Diffuser and manufacturing method therefor, and airbag module comprising diffuser

Abstract

A diffuser for an airbag module, comprising: an insertion hole for insertion of a gas generator; and at least one gas outlet for distributing gas generated by the gas generator into an internal volume of an airbag of the airbag module, wherein the diffuser is formed by sewing material panels, and a sewing path of at least one sewing portion at the insertion hole is inclined relative to the longitudinal axis of the gas generator, such that a minimum opening size of the insertion hole formed by sewing is equal to or smaller than the diameter of the gas generator, and the minimum opening size is adjustable to match the diameter of a gas generator to be inserted. The present disclosure ensures the sealing performance of the connection between the diffuser and the gas generator without adding additional costs and without adding additional process steps. The present disclosure also relates to a manufacturing method for the diffuser, and the airbag module comprising the diffuser.

Description

A diffuser, a method for manufacturing the same, and an airbag module including the diffuser Technical Field

[0001] This disclosure generally relates to airbag modules for vehicles. More specifically, this disclosure also relates to a diffuser for an airbag module and a method of manufacturing the same. Background Technology

[0002] To protect vehicle occupants in the event of an accident, vehicles typically include airbag modules. In the event of an accident, gas flows into the airbag module, causing it to inflate and protect the vehicle occupants.

[0003] Currently, vehicle airbag modules are mainly divided into two types: driver airbag modules and side airbag modules. The driver airbag module is typically installed inside the steering wheel to protect the driver's head and chest in a frontal collision. A similar driver airbag module may also be installed in the front passenger seat. Side airbag modules are usually located in or near the seats and doors, such as curtain airbag modules, designed to provide additional protection for passengers in side collisions, especially protecting the head and chest to prevent injury.

[0004] In addition to these two basic types, vehicles can also be equipped with other airbag modules, such as knee airbag modules, to enhance passenger safety. Of course, airbag modules can be installed in any desired location within the vehicle, as needed.

[0005] To ensure rapid and uniform deployment of the airbag module for effective protection, a gas distribution channel is introduced inside the airbag. This channel also protects the airbag from excessive impact from the high temperature and / or high pressure airflow generated by the gas generator. For this purpose, the gas distribution channel can, for example, surround the outflow area of ​​the elongated gas generator, thereby both protecting the airbag and deflecting and distributing the airflow. This gas distribution channel is commonly referred to as a "diffuser." The main function of the diffuser is to control the gas flow, enabling it to fill the airbag quickly and evenly, reducing uneven airbag deployment caused by gas concentration in one area.

[0006] Diffusers are typically made of sewn-together fabric sheets, as described in prior art documents KR1020230143016A, CN104853962A, CN105922967A, and JP5488390B2. In particular, the stitching path at the insertion hole of the diffuser where it connects to the gas generator is substantially parallel to the longitudinal axis of the elongated gas generator, as shown by reference numeral 4' in Figures 7 and 8, for example. After this stitching, the insertion hole is typically slightly larger than the diameter of the gas generator to allow insertion, resulting in a gap between the diffuser and the gas generator. While this gap may decrease after securing the gas generator to the diffuser with clamps, the reduced gap still causes gas leakage, leading to a decrease in the working pressure within the gas bag.

[0007] Recently, as countries have increasingly stringent requirements for the airtightness of airbag systems, the existence of this gap can no longer meet the requirements of relevant standards.

[0008] Therefore, it is necessary to improve the existing diffuser and the airbag module that includes the diffuser to ensure the sealing of the connection between the diffuser and the gas generator and to prevent gas leakage. Summary of the Invention

[0009] One objective of this disclosure is to improve existing diffusers and their manufacturing methods without increasing costs or adding process steps, thereby eliminating the aforementioned gaps as much as possible to ensure the sealing of the connection between the diffuser and the gas generator and prevent gas leakage. Furthermore, the diffuser of this disclosure can be adapted to gas generators of different diameters.

[0010] In one aspect of this disclosure, a diffuser for an airbag module is provided, comprising an insertion port for inserting a gas generator and at least one gas outlet for distributing gas generated by the gas generator to the internal volume of the airbag of the airbag module. The diffuser is formed by sewing together a sheet of material, wherein the stitching path of at least one stitch at the insertion port is inclined relative to the longitudinal axis of the gas generator, such that the minimum opening size of the sewn insertion port is equal to or smaller than the diameter of the gas generator, and the minimum opening size is adjustable to fit the diameter of the gas generator to be inserted.

