Airbag and method of manufacturing the same

Abstract

In order to reduce the leakage of the inflation gas from the sewn portion of the air bag, an operation of applying a coating material to the sewn portion is performed. Although there are techniques of applying from one side or from both sides, when applying to the opposite side from the initially applied side, there is a problem that the coating material initially applied adheres to the table or runs off. This can be prevented by making the viscosity of the adhesive material initially applied to the sewn portion of one side of the base fabric higher than the viscosity of the adhesive material subsequently applied to the sewn portion of the opposite side of the base fabric.

Description

Technical Field

[0001] This invention relates to the bag body of an airbag and its manufacturing method. Background Technology

[0002] As a safety device for automobiles, following seat belts, Japan began offering SRS airbags (seat belt assist devices, hereinafter referred to as airbags) as optional equipment in 1987. Initially, they were installed in the driver's seat. With the changing times, airbags have become standard equipment in the driver's seat (handlebar) and are also installed in the front passenger seat. When a collision is detected by an acceleration sensor, the airbag is injected with gas and inflates instantaneously in 0.01-second increments. When fully inflated and deployed, the gas is expelled and the airbag contracts. Through this series of actions, the airbag assists the seat belt in reducing the impact of collisions between the driver and the handrail, or between the front passenger and the dashboard. In addition to the aforementioned airbags, various other types of airbags are being developed and put into practical use, such as airbags that inflate between the side window and the head to reduce impact, airbags that inflate from the side of the seat back towards the side or front of the occupant's body to protect the abdomen or chest, and pedestrian-facing airbags that deploy on the bonnet in case of a collision with a pedestrian to reduce the impact between the pedestrian and the bonnet.

[0003] When a car collides with an obstacle, although the vehicle decelerates suddenly, the occupants continue to move forward due to inertia. Therefore, even if the driver is wearing a seatbelt, there is a risk of impact to the chest or head from the airbag. Thus, an airbag is installed in the airbag unit as described above. After detecting a collision, the airbag fully inflates in approximately 0.03 seconds, supporting the driver, absorbing energy, and then deflates. The entire process from the collision to the airbag's inflation and deflation takes approximately 0.2 seconds. If the airbag inflates late, the driver will impact the airbag. For rapid inflation, in addition to the method of generating the inflation gas, it is also important that during inflation, a predetermined amount of inflation gas is not leaked from undesirable locations within the airbag to ensure complete and adequate inflation of the airbag's bag. On the other hand, there are side curtain airbags designed to prevent injury to occupants (including the driver) or ejection from the vehicle due to impact with the side glass or the side of the passenger compartment, or contact with broken side glass or the outside of the vehicle during a side collision. There is also a center airbag positioned between the driver and front passenger seats to prevent collisions between the driver and front passenger, or contact with interior components such as doors on the opposite side (non-collision side). These airbags are designed to maintain an inflation time longer than the airbags at the handle.

[0004] Patent document 1 discloses a technique that attempts to prevent the expansion gas from leaking from the seam, thus preventing it from expanding sufficiently or expanding slowly, by sewing the bag body of the airbag together and applying a coating material to the sewn part.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-533293 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In Patent Document 1, when applying a coating material to the seam, it is designed to apply the material only to one side and extend it along the seam opening to the opposite side, or to apply the material to both sides to cover the seam. Since the viscosity of the coating agent when applying to both sides is not specifically disclosed, it is conceivable to use the same coating material on both the initially coated side and the subsequently coated side. When using a low-viscosity coating agent (the adhesive material in this application), the following problem arises: when applied to the initial side, the coating material penetrates to the opposite side and adheres to the platform supporting the bag, or the coating material adhering to the platform re-adheres to an unintended part of the bag. Furthermore, regardless of whether it is two-sided coating (coating both sides) or one-sided coating (coating only one side), depending on the viscosity of the coating agent, if the thread is twisted, the coating agent will not penetrate into the fibers constituting the twisted thread. As a result of the twisting and tightening of the thread due to the large tension applied to the thread when the airbag inflates, a gap is generated in the seam portion between the seam thread and the seam thread insertion section of the base fabric, and the gas for airbag inflation may leak.

[0010] Therefore, the present invention is configured such that at least a portion of the fibers of the suture are bonded by an adhesive material, and the "twisting" of the thread does not tighten when the air bladder inflates. This is because the presence of an adhesive material layer between the fibers prevents the fibers from shifting apart and the fiber spacing from narrowing. Consequently, gaps are less likely to form between the suture and the suture insertion cross-section of the base fabric in the seam opening. When the adhesive material is applied to the seam portion, to prevent adhesion to the surface opposite to the coated surface, the exposure rate of the adhesive material on the portion of the suture outside the seam opening on the base fabric and the ratio of the suture covered by the adhesive material are specified. Furthermore, regarding the ratio of the adhesive material between the fibers constituting the suture, the area ratio of the suture cross-section (the cross-sectional area ratio of the adhesive material relative to the cross-sectional area of ​​the thread) is specified. Alternatively, if the viscosity range of the adhesive material (equivalent to the "coating agent" mentioned in Patent Document 1) is optimized and the coating is applied from both sides, an adhesive material with a higher viscosity than the adhesive material applied to the opposite side is used as the initial adhesive material. This prevents the adhesive material with a lower viscosity from adhering to the support table when the adhesive material is applied from the opposite side through the bag body and the seam of the bag body during the coating operation.

[0011] In the case of single-sided coating, the seam can be efficiently sealed by specifying the viscosity, the flow of the adhesive material into the base fabric surface on the side opposite to the coating surface can be adjusted, and a specified ratio of adhesive material can be dispersed between the fibers constituting the seam. In the case of double-sided coating, an adhesive material with a lower viscosity than the initially coated adhesive material is used as the adhesive material applied to the opposite side, so that the adhesive material can easily penetrate between the fibers constituting the twisted thread, and can be integrated with the initially coated adhesive material to efficiently seal the seam. Furthermore, the aim is to provide a method for manufacturing an airbag body in which at least a portion of the fibers constituting the seam are bonded in a manner that minimizes gaps between the seam and the seam insertion section of the base fabric in the seam opening, as a result of the "twisting" and tightening of the twisted thread, i.e., the fibers of the seam.

[0012] Solution for solving the problem

[0013] To address the aforementioned problems, the following content is provided in this invention.

[0014] As the first invention An airbag is provided, comprising a sheet-like first base fabric, a sheet-like second base fabric, and a suture. The suture is formed by twisting multiple fibers together and then sewing the first and second base fabrics together to create a gas injection space. In the suture, at least a portion of the fibers are bonded together with an adhesive material so that gaps are less likely to form between the suture and the base fabric in the seam opening, as the twisting degree of the suture is tightened due to the tension generated by the suture.

[0015] As a second invention, an airbag based on the first invention is provided, wherein, At least a portion of the stitching is exposed from the adhesive material in the portion other than the perforated portion of at least one of the first or second base fabrics.

[0016] As a third invention, an airbag based on either the first or second invention is provided, wherein... In an area on the surface of the base fabric on the side where the adhesive material is applied to the seam of one of the base fabrics, the two-dimensional area ratio of at least a portion of the suture exposed from the adhesive material is greater than 0% and less than 30%.

