Ignition system and method of manufacturing the same, gas generator, and airbag

Abstract

The present application relates to an ignition system for a gas generator, the ignition system (10) comprising: an ignition tube (1); a base (2) having a receptacle into which the ignition tube is press-fitted, the ignition tube projecting from the base with its head (11), the base being configured as an integral injection-moulded part, wherein a metal insert (4) is injection-moulded into a plastics material, the insert being configured as a disc, a receptacle aperture of the insert providing part of the receptacle, the receptacle aperture comprising a first cylindrical aperture section and a second conical aperture section, the plastics material of the base defining a third cylindrical aperture section; and a container (3) having an opening (33) through which the base together with the ignition tube is press-fitted into the container with the head of the ignition tube facing forwards. The present application also relates to a gas generator comprising the ignition system, to a safety airbag and to a method for producing the ignition system. The ignition system can have a compact size, an optimized weight, reduced manufacturing costs, reliable working performance.

Description

Technical Field

[0001] This application relates to an ignition system for a gas generator and a method for manufacturing the same, as well as a gas generator including the ignition system and a safety airbag including the gas generator. Background Technology

[0002] Airbags are widely used in transportation vehicles, especially land transportation vehicles, and particularly motor vehicles, as a safety protection device for occupants. An airbag consists of a folding airbag and a gas generator. Under predetermined operating conditions of the vehicle, such as in a collision, the gas generator is activated, rapidly producing gas. This gas fills the airbag, causing it to inflate and deploy, providing cushioning for the occupant and preventing their head or other body parts from colliding with hard or sharp objects. The gas generator can also be called an inflator. Examples of airbags include driver's side airbags installed in the steering wheel, passenger side airbags installed in the dashboard, curtain airbags, and so on.

[0003] In vehicle technology, inflatable restraint systems such as airbags have been developed to complement conventional seatbelt restraint systems. Typically, when an airbag is activated, it protects vehicle occupants by utilizing the elasticity of the inflated airbag to absorb the physical impact caused by a vehicle collision. In a collision, the airbag deploys into the space between the occupant and interior objects or surfaces within the vehicle, providing cushioning and reducing the likelihood of injury due to unintended contact with these objects or surfaces.

[0004] Airbags can be part of a vehicle's safety protection system, which comprises multiple structural components. Typically, these components include the airbag itself, a gas generator, sensors, and an electronic control unit (ECU). Sensors acquire data relevant to vehicle emergency situations. The ECU processes this data and determines whether a collision is imminent or ongoing. The gas generator is energized and activated by inputting a trigger signal, thus supplying or generating gas.

[0005] In practice, a gas generator is known in which a chamber surrounding an ignition tube is sealed with a ruptured membrane. When the ignition tube is activated, the shock wave generated by the ignition tube opens the ruptured membrane. Typically, the ruptured membrane needs to be installed by welding to hermetically seal the container of the ignition system. The manufacturing process for such an ignition system is costly.

[0006] In addition, a type of compressed gas generator, also known as a "compressed gas filling machine," is known in practice. This gas generator includes a pressure vessel, within which a pressure chamber is defined for containing compressed gas. When the ignition tube of the gas generator is activated, it ignites the gunpowder in the gunpowder chamber, instantly generating a high-temperature, high-pressure gas. This high-temperature, high-pressure gas mixes with the cooler compressed gas, causing the compressed gas to heat up and pressurize. The mixed gas is then transported from the gas generator to the gas bag through a diffuser. In this known gas generator, the ignition tube is fitted with a base, wherein a machined metal body is used to ensure the supporting strength of the base; or a metal body is used as the base body, and a covering plastic body is used to form the ignition tube and the base into an integral structural unit in an injection molding process to ensure the supporting strength of the base. Such an ignition system has a large size, a large weight, and a high manufacturing cost. Related prior art patent documents can be found in CN107000670B and CN111565980A. Summary of the Invention

[0007] The purpose of this application is to provide an ignition system for a gas generator and a method for manufacturing the same, as well as a gas generator including the ignition system and an airbag including the gas generator, wherein the ignition system can have a compact size, is lightweight, and can advantageously reduce manufacturing costs.