[0011] In another aspect of this disclosure, a method for manufacturing a diffuser for an airbag module is provided. The method includes: providing a material sheet comprising a first sheet portion and a second sheet portion; assembling the first sheet portion and the second sheet portion into the shape of the diffuser; sewing together an insertion portion of the material sheet to be formed into the insertion hole; and sewing together the remaining portion of the material sheet. Wherein, the sewing path of at least one sewn portion of the insertion hole portion is inclined relative to the longitudinal axis of a gas generator, such that the minimum opening size of the sewn insertion hole is equal to or smaller than the diameter of the gas generator, and the minimum opening size is adjustable to adapt to the diameter of the gas generator to be inserted.

[0012] In another aspect of this disclosure, an airbag module is provided, comprising an airbag, a gas generator, and a diffuser as described above, wherein the diffuser is fitted inside the airbag and the gas generator is partially inserted into the diffuser.

[0013] According to some embodiments of this disclosure, the insert portion of the material sheet forming the insert has opposing first side edges and second side edges, and a first stitch and a second stitch are formed at the first side edges and the second side edges, respectively, and the stitching path of at least one of the first stitch and the second stitch is inclined relative to the longitudinal axis of the gas generator.

[0014] According to some embodiments of this disclosure, the suture path of the first suture portion at the first side edge is inclined relative to the longitudinal axis of the gas generator, while the suture path of the second suture portion at the second side edge is substantially parallel to the longitudinal axis of the gas generator.

[0015] According to some embodiments of this disclosure, the stitching paths of the first stitch at the first side edge and the second stitch at the second side edge are both inclined relative to the longitudinal axis of the gas generator.

[0016] According to some embodiments of this disclosure, the thread end of the suture at the minimum opening of the at least one suture portion of the pier is free and loose, without knotting or backstitching.

[0017] When the stitching paths of the first stitch at the first side edge and the second stitch at the second side edge are both inclined relative to the longitudinal axis of the gas generator, the thread ends of the stitches at the minimum opening of both the first stitch and the second stitch, preferably only one of the first stitch and the second stitch, are free and loose, without knots or backstitching.

[0018] According to some embodiments of this disclosure, the suture path of the at least one suture portion is tilted at an angle of 5 to 30 degrees relative to the longitudinal axis of the gas generator, preferably in the range of 10 to 15 degrees.

[0019] According to some embodiments of this disclosure, the needle density of the suture path of the at least one suture portion is in the range of 28 mm / 10 stitches to 50 mm / 10 stitches, preferably in the range of 28 mm / 10 stitches to 35 mm / 10 stitches.

[0020] According to some embodiments of this disclosure, the first sheet portion and the second sheet portion are integral parts of a single material sheet, which are folded together along the fold line therebetween to form the shape of the diffuser.

[0021] According to some embodiments of this disclosure, the first sheet portion and the second sheet portion are two separate material sheets that are stacked together to form the shape of the diffuser.

[0022] According to some embodiments of this disclosure, each material sheet can be made of one or more layers of fabric.

[0023] According to some embodiments of this disclosure, the gas generator is fixed together with the diffuser by a clamp, and the suture path of the at least one suture can be extended long enough that when the minimum opening of the socket is adapted to the diameter of the gas generator as it is inserted, the suture at the minimum opening can be pressed by the clamp to ensure that the suture will not come loose after assembly, thereby improving stability and thus improving the sealing effect.

[0024] According to some embodiments of this disclosure, the gas generator includes a bracket that is fixed to the diffuser by a clamp. The stitching path of the at least one stitch can extend long enough that when the minimum opening of the jack is adapted to the diameter of the gas generator as it is inserted, the stitch at the minimum opening can abut against the bracket or be pressed by the bracket to ensure that the stitch will not come loose after assembly, thereby improving stability and further improving the sealing effect.

[0025] It should be noted that aspects of this disclosure described with respect to one embodiment or clause may be included in other different embodiments or clauses, although no specific description is given of said other different embodiments or clauses. In other words, all embodiments or clauses and / or features of any embodiment or clause may be combined in any manner and / or combination, as long as they do not contradict each other. Attached Figure Description

[0026] A better understanding of the various aspects of this disclosure and its advantages will be achieved by reading the following detailed description in conjunction with the accompanying drawings. In the drawings:

[0027] Figure 1 is a schematic diagram of an airbag module according to an exemplary embodiment of the present disclosure;

[0028] Figure 2 is a schematic diagram of an airbag module deployed according to an exemplary embodiment of the present disclosure, wherein the gas generator has been removed for clarity.