[0017] As a fourth invention, an airbag based on any one of the first to third inventions is provided, wherein, In an area on the surface of the base fabric on the side of the base fabric where the adhesive material is not applied to the seam of the base fabric, the area covered by the adhesive material (including both the seam and the base fabric) is approximately the same width as the seam along the seam direction (and may also include the seam from the opposite side of the base fabric), the two-dimensional area ratio of the portion covered by the adhesive material is 5% or more.

[0018] As a fifth invention, an airbag based on any one of the first to fourth inventions is provided, wherein, In the suture on the base fabric side coated with adhesive material, the cross-sectional area of ​​the adhesive material relative to the cross-sectional area of ​​the suture is 10% or more and 25% or less (the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture is 55% or more and 100% or less).

[0019] As a sixth invention, an airbag based on any one of the first to fifth inventions is provided, wherein, In the suture on the base fabric side where the adhesive material is not applied, the cross-sectional area of ​​the adhesive material relative to the cross-sectional area of ​​the suture is 5% or more and 25% or less (the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture is 35% or more and 100% or less).

[0020] As the seventh invention, an airbag based on the first invention is provided, wherein, In cases where at least a portion of the seam of the first base fabric and / or the second base fabric is composed of fabric, The fibers of the fabric forming the seam are bonded together by an adhesive material so that the fibers of the fabric forming the seam of the first base fabric or / and the second base fabric are not easily loosened.

[0021] As an eighth invention, an airbag based on either the first or seventh invention is provided, wherein the fibers near the seam are bonded by an adhesive material to prevent the fibers of the fabric constituting the first base fabric and / or the second base fabric from coming loose.

[0022] As a ninth invention, a method for manufacturing an airbag is provided, which is a method for manufacturing an airbag of any one of the first, seventh, or eighth inventions, comprising: a first base fabric permeation step, wherein a first adhesive material is permeated from the seam portion of the first base fabric into the seam; and a second base fabric permeation step, wherein a second adhesive material is permeated from the seam portion of the second base fabric into the seam.

[0023] As the tenth invention, a method for manufacturing an airbag based on the ninth invention is provided, wherein, The first and second adhesive materials have different viscosities.

[0024] As the eleventh invention, a method for manufacturing an airbag based on either the ninth or tenth invention is provided, wherein, A first adhesive material and a second adhesive material are applied onto a flat platform, wherein the first adhesive material applied has a higher viscosity than the second adhesive material applied.

[0025] As the twelfth invention, a method for manufacturing an airbag based on any one of the ninth to eleventh inventions is provided, wherein an initially coated adhesive material with relatively high viscosity is applied to the face line side bound to the surface of the base fabric by a bottom line during a one-line through-stitch performed on the base fabric.

[0026] As the thirteenth invention, a method for manufacturing an airbag is provided, which is the method for manufacturing an airbag according to the first invention, and has the following characteristics: The adhesive material penetration step involves applying an adhesive material to the seam portion of the surface of either a first or a second base fabric, and penetrating the adhesive material from the seam opening into the spaces between the fibers forming the suture thread within the seam opening; and The opposite base fabric side stitch fiber bonding material penetration step causes the bonding material to penetrate from the seam portion into at least a portion of the fibers forming the stitch line (a different stitch line from the stitch line exposed between the seams on the base fabric surface opposite to the base fabric coated with the bonding material) that is exposed between the seams on the base fabric surface opposite to the base fabric coated with the bonding material.

[0027] As the fourteenth invention, a method for manufacturing an airbag based on the thirteenth invention is provided, wherein, It also has a base fabric bonding step, in which a portion of the adhesive material that seeps out from the slit portion remains between the first base fabric and the second base fabric, thus bonding the first base fabric and the second base fabric together.

[0028] As the fifteenth invention, a method for manufacturing an airbag based on any one of the ninth to twelfth inventions is provided, wherein, The viscosity difference of the adhesive materials during coating is expressed in Pascals per second (Pa), and the viscosity range between the high-viscosity and low-viscosity adhesive materials is 3.0 mPa. s~90Pa s.

[0029] As the sixteenth invention, a method for manufacturing an airbag based on any one of the thirteenth or fourteenth inventions is provided, wherein, The viscosity difference of the adhesive materials during coating is expressed in Pascals per second (Pa), and the viscosity range between the high-viscosity and low-viscosity adhesive materials is 3.0 mPa. s~90Pa s.

[0030] The effects of the invention

[0031] With the above configuration, the present invention is configured such that at least a portion of the fibers of the suture are bonded by an adhesive material, and the "twisting" of the thread will not tighten even when the air bladder inflates. This is because an adhesive material layer exists between the fibers, and the fibers are bound together by the adhesive, so the fibers are less likely to shift or the fiber spacing is less likely to narrow. Therefore, it is configured such that gaps are less likely to occur between the suture and the suture insertion cross-section of the base fabric in the seam opening. When the adhesive material is applied to the seam, in order to prevent adhesion to the surface opposite to the coated surface, the exposure rate of the adhesive material on the portion of the suture outside the seam opening on the base fabric and the ratio of the suture covered by the adhesive material are specified. Furthermore, regarding the ratio of the adhesive material between the fibers constituting the suture, the area ratio of the suture cross-section (the cross-sectional area ratio of the adhesive material relative to the cross-sectional area of ​​the thread) is specified. Alternatively, by optimizing the viscosity range of the adhesive material (equivalent to the "coating agent" mentioned in Patent Document 1), when coating is applied from both sides, an adhesive material with a higher viscosity than the adhesive material applied to the opposite side is used as the initial adhesive material, preventing the low-viscosity adhesive material from adhering to the support table when applying the adhesive material from the opposite side through the bag body and the seam of the bag body during the coating operation.

[0032] In the case of single-sided coating, the seam can be efficiently sealed by specifying the viscosity. The flow of the adhesive material into the base fabric surface opposite to the coating surface can be adjusted, allowing a specified ratio of adhesive material to be dispersed between the fibers constituting the seam. In the case of double-sided coating, an adhesive material with a lower viscosity than the initially coated adhesive material is used as the adhesive material applied to the opposite side. This allows the adhesive material to easily penetrate between the fibers constituting the twisted thread and integrates with the initially coated adhesive material for efficient sealing of the seam. Furthermore, a method for manufacturing an airbag can be provided, in which at least a portion of the fibers constituting the seam are bonded in the airbag body in a manner that minimizes gaps between the seam and the seam insertion section of the base fabric at the seam opening, resulting from the "twisting" and tightening of the twisted thread (i.e., the seam fiber). Attached Figure Description

[0033] Figure 1 This is a plan view of the suture portion of the airbag according to Embodiment 1 of the present invention.

[0034] Figure 2 This is a schematic diagram of the cross-section AA′ of the suture portion of the airbag according to Embodiment 1 of the present invention.

[0035] Figure 3 This is a planar schematic diagram of the suture portion of Embodiment 1 of the present invention when the airbag is inflated.

[0036] Figure 4 This is a schematic diagram of the cross-section of the suture portion of Embodiment 1 of the present invention when the airbag is inflated.