[0008] A first aspect of the invention relates to an ignition system for a gas generator, the ignition system comprising an ignition tube, a base, and a container. The base has a receiving portion into which the ignition tube is press-fitted, the ignition tube extending from the base, and the base is configured as an integral injection-molded component, wherein a metal insert is injection-molded into a plastic material, the insert providing a portion of the receiving portion. The container has an opening into which the base, together with the ignition tube, is press-fitted with the head of the ignition tube facing forward through the opening.

[0009] The technical measures of this invention enable the realization of improved gas generators, such as mixed gas generators. On the one hand, it avoids the disadvantages associated with welding a ruptured membrane onto the container during the manufacturing process of the ignition system in the prior art. On the other hand, compared to the prior art that simply uses a metal body as a base or uses a metal body as the base body and covers it with a plastic body, it achieves the requirement of overall lightweight ignition system, simplifies the manufacturing process, enables a compact size, and allows the base to have a flexible mounting interface that easily accommodates different sizes and types of ignition tubes.

[0010] In some embodiments, the insert may be configured as a metal disc or a disc comprising a metal, the disc having a central receiving hole that provides a portion of the receiving portion.

[0011] In some embodiments, the receiving hole may include a first cylindrical hole segment adjacent to a first side of the disc body and a second tapered hole segment adjacent to the first cylindrical hole segment that expands toward a second side of the disc body opposite to the first side, and the plastic material of the base defines a third cylindrical hole segment adjacent to the second tapered hole segment. The second tapered hole segment may have the diameter of the first cylindrical hole segment on one side and the diameter of the third cylindrical hole segment on the other side.

[0012] In some embodiments, the inlay may have a structure for reinforcing the bonding between the plastic material and the inlay.

[0013] In some embodiments, the structure may include: a plurality of holes, such as blind holes or through holes, distributed around the central receiving hole, and / or a plurality of notches distributed on the edge of the insert.

[0014] In some embodiments, the structure may include: a plurality of through holes evenly distributed around the central receiving hole and a plurality of notches evenly distributed on the edge of the insert, wherein, with reference to the axis of the receiving hole in the circumferential direction, each of the plurality of notches is centrally arranged between two adjacent through holes in the plurality of through holes.

[0015] In some embodiments, the container may be tapered on the open side to retain the base along with the ignition tube within the container.

[0016] In some embodiments, the base may include a first segment and a second segment adjacent to the first segment, having a smaller diameter than the first segment, the insert being embedded in the plastic material of the first segment.

[0017] In some embodiments, apart from the metal disc, the rest of the base is made entirely of plastic material.

[0018] In some embodiments, in addition to the metal disc, the insert may also include a hollow cylindrical metal handle connected to the disc.

[0019] In some embodiments, in addition to the metal disc that serves as the inlay, the base may also include an inlay of another metal separate from the metal disc.

[0020] In some embodiments, the base may include a first segment and a second segment adjacent to the first segment having a smaller diameter than the first segment, the disc of the insert being embedded in the plastic material of the first segment, the shank of the insert surrounding and defining the second segment, the plastic material being injection molded on the inner circumferential surface of the shank of the insert and forming a cavity, and the plastic materials of the base in the first segment and the plastic materials in the second segment being integrally connected.

[0021] In some embodiments, the container may be closed on the open side after the base, together with the ignition tube, is press-fitted into the container.

[0022] In some embodiments, the container may include: a hollow body portion having the opening and a bottom opposite to the opening; and a hollow protrusion extending from the bottom of the body portion.

[0023] In some embodiments, the base may be received in the main body portion and abut against the bottom of the main body portion, and the head of the ignition tube extending from the base may be received in the protrusion, the tip of the protrusion being configured to be opened by a shock wave generated by the ignition tube when the ignition system is activated.

[0024] In some embodiments, the protrusion may have a gradually decreasing wall thickness in the direction away from the main body, and / or the protrusion may have a weakening groove at its apex. Due to the gradually decreasing wall thickness design for the hollow protrusion of the container, and / or the weakening design in the thin-walled region at the apex of the protrusion, it is possible to ensure that the shock wave generated by the ignition tube when activated can smoothly open the apex of the container's protrusion, reliably igniting the gunpowder contained in the propellant chamber.