[0029] Figure 3 is a schematic diagram of a diffuser according to an exemplary embodiment of the present disclosure, wherein a gas generator is inserted;

[0030] Figure 4 is a partial cross-sectional view of a diffuser taken along the circumference of the fixture according to an exemplary embodiment of the present disclosure, schematically showing how the "bulge" gaps caused by non-compaction in the prior art are eliminated by oblique stitching;

[0031] Figure 5 is a flowchart of a method for manufacturing a diffuser according to an exemplary embodiment of the present disclosure;

[0032] Figures 6A to 6D are schematic diagrams illustrating a manufacturing process for a diffuser according to an exemplary embodiment of the present disclosure;

[0033] Figure 7 is a schematic diagram of the thread end of a suture in an inclined suture path according to an exemplary embodiment of the present disclosure;

[0034] Figure 8 is a schematic diagram of a prior art airbag module;

[0035] Figure 9 is a schematic diagram of the parallel stitching at the socket of the prior art diffuser;

[0036] Figure 10 is a partial cross-sectional view of a prior art diffuser taken along the circumference of the fixture, schematically showing the "bulge" gaps caused by lack of compaction in areas without supports and folds in the case of parallel stitching.

[0037] It should be understood that in all the accompanying drawings, the same or similar elements will be represented by the same or similar reference numerals. In the drawings, for clarity, the dimensions of some features may be altered and not drawn to scale. Detailed Implementation

[0038] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0039] It should be understood that the expressions used in this specification are for describing exemplary embodiments of this disclosure and are not intended to limit this disclosure. All terms used herein, unless otherwise defined, have the meanings commonly understood by those skilled in the art. For the sake of brevity and / or clarity, well-known functions or structures may not be described in detail.

[0040] The singular forms “a,” “the,” and “the” used herein include the plural forms unless explicitly stated otherwise. The expressions “comprising,” “including,” and “having,” and their derivatives, used herein, indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The expression “and / or” used herein includes any and all combinations of one or more of the related listed items.

[0041] In this document, when an element is referred to as being "on", "attached" to, "connected" to, "joined" to, or "in contact" with another element, the element may be directly located on, attached to, connected to, joined to, or in contact with the other element, or there may be an intermediate element present.

[0042] In this document, the terms "first," "second," "third," etc., are used for ease of explanation only and are not intended to refer to any particular order or sequence. Any technical feature represented by "first," "second," "third," etc., is interchangeable.

[0043] In this document, spatial relationship descriptions such as "up," "down," "front," "back," "top," "bottom," "left," and "right" are used to describe the relationship between one feature and another in the accompanying drawings. It should be understood that spatial relationship descriptions include not only the orientation shown in the drawings but also different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a feature previously described as "below" other features can now be described as "above" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be interpreted accordingly.

[0044] It should be understood that the term "diameter" used herein refers to the equivalent diameter, also known as the equivalent diameter. The equivalent diameter is the diameter of an object of a specific shape that, for the sake of calculation or comparison, is assumed to have a circumference equivalent to that of a circular object. For example, the equivalent diameter of an object with a circular cross-section is the diameter of that circular cross-section, while for an object with a non-circular cross-section, its equivalent diameter is the diameter of a circular cross-section with the same circumference. The expression "diameter of the gas generator" specifically refers to the diameter, or equivalent diameter, of the outer contour portion of the gas generator inserted into the diffuser's socket and in contact with the inner wall of the socket. The term "opening size" or "opening dimensions" used herein refers to the equivalent diameter of the opening.

[0045] It should be understood that the terms “inside” and “outside” used in this article refer to the interior of the diffuser or air bag.

[0046] All figures used in the specification and claims should be understood to be modified by the term "about" in all cases. "About" means within 25 percent of the value, such as 10 percent, 5 percent, etc. Furthermore, unless otherwise specified, all numerical ranges also include the maximum and minimum values, as well as all possible intermediate ranges.

[0047] The descriptive terms "approximately," "generally," or "basically" refer to possible deviations from the absolute shape or relationship described in the text, but do not affect the normal implementation of the structure and function of the subject matter in this disclosure. For example, the term "approximately parallel" not only covers an absolutely or completely parallel state, but can also indicate a state that deviates slightly from absolute or complete parallelism, such as an angle of deviation not greater than ±1°, not greater than ±2°, not greater than ±5°, not greater than ±10°, etc.