[0037] Figure 5 This is a plan view of the suture portion of the airbag according to Embodiment 2 of the present invention.

[0038] Figure 6a This is a schematic diagram of the cross-section of the suture portion of the airbag according to Embodiment 2 of the present invention. Figure 1 .

[0039] Figure 6b This is a schematic diagram of the cross-section of the suture portion of the airbag according to Embodiment 2 of the present invention. Figure 2 .

[0040] Figure 7 This is an example of a flowchart of the manufacturing method according to Embodiment 4 of the present invention.

[0041] Figure 8 This is a plan view showing an example of the termination of the first base fabric permeation step of the airbag according to Embodiment 5 of the present invention.

[0042] Figure 9 This is a cross-sectional schematic diagram of an example of the first base fabric permeation step of the airbag in Embodiment 5 of the present invention when it is terminated.

[0043] Figure 10 This is a plan view showing an example of the second base fabric permeation step of the airbag in Embodiment 5 of the present invention being terminated.

[0044] Figure 11 This is a cross-sectional schematic diagram of an example of the second base fabric permeation step of the airbag in Embodiment 5 of the present invention when it is terminated.

[0045] Figure 12 This is a plan view showing an example of the second base fabric permeation step before the start of the airbag according to Embodiment 6 of the present invention.

[0046] Figure 13 This is a cross-sectional schematic diagram of an example of the second base fabric permeation step of the airbag in Embodiment 6 of the present invention before the start of the permeation step.

[0047] Figure 14 This is a plan view showing the suture portion of the airbag according to Embodiment 7 of the present invention.

[0048] Figure 15 This is a longitudinal cross-sectional schematic diagram showing the stitched portion of the airbag according to Embodiment 7 of the present invention.

[0049] Figure 16 This is a schematic cross-sectional view of the suture portion after the adhesive material of the airbag in Embodiment 7 of the present invention has permeated.

[0050] Figure 17 This is a schematic diagram illustrating an example of the structure of the suture of the present invention.

[0051] Figure 18 This is a schematic diagram illustrating an example of the cross-sectional structure of the suture of the present invention.

[0052] Figure 19 It is a time-varying coordinate graph of the pressure inside the air bladder during inflation.

[0053] Figure 20 This is a graph showing the relationship between the viscosity of the adhesive material and the gas retention within the airbag during the coating process of this invention.

[0054] Figure 21 This is a schematic diagram illustrating the curing of the adhesive material in this invention.

[0055] Figure 22 This is a schematic diagram illustrating an example of pre-coating an adhesive material onto the suture of the present invention.

[0056] Figure 23 This is a schematic diagram illustrating an example of the cured dimensions of the adhesive material of the present invention.

[0057] Figure 24 This is an illustration of the types of airbags used in passenger vehicles.

[0058] Figure 25 This is a planar schematic diagram of the suture portion according to the second embodiment of the present invention.

[0059] Figure 26 This is a longitudinal cross-sectional schematic diagram of the suture portion according to the second embodiment of the present invention.

[0060] Figure 27 This is a SEM image of the surface near the suture line on the base fabric surface coated with adhesive material at the seam.

[0061] Figure 28 This is a surface SEM image of the area near the suture line on the side of the base fabric where the adhesive material is not applied.

[0062] Figure 29 This is a cross-sectional SEM image of the pores where adhesive material has been applied to one side of the upper base fabric.

[0063] Figure 30 This is an example of a flowchart of the manufacturing method according to Embodiment 13 of the present invention.

[0064] Figure 31 This is an example of a flowchart of the manufacturing method according to Embodiment 14 of the present invention.

[0065] Figure 32This is a schematic diagram of a longitudinal section along the stitching direction near the suture hole in Embodiment 14 of the present invention. Detailed Implementation

[0066] Hereinafter, embodiments of the present invention will be described. However, the present invention should not be limited to these embodiments in any way, and can be implemented in various ways without departing from its spirit. The description of the invention's structure and the reference numerals in the accompanying drawings are indicated by four digits, the first two digits indicating the drawing number and the last two digits indicating the inherent number assigned to each part. Furthermore, the figures shown... Figure 7 The reference numerals indicating the various action steps in the flowchart are not added according to a method of adding reference numerals, but according to the order of processing.

[0067] <Airbag: Structure>

[0068] An airbag consists of an inflator that generates gas to inflate the bag (the inflator that ignites gunpowder is the most common), an acceleration sensor for detecting collisions, a control circuit, the bag itself, and a rotating connector (only for the driver's seat). However, in this manual, the bag itself is referred to as an airbag in the narrow sense.

[0069] <Airbags: Types>

[0070] Airbags are used in various vehicles, but the most intimate airbags are those used in passenger cars. Figure 24 This diagram shows an example of an airbag installed in a car passenger compartment. The airbags in the passenger compartment include various types such as: a driver's side airbag (2420), housed in the handle of the driver's seat, protecting the driver's head and chest in a frontal collision; a passenger side airbag (2421), housed in the dashboard on the passenger side, protecting the passenger's head and chest in a frontal collision; a side curtain airbag (2422), installed above the door opening, deploying to cover the window, protecting the head and neck of the driver, passenger, or rear seat occupants in a side collision or vehicle rollover; side airbags (2423), housed on the left and right sides of the seats, protecting the chest and abdomen of the driver, passenger, or rear seat occupants in a side collision; and a knee airbag (2424), protecting the occupant's legs and reducing impact on the knees. A center airbag (2425) is positioned between the driver's and passenger's seats. It is an airbag used to prevent the driver and front passenger from colliding, and to prevent the head from contacting interior parts such as doors on the side opposite to the collision side (non-collision side).

[0071] Among them, the driver's side airbag (2420) and the front passenger airbag (2421) have increased volume when inflated, and the occupant will be hit in an accident. Therefore, the occupant will be injured by colliding with the airbag in its inflated state. Therefore, if the airbags used in the front seats absorb and weaken the forward inertia of the occupant after inflating, the inflated gas needs to be released immediately, so a venting valve is also provided. The side curtain airbag (2423) among the other airbags inflates between the occupant and the window in a side collision. In order to prevent the occupant from being injured or thrown out of the vehicle due to contact with the window, broken window glass, or outside the vehicle when swaying laterally, it must be maintained inflated for several seconds longer (e.g., more than 6 seconds) than the driver's or front passenger airbags. The center airbag is also an airbag that deploys to protect the occupant in a side collision. Although it does not deploy for as long as the side curtain airbag, it should be maintained in an inflated state. In addition, although in Figure 24 Not illustrated, but the pedestrian protection airbag deployed on the hood should also be an airbag that does not actively expel gas but remains inflated to a certain degree for a period of time. Therefore, these airbags are preferably those that do not easily expel the inflating gas, making them suitable for the application of the airbags of the present invention or their manufacturing methods.

[0072] <Implementation Method 1>

[0073] <Summary of Embodiment 1> Mainly claims 1

[0074] The airbag of this embodiment includes a sheet-like first base fabric and a sheet-like second base fabric, and a suture thread that sews the two together, configured such that at least a portion of the fibers in the suture thread are bonded together by an adhesive material.