[0025] In some embodiments, the ratio 'a' of the minimum to the maximum wall thickness of the protrusion can satisfy 0.5 < a < 1, and / or the ratio 'b' of the height of the protrusion to the outer diameter of the head of the ignition tube can satisfy b ≥ 1. When the hollow protrusion of the container has the predetermined height, a reliable ignition path can be provided to ensure the reliable operation of the propellant in the propellant chamber of the ignition gas generator, especially a mixed gas generator.

[0026] In some embodiments, the ignition system may be a rotationally symmetric structural unit with a longitudinal axis.

[0027] In some embodiments, the base and / or the container and / or the ignition tube may be rotationally symmetric components with a longitudinal axis.

[0028] In some embodiments, the base has a front end face and a back end face, and preferably, at least one, and especially both, end faces are planar.

[0029] In some embodiments, the container may have a slope inside it that matches the ignition tube in the transition region from the body to the protrusion, to provide a support and fixing interface for the ignition tube.

[0030] A second aspect of the invention relates to a gas generator comprising an ignition system and a gunpowder chamber according to any embodiment of the invention, the ignition system and the gunpowder chamber being configured such that the ignition system, when activated, ignites gunpowder contained in the gunpowder chamber.

[0031] In some embodiments, the gas generator may be a mixing gas generator, which includes a pressure vessel defining a pressure chamber for containing compressed gas, wherein the ignition system and the propellant chamber are configured such that the ignition system, when activated, ignites the propellant contained in the propellant chamber, and the gas generated by the combustion of the propellant can be mixed with the compressed gas.

[0032] In some embodiments, the gas generator may be configured for use in a driver's airbag, passenger's airbag, side curtain airbag, seat airbag, or other airbag.

[0033] A third aspect of the present invention relates to a method for manufacturing an ignition system, the method comprising the following steps:

[0034] Provide ignition tubes;

[0035] A base is provided having a receiving portion, the base being configured as an integral injection-molded component, wherein a metal insert is injection-molded into a plastic material, the insert providing a portion of the receiving portion;

[0036] A container is provided, the container having an opening;

[0037] The ignition tube is press-fitted into the receiving portion, wherein the ignition tube extends from the base with its head protruding from the base;

[0038] The base, together with the ignition tube, is pressed into the container through the opening with the ignition tube head facing forward.

[0039] In some embodiments, the method may further include: after the base and ignition tube are press-fitted into the container, closing the container at the open side.

[0040] A fourth aspect of the invention relates to an airbag comprising an air bag, particularly a folded air bag, and a gas generator according to any embodiment of the invention, preferably, the airbag being a side curtain airbag.

[0041] The fifth aspect of the invention relates to a means of transport, particularly a motor vehicle, which includes an airbag according to the fourth aspect of the invention.

[0042] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features. Attached Figure Description

[0043] The invention will now be described in more detail with reference to the accompanying drawings and exemplary embodiments. A brief description of the drawings is as follows:

[0044] Figure 1 This is a schematic longitudinal sectional view of a gas generator according to an embodiment of the present invention.

[0045] Figure 2 yes Figure 1 A schematic longitudinal sectional view of the ignition system of a gas generator.

[0046] Figure 3A and 3B yes Figure 2 Perspective and longitudinal sectional views of the base of the ignition system.

[0047] Figure 3C yes Figure 3A and 3B A perspective view of the metal inlay of the base.

[0048] Figure 3D This is a schematic longitudinal sectional view of the container before assembly.

[0049] Figures 4A-4C yes Figure 3D A schematic top view of the protrusions of the container.

[0050] Figures 5A-5C It is used for manufacturing Figure 2 A schematic diagram of the multiple steps of an ignition system.

[0051] Figure 6A and 6B These are perspective and longitudinal sectional views of the base according to another embodiment.

[0052] Figure 6C Yes, yes Figure 6A and 6B A perspective view of the metal inlay of the base. Detailed Implementation

[0053] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. It should be understood that elements not essential for understanding the invention may be omitted from the drawings for ease of illustration and understanding. In the drawings, the same reference numerals denote the same parts or parts that function identically. In the following description, numerous specific details, such as examples of specific parts, devices, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that not all of these specific details are necessarily required. Exemplary embodiments should not be construed as limiting.