[0048] Figures 1 to 3 illustrate an airbag module according to an exemplary embodiment of the present disclosure. A curtain airbag module is shown here as an example, which can be installed in the area of ​​the vehicle's roof edge, extending along the vehicle's longitudinal direction. It should be understood that the concept of the present disclosure is also applicable to any other type of airbag module, including but not limited to driver's airbag modules, side airbag modules, knee airbag modules, etc.

[0049] The airbag module includes an airbag 5, a gas generator 7, a diffuser 3 (shown in Figures 2 and 3), a bracket 2, a clamp 1, and a strap 6. The diffuser 3 is housed within the airbag 5 and is therefore not visible in Figure 1. The gas generator 7 is an elongated (e.g., generally cylindrical) structure that is partially inserted into the diffuser 3 and mounted via the bracket 2 to, for example, a longitudinal beam area on the roof edge of a vehicle's door side. At the end of the bracket 2 facing the air outlet of the gas generator 7, the clamp 1 holds the bracket 2, airbag 5, diffuser 3, and gas generator 7 together. The strap 6 secures the main body of the airbag 5 to the gas generator 7.

[0050] Figure 2 is a partial schematic diagram of an airbag module in a flattened state according to an exemplary embodiment of the present disclosure. The airbag 5 can be made of any suitable material, such as nylon, and can be constructed in any suitable manner. For example, the airbag can have a one-piece woven structure made of a single sheet of material. As another example, the airbag can include two or more sheets that are joined together by known methods (e.g., sewing, welding, bonding, etc.) to form the airbag. The airbag can be uncoated, coated with an impermeable material such as rubber or silicone, or laminated with an impermeable material such as a film.

[0051] The airbag 5 has an opening 52 at its upper edge. This opening 52 extends obliquely upward relative to the upper edge of the airbag 5. The diffuser 3 is configured to be fitted into this opening 52. A series of mounting tabs 51 (only one shown in Figure 2) are spaced apart along the upper edge of the airbag 5. Each mounting tab 51 may have one or more mounting holes, facilitating the connection of the airbag to the vehicle. In this example, the strap 6 is integrally formed with the airbag 5, particularly the main body; that is, the strap 6 is an integral part of the airbag 5. Of course, the strap 6 could also be a separate component, then attached to the main body of the airbag 5.

[0052] The airbag 5 is also provided with various joints 53 (e.g., stitching or tying) that join the front and back sheet portions of the airbag together. These joints are used to form airflow channels and / or to divide the inflatable volume of the airbag into, for example, a front internal volume and a rear internal volume.

[0053] When the airbag module is not activated, the deflated and flattened airbag 5 can be in a rolled-up and / or folded state. For example, this can be achieved by rolling up and / or folding the lower edge of the airbag 5 upwards toward the upper edge. In other words, the airbag 5 remains rolled up and / or folded in the storage state, allowing the airbag module to be installed in the vehicle as a unit.

[0054] The diffuser 3 includes a socket 35 for inserting the gas generator 7 and two gas outlets 36 and 38 for distributing the high-pressure gas generated by the gas generator 7 to the front and rear internal volumes of the gas bag 5. It should be understood that although two gas outlets are shown in this figure, one or more gas outlets may be provided, depending on factors such as the layout of the gas bag, the installation location of the gas generator, etc. The diffuser 3 also includes a tab 37 for connecting to the gas bag 5.

[0055] When the airbag module is activated in the event of a collision, the gas generator 7 produces high-pressure gas. The high-pressure gas flows into the front and rear internal volumes of the airbag 5 through the two gas outlets 36 and 38 of the diffuser 7, causing the airbag to inflate and deploy. The airbag 5 then unfolds downwards from the upper side of the front and rear doors, covering the windows of the front and rear doors like a curtain, thereby protecting the head and body of the occupants during a vehicle collision.

[0056] The diffuser 3 ensures that the airbag 5 deploys quickly and evenly to provide effective occupant protection, and also protects the airbag 5 from excessive impact from the high temperature and / or high pressure airflow generated by the gas generator 7.

[0057] The diffuser 3 can be made of a sheet of fabric (e.g., polyester, polyamide, polypropylene, etc.) sewn together. Reference numeral "4" in Figures 1-3 schematically represents an example of an inclined stitching path at the socket according to an exemplary embodiment of this disclosure (described in detail later). In contrast, reference numeral "4'" in Figures 8 and 9 schematically represents an example of a parallel stitching path at the socket according to the prior art.

