Gas generator and vehicle

Abstract

The utility model discloses a kind of gas generator and vehicle, gas generator includes: shell, the shell inside is formed with the gas cavity suitable for accommodating gaseous medium, the shell is formed with the first interface in one end in first direction with the gas cavity communication;Diffuser, the diffuser is set to the first interface and inside is formed with communication cavity, the end of the communication cavity in first direction is opened to the gas cavity to form open end, the open end is communicated with the gas cavity to make the communication cavity receive gaseous medium in the gas cavity, the side wall of the diffuser in second direction is also formed with the communication hole with the communication cavity communication, the second direction is crossed with the first direction, at least part of the hole wall of the communication hole gradually expands in the direction away from communication cavity. According to the gas generator designed in the utility model, the shape of communication hole is designed to accelerate the response speed of gas generator, so as to improve use safety.

Description

Technical Field

[0001] This utility model relates to the field of vehicles, and in particular to a gas generator and a vehicle. Background Technology

[0002] In related technologies, automotive airbag systems typically use gas generators to produce gas for inflating the airbags. These gas generators generally employ ignition propellants that can burn rapidly and generate shock waves. To accelerate the response speed of the gas generator, it often needs to produce a large amount of gas in a short period.

[0003] In some existing technologies, gas generators employ large, cylindrical ignition propellants. Their working principle involves using the combustion of the propellant to propel the gas mixture through the rupture membrane, increasing the propellant size to enhance the shock wave growth space and thus accelerate the response. However, while this design speeds up the response, it also leads to more severe problems with high temperatures, flashes, and combustion products. This not only exacerbates the potential hazards to occupants but also presents greater challenges to cooling the gas generator and protecting the occupants. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. Therefore, one objective of this invention is to provide a gas generator. The gas generator designed according to this invention improves its safety by designing the shape of the connecting hole to accelerate the response speed of the gas generator.

[0005] This utility model also proposes a vehicle having the above-mentioned gas generator.

[0006] The gas generator according to this utility model includes: a housing, wherein a gas cavity suitable for containing a gaseous medium is formed inside the housing, and a first interface communicating with the gas cavity is formed at one end of the housing in a first direction; a diffuser, wherein the diffuser is disposed at the first interface and a communicating cavity is formed inside the diffuser, the communicating cavity being open at the end of the gas cavity in the first direction to form an open end, the open end communicating the communicating cavity with the gas cavity so that the communicating cavity receives the gaseous medium in the gas cavity, and a communicating hole communicating with the communicating cavity is also formed on the sidewall of the diffuser in a second direction, the second direction intersecting the first direction, and at least a portion of the hole wall of the communicating hole gradually expands in a direction away from the communicating cavity.

[0007] According to the gas generator of this utility model, the connecting hole of the diffuser is designed such that at least part of the hole wall gradually expands in the direction away from the connecting cavity. This allows the gaseous medium ejected from the connecting hole to continue to diffuse in the connecting hole after reaching the speed of sound, converting its internal energy into kinetic energy and ejecting supersonic gaseous medium. This accelerates the gaseous medium, thereby speeding up the response speed of the gas generator. The gas generator can produce a large amount of gaseous medium in a short time without increasing the amount of ignition propellant. It can effectively reduce the temperature of the ejected gaseous medium while keeping the total energy constant, achieving the purpose of cooling the output product of the gas generator and improving the safety performance of the gas generator.

[0008] According to some embodiments of the present invention, the connecting hole has a first opening and a second opening on both sides in the second direction, the first opening is connected to the connecting cavity, the second opening is located on the side of the first opening away from the connecting cavity, and the connecting hole includes at least a tapered hole segment connected to the second opening, the tapered hole segment having a cone angle of α, satisfying: 0°<α<180°.

[0009] According to some embodiments of this utility model, the following condition is satisfied: 0° < α < 60°.

[0010] According to some embodiments of the present invention, the connecting holes are configured as a plurality of holes spaced apart in the first direction and / or the second direction of the diffuser, the total area of ​​the first opening of the plurality of connecting holes is S1, and the area of ​​the open end is S2, satisfying: S2 < S1.