[0054] Figure 1 This is a schematic longitudinal sectional view of a gas generator 100 according to an embodiment of the present invention. The gas generator 100 can be configured as a mixing gas generator. Although the invention will be described exemplarily below with particular reference to a mixing gas generator, those skilled in the art will understand and recognize, based on the teachings provided herein, that the invention is not limited to mixing gas generators, and that the gas generator 100 of the present invention can be generally applied to various types of airbags, such as knee airbags, distal airbags, seat side airbags, etc. Those skilled in the art will understand and recognize that the ignition system 10, the gas generator 100 including the ignition system 10, and the airbag including the gas generator 100 can generally be applied to vehicles of transport, such as land vehicles, water vehicles, or air vehicles, and particularly to motor vehicles. Motor vehicles can refer to passenger cars or trucks.

[0055] like Figure 1The gas generator 100 shown may include an elongated, linearly or curved—e.g., hollow cylindrical—pressure vessel 80, within which a pressure chamber 30 is formed for containing compressed gas. The compressed gas is typically an inert gas. The pressure vessel 80 may be configured as a tubular member having a circular or non-circular cross-section. An ignition system 10 and a propellant chamber 20 are provided at a first axial end of the pressure vessel 80, and a diffuser 40 is provided at a second axial end opposite the first axial end. The pressure chamber 30 is hermetically sealed at the first axial end by the ignition system 10 and at the second axial end by the diffuser 40. The ignition system 10 is fixed as a structural unit to the first axial end of the pressure vessel 80, for example, hermetically connected to the inner wall of the pressure vessel 80 by welding. The propellant chamber 20 is defined by a first partition element 50 and a second partition element 60 and is filled with propellant in block, flake, spherical, or other suitable forms. The first separating element 50 abuts against the ignition system 10 and has a central hole into which the protrusion 32 of the ignition system 10 extends. The second separating element 60 may have a plurality of orifices, the size of which should ensure that gunpowder does not pass through the propellant chamber 20 into the pressure chamber 30 containing compressed air. The diffuser 40 may be sealed with a ruptured membrane 70 on its end face facing the pressure vessel 80.

[0056] When the ignition system 10 is activated, the gunpowder contained in the gunpowder chamber 20 is ignited by the ignition system 10. The combustion of the gunpowder generates hot gas with high temperature and high pressure. This hot gas enters the pressure chamber 30 through the small hole of the second separating element 60 and mixes with the cold compressed gas, causing the cold compressed gas to heat up and pressurize. As a result, the rupture membrane 70 on the diffuser 40 ruptures under the action of shock wave and / or pressure. The mixed gas is output through the diffuser 40 into the folded air bag of the airbag (not shown), causing the air bag to inflate and thus providing the predetermined safety protection function.

[0057] In such Figure 1 In the illustrated embodiment, the ignition system 10 is applied to a mixed gas generator. It is understood that the ignition system 10 is not limited to application in mixed gas generators, but can be applied to a wide variety of gas generators.

[0058] Now refer to Figure 2 and Figures 3A-3D as well as Figures 4A-4C The ignition system 10 for the gas generator 100 and its components will be described in more detail.

[0059] The ignition system 10 includes an ignition tube 1, a base 2, and a container 3. The ignition tube 1 is known in practice and can be a standardized product. The ignition tube 1 can also be referred to as an initiator or initiator assembly. The ignition tube 1 may contain a reactive filler, wherein when the conductive lead 12 of the ignition tube 1 is energized, the reactive filler rapidly undergoes a chemical reaction, generating a shock wave that opens the top of the container 3, thereby igniting the gunpowder in the powder chamber 20 and achieving the detonation function.

[0060] The base 2 is configured as an integral injection-molded component, wherein the metal insert 4 is injection-molded into a plastic material. The plastic material can be a thermoplastic or a thermosetting plastic. The plastic material can be a single type of plastic or a combination of multiple plastics. The plastic material may contain reinforcing fibers, such as glass fiber or carbon fiber. The plastic material can be an elastomeric plastic or a substantially inelastic plastic. Exemplary plastic materials may be F30, F40, PA, PC, PVC, or PPR. The metal material used for the insert 4 may be, for example, carbon steel or stainless steel. The material used for the container 3 may be the same as or different from the plastic material used for the base 2; for example, it may be a glass fiber or carbon fiber reinforced plastic.