[0058] During assembly, the diffuser 3 is inserted into the opening 52 of the airbag 5, and then the gas generator 7 is inserted into the insertion hole 35 of the diffuser 3. The minimum opening of the insertion hole 35, which is formed by oblique stitching, can be adjusted to the diameter of the gas generator as the gas generator 7 is inserted, so that the minimum opening can be adapted to the diameter of the gas generator (which will also be described in detail later). After the insertion hole 35 of the diffuser 3 is adapted to the inserted gas generator 7, the excess part of the opening 52 of the airbag 5 and the insertion hole 35 of the diffuser 3 that is not tightly attached to the gas generator 7 is folded around the outer surface of the gas generator 7 to form a folded part 31 (see Figure 4). Then, the bracket 2, the opening 52 part of the airbag 5, the insertion hole 35 part of the diffuser 3, the folded part 31, and the gas generator 7 are clamped together with the clamp 1. Finally, the strap 6 is fastened to the gas generator 7. In this way, the entire airbag module is assembled and ready to be installed in the vehicle.

[0059] The inclined stitching of this disclosure will now be explained in detail with reference to an example of a method for manufacturing a diffuser according to an exemplary embodiment of this disclosure.

[0060] Figure 5 shows a flowchart of a method for manufacturing a diffuser according to an exemplary embodiment of the present disclosure. Figures 6A to 6D are schematic diagrams illustrating a manufacturing process for a diffuser according to an exemplary embodiment of the present disclosure.

[0061] As shown in Figure 5, the manufacturing method includes: in step S1, providing a material sheet 30, which includes a first sheet portion 301 and a second sheet portion 302 (see Figure 6A). A fold line 33 is provided between the first sheet portion 301 and the second sheet portion 302. In step S2, the first sheet portion 301 and the second sheet portion 302 are folded together along the fold line 33 to form a diffuser shape (see Figure 6B). The first sheet portion 301 and the second sheet portion 302 can be individually cut into the shape of a diffuser before or after folding.

[0062] Then, in step S3, the insertion portion of the material sheet to be formed into an insertion hole is sewn together, wherein the sewing path 4 of at least one sewn portion of the insertion hole portion is inclined relative to the longitudinal axis of the gas generator to be inserted, such that the minimum opening size of the sewn insertion hole 35 (see FIG. 6D) is equal to or smaller than the diameter of the gas generator, and the minimum opening size is adjustable to be adapted to the diameter of the gas generator to be inserted. In particular, for example, referring to FIG. 6C, an inclined sewing (forming the first sewn portion of the insertion hole) is performed on the first side edge A of the insertion portion of the insertion hole 35 to be formed in the first sheet portion 301 and the second sheet portion 302, that is, on the side edge near the generally U-shaped recess of the first sheet portion 301 and the second sheet portion 302, wherein the sewing path 4 of the first side edge A of the insertion hole portion is inclined relative to the longitudinal axis X of the gas generator 7 (shown in FIG. 3).

[0063] In this step, the second side edge B of the insertion portion to be formed into the insertion hole 35 is also sewn together (i.e., the side edge facing away from the generally U-shaped recess of the first sheet portion 301 and the second sheet portion 302, opposite to the first side edge A, thereby forming the second sewn portion of the insertion hole). For example, the second side edge B of the insertion portion can be sewn parallel in a conventional manner (see, for example, FIG. 6D), such that the sewing path of the second side edge B is parallel to the longitudinal axis X of the gas generator 7. Alternatively, the second side edge B can also be sewn in a similar manner to the first side edge A, i.e., oblique sewing, such that the sewing path of the second side edge B is oblique relative to the longitudinal axis X of the gas generator 7. Regardless of how it is sewn, the opening size of the insertion hole ultimately formed by sewing the first side edge A and the second side edge B gradually decreases along the insertion direction of the gas generator 7, and the minimum opening size is equal to or less than the diameter of the gas generator 7. It should be understood that the sewn insertion hole has the minimum opening size at the innermost end of the oblique sewing path 4. Alternatively, parallel stitching can be performed on the first side edge A and oblique stitching on the second side edge B, provided that the opening size of the final sewn pier gradually decreases along the insertion direction of the gas generator 7, and the minimum opening size is equal to or less than the diameter of the gas generator 7.

[0064] Finally, in step S4, the remaining portions of the material sheets are sewn together. Still referring to FIG6D, the remaining portions of the first sheet portion 301 and the second sheet portion 302 are sewn together, including the edge between the second side edge B of the insertion portion and the gas outlet 38 (forming a main sewn portion parallel to the longitudinal axis of the gas generator) and the edge of the generally U-shaped recess between the first side edge A of the insertion portion and the other gas outlet 36 (forming a U-shaped sewn portion). The sewing of the remaining portions can be performed, for example, in a conventional manner.