[0075] <Implementation Method 1 Configuration>

[0076] use Figure 1 , Figure 2 The structure of this embodiment 1 will be explained. Figure 1 This is a planar schematic diagram of a seam of the airbag (0100) viewed from the normal direction of the base fabric surface. The suture line (0104) constituting the seam is shown, as well as the adhesive material (0105) covering the upper surface and two sides of the suture line (0104). The suture line (0104) appears discontinuous because the suture line (0104) on the viewing side is pulled by the suture line (0104) on the inner side, forming a seam opening invisible from the base fabric surface on the viewing side. Furthermore, in Figure 1 In the diagram, the portion shown with a thick solid line as the suture line (0104) does not indicate that the suture line (0104) is directly exposed on the observation surface of the airbag (0100), as shown below. Figure 2 The image shows the portion of the adhesive material (0205) covering the upper surface of the suture (0204). If the adhesive material is transparent, the suture can be visually observed.

[0077] <Structural outline of the suture section in Embodiment 1: Plan view>

[0078] Figure 1 This is a schematic plan view of the seam of the base fabric of the airbag from Embodiment 1. The solid horizontal line at the top of the figure represents the end face of the airbag, and the wavy lines on the left, right, and bottom indicate portions that are omitted from their preceding sections. This will be used in the description of other embodiments described later. Figure 3 , Figure 5 , Figure 8 , Figure 10 , Figure 12 , Figure 14 , Figure 25 China is with Figure 1 Similar notation. Furthermore, in the figures of this specification, the stitching at the end of the airbag is illustrated as being located at the end, but is not limited to the end; even stitching located on the inner side of the base fabric or other stitchings located between the airbag and the end can be subject to this invention.

[0079] <Implementation Method 1: Structural Overview of the Suture Section: Longitudinal Section View>

[0080] Figure 2 It is along in Figure 1 A schematic longitudinal section of the suture line (0104) of the suture portion shown in AA′, representing the portion near the suture hole. Figure 1 The part indicated by B in the middle is Figure 1 The sutures on the viewing side of the central airbag are pulled by the inner sutures, and the portion of the suture opening that is not visible is covered with adhesive material. (Including...) Figure 1 In the following description of this instruction manual, only one suture is shown, but the airbag suture can also be configured with multiple sutures in parallel. Furthermore, in Figure 2 The illustration shows that the adhesive material (0205) completely covers the suture (0204) on the surface of the base fabric, but at least a portion of the suture can also be exposed from the adhesive material. Additionally, Figure 2 The thickness of the adhesive material (0205) on the surface of the upper first base fabric (0201) or the lower second base fabric (0202) shown can also be different.

[0081] Figure 2 This is a schematic diagram of a longitudinal section along the sutured portion of the airbag. The sutured portion of the airbag includes a first base fabric (0201), a second base fabric (0202), fibers constituting the suture thread (0203), a suture thread (0204) formed by binding multiple fibers (0203), and an adhesive material (0205). To distinguish the suture thread that encounters the top thread and bottom thread when sewing with a sewing machine, etc., in... Figure 2The diagram illustrates the use of white and light gray sutures. In practice, sutures of the same color can be used, or the color can be intentionally changed (the same applies below).

[0082] <Implementation Method 1: First Base Fabric (0201), Second Base Fabric (0202)>

[0083] The “first base fabric” (0201) and the “second base fabric” (0202) are sheet-like. In order to form a gas injection space using the first base fabric (0201) and the second base fabric (0202), the two are sewn together to form a bag body.

[0084] The "first base fabric" and the "second base fabric" are each formed into a sheet shape. The base fabric can be a fabric made of braided yarn, a woven cloth, a non-woven fabric, a sheet made by stretching synthetic resin into a thin film, etc., and can be appropriately selected according to the desired performance.

[0085] <Implementation Method 1: First Base Fabric / Second Base Fabric: Raw Materials for the Base Fabric>

[0086] The airbag, formed by sewing together the first and second base fabrics, is inflated by the gases from burning gunpowder using an inflator. Therefore, the first and second base fabrics constituting the airbag need to be as soft as possible while also considering the need to support the passenger, possessing the strength to withstand the rapid expansion caused by instantaneous high temperature and pressure of the gas and to avoid damage from impacts caused by contact with the passenger. If the two base fabrics are fabrics, the airbag can also use fabrics such as nylon, polyethylene terephthalate, and polyester, which are used in known airbag applications. When the base fabric is fabric, coated fabrics (mostly coated on one side of each base fabric) or uncoated fabrics can be used. The coated fabric can be configured such that the coated surface of the bag extends to the outside or the inside of the bag. The combination of the coated resin (silicone resin or polyurethane resin, etc.) and the adhesive material described later can be appropriately selected based on the bond strength between them.

[0087] The presence or absence of a coating on the fabric, and the linear density of the fabric, affect the method of releasing the inflating gas from the inflated airbag. Therefore, the appropriate selection can be made based on the type and specifications of the airbag to be used. For example, airbags for the driver's or passenger's seat, which have a large bag body and a large amount of inflating gas, and have vents for releasing gas after inflating, are made with uncoated fabric. Side curtain airbags, which are thin and do not have vents, and require maintaining a small amount of gas for a relatively long time, are made with coated fabric. The presence or absence of a coating, the fabric density, or the raw material of the fabric can also be changed between the first and second base fabrics. The appropriate selection can be made based on the design of the airbag's inflation and deflation method.

[0088] <Implementation Method 1: First Base Fabric / Second Base Fabric: Base fabric constituting the airbag>

[0089] In the description of this application, the first and second base fabrics are illustrated as each consisting of a single sheet, but they may also consist of multiple sheets (e.g., attaching a thin strip of fabric near the seam, sewing it on, and reinforcing it; or overlapping approximately identical fabrics to form a base fabric on one side, etc.). Alternatively, one may consist of a single sheet, while the other may consist of multiple sheets. The first or second base fabric may be separate sheet-like base fabrics joined together, or multiple sheet-like base fabrics may be joined together. In the case of a joined structure, sheet-like base fabrics of different materials may be joined instead of sheet-like base fabrics of the same material. Furthermore, the airbag body may be constructed not by overlapping and sewing together the first and second base fabrics of approximately the same shape, but by sewing together base fabrics of different shapes to form a three-dimensional shape. It may also be a cylindrical shape including a top surface, bottom surface, and sides, or a mushroom-shaped (hamburger bun shape) shape formed by three-dimensionally sewing together fabrics of different shapes. The stitching section basically stitches together the two types of sheet-like first base fabric and sheet-like second base fabric. However, in the structural design of the airbag, even if more than two types of sheet-like base fabric are stitched together, it is still possible to carry out the work within the scope of this invention.

[0090] <Implementation Method 1: Suture (0204)>

[0091] Figure 2 The suture (0204) shown is constructed by twisting and binding multiple fibers (0203) together, and is used to sew the first base fabric and the second base fabric together. In addition, at least a portion of the fibers of the suture are bonded together with an adhesive material described later, so that gaps are less likely to form between the suture and the base fabric in the seam opening due to the tightening of the twist caused by the tension generated by the suture.