[0011] According to some embodiments of the present invention, the gas generator further includes: a bursting membrane, the bursting membrane being disposed on the diffuser and covering the open end, the bursting membrane being adapted to be welded to the diffuser.

[0012] According to some embodiments of the present invention, the diffuser having a transition surface at the edge of the open end is designed, and the transition surface extends in a first direction toward a direction away from the open end.

[0013] According to some embodiments of the present invention, the gas generator further includes: a medicine box, the medicine box being disposed in the gas cavity and having a generating cavity inside suitable for containing a solid medium, the solid medium being suitable for burning after being ignited to generate the gaseous medium, the medicine box having a recessed portion on one side in a first direction that is recessed toward the interior of the generating cavity, the bottom of the recessed portion in the first direction having a hole, the hole communicating the generating cavity with the gas cavity so that the gas cavity receives the gaseous medium in the generating cavity.

[0014] According to some embodiments of the present invention, the medicine box includes: a side wall, the side wall being annular and extending in a first direction; a bottom wall, the bottom wall being disposed on one side of the side wall in the first direction and connected to the side wall, at least a portion of the bottom wall being the recessed portion; wherein the recessed portion includes: a first wall body, the first wall body being a conical circumferential wall body and gradually narrowing in the direction toward the interior of the generating cavity; a second wall body, the second wall body being disposed on the small-diameter end face of the first wall body and having the hole formed at the center in the second direction.

[0015] According to some embodiments of the present invention, the cone angle of the first wall is β, which satisfies: 35° < β < 70°.

[0016] The vehicle according to another embodiment of the present invention is briefly described below.

[0017] The vehicle according to this utility model includes the gas generator described in any of the above embodiments. Since the vehicle according to this utility model is equipped with the gas generator of the above embodiments, the vehicle is safer to use.

[0018] In summary, according to the gas generator of this utility model, the connecting hole of the diffuser is designed such that at least part of the hole wall gradually expands in the direction away from the connecting cavity. This allows the gaseous medium ejected from the connecting hole to continue to diffuse in the connecting hole after reaching the speed of sound, converting its internal energy into kinetic energy and ejecting supersonic gaseous medium. This accelerates the gaseous medium, thereby speeding up the response speed of the gas generator. The gas generator can produce a large amount of gaseous medium in a short time without increasing the amount of ignition propellant. It can effectively reduce the temperature of the ejected gaseous medium while keeping the total energy constant, achieving the purpose of cooling the output product of the gas generator and improving the safety performance of the gas generator.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is an overall structural diagram of the gas generator according to an embodiment of the present utility model.

[0021] Figure 2 yes Figure 1 Exploded view of the structure.

[0022] Figure 3 yes Figure 1 A cross-sectional view of the structure.

[0023] Figure 4 This is a cross-sectional view of the diffuser portion according to an embodiment of the present invention.

[0024] Figure 5 This is a cross-sectional view of a medicine box according to an embodiment of the present utility model.

[0025] Figure label: 1. Gas generator; 10. Housing; 10a. Air cavity; 10b. First interface; 20. Diffuser; 20a. Communicating cavity; 20b. Open end; 20c. Communicating hole; 20d. First opening; 20e. Second opening; 21. Transition surface; 30. Bursting membrane; 40. Medicine box; 40a. Generating cavity; 41. Side wall; 42. Recess; 42a. Hole; 421. First wall; 422. Second wall; 51. Shorting bar; 52. Base; 53. Ignition tube; 54. Ignition tube cover; 55. Buffer ring; 56. Stud; 57. Steel ball. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In related technologies, automotive airbag systems typically use gas generators to produce gas for inflating the airbags. These gas generators generally employ ignition propellants that can burn rapidly and generate shock waves. To accelerate the response speed of the gas generator, it often needs to produce a large amount of gas in a short period.

[0032] In some existing technologies, gas generators employ large, cylindrical ignition propellants. Their working principle involves using the combustion of the propellant to propel the gas mixture through the rupture membrane, increasing the propellant size to enhance the shock wave growth space and thus accelerate the response. However, while this design speeds up the response, it also leads to more severe problems with high temperatures, flashes, and combustion products. This not only exacerbates the potential hazards to occupants but also presents greater challenges to cooling the gas generator and protecting the occupants.