[0065] In other words, to overcome the problem of gas leakage caused by gaps between the diffuser and gas generator due to parallel stitching of the insertion hole in existing technologies, this disclosure employs inclined stitching. Specifically, the stitching path of at least one stitched portion at the insertion hole is inclined relative to the longitudinal axis of the gas generator. This causes the opening size of the stitched insertion hole to gradually decrease along the insertion direction of the gas generator, with the minimum opening size equal to or smaller than the diameter of the gas generator. Furthermore, the minimum opening size is adjustable to match the diameter of the gas generator to be inserted. Thus, when the gas generator is inserted into the diffuser's insertion hole, because the minimum opening size of the insertion hole is equal to or smaller than the diameter of the gas generator, the minimum opening of the insertion hole can be adjusted to match the diameter of the gas generator as it is inserted. This ensures that the minimum opening matches the diameter of the gas generator, preventing gaps between the diffuser and the gas generator and thus avoiding gas leakage.

[0066] The oblique stitching technique disclosed herein also offers several additional advantages. For example, it eliminates the need for additional fabric, which would otherwise increase material costs; it has no impact on current manufacturing processes; the diffuser can be adapted to gas generators of different diameters because the minimum opening of the jack can be adjusted to match the diameter of the gas generator as it is inserted; and the diffuser can be easily inserted into the jack by starting from a larger opening position, as the opening of the jack formed by the oblique stitching tapers along the insertion direction; and so on.

[0067] In order to make the minimum opening size adjustable, according to some embodiments of the present disclosure, the thread end of the stitch at the minimum opening of the jack is free and loose, without knotting or backstitching.

[0068] Referring to Figure 7, a schematic diagram is shown of the portion of the thread end of the inclined seam path 4, including the minimum opening, according to an exemplary embodiment of the present disclosure. The sewing is performed using a sewing machine, employing a top thread or face thread 401 and a bottom thread or back thread 402. The sewing machine needle, carrying the face thread 401, passes through the material sheet, then around the bottom thread 402, pulls back, and passes through the material sheet again, repeating the cycle; during this process, the material sheet simultaneously moves along a predetermined path. The stitch pattern of the face thread 401 is, for example, approximately "bow" shaped, while the stitch pattern of the bottom thread 402 is, for example, approximately straight. The thread end at the minimum opening (i.e., the innermost end of the inclined seam path 4) is free and loose, not knotted or backstitched, and can be, for example, cut directly. The sewing pattern shown here is merely an example; any other sewing pattern may be used. It should also be noted that, in order to show the sutures of the inclined suture path, the schematic diagram in Figure 7 is not a cross-sectional view taken along the direction perpendicular to the longitudinal axis, but a partial cross-section taken along the direction inclined to the longitudinal axis of the gas generator, and is not drawn to scale, so as to clearly illustrate how the suture ends are handled.

[0069] When the first side edge A and / or the second side edge B are obliquely sewn, the thread end of the suture at the minimum opening of the jack is free and loose at the obliquely sewn side edge, without knotting or backstitching. When both the first side edge A and the second side edge B are obliquely sewn, the thread end of the suture at the minimum opening of the jack is free and loose at both the first and second side edges, preferably only at one of the first and second side edges, without knotting or backstitching. When the gas generator is inserted into the jack of the diffuser, the suture here will loosen to allow the opening size of the jack to adapt to the diameter of the gas generator.

[0070] According to some embodiments of this disclosure, the angle of inclination of the inclined stitching path 4 at the jack relative to the longitudinal axis of the gas generator is in the range of 5 degrees to 30 degrees, preferably in the range of 10 degrees to 15 degrees.

[0071] According to some embodiments of this disclosure, the needle density of the sutures in the inclined suture path 4 at the insertion hole is in the range of 28 mm / 10 stitches to 50 mm / 10 stitches, preferably in the range of 28 mm / 10 stitches to 35 mm / 10 stitches.

[0072] In the exemplary embodiments shown in Figures 6A to 6D, the first sheet portion 301 and the second sheet portion 302 shown are integral portions of a single material sheet 30, both folded together along the fold line 33 therebetween. This single material sheet can be a sheet made of one or more layers of fabric.