[0092] <Implementation Method 1: Suture (0204): Structure>

[0093] Figure 17 This is a schematic diagram illustrating an example of the structure of a suture. Figure 17 The diagram illustrates the suture structure for ease of understanding; the twist loosens as it goes upwards. Figure 17The example suture is made by further twisting three single fibers (1703) into a small-diameter twist in an S-direction to form a large-diameter twist in a Z-direction, i.e., the suture (1704). S-direction twist and Z-direction twist are distinctions in the twisting direction of the thread. When viewed laterally, the direction of the small-diameter twisted fibers (which are small-diameter twisted relative to the large-diameter twisted fibers) is upward to the left, called S-direction twist; if it is upward to the right, called Z-direction twist. However, this twisting process is just one example; if several twisting processes are performed on the thread, it conforms to the suture described in this invention. Figure 17 In the example shown, the adhesive material (1705), indicated in gray, permeates throughout the suture (1704), and the fibers (1703), which are at least part of the monofibrils, are bonded together by the adhesive material and are not easily shifted. In addition, not only between the fibers (1703) that are monofibrils, but also between the three small-diameter twisted threads formed by twisting the monofibrils, at least part of them are bonded together by the adhesive material (1705), and the three small-diameter twisted threads are not easily shifted.

[0094] Figure 18 It is shown Figure 17 A schematic diagram of the cross-section of the dd′ portion. The small circle shows the fiber (1803) as a single fiber. Multiple fibers (42 fibers each) are divided into three groups surrounded by circular dashed lines, which are the small-diameter twisted threads. The circular dashed lines surrounding the three small-diameter twisted threads show the suture line (1804) as a large-diameter twisted thread. At least a portion of the fibers (1803) and the small-diameter twisted threads are bonded together by an adhesive material (1805). Furthermore, in the... Figure 2 The diagram does not show the case where adhesive material (0205) permeates between at least a portion of the fibers (0203) of the suture (0204). Although it will not be shown in the following diagrams unless specifically described, the suture is designed such that adhesive material permeates between at least a portion of the fibers constituting the suture and bonds it, preventing it from shifting.

[0095] <Effect of Adhesive Material in Embodiment 1 Suture (0204)>

[0096] Even when the tension on the suture (1704) is further increased during airbag inflation in addition to the tension applied during suturing, the bonding material (1705) between the fibers (1703) prevents misalignment, as the bonding material fixes the fibers (1703) and / or the small-diameter twists. The distance between adjacent fibers (1703) or adjacent small-diameter twists will not narrow, and the diameter of the suture will not become thinner. Figure 21 The table will be used for explanation. Figure 21The left column shows sutures without adhesive material penetration, while the right column shows sutures where adhesive material has penetrated at least a portion of the fibers constituting the suture. The upper section shows the suture before the application of airbag tension during inflation, and the lower section shows the suture after the application of airbag tension. The left side of each column is a simplified diagram illustrating the shape of the suture, used to show changes in diameter. The right side of each column is a cross-sectional view showing a portion of the fibers constituting the suture. The distance between the fibers of the suture before the application of airbag tension, or the diameter of the suture, is approximately the same with and without adhesive material penetration. The cross-section of the twisted fibers is elliptical because they are obliquely transverse. In sutures where adhesive material has penetrated, at least a portion of the fibers are bonded together by the adhesive material.

[0097] When the tension of the airbag inflation is applied, the fibers of the suture in the lower left column, which is not permeated with adhesive material, are stretched, causing the fibers to shift relative to each other, reducing the gaps between the fibers, and sometimes causing the angle of the fibers crossing the cross section to approach the vertical direction, moving from an ellipse to a circle. Due to these effects, the diameter of the suture decreases. When the tension of the airbag inflation is further applied to the suture in the lower right column, where the adhesive material has permeated at least partly, the fibers bonded by the adhesive material are less prone to shifting, and the distance between the fibers does not change. Therefore, the cross section of the fibers crossing the cross section also remains approximately the same elliptical shape as before the tension was applied. Through these effects, the thickness of the suture remains approximately the same as before the tension was applied. Therefore, no gaps are created between the suture and the base fabric in the seam opening, preventing leakage of inflation gas during airbag inflation. Without adhesive material, as... Figure 21 As shown in the lower left column (without adhesive material, after tension is applied), the diameter of the suture (1704) becomes thinner when tension is applied during airbag inflation. Therefore, a gap is created in the seam opening between the suture and the intersecting section of the base fabric, causing leakage of gas during airbag inflation. This gas leakage during airbag inflation can be prevented by pre-permeating the adhesive material between at least a portion of the fibers of the suture.

[0098] <Effective Implementation 1: Suture (0204): Raw Materials>

[0099] The fiber (0203) can be any known thread used for sewing airbags, such as polyamide fiber, polyester fiber, or biopolyester fiber. In particular, the adoption of biopolyester fiber can be considered and promoted in response to the increasing consumer awareness of environmental issues and concerns about SDGs in recent years.

[0100] <Implementation Method 1: Suture (0204): Thickness, Fineness>

[0101] The diameter of the fibers can be appropriately selected according to the specifications required for the thread constituting the suture. If the fiber diameter is large, when used as a suture thread, it becomes a thread with fewer fibers forming the suture thread and high rigidity, making it difficult to sew. Examples of suture thread specifications are threads with a single thread fineness of 10 dtex or less and a total fineness of 200 to 3100 dtex, more preferably 900 to 1800 dtex (130 to 210 fibers), which can be appropriately selected. Compared to suture threads made of single fibers, such as nylon fishing lines, twisting and binding multiple fine fibers together makes them more flexible, thus easier to handle during sewing, and less prone to breakage even due to damage, which is preferable. In the case of single fibers, if damage occurs and the damage spreads due to tension applied to the thread, it will break, but if it is composed of multiple fibers, it can be supported by undamaged fibers, thus making it less prone to breakage.

[0102] As an example of a suture, it is constructed by twisting approximately 20 to 50 single nylon fibers with a diameter of 0.02 to 0.04 mm together to form three small-diameter twists with a diameter of 0.1 to 0.3 mm, which are then further twisted together to form one large-diameter twist (approximately 0.5 mm in diameter), i.e., the suture (approximately 1000 dtex). However, the number of small-diameter twists is not limited to three; more are preferred. Two to seven twists are preferred. Alternatively, a single thread can be formed by twisting 130 to 210 single fibers together without creating small-diameter twists. However, in this case, a lower viscosity adhesive material is needed to allow the adhesive material to penetrate to the center of the suture. A viscosity of 0.05 Pa is suitable in this case. s to 2.0Pa Adhesive materials of degree s.

[0103] <Embodiment 1: Suture (0204): Sutured portion>

[0104] When sewing with a sewing machine, two types of thread are used: top thread and bottom thread. However, they can not be the same thread; different materials or strengths can be used depending on the purpose. For example... Figure 15 As shown, when the suture is asymmetrical when viewed in section, it can be designed so that the shear strength of the suture on the side subjected to tension during the inflation of the airbag is higher than that of the suture on the other side. Figure 15 In the case of the stitching method, since the tension increases during the inflation of the airbag due to the tension of the sutures (1504a) pulled into the seam side, it is preferable that the shear strength of these sutures (1504a) be higher than that of the other suture (1504b). To distinguish between the first and second base fabric sides, or to distinguish between the top and bottom threads, the colors of the top and bottom threads can be changed, for example, such as blue and red. Only an example of straight stitching is shown in the figures of this specification, but other stitching methods are also possible.