[0033] The following is for reference. Figures 1-5 A gas generator 1 according to an embodiment of the present invention is described.

[0034] like Figure 1As shown, the gas generator 1 according to the present invention includes: a housing 10 and a diffuser 20. The housing 10 has a gas cavity 10a formed inside, which is suitable for containing a gaseous medium. One end of the housing 10 in a first direction has a first interface 10b that communicates with the gas cavity 10a. The diffuser 20 is disposed at the first interface 10b and has a connecting cavity 20a formed inside. The connecting cavity 20a is open at the end of the gas cavity 10a in the first direction to form an open end 20b. The open end 20b connects the connecting cavity 20a with the gas cavity 10a so that the connecting cavity 20a receives the gaseous medium in the gas cavity 10a. The sidewall 41 of the diffuser 20 in the second direction also has a connecting hole 20c that communicates with the connecting cavity 20a. The second direction intersects the first direction. At least a portion of the hole wall of the connecting hole 20c gradually expands in the direction away from the connecting cavity 20a.

[0035] Specifically, when the gas generator 1 is in use, the ignition propellant in the gas chamber 10a burns rapidly to generate a gaseous medium. This gaseous medium can quickly flow towards the first interface 10b. The diffuser 20 is disposed at the first interface 10b, allowing the gaseous medium in the gas chamber 10a to enter the communicating cavity 20a through the open end 20b, and then flow towards the outside of the gas generator 1 through the communicating hole 20c. Here, the diffuser 20 has an open end 20b in the first direction and a communicating hole 20c in the second direction, allowing the diffuser 20 to change the flow direction of the gaseous medium, enabling the high-speed gaseous medium flowing in the first direction to diffuse outward along the second direction. In some embodiments, the second direction is any direction on a plane intersecting the first direction. When the diffuser 20 is cylindrical, the first direction is consistent with the axial direction of the diffuser 20, and the second direction is consistent with the radial direction of the diffuser 20.

[0036] You can refer to this. Figure 4 The two ends of the connecting hole 20c are connected to the connecting cavity 20a and the outside of the gas generator 1, respectively. It can be understood that the flow velocity of the gaseous medium is very high. According to compressible fluid mechanics, if the connecting hole 20c is a straight hole, that is, the diameter of the connecting hole 20c is the same everywhere, then the internal energy of the high-speed gaseous medium will be converted into kinetic energy and discharged outward. However, when the flow velocity of the gaseous medium reaches its own speed of sound, the connecting hole 20c will be blocked by the gaseous medium. That is, no matter how much the pressure difference across the connecting hole 20c is increased, the flow rate and velocity of the gaseous medium flowing through the connecting hole 20c will not continue to increase.

[0037] Therefore, in the gas generator 1 designed in this utility model, as Figure 4As shown, the connecting hole 20c is designed such that at least part of its hole wall gradually expands in the direction away from the connecting cavity 20a. This allows the gaseous medium ejected from the connecting hole 20c to continue diffusing in the connecting hole 20c after reaching the speed of sound, converting its internal energy into kinetic energy and ejecting a supersonic gaseous medium. This accelerates the gaseous medium, thereby speeding up the response speed of the gas generator 1. The gas generator 1 can generate a large amount of gaseous medium in a short time without increasing the amount of ignition propellant. Under the premise of unchanged total energy, the temperature of the ejected gaseous medium can be effectively reduced, achieving the purpose of cooling the output product of the gas generator 1 and improving the safety performance of the gas generator 1.

[0038] According to some embodiments of this utility model, such as Figure 4 As shown, the connecting hole 20c has a first opening 20d and a second opening 20e on both sides in the second direction. The first opening 20d is connected to the connecting cavity 20a, and the second opening 20e is located on the side of the first opening 20d away from the connecting cavity 20a. The connecting hole 20c includes at least a tapered hole segment connected to the second opening 20e. The tapered angle of the tapered hole segment is α, which satisfies: 0°<α<180°.

