residue contained in the gas can be removed more efficiently.

[0051] Furthermore, as explained above, in gas generator 100 in the first embodiment of the present invention described above, the plurality of protrusions 13 form a plurality of protrusion rows 13a, 13b, 13c, 13d, 13e, 13f, 13g provided at different positions in the axial direction of peripheral wall portion 11.

[0052] This further increases the area of ​​the peripheral wall 11 that the gas comes into contact with, making it easier for the gas to come into contact with the protrusions 13, so that residue contained in the gas can be removed more efficiently.

[0053] Furthermore, as explained above, in the gas generator 100 in the first embodiment of the present invention described above, of the plurality of convex portion rows 13a, 13b, 13c, 13d, 13e, 13f, 13g, any two adjacent convex portion rows have the plurality of convex portions 13 in different (shifted) positions in the circumferential direction of the peripheral wall portion 11.

[0054] This allows the gas to come into contact with the protrusions 13 more easily, so that residue contained in the gas can be removed more efficiently.

[0055] As explained above, in gas generator 100 in the first embodiment of the present invention described above, multiple protrusions 13 face filter 80 in the radial direction of peripheral wall portion 11.

[0056] This allows the gas to come into contact with the protrusions 13 more easily, so that residue contained in the gas can be removed more efficiently.

[0057] As explained above, in gas generator 100 in the first embodiment of the present invention described above, gas outlet 14 faces filter 80 in the radial direction of peripheral wall portion 11.

[0058] This allows the gas to be ejected from the gas ejection port 14 efficiently.

[0059] As explained above, in gas generator 100 in the first embodiment of the present invention described above, gas outlet 14 is provided on one side of multiple protrusions 13 in the axial direction of peripheral wall portion 11.

[0060] According to this, by flowing the gas from the other side to one side in the axial direction in the space 15, the gas can be brought into contact with the protrusions 13 and then efficiently ejected from the gas ejection port .

[0061] Furthermore, as explained above, in gas generator 100 in the first embodiment of the present invention described above, filter 80 is annular along the circumferential direction of peripheral wall portion 11, and is provided so that gas passes from the inside to the outside in the radial direction of peripheral wall portion 11.

[0062] This allows a larger amount of gas to pass through the filter 80, and the gas that has passed through the filter 80 can be ejected from the gas ejection port 14 efficiently.

[0063] Second Embodiment A gas generator 200 according to a second embodiment of the present invention will now be described with reference to Fig. 4. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are similar to the parts in the first embodiment, and therefore descriptions thereof may be omitted. Furthermore, parts in this embodiment that are not particularly described are also similar to those in the first embodiment, and therefore descriptions and illustrations thereof may be omitted.

[0064] FIG. 4 is a schematic enlarged cross-sectional view showing a part of a gas generator 200 according to a second embodiment of the present invention.

[0065] As shown in FIG. 4, gas generator 200 differs from gas generator 100 mainly in that a plurality of protrusions 113 are in contact with filter 180.

[0066] Since the plurality of protrusions 113 contact the filter 180, the plurality of protrusions 113 can support the filter 180 in the radial direction. Therefore, there is no need to support the filter 180 in the radial direction by the second cylindrical portion 152, and the outer diameter of the second cylindrical portion 152 can be smaller than the outer diameter of the second cylindrical portion 52 in the first embodiment. The outer diameter of the second cylindrical portion 152 may be the same as the outer diameter of the second cylindrical portion 52 in the first embodiment. Alternatively, the outer diameter of the second cylindrical portion 152 may be the same as the outer diameter of the first cylindrical portion 151, eliminating the stepped shape and allowing the end of the filter 180 and the end of the second cylindrical portion 152 to abut against each other. This facilitates the manufacture of the flow path forming member 150.

[0067] As explained above, in gas generator 200 in the second embodiment of the present invention described above, multiple protrusions 113 come into contact with filter 180.

[0068] This allows the filter 180 to be supported by the plurality of protrusions 113, while allowing residue contained in the gas to be removed more efficiently.

[0069] Third Embodiment A gas generator 300 according to a third embodiment of the present invention will now be described with reference to Fig. 5. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are similar to the parts in the first embodiment, and therefore descriptions thereof may be omitted. Furthermore, parts in this embodiment that are not particularly described are also similar to those in the first embodiment, and therefore descriptions and illustrations thereof may be omitted.

[0070] FIG. 5 is a schematic enlarged cross-sectional view showing a part of a gas generator 300 according to a third embodiment of the present invention.