[0061] like Figure 3A and 3B As shown, the base 2 includes a first segment 21 with a larger diameter and a second segment 22 adjacent to the first segment 21 with a smaller diameter compared to the first segment 21. The insert 4 is embedded in the plastic material of the first segment 21. The first segment 21 and the second segment 22 may have an arcuate transition portion 26. The base 2 has a front end face 24 and a back end face 25. The base 2 has a receiving portion 23 that opens towards the front end face 24. The ignition tube 1 can be press-fitted into the receiving portion 23 of the base 2. In the assembled state of the ignition tube 1 and the base 2, the ignition tube 1 extends from the front end face 24 of the base 2.

[0062] The receiving portion 23 of the base 2 includes multiple hole segments 231, 232, and 233. For example... Figure 3B and 3CAs shown, the insert 4 can be configured as a metal disc. The insert 4 has a central receiving hole 41. The receiving hole 41 includes a first cylindrical hole segment 231 adjacent to a first side of the insert 4 and a second tapered hole segment 232 adjacent to the first cylindrical hole segment 231 and expanding toward a second side of the insert 4 opposite to the first side. The insert 4 provides two hole segments 231, 232 for the receiving portion 23 of the base 2. The plastic material of the first section 21 of the base 2 defines a third cylindrical hole segment 233 adjacent to the second tapered hole segment 232, which is part of the receiving portion 23. The plastic material of the base 2 defines a recess 234 in the second section 22 into which the lead 12 of the ignition tube 1 extends. Advantageously, the base 2 can be a rotationally symmetric body.

[0063] To enhance the bonding strength between the plastic material of the base 2 and the metal inlay 4, the inlay 4 may have a structure. The structure may be a protrusion extending from the surface of the inlay, such as a post, a bump, a pyramid, or the like. Alternatively or supplementary, the structure may be a recess, such as a through hole, a blind hole, a notch, or the like. Figure 3C In the exemplary embodiment shown, the structure includes six through holes 42 evenly distributed around the receiving hole 41 and six notches 43 evenly distributed on the edge of the insert 4, wherein the axis of the receiving hole 41 of the reference insert 4 is in the circumferential direction, each of the six notches 43 is centrally arranged between two adjacent through holes 42, each through hole 42 has an angular spacing of 60°, each notch 43 has an angular spacing of 60°, and each notch 43 has an angular spacing of 30° with any adjacent through hole 42.

[0064] like Figure 2 and Figure 3D As shown, the container 3 includes a hollow main body portion 31, the main body portion 31 having an opening 33 and a bottom 37 opposite to the opening 33. The container 3 also includes a hollow protrusion 32 extending from the bottom 37 of the main body portion 31. The protrusion 32 may include a short hollow cylinder and a hollow hemisphere. Figure 3D As shown, the main body 31 of the container 3 is cylindrical before assembly. During assembly, the base 2, together with the ignition tube 1, is press-fitted into the container 3 through the opening 33 with the head 11 of the ignition tube 1 facing forward (i.e. towards the container).

[0065] like Figure 2As shown, after assembly, the container 3 narrows in the axial section adjacent to the opening 33, thus forming a first section 34 with a larger diameter and a second section 35 with a smaller diameter. Through the narrowing of the container 3, the base 2, together with the ignition tube 1, is securely held within the container 3, and even when the ignition system 10 is activated, the base 2, together with the ignition tube 1, will not detach from the container 3 through the opening 33.

[0066] In the assembled state of the ignition system 10, the base 2 is received within the main body 31 and abuts against the bottom 37 of the main body 31, and the head 11 of the ignition tube 1 extending from the base 2 is received in the protrusion 32. The top of the protrusion 32 is configured to be opened by the shock wave generated by the ignition tube 1 when the ignition system 10 is activated. The first section 34 of the main body 31 of the container 3 surrounds the first section 21 of the base 2, and the second section 35 of the main body 31 of the container 3 surrounds the second section 22 of the base 2. The container 3 may have a slope 36 matching the ignition tube 1 in the transition region from the main body 31 to the protrusion 32 inside, to provide support and fixation interface for the ignition tube 1.

[0067] Advantageously, the protrusion 32 has a wall thickness that gradually decreases in the direction away from the main body portion 31, and thus has a minimum wall thickness at the apex and a maximum wall thickness at the root adjacent to the bottom 37 of the main body portion 31. Advantageously, the ratio 'a' of the minimum wall thickness to the maximum wall thickness of the protrusion 32 can satisfy the formula: 0.5 < a < 1. Furthermore, advantageously, the ratio 'b' of the height H of the protrusion to the outer diameter D of the head 11 of the ignition tube 1 can satisfy the formula: b ≥ 1.