[0039] Specifically, the connecting hole 20c has a first opening 20d and a second opening 20e on both sides in the second direction, wherein the first opening 20d is connected to the connecting cavity 20a, and the second opening 20e is connected to the outside of the gas generator 1. The shape of the connecting hole 20c can be designed according to the Munro effect. Here, the conical section of the connecting hole 20c connected to the second opening 20e gradually expands in the direction away from the connecting cavity 20a. This part of the section is a conical section to optimize the jet performance of the connecting hole 20c. The cone angle α of the conical section satisfies: 0°<α<180°, so as to convert the internal energy of the gaseous medium into kinetic energy, realize the acceleration of the gaseous medium, thereby speeding up the response speed of the gas generator 1, so that the gas generator 1 can generate a large amount of gaseous medium in a short time.

[0040] According to some embodiments of this utility model, such as Figure 4 As shown, the following condition must be met: 0° < α < 60°. It is understandable that a cone angle α greater than 0 is sufficient to ensure the cooling effect of the connecting hole 20c on the high-speed gaseous medium. However, if the cone angle α is too large, the high-speed gaseous medium flowing out from the second opening 20e will disperse and form turbulence. Its flow direction is irregular and uncontrollable, making it difficult to guarantee the cooling effect. Therefore, the cone angle α of the cone segment must satisfy: 0° < α < 60°, to control the flow direction of the high-speed gaseous medium while ensuring the cooling effect of the connecting hole 20c on the high-speed gaseous medium, thus improving the safety of the gas generator 1. For example, the cone angle α of the cone segment can be 10°, 40°, 45°, etc. In some embodiments, the cone angle α of the cone segment is 40°.

[0041] According to some embodiments of this utility model, such as Figure 4 As shown, the connecting holes 20c are configured as a plurality of holes spaced apart in the first direction and / or the second direction of the diffuser 20. The total area of ​​the first openings 20d of the plurality of connecting holes 20c is S1, and the area of ​​the open end 20b is S2, satisfying that S2 < S1. Specifically, the area S2 of the open end 20b is smaller than the total area S1 of the first openings 20d of the plurality of connecting holes 20c, so that the high-speed gaseous medium flows out of the connecting holes 20c at a lower temperature and a faster flow rate than it is in the connecting cavity 20a, thereby reducing the gas temperature.

[0042] According to some embodiments of this utility model, such as Figure 4 As shown, the gas generator 1 also includes a rupture membrane 30, which is disposed on the diffuser 20 and covers the open end 20b. The rupture membrane 30 is adapted to be welded to the diffuser 20. Specifically, the rupture membrane 30 is an overpressure protection device within the gas generator 1. It can rupture instantaneously after the gas chamber 10a reaches a preset pressure, allowing the gas chamber 10a to connect with the connecting chamber 20a, enabling the high-speed gaseous medium in the gas chamber 10a to enter the connecting chamber 20a. Before the pressure in the gas chamber 10a reaches the preset pressure, the rupture membrane 30 can maintain the seal of the connecting chamber 20a. Here, the rupture membrane 30 is welded to the diffuser 20, specifically by laser welding, to ensure the sealing performance of the rupture membrane 30 on the connecting chamber 20a.

[0043] According to some embodiments of this utility model, such as Figure 4 As shown, the diffuser 20 has a transition surface 21 at the edge of its open end 20b, which extends in a first direction away from the open end 20b. Specifically, the design of the transition surface 21 ensures that the portion connecting the rupture membrane 30 and the open end 20b is a surface contact rather than a point contact. This ensures that when the rupture membrane 30 is subjected to force, the burst point is located at the center of the rupture membrane 30 in a second direction, avoiding stress concentration caused by point contact. This prevents the rupture membrane 30 from shearing from the stress concentration point, making the flow direction of the high-speed gaseous medium controllable. In some embodiments, the edge of the diffuser 20 with the open end 20b is chamfered, and the transition surface 21 is a chamfered arc surface.

[0044] According to some embodiments of this utility model, such as Figure 3 , Figure 5As shown, the gas generator 1 also includes a medicine box 40, which is disposed in the gas cavity 10a and has a generating cavity 40a inside that is suitable for containing a solid medium. The solid medium is suitable for burning after being ignited to generate a gaseous medium. The medicine box 40 has a recessed portion 42 on one side in the first direction that is recessed toward the inside of the generating cavity 40a. The bottom of the recessed portion 42 in the first direction has a hole 42a that connects the generating cavity 40a with the gas cavity 10a so that the gas cavity 10a receives the gaseous medium in the generating cavity 40a.