[0071] As shown in FIG. 5, gas generator 300 differs from gas generator 100 mainly in that a protrusion 213 is provided at the position where ejection port 214 is provided.

[0072] In gas generator 300, a plurality of convex portions may or may not be provided at the same positions as the plurality of convex portions 13 in gas generator 100 in the first embodiment.

[0073] As explained above, in the gas generator 300 in the third embodiment of the present invention described above, the convex portion 213 is provided at the position where the ejection port 214 is provided.

[0074] This allows the gas to come into contact with the protrusions 213 more easily, so that residue contained in the gas can be removed more efficiently.

[0075] <Fourth embodiment> A gas generator 400 according to a fourth embodiment of the present invention will now be described with reference to FIG.

[0076] FIG. 6 is a schematic cross-sectional view showing a gas generator 400 according to a fourth embodiment of the present invention.

[0077] As shown in FIG. 6, gas generator 400 is a cylinder-type gas generator having a long, approximately cylindrical outer shape, and includes housing 310, holder 320, igniter 330, cup-shaped member 340, partition member 350, sealing tape 360, gas generating agent 370, and filter 380.

[0078] The housing 310 is cylindrical and has a peripheral wall portion 311 and a closing portion 312, and accommodates an igniter 330, a cup-shaped member 340, a partition member 350, a sealing tape 360, a gas generating agent 370, a filter 380, and the like.

[0079] The peripheral wall portion 311 is a long cylindrical shape having openings at both ends in the axial direction. Note that, hereinafter, the axial direction of the peripheral wall portion 311 may be simply referred to as the axial direction. Also, the radial direction of the peripheral wall portion 311 may be simply referred to as the radial direction. Also, the circumferential direction of the peripheral wall portion 311 may be simply referred to as the circumferential direction. The peripheral wall portion 311 has a plurality of gas ejection ports 314.

[0080] Gas outlets 314 are holes for ejecting gas generated inside gas generator 400 to the outside, and a plurality of them are provided along the circumferential and axial directions. The plurality of gas outlets 314 eject gas flowing through space 315 to the outside of housing 310. In other words, the gas flowing through space 315 is ejected from gas outlets 314 to the outside of housing 310. The plurality of gas outlets 314 face filter 380 in the radial direction.

[0081] The blocking portion 312 is attached to an open end portion on one axial side of the peripheral wall portion 311 and closes the open end portion. For example, the blocking portion 312 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy. The blocking portion 312 has a plurality of protrusions 318.

[0082] The multiple protrusions 318 are provided to remove residue contained in the gas generated by the combustion of the gas generating agent 370. The multiple protrusions 318 protrude toward the inside of the housing 310 in a space 319 through which the gas flows before passing through the filter 380. In this embodiment, the multiple protrusions 318 are formed on an end face of the blocking portion 312 facing the space 319, protrude toward the other side in the axial direction, and are aligned in the radial direction, circumferential direction, etc. Furthermore, the space 319 is a space inside the filter 380 in the radial direction. The protrusions 318 may be formed by increasing the surface roughness of the blocking portion 312.

[0083] Holder 320 is attached to the other open end of peripheral wall portion 311 in the axial direction and closes the open end. Holder 320 holds igniter 330. For example, holder 320 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy.

[0084] The igniter 330 is capable of igniting and burning the gas generating agent 370. The igniter 330 is disposed at the other axial end of the housing 310 (i.e., the portion closer to the holder 320) as an ignition means for the gas generating agent 370. The igniter 330 and the holder 320 to which the igniter 330 is fixed function as an ignition means for generating a flame for burning the granular gas generating agent 370, which will be described later.

[0085] The igniter 330 includes a squib cup 331 and a pair of terminal pins 332. The igniter 330 is similar to the igniter 30 in the first embodiment, and therefore a detailed description of the igniter 330 will be omitted.

[0086] The cup-shaped member 340 has a generally cylindrical shape with a bottom and an open end on the other axial side, and includes a space (also called a transfer chamber) for accommodating a transfer charge (not shown) therein. The cup-shaped member 340 is attached to the holder 320 so that the space therein faces the igniter 330. The cup-shaped member 340 has no openings in either the side wall or the top wall, and surrounds the space therein. When the transfer charge in the transfer chamber is ignited by the activation of the igniter 330, the cup-shaped member 340 bursts, deforms, or melts due to an increase in pressure in the internal space and the conduction of the generated heat.