[0068] The protrusion 32 may or may not have a weakening groove at its top. The weakening groove may be in the shape of a line, cross, plum blossom, star, or any other suitable form. Figures 4A-4C Three exemplary weakened grooves are shown. In Figure 4A In the example shown, the top of the protrusion 32 has three intersecting straight grooves. Figure 4B In the example shown, the top of the protrusion 32 is provided with a quincunx groove. Figure 4C In the example shown, the top of the protrusion 32 is provided with a pentagonal groove.

[0069] The container 3 can adopt a gradually changing wall thickness design, wherein a larger wall thickness is used for the hollow main body 31, in order to ensure particularly good assembly of the container 3 with other components of the gas generator 100, and to ensure sufficient fastening strength of the container 3 to the base on its open side; for the hollow protrusion 32, a gradually decreasing wall thickness is used, and preferably the height H of the protrusion is greater than or equal to the outer diameter D of the head 11 of the ignition tube 1, in order to ensure that the shock wave generated by the ignition tube 1 when the ignition tube 1 is activated can open the closed top of the protrusion 32 in time.

[0070] Figures 5A-5C It is used to manufacture such as Figure 2 A schematic diagram of multiple steps of the ignition system 100 shown.

[0071] like Figure 5A As shown, after providing the ignition tube 1 and the base 2, the ignition tube 1 is press-fitted into the receiving portion 23 of the base 2, as schematically indicated by arrow P1. The ignition tube 1 and the receiving portion 23 of the base 2 have complementary shapes, and the ignition tube 1 is securely held in the receiving portion 23 of the base 2 by an interference fit. The two conductive leads 12 of the ignition tube 1 extend into the recess 234 on the back side of the base 2. During press-fitting, the base 2 can be kept stationary while the ignition tube 1 can move; or the opposite movement can be achieved; or not only the base 2 can move, but also the ignition tube 1 can move.

[0072] like Figure 5B As shown, after the base 2 and ignition tube 1 are assembled, a container 3 is provided. The base 2, together with the ignition tube 1, is pressed into the container 3 through the opening 33 of the container 3 with the head 11 of the ignition tube 1 facing forward, as schematically indicated by the two arrows P2. During pressing, the assembled base 2 and ignition tube 1 can be kept stationary while the container 3 moves; or the opposite movement can be achieved; or not only can the assembled base 2 and ignition tube 1 move, but the container 3 can also move.

[0073] like Figure 5C As shown, after the assembled base 2 and ignition tube 1 are press-fitted into the container 3, the container 3 is closed on the open side. This closing step can be achieved, for example, by a riveting device 90, schematically shown. Alternatively, the closing can be achieved by a pressing tool.

[0074] The following reference Figures 6A-6C This describes a base 2 according to another embodiment, which can be used with, for example... Figure 2 The ignition tube 1 and container 3, which are configured in the same or similar manner as those in the ignition system 10 shown, are assembled into an ignition system according to another embodiment, wherein the assembly method can be the same as that shown. Figures 5A-5CThe assembly method shown is implemented in the same or similar manner. The base 2 is constructed as an integral injection-molded component, wherein the metal insert 4 is injection-molded into the plastic material.

[0075] like Figure 6C As shown, the metal insert 4 includes a metal disc and a hollow cylindrical metal shank 45 connected to, and particularly integrally connected to, the disc. Here, the disc can be connected to, for example... Figure 3C The disks shown are constructed in the same or similar manner.

[0076] like Figure 6A and 6B As shown, the base 2 includes a first segment 21 with a larger diameter and a second segment 22 adjacent to the first segment 21 with a smaller diameter compared to the first segment 21. The metal disc of the insert 4 is embedded in a first plastic material 48 in the first segment 21. The shank 45 of the insert 4 surrounds and defines the second segment 22. A second plastic material 47 is injection molded on the inner circumferential surface of the shank 45 of the insert 4 and forms a cavity. The first plastic material 48 in the first segment and the second plastic material 47 in the second segment of the base 2 are integrally connected.