[0045] Specifically, the cartridge 40 is disposed within the housing 10. The generating chamber 40a inside the cartridge 40 is adapted to contain a solid medium. After being ignited, the solid medium burns to produce a gaseous medium. The gaseous medium flows into the gas chamber 10a of the housing 10 through the orifice 42a. The gas chamber 10a of the housing 10 is adapted to contain the gaseous medium. The communicating chamber 20a of the diffuser 20 is selectively connected to the gas chamber 10a of the housing 10. When the communicating chamber 20a is connected to the gas chamber 10a, the gaseous medium flows from the gas chamber 10a to the communicating chamber 20a and exits the gas generator 1 through the communicating hole 20c on the diffuser 20. The cartridge 40 is provided to store the solid medium, which is generally an ignition agent. When the gas generator 1 is activated, the solid medium inside the cartridge 40 burns into a high-temperature gaseous medium and flows towards the gas chamber 10a at a high flow rate in the first direction.

[0046] According to some embodiments of this utility model, such as Figure 5 As shown, the medicine box 40 includes a side wall 41 and a bottom wall. The side wall 41 is annular and extends in a first direction. The bottom wall is disposed on one side of the side wall 41 in the first direction and connected to the side wall 41. At least a portion of the bottom wall is a recess 42. The recess 42 includes a first wall 421 and a second wall 422. The first wall 421 is a conical circumferential wall and gradually narrows in the direction toward the interior of the generating cavity 40a. The second wall 422 is disposed on the small-diameter end face of the first wall 421 and has a hole 42a at its center in the second direction.

[0047] Specifically, the first wall 421 can be designed as a conical circumferential wall based on the Monroe effect. According to the armor-piercing theory, the longer the generatrix of the first wall 421, the greater the initial jet velocity and jet length of the high-temperature gaseous medium, and the stronger its penetrating ability. The high-temperature gaseous medium flows from the orifice 42a toward the gas cavity 10a and is ejected as a jet along the first wall 421.

[0048] Furthermore, such as Figure 5As shown, the cone angle of the first wall 421 is β, satisfying: 35° < β < 70°. Specifically, when the cone angle β of the first wall 421 is small, the head velocity of the high-temperature gaseous medium jet is high and the velocity gradient is large, which is beneficial to improving the penetration of the high-temperature gaseous medium. However, when the cone angle β of the first wall 421 is too small, the stability of the jet formation deteriorates. When the cone angle β of the first wall 421 is large, the mass of the high-temperature gaseous medium jet increases, the penetration is low, the stability is good, and it will cause excessive aftereffects. However, excessive aftereffects may damage the diffuser 20 and block the connecting hole 20c. When the cone angle β of the first wall 421 is too large, its penetration decreases significantly, making it difficult to form a stable jet. Therefore, the cone angle β of the first wall 421 satisfies: 35° < β < 70°, in order to improve the jet penetration while ensuring jet stability. For example, the cone angle β of the first wall 421 can be 40°, 45°, 60°, etc.

[0049] Furthermore, the specific penetration depth of the high-temperature gaseous medium jet can be calculated using its empirical formula:

[0050] In the formula, L represents the penetration depth, k is a coefficient related to the material of the medicine box 40, θ is half the cone angle of the first wall 421, γ is a coefficient related to the cone angle, v is the critical velocity for the penetration of the high-temperature gaseous medium fluid, which is a coefficient related to the material of the medicine box 40, and D is the shock wave velocity of the high-temperature gaseous medium jet. It can be seen that factors affecting the penetration power of the high-temperature gaseous medium jet include not only the cone angle of the first wall 421 but also the material of the medicine box 40.