[0087] Suitable materials for the cup-shaped member 340 include metal members such as stainless steel, steel, aluminum, aluminum alloy, stainless steel, stainless steel alloy, etc., and resin members such as thermosetting resins typified by epoxy resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (e.g., nylon 6, nylon 66, etc.), polypropylene sulfide resin, polypropylene oxide resin, etc. In particular, aluminum alloys or iron-based metal materials such as stainless steel and steel, which have relatively higher mechanical strength than aluminum, are preferred.

[0088] The partition member 350 is cylindrical and serves to separate the space in which the gas generating agent 370 is accommodated from the space 319. The partition member 350 is fixed to the inner circumferential surface of the peripheral wall portion 311, and supports the other end of the filter 380 in the axial direction and radially.

[0089] The sealing tape 360 ​​is attached as a sealing member to the end face on the other side of the partition member 350 in the axial direction so as to close the open end on the other side of the partition member 350 in the axial direction. For example, the sealing tape 360 ​​is made of metal. Aluminum foil with an adhesive material applied to one side can be suitably used as the sealing tape 360, and the sealing tape 360 ​​ensures the airtightness of the combustion chamber (the space in which the gas generating agent 370 is accommodated) inside the housing 310.

[0090] The gas generating agent 370 is contained in the housing 310 and generates gas by burning. Specifically, the gas generating agent 370 is contained between the partition member 350 and the cup-shaped member 340. The gas generating agent 370 is similar to the gas generating agent 70 in the first embodiment, and therefore a detailed description of the gas generating agent 370 will be omitted.

[0091] The filter 380 is passed through by the gas generated by the combustion of the gas generating agent 370. The filter 380 is annular in the circumferential direction and is provided so that the gas passes through from the inside to the outside in the radial direction. The filter 380 is elongated in the axial direction. One end of the filter 380 in the axial direction is supported by the blocking portion 312, and the other end of the filter 380 in the axial direction is supported by the partition member 350. The filter 380 is similar to the filter 80 in the first embodiment, and therefore a detailed description of the filter 380 will be omitted.

[0092] Next, an operation of the gas generator 400 described above during activation will be described. When a vehicle equipped with an airbag device incorporating gas generator 400 of the present embodiment collides, the collision is detected by collision detection means separately provided in the vehicle, and igniter 330 is activated based on this detection. When igniter 330 is activated, the pressure inside igniter 330 increases due to combustion of the ignition charge, causing the tip of squib cup 331 of igniter 330 to burst and flow into a transfer chamber inside cup-shaped member 340. The flame that has flowed into the transfer chamber ignites the transfer charge inside the transfer chamber, and as the pressure in the internal space increases and the generated heat is conducted, the tip of cup-shaped member 340 bursts, deforms, or melts. Thereafter, the flame caused by the ignited transfer charge flows through the ruptured, deformed or melted cup-shaped member 340 and flows out from the tip of the squib cup 331 of the igniter 330 to the gas generating agent 370 side.

[0093] The flame flowing in in this manner ignites and burns the gas generating agent 370, generating a large amount of gas. This combustion of the gas generating agent 370 increases the pressure inside the housing 310, and the generated gas penetrates the sealing tape 360 ​​and flows into the space 319. The generated gas comes into contact with the protrusion 318 in the space 319, flows toward the filter 380 (see the thick arrow in FIG. 2), passes through the filter 380, flows into the space 315, and is ejected from the gas outlet 314 to the outside of the housing 310. The gas ejected from the gas outlet 314 is then guided into the interior of the airbag, inflating and deploying the airbag. Note that the pressure inside the filter 380 is greater than that in the space 315, so the gas that passes through the filter 380 and flows into the space 315 can flow through the space 315 without returning to the inside of the filter 380. Furthermore, before being ejected from gas outlet 314, the gas passes through filter 380 and comes into contact with protrusions 318, so that residue contained in the gas can be efficiently removed and the gas can be cooled to a predetermined temperature. In this way, by providing protrusions 313, the amount of residue that can be removed can be increased and the gas can be cooled without increasing the size of filter 380, so that increases in weight, cost, etc. due to an increase in the size of filter 380 can be suppressed.

[0094] As explained above, gas generator 400 in the fourth embodiment of the present invention described above comprises cylindrical housing 310 having peripheral wall portion 311 and closing portion 312 closing the open end on one axial side of peripheral wall portion 311, gas generating agent 370 that is housed in housing 310 and generates gas by combustion, igniter 330 that is capable of igniting and burning gas generating agent 370, and filter 380 that is housed in housing 310 and through which gas passes, with closing portion 312 having a plurality of protrusions 318 that protrude towards the inside of housing 310 in space 319 through which gas flows before passing through filter 380, and peripheral wall portion 311 having gas outlet 314 that ejects gas that has passed through filter 380 to the outside of housing 310.