[0073] Alternatively, according to some embodiments of this disclosure, the first sheet portion and the second sheet portion may also be two separate material sheets, which are stacked together. In this case, the aforementioned fold line 33 is not present, but the edge at that location still needs to be sewn to form another main seam located between gas outlet 38 and another gas outlet 36, which can be sewn in, for example, a conventional manner. Similarly, each of the two separate material sheets here may be a sheet made of one or more layers of fabric.

[0074] Preferably, according to some embodiments of the present disclosure, the inclined stitching path 4 can be extended long enough that when the minimum opening of the jack is adapted to the diameter of the gas generator as the gas generator is inserted, the stitch at the minimum opening can be pressed by the clamp 1 to ensure that the stitch will not come loose after assembly, thereby improving stability and thus improving the sealing effect.

[0075] Preferably, according to some embodiments of this disclosure, the inclined stitching path 4 can extend sufficiently long so that when the minimum opening of the socket is adapted to the diameter of the gas generator as it is inserted, the stitch at the minimum opening can abut against the bracket 2, thereby further improving the sealing effect; or it can be pressed tightly by the bracket 2 to ensure that the stitch will not loosen after assembly, thus improving stability. Specifically, the applicant has found that, in addition to the gaps caused by the diameter difference between the gas generator and diffuser sockets discussed in the background section, the prior art parallel stitching scheme may also cause "bulge" gaps in areas where there are no brackets and folds due to lack of compaction. These gaps can also cause gas leakage problems, which will be described in detail below with reference to Figure 10.

[0076] Figure 10 shows a partial cross-sectional view of a prior art diffuser taken circumferentially from the fixture. In the inactive, stored state after assembly, the fixture 1 holds the support 2, air bag 5, diffuser 3, and gas generator 7 together. On the one hand, the support 2 has a significant thickness, but it only extends partially circumferentially; on the other hand, after the diffuser 3 is fitted with the gas generator 7 inserted therein, the opening 52 of the air bag 5 and the excess portion of the diffuser 3 that is not in close contact with the gas generator 7 (including the portion outside the stitching path at the edge) need to be folded around the outer surface of the gas generator 7, thereby creating a folded portion 31. Typically, one folded portion is created at each of two locations with opposite diameters, that is, there are two opposing folded portions 31. Such folded portions also have some thickness (but significantly less than the thickness of the support 2). There is a region between the end of the significantly thick support 2 and the adjacent slightly thicker folded portion 31. In this region, between the rigid gas generator 7 and the rigid clamp 1, only the air bag 5 and diffuser 3 exist; the support 2 and folded portion 31 are absent. This results in the air bag 5 and diffuser 3 not being compacted in this region compared to other areas. Consequently, when the clamp 1 is tightened, the air bag 5 and diffuser 3 in this region often experience a "bulge" due to the lack of compaction, forming a "bulge" gap. Simply moving the support 2 or folded portion 31 so that one end of the support abuts against one folded portion cannot eliminate the "bulge" gap. This is because the presence of two folded portions increases the area between the other end of the support and the other folded portion, further increasing the "bulge" gap in that area.

[0077] In contrast, in this disclosure, the inclined stitching path 4 extends sufficiently long that when the minimum opening of the socket is adapted to the diameter of the gas generator as it is inserted, the stitch at the minimum opening can abut against the bracket 2. This eliminates the aforementioned area that causes the "bulge" phenomenon, as shown in FIG4, thereby further preventing gas leakage. When the inclined stitching is performed only at one side edge A or B, the position of the bracket 2 or the fold 31 can be adjusted so that one end of the bracket abuts against a fold, while the area between the other end and the other fold is eliminated by having the stitch at the minimum opening abut against the bracket 2 when the socket is adapted to the gas generator. This eliminates the "bulge" gap in both areas. Furthermore, the stitch at the minimum opening can also be located below the bracket 2, so that the stitch at the minimum opening can be clamped by the bracket 2 when the socket is adapted to the gas generator, thus ensuring that the stitch will not come loose after assembly and improving stability.

[0078] Furthermore, it should be noted that, in both the prior art and this disclosure, in the area on the outer periphery of the gas generator opposite to the clamp 1 and between the two folding portions 31, there are only the gas bag 5 and the diffuser 3 between the rigid gas generator 7 and the rigid clamp 1, and there is no support 2 and folding portion 31. However, since the thickness of the folding portion 31 is small and the circumferential length of this area is much larger, the above-mentioned "bulging" phenomenon is almost not produced.