[0051] The material chosen for the medicine box 40 should be resistant to breakage during operation and possess good plasticity and high density. Stainless steel, copper, cast iron, lead, or aluminum can be used. Copper offers the best performance, with strong armor-piercing capability and good processability, but it is relatively expensive. While cast iron is brittle under normal conditions, it exhibits excellent plasticity when forming a jet, but its poor processability makes large-scale application difficult. Stainless steel has lower penetrating power than the first two materials, but it can still generate a jet, achieving 70%-80% of the penetrating power of copper medicine box 40 under the same charge conditions, and it is also easy to process and inexpensive. Lead is prone to vaporization, and aluminum has a lower density, resulting in lower penetrating power.

[0052] The gas generator 1 designed according to this utility model incorporates a diffuser 20 and a cartridge 40. The cartridge 40 employs a novel loading structure, using extruded particles to hold BK ignition powder. Combined with a conical first wall 421, the cartridge 40 is connected to the gas chamber 10a via a hole 42a. During inflation, this allows for pressure balance between the inside and outside. However, during the deflagration of the BK ignition powder, the hole 42a is insufficient to instantly balance the pressure inside and outside the cartridge 40. The deflagration of the BK ignition powder within the sealed space of the cartridge 40 causes a rapid increase in internal pressure, generating a shock wave. This shock wave, under the action of the first wall 421, generates a jet, concentrating energy towards the hole 42a, thereby opening the rupture membrane 30 to connect the gas chamber 10a with the connecting chamber 20a, increasing the reliability of the rupture.

[0053] In some embodiments, the cartridge 40 may not have the perforation 42a, and the agent inside the cartridge 40 may be filled by casting or press-fitting. Without the perforation 42a, the cartridge 40 will fully withstand the pressure of the external high-pressure gas, which places higher demands on the strength of the cartridge 40 itself, and therefore also on the shock wave generated during the explosive combustion of the agent. Therefore, when the cartridge 40 does not have the perforation 42a, it is preferable to use casting or press-fitting methods for filling the agent, allowing sufficient space for the shock wave to grow within the solid agent.

[0054] In some embodiments, such as Figures 1-3 As shown, the gas generator 1 consists of a short-circuit strip 51, a base 52, an ignition tube 53, an ignition tube cover 54, a buffer ring 55, a propellant cartridge 40, a housing 10, studs 56, steel balls 57, a rupture membrane 30, and a diffuser 20. The rupture membrane 30 is fixed to the diffuser 20 by laser welding. The base 52 and the diffuser 20 are both fixed to the two ends of the housing 10 in the first direction by pressing and then laser welding. The diffuser 20 adopts a cold-forging and machining structure, avoiding the processing techniques that damage the internal flow lines of the metal in the diffuser 20. This solves the problem of slow leakage of small molecule gases caused by the destruction of metal flow lines after cold forging and machining. The solid ignition propellant is contained in the space formed by the ignition tube cover 54, the buffer ring 55, and the propellant cartridge 40. The propellant cartridge 40, the ignition tube cover 54, and the buffer ring 55 form a relatively sealed structure, allowing the pressure around the ignition propellant to remain relatively stable during combustion.

[0055] The ignition tube 53 is connected to the base 52 by a riveted connection, and the ignition tube cover 54 is welded to the base 52. The ignition tube cover 54 can withstand a static pressure of 50 MPa for an extended period, serving a sealing function. When the ignition tube 53 is activated, the propellant within the sealed space formed by the ignition tube cover 54 and the ignition tube 53 will rapidly explode, facilitating the generation of a shock wave. After the ignition tube cover 54 and the ignition tube 53 are welded together, a buffer ring 55 is fitted onto the ignition tube cover 54. The buffer ring 55 forms a relatively sealed fixed cavity with the propellant cartridge 40, serving to restrain the granular propellant; simultaneously, it acts as a buffer during the explosive combustion of the propellant, preventing the shock wave from severely damaging the connection structure between the base 52 and the housing 10.

[0056] Before inserting the base 52, the powder box 40 is inserted first. Ignition powder is added to the powder box 40. The powder box 40 can be stamped to form an outer edge, which overlaps with the shell 10 during ignition to prevent the powder box 40 from being blown away. The powder box 40 has a hole 42a. During inflation, high-pressure gas from the shell 10 can enter the powder box 40 through the hole 42a, balancing the pressure inside and outside the powder box 40. Simultaneously, the higher initial pressure facilitates rapid deflagration when the ignition powder is ignited, thus promoting the generation of a shock wave. The entire product contains only one type of pyrotechnic agent, which not only makes the overall stability of the product more controllable and results in a lower gas production temperature compared to traditional pyrotechnic gas generators 1, but also increases safety during the production process.