[0095] According to this, the gas generated by the gas generating agent 370 passes through the filter 380, so that residue contained in the gas can be removed by the filter 380. Furthermore, by providing the convex portion 318, the area with which the gas comes into contact in the blocking portion 312 can be increased compared to a case in which the convex portion 318 is not provided. As a result, by bringing the gas into contact with the convex portion 318, the residue contained in the gas can be attached to the convex portion 318, so that the residue contained in the gas can be more effectively removed by the convex portion 318. In this way, the residue contained in the gas can be efficiently removed.

[0096] Fifth Embodiment A gas generator 500 according to a fifth embodiment of the present invention will now be described with reference to Fig. 7. In this embodiment, parts having the same reference numerals as those in the fourth embodiment down to the last two digits are similar to the parts in the fourth embodiment, and therefore descriptions thereof may be omitted. Furthermore, parts in this embodiment that are not particularly described are also similar to those in the fourth embodiment, and therefore descriptions and illustrations thereof may be omitted.

[0097] FIG. 7 is a schematic enlarged cross-sectional view showing a part of a gas generator 500 according to a fifth embodiment of the present invention.

[0098] As shown in FIG. 7, gas generator 500 differs from gas generator 400 mainly in that gas generator 500 is provided with a plurality of protrusions 413.

[0099] The multiple protrusions 413 are provided to remove residue contained in gas generated by combustion of the gas generating agent. The multiple protrusions 413 protrude toward the inside of the housing 410 in a space 415 through which gas that has passed through the filter 480 flows. In this embodiment, the protrusions 413 are formed by recessing the outer peripheral surface of the peripheral wall portion 411 toward the inside, causing the inner peripheral surface of the peripheral wall portion 411 to protrude toward the inside. The space 415 is a space sandwiched between the peripheral wall portion 411 and the filter 480 in the radial direction. The protrusions 413 are an example of a first protrusion, and the space 415 is an example of a first space. The protrusions 418 are an example of a second protrusion, and the space 419 is an example of a second space. The protrusions 413 may be formed by increasing the surface roughness of the inner peripheral surface of the peripheral wall portion 411.

[0100] The plurality of protrusions 413 includes a plurality of protrusions 413 that are lined up in the circumferential direction and that form protrusion rows 413a, 413b, and 413c. That is, the plurality of protrusions 413 include a plurality of protrusions 413 that form protrusion row 413a, a plurality of protrusions 413 (not shown) that form protrusion row 413b, and a plurality of protrusions 413 that form protrusion row 413c. Protrusion rows 413a, 413b, and 413c are an example of a first protrusion row.

[0101] The plurality of protrusions 413 constitute a plurality of protrusion rows 413a, 413b, and 413c that are provided at different positions in the axial direction. That is, the plurality of protrusion rows 413a, 413b, and 413c are provided at mutually different positions in the axial direction. In this embodiment, the plurality of protrusion rows 413a, 413b, and 413c are provided at equal intervals in this order from the igniter side toward the blocking portion 412 side in the axial direction.

[0102] Among the plurality of convex portion rows 413a, 413b, and 413c, two adjacent convex portion rows have convex portions 413 that are different from each other in the circumferential direction. That is, among the two adjacent convex portion rows 413a and 413b, the circumferential positions of the plurality of convex portions 413 that make up convex portion row 413a are different from the circumferential positions of the plurality of convex portions 413 that make up convex portion row 413b. The same is true for the two adjacent convex portion rows 413b and 413c. In this embodiment, the positions of the plurality of convex portions 413 in the circumferential direction are the same for the plurality of convex portion rows 413a and 413c.

[0103] The plurality of protrusions 413 face the filter 480 in the radial direction. In this embodiment, the plurality of protrusions 413 are in contact with the filter 480. Note that the plurality of protrusions 413 do not necessarily have to be in contact with the filter 480.

[0104] The plurality of gas outlets 414 are provided on one side in the axial direction relative to the plurality of protrusions 413. In this embodiment, the plurality of gas outlets 414 are provided on the opposite side of the igniter side in the axial direction relative to the plurality of protrusions 413. In other words, the plurality of protrusions 413 are provided on the igniter side in the axial direction relative to the plurality of gas outlets 414.

[0105] As described above, according to gas generator 400 in the fifth embodiment of the present invention described above, the same effects as those of gas generator 100 in the first embodiment are achieved.