[0077] Similar to or analogous to the previous embodiment, the base 2 has a front end face 24 and a back end face 25. The base 2 has a receiving portion 23 that opens towards the front end face 24. An ignition tube (not shown) can be press-fitted into the receiving portion 23 of the base 2. The front end face 24 of the base 2 is provided by a first plastic material 48. The back end face 25 of the base 2 is jointly provided by the handle 45 of the metal insert 4 and a second plastic material 47.

[0078] like Figure 6A and 6B As shown, the through-hole 42 in the disc of the insert 4 is used to be filled with plastic material during injection molding, so that the injection-molded material is firmly connected to the metal insert. (Similar to...) Figure 3A and 3B In a different embodiment, the notch 43 at the edge of the disc of the insert 4 is not used for the connection between the injection molding material and the metal insert, but together with the corresponding notch in the first plastic material 48, it forms a notch 46 that runs through the entire axial length of the first section.

[0079] like Figure 6A and 6B The base 2 shown can be particularly well adapted to be assembled with the container 3 by riveting. The base 2 can have improved overall strength and combines the advantages of light weight and high strength.

[0080] It should be noted that, within the scope of this application, the column shape is preferably cylindrical or substantially cylindrical. It is understood that other column shapes or approximate column shapes deviating from a cylindrical shape are also acceptable.

[0081] It should be noted that the terminology used herein is for illustrative purposes only and is not intended to limit the disclosure. The singular forms “a” and “the one” as used herein should include the plural forms unless the context explicitly states otherwise. It is understood that the terms “comprising” and “including,” and other similar terms, when used in the application documents, specifically describe the presence of the stated operation, element, and / or component, without excluding the presence or addition of one or more other operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes all arbitrary combinations of one or more of the associated listed items. In the description of the drawings, similar reference numerals always denote similar elements.

[0082] The thickness of the elements in the accompanying drawings may be exaggerated for clarity. It is also understood that if an element is described as being on, coupled to, or connected to another element, then the element may be directly formed on, coupled to, or connected to the other element, or there may be one or more intermediate elements between them. Conversely, if the expressions "directly on," "directly coupled to," and "directly connected to" are used herein, it indicates that there is no intermediate element. Other terms used to describe relationships between elements should be interpreted similarly, such as "between" and "directly between," "attached" and "directly attached," "adjacent" and "directly adjacent," etc.

[0083] Terms such as “top,” “bottom,” “above,” “below,” “over,” “under,” etc., are used to describe the relationship of one element, layer, or region relative to another element, layer, or region, as shown in the accompanying drawings. It is understood that these terms should also encompass other orientations of the device in addition to those described in the accompanying drawings.

[0084] It is understood that although the terms "first," "second," etc., may be used herein to describe different elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. Therefore, a first element may be referred to as a second element without departing from the teachings of the inventive concept.

[0085] It can also be considered that all the exemplary embodiments disclosed herein can be arbitrarily combined with each other. Finally, it should be noted that the above embodiments are merely for understanding the present invention and do not constitute a limitation on the scope of protection of the present invention. For those skilled in the art, modifications can be made based on the above embodiments, and these modifications do not depart from the scope of protection of the present invention.

Claims

1. Ignition system for a gas generator, comprising an ignition tube (1), characterized in that, The ignition system further comprises: a base (2) having a receptacle (23) into which the ignition tube is press-fitted with its head (11) protruding from the base, the base being configured as an integral injection-molded part in which a metal insert (4) is injection-molded into a plastic material, the insert providing a portion of the receptacle; and a container (3) having an opening (33) through which the base together with the ignition tube is press-fitted into the container with the head of the ignition tube facing forward; wherein the insert is configured as or comprises a metal disc having a central receptacle hole (41) providing the portion of the receptacle; the receptacle hole comprises a first cylindrical hole section (231) adjoining a first side of the disc and a second conical hole section (232) adjoining the first cylindrical hole section and expanding towards a second side of the disc opposite the first side, and the plastic material of the base defines a third cylindrical hole section (233) adjoining the second conical hole section.

2. The ignition system for a gas generator according to claim 1, characterized by, The disc has a structure for enhancing the bonding of the plastic material to the insert.