[0079] Please note that Figures 4 and 10 are schematic cross-sectional views, intended only to illustrate the appearance and elimination of bulges and voids, and are not drawn to scale; therefore, areas of uneven thickness may exist. In particular, the thickness of the folded portion 31 is actually significantly less than the thickness of the support 2; Figures 4 and 10 only magnify the thickness of the folded portion to clearly illustrate the appearance and elimination of the bulge. Furthermore, in reality, wrinkles may appear on the material sheet in the seam area of ​​the folded portion due to the clamping of the clamp 1 and the support 2; here, only the arrangement of the folded portion is shown for clarity.

[0080] Exemplary embodiments according to this disclosure have been described above with reference to the accompanying drawings. However, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope of this disclosure. All changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A diffuser for an airbag module, comprising an insertion port for inserting a gas generator and at least one gas outlet for distributing gas generated by the gas generator to the internal volume of the airbag of the airbag module, said diffuser being formed by sewing together sheets of material, wherein, The stitching path of at least one stitch at the insertion hole is inclined relative to the longitudinal axis of the gas generator, such that the minimum opening size of the stitched insertion hole is equal to or less than the diameter of the gas generator, and the minimum opening size is adjustable to match the diameter of the gas generator to be inserted.

2. The diffuser according to claim 1, wherein, The insertion portion of the material sheet has opposing first and second side edges, and a first stitch and a second stitch are formed at the first and second side edges respectively. The stitching path of at least one of the first and second stitches is inclined relative to the longitudinal axis of the gas generator.

3. The diffuser according to claim 2, wherein, The suture path of the first suture at the first side edge is inclined relative to the longitudinal axis of the gas generator, while the suture path of the second suture at the second side edge is approximately parallel to the longitudinal axis of the gas generator.

4. The diffuser according to claim 2, wherein, The stitching paths of the first stitch at the first side edge and the second stitch at the second side edge are both inclined relative to the longitudinal axis of the gas generator.

5. The diffuser according to any one of claims 1 to 4, wherein, The thread end of the at least one suture of the insertion hole at the minimum opening is free and loose, without knotting or backstitching.

6. The diffuser according to claim 4, wherein, Only the thread ends of the sutures at the minimum opening of either the first or second suture section are free and loose, without being knotted or backstitched shut.

7. The diffuser according to any one of claims 1-4, wherein, The angle of inclination of the suture path of the at least one suture at the insertion hole relative to the longitudinal axis of the gas generator is in the range of 5 degrees to 30 degrees, preferably in the range of 10 degrees to 15 degrees.

8. The diffuser according to any one of claims 1-4, wherein, The gas generator is fixed to the diffuser by a clamp, and the suture path of the at least one suture extends long enough that the suture at the minimum opening of the insertion hole can be pressed by the clamp when the minimum opening of the insertion hole is adapted to the diameter of the gas generator as it is inserted.

9. The diffuser according to any one of claims 1-4, wherein, The gas generator includes a bracket that is fixed to the diffuser by a clamp, and the suture path of the at least one suture extends long enough that when the minimum opening of the jack is adapted to the diameter of the gas generator as it is inserted, the suture at the minimum opening can abut against the bracket or be pressed by the bracket.

10. A method for manufacturing a diffuser for an airbag module according to any one of claims 1 to 9, the method comprising: A material sheet is provided, the material sheet comprising a first sheet portion and a second sheet portion; The first sheet portion and the second sheet portion are combined to form the shape of a diffuser; The insertion hole portion of the material sheet to be formed is sewn together; as well as Sew together the remaining portion of the material sheet. Wherein, the stitching path of at least one stitched portion of the insertion hole is inclined relative to the longitudinal axis of the gas generator, such that the minimum opening size of the stitched insertion hole is equal to or less than the diameter of the gas generator, and the minimum opening size is adjustable to match the diameter of the gas generator to be inserted.

11. The manufacturing method according to claim 10, wherein, The needle density of the suture path of the at least one suture portion is in the range of 28 mm / 10 stitches to 50 mm / 10 stitches, preferably in the range of 28 mm / 10 stitches to 35 mm / 10 stitches.

12. The manufacturing method according to claim 10 or 11, wherein, The first sheet portion and the second sheet portion are integral parts of a single material sheet, which are folded together along the fold line between them to form the shape of the diffuser.

13. The manufacturing method according to claim 10 or 11, wherein, The first sheet portion and the second sheet portion are two separate material sheets that are stacked together to form the shape of the diffuser.

14. An airbag module comprising an airbag, a gas generator, and a diffuser for the airbag module according to any one of claims 1 to 9, wherein, The diffuser is assembled inside the gas bag, and the gas generator is partially inserted into the diffuser.

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