[0106] Furthermore, as explained above, in gas generator 400 in the above-mentioned fifth embodiment of the present invention, housing 410 has closing portion 412 that closes the open end on one axial side of peripheral wall portion 411, and closing portion 412 has a plurality of protrusions 418 that protrude towards the inside of housing 410 in space 419 through which gas flows before passing through filter 480.

[0107] According to this, by providing the convex portions 418, the area with which the gas comes into contact in the blocking portion 412 is increased, and by bringing the gas into contact with the convex portions 418, the residue contained in the gas can be attached to the convex portions 418, and therefore the residue contained in the gas can be removed by the convex portions 418. In this way, the residue contained in the gas can be efficiently removed.

[0108] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not particularly limit the present invention, and specific configurations and the like can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. For example, a gas generator may be formed by appropriately combining the first to fifth embodiments described above.

[0109] In the above-described first to fifth embodiments, gas generators 100, 200, 300, 400, and 500 are described as being cylindrical gas generators, but the present invention is not limited to this. For example, the gas generator may be a disk-type gas generator provided with a short, substantially cylindrical housing.

[0110] In the first embodiment described above, the peripheral wall 11 has a plurality of protrusions 13, but this is not limiting. For example, the peripheral wall may have a single protrusion instead of a plurality of protrusions. The same applies to the second, third, and fifth embodiments.

[0111] In the fourth embodiment described above, the blocking portion 312 has a plurality of protrusions 318, but this is not limiting. For example, the blocking portion may have a single protrusion instead of a plurality of protrusions. The same applies to the fifth embodiment. [Explanation of symbols]

[0112] 10,110,210,310,410 Housing 11,111,211,311,411 Peripheral wall part 12,212,312,412 Occlusion 13,113,213,318,413,418 Convex 13a, 13b, 13c, 13d, 13e, 13f, 13g, 113a, 113b, 113c, 113d, 113e, 113f, 113g, 213a, 213b, 213c, 213d, 213e, 413a, 413b, 413c Convex row 14,214,314,414 Gas outlet 15,115,215,315,319,415,419 space 16, 17, 216 Sealing material 20,320 holders 30,330 Igniters 31,331 Squib Cups 32,332 terminal pins 40,140,340 Cup-shaped member 50,150,250 Flow path forming member 51,151 First cylindrical part 52,152 Second cylindrical section 53,153,253 Third cylindrical section 54,154,254 through holes 60,260 Plate-shaped members 70,170,270,370 Gas Generator 80,180,280,380,480 filters 90,290,360 Sealing tape 100, 200, 300, 400, 500 gas generators 350,450 Partition material

Claims

1. a cylindrical housing having a peripheral wall portion; a gas generating agent contained in the housing and configured to generate gas by combustion; an igniter capable of igniting and burning the gas generating agent; a filter housed in the housing and through which the gas passes; Equipped with the peripheral wall portion has one or more first convex portions that protrude toward the inside of the housing in a first space formed between the peripheral wall portion and the filter so that the gas that has passed through the filter flows, and a gas outlet that ejects the gas flowing in the first space to the outside of the housing.

2. 2. The gas generator according to claim 1, wherein the one or more first protrusions include a plurality of first protrusions arranged in a circumferential direction of the peripheral wall portion to form a first protrusion row.

3. 3. The gas generator according to claim 2, wherein the one or more first protrusions form a plurality of first protrusion rows provided at different positions in the axial direction of the peripheral wall portion.

4. 4. The gas generator according to claim 3, wherein two adjacent first convex portion rows among the plurality of first convex portion rows have the plurality of first convex portions at different positions in the circumferential direction of the peripheral wall portion.

5. 5. The gas generator according to claim 1, wherein the one or more first protrusions are in contact with the filter.

6. 5. The gas generator according to claim 1, wherein the gas outlet is provided downstream of the one or more first convex portions in an axial direction of the peripheral wall portion when the gas flows in the first space during operation.

7. the housing has a closing portion that closes an open end portion on one side in the axial direction of the peripheral wall portion, 5. The gas generator according to claim 1, wherein the obstructing portion has one or more second convex portions that protrude toward an inside of the housing in a second space through which the gas flows before passing through the filter.

8. a cylindrical housing having a peripheral wall portion and a closing portion that closes an open end portion on one axial side of the peripheral wall portion; a gas generating agent contained in the housing and configured to generate gas by combustion; an igniter capable of igniting and burning the gas generating agent; a filter housed in the housing and through which the gas passes; the obstructing portion has one or more protrusions that protrude toward the inside of the housing in a space through which the gas flows before passing through the filter, a gas generator, wherein the peripheral wall portion has a gas outlet for ejecting the gas that has passed through the filter to the outside of the housing;

Images