3. The ignition system for a gas generator according to claim 2, characterized by, The structure comprises a plurality of through-holes (42) distributed around the central receptacle hole and / or a plurality of notches (43) distributed on an edge of the insert.

4. The ignition system for a gas generator according to claim 2, characterized by, The structure comprises a plurality of through-holes uniformly distributed around the central receptacle hole and a plurality of notches uniformly distributed on an edge of the insert, wherein each notch among the plurality of notches is centrally arranged between a respective two adjacent through-holes among the plurality of through-holes with respect to an axis of the receptacle hole in a circumferential direction.

5. The ignition system for a gas generator according to any one of claims 1 to 4, characterized by, In addition to the metal disc, the insert comprises a hollow cylindrical metal shank connected to the disc.

6. The ignition system for a gas generator according to any one of claims 1 to 4, characterized by, The container is necked on the opening side so as to retain the base together with the ignition tube in the container.

7. The ignition system for a gas generator according to any one of claims 1 to 4, characterized by, The base comprises a first section (21) and a second section (22) adjoining the first section and having a reduced diameter compared to the first section, the insert is embedded in the plastic material of the first section, and the container is necked on the opening side after the base together with the ignition tube is press-fitted into the container.

8. The ignition system for a gas generator according to claim 5, characterized by, The base comprises a first section (21) and a second section (22) adjoining the first section and having a reduced diameter compared to the first section, the disc of the insert is embedded in the plastic material of the first section, the shank of the insert surrounds defines the second section, the plastic material is injection-molded on an inner peripheral surface of the shank of the insert and forms a cavity, and the plastic material of the base in the first section and the plastic material in the second section are integrally connected.

9. The ignition system for a gas generator according to any one of claims 1 to 4, characterized by, The container comprises: a hollow body portion (31) having the opening and a bottom (37) opposite the opening; and a hollow protrusion (32) protruding from the bottom of the body portion; wherein the base is received in the body portion and abuts against the bottom of the body portion, the head of the ignition tube protruding from the base is received in the protrusion, and a top end of the protrusion is configured to be opened by a shock wave generated by the ignition tube upon activation of the ignition system.

10. The ignition system for a gas generator according to claim 9, characterized by The protrusion has a wall thickness which decreases in the direction away from the body portion, and / or the protrusion is provided with a weakening groove at its top end.

11. The ignition system for a gas generator according to claim 10, characterized by The ratio a of the minimum wall thickness to the maximum wall thickness of the protrusion satisfies 0.5 < a < 1, and / or the ratio b of the height (H) of the protrusion to the outer diameter (D) of the head of the ignition tube satisfies b > 1.

12. The ignition system for a gas generator according to claim 9, characterized by, The container is provided with a slope (36) in its interior in the transition area from the body portion to the protrusion, which matches the ignition tube, for providing a support and fixing interface for the ignition tube.

13. A gas generator comprising an ignition system (10) and a charge chamber (20), the ignition system and charge chamber being configured such that the ignition system ignites a charge contained in the charge chamber when it is activated, characterised in that, The ignition system is according to any one of claims 1 to 12.

14. A gas generator according to claim 13, characterised in that The gas generator is a hybrid gas generator comprising a pressure vessel (80) in which a pressure chamber (30) for containing compressed gas is defined, wherein the ignition system and the powder chamber are configured such that the ignition system ignites the powder contained in the powder chamber when it is activated, the gas produced by the combustion of the powder being able to mix with the compressed gas.

15. An airbag comprising a gas bag and a gas generator fluidly connected with the gas bag, characterized in that, The gas generator is according to claim 13 or 14.

16. A method for manufacturing an ignition system according to any one of claims 1 to 12, the method comprising the following steps: providing an ignition tube; providing a base having a receptacle, the base being configured as an integral injection-moulded part, wherein a metal insert is injection-moulded into a plastics material, the insert providing a part of the receptacle; providing a container having an opening; press-fitting the ignition tube into the receptacle, wherein the ignition tube projects with its head from the base; press-fitting the base together with the ignition tube into the container through the opening with the head of the ignition tube facing forwards.

17. The method according to claim 16, characterized in that the base comprises a first section and a second section adjoining the first section, which has a reduced diameter compared to the first section, the disc being embedded in the plastics material of the first section; the method comprises, after the base together with the ignition tube has been press-fitted into the container, trimming the container on the side of the opening.

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