[0105] <Effective Implementation 1: Suture (0204): Sutured section: Multiple rows>

[0106] In this application specification, a single row of seams is illustrated and explained, but a configuration with more than one row is possible (the explanation of multiple rows is the same in other embodiments). When sewing with thread, a single row of seams is acceptable, but multiple rows of seams are preferred as they are more effective at resisting the force applied when the airbag inflates. When the seams are arranged in two rows, the seams on the inner side of the airbag can bear the force applied to the seam when the airbag inflates, reducing the force applied to the outer seams and reducing leakage of the inflation gas. The number of seams can also be three or more rows than two. When sewing the base fabric with a number of seams that is greater than the number of needles on a sewing machine, multiple sewing operations are possible. A single sewing operation can also be performed using a sewing machine equipped with multiple needles corresponding to the number of seams. Increasing the number of rows increases manufacturing costs and the weight of the airbag itself (due to the increased seam area where the seams are seams and the bonding material applied to the seams). It also causes side effects such as difficulty in folding. To maintain strength while minimizing side effects, the number of sutures should be three or fewer, preferably two.

[0107] When multiple rows of seams are provided, the distance between the rows of seams (the distance between the center lines of the seams) is 1 mm or more and 10 mm or less, preferably 7 mm or less, and more preferably 5 mm or less.

[0108] <Implementation Method 1: Suture (0204): Penetration of Adhesive Material>

[0109] Before being used to sew the base fabric, at least a portion of the fibers of the suture thread can be pre-bonded with the bonding material described later. For example... Figure 22As shown, when manufacturing a suture, before winding it onto a winding wheel (2210), the adhesive material (2205) is applied intermittently from a nozzle (2211) to the suture (2204) in a manner that involves applying a length equivalent to 1 mm and leaving a gap of 0.5 mm without applying the adhesive material. This allows the adhesive material to penetrate between the fibers. The suture is then heated using an infrared lamp heater (2212) or similar means to provide suitable curing and drying conditions for the adhesive material, and then wound up. This process enables the manufacture of a suture in which the adhesive material has pre-penetrated between at least a portion of the fibers. Alternatively, when sewing a base fabric using a sewing machine, the suture can be configured such that the adhesive material penetrates the suture before it is pulled out and passes through the base fabric. However, since sewing the first and second base fabrics together allows for the application of sewing tension (based on the tension generated between the sewing lines and the tension exerted by the base fabric) to the free suture, it is preferable to apply the adhesive material after the sewing tension has been applied. Furthermore, since a predetermined time elapses after sewing until these tensions become constant, it is preferable to apply the adhesive material after the tension has become constant. The time it takes for the tension to become constant is more than 1 second and approximately 5 minutes. This time varies depending on the type of suture and the raw material of the base fabric.

[0110] <Embodiment 1: Adhesive Material (0205)>

[0111] For the bonding material (0205), at least a portion of the fibers (0203) of the suture (0204) are bonded together in such a way that gaps are not easily generated between the suture and the base fabric in the seam opening, as a result of the tightening of the twist caused by the tension generated in the suture (0204).

[0112] <Implementation Method 1: Adhesive Material: Raw Materials and Properties>

[0113] The raw materials for the adhesive material (0205) can be selected from resins such as silicone resin, polyvinyl chloride resin, polyurethane resin, polyester resin, or other elastomers. When the airbag is housed in a designated location within the vehicle's passenger compartment, such as a handle, seat, pillar, or upper part of a side window, the seam where the adhesive material is applied is folded; therefore, even after the adhesive material has dried, it needs to be a flexible material. As for the hardness after curing, when measured using a hardness tester of type E or A as specified in JIS K 6253-3, it is preferably between 0 and 30. More preferably, it is between 5 and 20, and most preferably, it is in the range of 5 to 15.

[0114] If the first and / or second base fabric is a coated fabric, it is preferable to use an adhesive material that includes a material of the same system as the coating material on the surface of the base fabric, as this is more likely to result in increased adhesive strength. For example, in a base fabric coated with silicone rubber, flame retardancy can be imparted to the silicone rubber itself by mixing it with a known flame retardant. Therefore, when using a base fabric with such a configuration, it is preferable to use a resin of the same silicone rubber system as the adhesive material. Furthermore, when the coating agent of the base fabric is a polyurethane resin system, it is also preferable to use a polyurethane resin system as the adhesive material; and when a polyvinyl chloride (PVC) resin is used as the coating agent, it is preferable to use a PVC resin system as the adhesive material.

[0115] For the bonding material to penetrate the fibers of the suture and bond them together, good adhesion to the fibers is essential. Nylon fibers are less likely to bond with adhesives compared to polyester fibers. When using sutures made of nylon fibers, silicone-based or polyurethane-based materials must be selected as the bonding material to bond the nylon. The bonding material should be selected based on the type of materials constituting the suture and / or the base fabric (e.g., fibers, coating materials of the base fabric, raw materials of the membrane base fabric, etc.).

[0116] <Implementation Method 1: Adhesive Material: Coating after stitching>

[0117] As an example of a method for permeating the adhesive material (0205) into the fibers of the suture, after the first base fabric (0201) and the second base fabric (0202) are sewn together with the suture (0204), the adhesive material is applied to the sewn portion using a dispenser or syringe, or by screen printing, inkjet printing, or by pen. Examples of adhesive material application methods include methods such as applying the material from the first base fabric side to the sewn portion and drying it, and then applying it from the opposite side (the second base fabric side) to the sewn portion. Alternatively, a unilateral application method may be used, for example, applying the material only from the first base fabric side to the sewn portion. The adhesive material permeates into the fibers of the suture exposed on the surface of the base fabric. Additionally, in the sewn portion, the adhesive material permeates from the openings of the sewn portion along the suture (0204) into the fibers (0203) constituting the suture (0204). As a result, at least a portion of the fibers (0203) constituting the suture (0204) are bonded with an adhesive material (0205), making it less likely for the fibers (0203) to shift or separate. Simultaneously with the adhesive material penetrating between the fibers, the gap between the base fabric of the seam and the suture (0204) is also filled with the adhesive material (0205). As explained in the description of the suture's effect on the adhesive material, even under the tension of airbag inflation, the diameter of the suture (0204) does not decrease, preventing gaps from forming between the suture and the base fabric in the seam opening.

[0118] In this embodiment Figure 1 , Figure 2 The example shown is an example of applying adhesive material (0205) to the suture using the method described above. However, it is also possible to suture using a suture (0204) pre-soaked with adhesive material (0205) as described in the explanation of the suture, and to sew without applying adhesive material to the suture after sewing.