[0057] After welding the base 52 of the ignition tube cover 54 and the structure of the bursting membrane 30, they are first pressed into the corresponding space reserved in the housing 10 using a press, and then connected to both ends of the housing 10 by laser welding. Compared with friction welding, laser welding has a higher penetration depth, and the use of laser welding as a connection method simplifies the process. After welding the base 52 and diffuser 20 to the housing 10, high-pressure inert gas is injected into the housing 10 through the reserved small holes. After inflation, the small holes on the housing 10 are welded shut with steel balls 57 to achieve a seal. The high-temperature gaseous medium discharged from the gas generator 1 generally enters the gas bag. The gas composition is a mixture of argon and helium. This mixture is safe, stable, non-toxic, and harmless, and also has flame-retardant properties. After thermal expansion, it is injected into the gas bag to safely complete inflation. In addition, the gas leakage rate of the product can be detected by detecting the helium leakage rate. The stud 56 is welded to the housing 10 by resistance welding to connect the generator to the upper-level module. The short-circuit strip 51 is mounted on the base 52 and contacts the two pins of the ignition tube 53, so that the ignition tube 53 is in a short-circuit state during transportation, production, assembly and other processes, so as to prevent the ignition tube 53 from accidentally igniting due to static electricity or stray current, thereby avoiding injury to personnel due to accidental action.

[0058] When ignition tube 53 receives an electrical signal from the upper-level system, the bridge wire of ignition tube 53 heats up, igniting the propellant in ignition tube 53, which in turn ignites the propellant in the lower-level propellant. The ignition propellant here is generally BK ignition propellant. The main active ingredients of BK ignition propellant are boron carbide and potassium nitrate. When ignited in a confined space, this propellant will rapidly detonate, generating a shock wave, incandescent combustion products, and a large amount of heat. On one hand, the shock wave generated by the propellant, under the action of the cartridge 40, produces a Munroe effect, making the fluid products generated by the detonation more concentrated, forming a jet that impacts the rupture membrane 30 at the tail. On the other hand, the combustion of the ignition propellant generates a large amount of heat and incandescent combustion products, causing the temperature of the argon-helium mixed high-pressure gas originally filling the casing 10 to rise rapidly, thus rapidly increasing its pressure, which is conducive to the opening of the rupture membrane 30. Under the combined action of the rapidly expanding internal pressure and the jet generated by the propellant 40, the rupture membrane 30 ruptures, releasing the argon-helium mixed gas originally filling it. After the bursting membrane 30 ruptures, the argon-helium mixed gas flows rapidly into the airbag through the connecting hole 20c on the diffuser 20, which serves to protect the crew in the event of an instantaneous impact.

[0059] The gas generator 1 designed according to this utility model adopts a hybrid generator structure. The main gas source is compressed gas that is filled into the gas generator 1 rather than gas produced by gunpowder combustion. Its output gas temperature is lower and more stable. Furthermore, it adopts an energy-concentrating powder box 40, which makes the output power stronger with the same amount of powder, increases the reliability of membrane breaking, and at the same time, the overall structure is simpler, reduces product cost, and improves the overall reliability of the product. Compared with other existing hybrid gas generators 1, it has lower cost and more reliable process.

[0060] The vehicle according to this utility model is briefly described below.

[0061] The vehicle according to this utility model includes the gas generator 1 described in any of the above embodiments. Since the vehicle according to this utility model is equipped with the gas generator 1 of the above embodiments, the vehicle is safer to use.