[0119] <Implementation Method 1: Adhesive Material: Sutures during airbag inflation>

[0120] use Figure 3 , Figure 4 To illustrate the sutures during airbag inflation. Figure 4 This is a schematic diagram of the cross-section of the airbag's suture section. Figure 3 It is used to show Figure 4 A planar schematic diagram of the suture portion of the airbag at the cross-sectional area CC′. (See diagram below.) Figure 4 As shown, the airbag is sandwiched between a first base fabric (0401) and a second base fabric (0402), and the space surrounded by a suture portion based on a suture line (0404) expands due to gas. In the suture portion, the first base fabric (0401) and the second base fabric (0402), positioned inside the suture portion, are as follows: Figure 4 As indicated by the arrows, the fabric is to be kept far apart, thus attempting to stretch the tension of the seam (0404) that connects the two base fabrics. When a stretching force is applied to the seam, the twist of the thread tightens, and the diameter of the thread decreases. Thus, if the seam of the base fabric is sewn only with seams that do not bond at least a portion of the fibers together with adhesive, the seam opening, which was roughly filled by the seam before inflation, is stretched and tightened by the tension of the air bladder during inflation. Therefore, the diameter of the seam decreases, creating a gap between the base fabric and the seam opening, causing the inflation gas to leak.

[0121] In this application invention, such as Figure 4 As shown, at least a portion of the suture (0404) at the seam opening is bonded by interpenetrating adhesive material between the fibers. Figure 17 As shown, by permeating and bonding the fibers (1703) constituting the suture (1704) or the small-diameter twisted threads composed of multiple fibers with an adhesive material (1705), the fibers are fixed, so the distance between the fibers or the small-diameter twisted threads does not shrink, the twist does not tighten, and the diameter of the suture does not become thinner. Therefore, gaps are less likely to form between the suture insertion section of the base fabric at the seam opening and the suture itself. Since gaps are less likely to form at the seam opening, leakage of expansion gas from the seam opening is reduced. Suture stretching is also less likely. Moreover, by... Figure 3 , Figure 4As in the example, the entire seam is covered from both base fabric surfaces with an adhesive material (0405), thereby further strengthening the seam and reducing gas leakage from the seam opening.

[0122] <Implementation Method 1: Adhesive Material: Coating Area>

[0123] like Figure 23 As shown, the following conditions are preferably met for the width (d1) of the adhesive material (2305) applied along the seam, the distance (d2) from the seam to the inner coating end, the distance (d3) from the seam to the outer base fabric end, and the distance (d4) to both the coating end and the base fabric end. Furthermore, the following describes the case where the seams are in a row. Since the adhesive material is applied substantially along the seam, it tends to expand approximately symmetrically with respect to the seam. This can sometimes become uneven if the base fabric is undulating or uneven due to the seams. Therefore, if d1 is narrow, d2 and d3 tend to be smaller, and if d1 is large, d2 and d3 tend to be larger. d1 is in the range of 3 to 30 mm, more preferably 5 to 20 mm, and most preferably 7 to 15 mm. d2 is 2 to 15 mm, more preferably 3 to 10 mm, and most preferably 4 to 8 mm. d3 is 1 to 15 mm, more preferably 2 to 10 mm, and most preferably 3 to 7 mm. d4 is 0 to 14 mm, preferably 5 to 13 mm, and most preferably 8 to 12 mm. The distance between the sewing portion and the base fabric end is 5 to 20 mm, preferably 10 to 15 mm.

[0124] When there are multiple rows of seams, the adhesive material can be applied to each seam (with gaps between the adhesive materials in each seam), or the adhesive material can be applied to cover the entire seam across multiple rows. In the case of multiple rows of seams... Figure 23 d3 and d4 are the distances to the seam closest to the end face of the base fabric, d2 is the distance to the seam furthest from the end of the base fabric, and d1 is d1 = (the sum of the intervals of multiple seams) + d2 + d3.

[0125] These dimensions can be used at the maximum or minimum positions of the adhesive material end face, or at the average position of the undulating end face. When the width of the coating area is too narrow, the fixation of the stitches to the base fabric becomes insufficient. During airbag inflation, due to the offset between the stitches and the base fabric, the gaps between the stitches shrink, and the stitched base fabric peels off, increasing the possibility of gas leakage pathways. When the coating width is too wide, the elasticity of the cured adhesive material may hinder the folding and storage of the airbag within the specified space. In addition, if the base fabric for the airbag stitching and adhesive material coating stages is made slightly larger than the final shape beforehand (e.g., 10 to 20 mm), and then re-cut to the final shape after the adhesive material coating dries, it can prevent the adhesive material before drying from expanding excessively and overflowing from the base fabric end, adhering to the coating apparatus table, or the adhesive material adhering to the table or itself re-adhering to unwanted areas during subsequent airbag coating operations.

[0126] In addition, depending on the flatness of the bag during coating, the adhesive material (2305) sometimes slides and spreads on the surface of the bag immediately after coating and... Figure 23 The angled portion extends as shown in the lower right corner. This angle is generated and formed randomly and discontinuously. By forming this angle, the adhesive strength between the cured adhesive material and the base fabric is improved, thereby increasing the strength of the fabric near the seam. When the overall width of the adhesive coating is increased, there is a concern that the elasticity of the adhesive material may compromise the flexibility of the airbag. Therefore, it is best not to increase the overall width, but to achieve a balance between strength and flexibility by setting angled portions. To intentionally form angled portions, it is also possible to locally increase or decrease the amount of adhesive sprayed, or to increase or decrease the tension of the stitching during sewing to make the sewn bag fluctuate, or to make the base fabric end face of the coating table raised, or to make the surface of the coating table wavy.

[0127] <Effects of Implementation Method 1>

[0128] In this invention, by allowing the adhesive material to penetrate between at least a portion of the fibers constituting the suture in the suture hole, the desired airbag inflation is achieved by preventing the suture from twisting and tightening during airbag inflation, creating a gap between the suture insertion section of the base fabric in the suture hole and the airbag itself, and preventing leakage of the inflation gas.

[0129] <Implementation Method 2>

[0130] <Summary of Embodiment 2> Mainly claims 2

[0131] In the airbag of Embodiment 2 based on Embodiment 1, at least a portion of the stitching is exposed from the adhesive material in the portion other than the perforated portion of at least one of the base fabrics, either the first base fabric or the second base fabric.

[0132] <Implementation Method 2 Configuration>

[0133] Regarding the suture used in Embodiment 2, which is based on Embodiment 1, Figure 25 and Figure 26 Please provide an explanation. Figure 25 This is a plan view of the seam from the side of the first base fabric. Figure 26 It is equivalent to Figure 25 The cross-sectional view of part AA′ in the diagram. Figure 25 The cross-section is shown with the slit portion indicated by B as the center. Figure 25 Part B (the part where the suture is interrupted) is the seam hole part, which is the part where the suture on the first base fabric side is pulled into the seam hole by the suture on the second base fabric side and is not visible from the first base fabric side.