[0062] In summary, according to the gas generator 1 of this utility model, the connecting hole 20c of the diffuser 20 is designed such that at least part of the hole wall gradually expands in the direction away from the connecting cavity 20a. This allows the gaseous medium ejected from the connecting hole 20c to continue to diffuse in the connecting hole 20c after reaching the speed of sound, converting its internal energy into kinetic energy and ejecting a supersonic gaseous medium. This accelerates the gaseous medium, thereby speeding up the response speed of the gas generator 1. The gas generator 1 can generate a large amount of gaseous medium in a short time without increasing the amount of ignition propellant. Under the premise of unchanged total energy, the temperature of the ejected gaseous medium can be effectively reduced, achieving the purpose of cooling the output product of the gas generator 1 and improving the safety performance of the gas generator 1.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0064] Although embodiments of the present invention have been shown and described above, variations, modifications, substitutions and alterations can be made to the above embodiments.

Claims

1. A gas generator, characterized in that, include: The housing (10) has a gas cavity (10a) inside which is suitable for containing a gaseous medium, and a first interface (10b) communicating with the gas cavity (10a) is formed at one end of the housing (10) in a first direction. A diffuser (20) is disposed at the first interface (10b) and has a connecting cavity (20a) formed inside. The connecting cavity (20a) is open in a first direction toward the end of the gas cavity (10a) to form an open end (20b). The open end (20b) connects the connecting cavity (20a) with the gas cavity (10a) so that the connecting cavity (20a) receives the gaseous medium in the gas cavity (10a). The diffuser (20) also has a connecting hole (20c) on its sidewall (41) in a second direction that communicates with the connecting cavity (20a). The second direction intersects the first direction. At least a portion of the hole wall of the connecting hole (20c) gradually expands in a direction away from the connecting cavity (20a).

2. The gas generator according to claim 1, characterized in that, The connecting hole (20c) has a first opening (20d) and a second opening (20e) on both sides in the second direction. The first opening (20d) communicates with the connecting cavity (20a), and the second opening (20e) is located on the side of the first opening (20d) away from the connecting cavity (20a). The connecting hole (20c) includes at least a tapered hole segment connected to the second opening (20e). The tapered hole segment has a cone angle of α, which satisfies the condition: 0° < α < 180°.

3. The gas generator according to claim 2, characterized in that, Satisfies: 0° < α < 60°.

4. The gas generator according to claim 2, characterized in that, The connecting holes (20c) are configured to be a plurality of holes spaced apart in the first direction and / or the second direction of the diffuser (20), the total area of ​​the first opening (20d) of the plurality of connecting holes (20c) is S1, and the area of ​​the open end (20b) is S2, satisfying: S2 < S1.

5. The gas generator according to claim 1, characterized in that, Also includes: A rupture membrane (30) is disposed on the diffuser (20) and covers the open end (20b), and the rupture membrane (30) is adapted to be welded to the diffuser (20).

6. The gas generator according to claim 5, characterized in that, The diffuser (20) has a transition surface (21) at the edge of the open end (20b), the transition surface (21) extending in a first direction away from the open end (20b).

7. The gas generator according to claim 1, characterized in that, Also includes: A medicine box (40) is disposed in the gas cavity (10a) and has a generating cavity (40a) inside that is suitable for containing a solid medium. The solid medium is suitable for combustion after being ignited to generate the gaseous medium. The medicine box (40) has a recess (42) on one side in a first direction that is recessed toward the inside of the generating cavity (40a). The recess (42) has a hole (42a) at the bottom in the first direction. The hole (42a) connects the generating cavity (40a) with the gas cavity (10a) so that the gas cavity (10a) receives the gaseous medium in the generating cavity (40a).

8. The gas generator according to claim 7, characterized in that, The medicine box (40) includes: Sidewall (41), said sidewall (41) is annular and extends in a first direction; A bottom wall, the bottom wall being disposed on one side of the side wall (41) in a first direction and connected to the side wall (41), wherein at least a portion of the bottom wall is configured as the recess (42); wherein The recess (42) includes: The first wall (421) is constructed as a conical circumferential wall and gradually narrows in the direction toward the interior of the generating cavity (40a); The second wall (422) is disposed on the small-diameter end face of the first wall (421) and the hole (42a) is provided at the center in the second direction.

9. The gas generator according to claim 8, characterized in that, The cone angle of the first wall (421) is β, which satisfies: 35° < β < 70°.

10. A vehicle, characterized in that, Includes the gas generator according to any one of claims 1-9.

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