[0134] exist Figure 25 An adhesive material (2505) is applied along the visible suture line (2504) on the surface of the first base fabric. If the amount of adhesive material applied is insufficient to cover the suture line, then... Figure 25 , Figure 26 As shown, at least a portion of the stitching (shown as (2608) in the figure) is exposed from the adhesive material. The stitching on each base fabric side within the seam opening is as follows: Figure 26 The suture is pulled into the suture hole from the opposite side. Therefore, the sutures introduced into the suture hole and the sutures near the suture hole are covered with adhesive material. Figure 26 The diagram illustrates a case where the amount of adhesive material on the first base fabric (2601) is greater than that on the second base fabric (2602). The adhesive material is applied in such an amount that the seepage of the adhesive material to the side opposite to the coated side is minimized. If at least a portion of the seam of the base fabric side opposite to the coated side is exposed in such an amount of coating, then when the adhesive material is applied to the bag body on the table, the possibility of the adhesive material penetrating through the seam or seam opening of the base fabric and adhering to the table surface can be reduced until the coating of the coated surface is completed.

[0135] Not only regarding the amount of adhesive material applied, but also in the case of single-sided coating, since it must penetrate through the seam openings to the fibers forming the suture on the opposite side, an adhesive material is selected with a viscosity not high enough to completely cover the suture on the coated base fabric side, and a viscosity not low enough to cover the suture on the base fabric surface opposite to the coated side. The viscosity range of the adhesive material for double-sided coating will be explained in Embodiment 15, which will be described later. The viscosity range of the adhesive material for single-sided coating will be explained in Embodiment 16, which will be described later.

[0136] <Effects of Implementation Method 2>

[0137] In the airbag of embodiment 2, if at least a portion of the seam of the base fabric side opposite to the coating side is exposed in such an amount of coating, then when the adhesive material is coated on the table, during the period until the coating of the surface coated with the adhesive material is completed, the possibility of the adhesive material passing through the seam or seam hole of the base fabric and adhering to the table surface can be reduced.

[0138] <Implementation Method 3>

[0139] <Summary of Embodiment 3> Mainly claims 3

[0140] In the airbag of Embodiment 3, which is based on either Embodiment 1 or Embodiment 2, the area ratio of the two-dimensional area of ​​the suture line exposed from the adhesive material in a region of approximately the same width as the suture line along the suture direction on the surface of the base fabric on the side where the adhesive material is applied to the suture portion of the base fabric is greater than 0% and less than 30%.

[0141] <Implementation Method 3>

[0142] Figure 27 This is a surface SEM image of the area near the suture line on a base fabric surface where an adhesive material has been applied to the seam. Figure 27 The white parts of the fibers attached to the seams or forming the base fabric in the photograph are adhesive materials. Figure 27 The following description of the embodiments uses Figures 28 to 30 In the SEM images, the stitches on the substrate with the adhesive coating are of the same specification as those on the uncoated side. Nylon fibers were used, and the thread was made by further twisting three small-diameter twisted threads together.

[0143] <Implementation Method 3: Ratio of exposed area of ​​suture from adhesive material>

[0144] Within a region of approximately the same width and thickness as the suture lines reflected in the surface SEM image, the area ratio of the portion appearing as white as the adhesive material is calculated. This area ratio is defined by a rectangular frame (approximately the same width as the suture line and the same length as the spacing between the suture sections)... Figure 27 The white frame (in the image) is placed on the image of the suture line. The area (in pixels) of the adhesive material within the frame is calculated by subtracting the area (in pixels) of the frame from the area (in pixels) of the frame itself, and then dividing the result by the area (in pixels) of the frame. Figure 27 In the example shown, the area ratio of the adhesive material is 25.6%.

[0145] When the adhesive material is applied to only one side of the base fabric, the area ratio of the two-dimensional suture exposed from the adhesive material on the base fabric is greater than 0% and less than 30%. To prevent gas leakage from the sutures during airbag inflation, at least a portion of the fibers constituting the sutures must be bonded by the adhesive material. Therefore, the area ratio must be less than 100%. Furthermore, with an amount of adhesive material where more than 30% of the sutures are exposed, there is a problem that the adhesive material may not easily penetrate to the fibers of the sutures on the opposite side of the base fabric; therefore, the area ratio must be less than 30%. Additionally, if the area of ​​the sutures exposed from the adhesive material on the base fabric surface on the adhesive-coated side is 0%, it means that the sutures are completely covered by the adhesive material.

[0146] <Effects of Implementation Method 3>

[0147] The airbag of embodiment 3 is obtained by defining a two-dimensional area ratio range of the sutures exposed on the base fabric on the side coated with adhesive material, thereby obtaining an airbag that allows the adhesive material to penetrate between the fibers of the sutures on the base fabric on the side opposite to the side coated with adhesive material.

[0148] <Summary of Implementation Method 4>

[0149] The airbag of Embodiment 4, based on any one of Embodiments 1 to 3, is configured such that, in a region on the surface of the base fabric on the side where the adhesive material is not applied to the sewn portion of the base fabric, the area covered by the adhesive material (including both the sewn line and the base fabric) is approximately the same width as the suture line along the sewing direction (and may also include the suture line from the opposite base fabric) is 5% or more in two dimensions.

[0150] <Implementation Method 4>

[0151] Figure 28 This is a surface SEM image of the area near the suture line on the side of the base fabric where the adhesive material is not applied at the seam. Figure 28The white parts of the fibers attached to the seams or forming the base fabric in the photograph are adhesive materials. Figure 28 As shown in the suture hole, the stitching line of the base fabric on the opposite side is drawn out and reflected.

[0152] <Ratio of the area covered by the adhesive material for suture in Embodiment 4>

[0153] Within a region of approximately the same width and thickness as the sutures reflected in the surface SEM image (including sutures from the opposite side of the base fabric), the area ratio of the portion appearing as white as the adhesive material was calculated. Therefore, this also includes the area (in pixels) of the adhesive material attached to the base fabric surface near the sutures. The area ratio is calculated by placing a rectangular frame on the suture image with approximately the same width as the sutures (including sutures from the opposite side of the base fabric) and the same length as the spacing between the sutures. Figure 28 The area of ​​the adhesive material within the white frame (in pixels) is calculated by dividing the area of ​​the frame by the area of ​​the frame itself (in pixels). Figure 28 In the example shown, the area ratio of the adhesive material is 11.7%.

[0154] When the adhesive material is applied only to one side, the area ratio of the sutures covered by the adhesive material on the base fabric opposite to the base fabric with the adhesive material applied (the base fabric without the adhesive material applied) is 5% or more. With an adhesive material penetration amount where the area ratio covered by the adhesive material is less than 5%, there is a problem that the adhesive material does not easily penetrate into the fibers of the sutures on the uncoated base fabric side. When penetration is difficult, the adhesive material cannot completely bond between the fibers of the sutures forming the base fabric surface side opposite to the coated base fabric, and the degree of twist may tighten due to the tension during airbag inflation.

[0155] The upper limit for the area covered by the adhesive material is less than 100%. It is necessary that during the adhesive material coating process, the adhesive material does not adhere to the surface of the table where the bag is placed during coating because it penetrates through seams or sutures. Preferably, it is 80% or less, more preferably 70% or less.

[0156] <Effects of Implementation Method 4>

[0157] The airbag of embodiment 4 can be obtained by specifying a two-dimensional area ratio range of the sutures covered by the adhesive material on the base fabric on the side not coated with adhesive material, so that the adhesive material can penetrate between the fibers of the sutures on the base fabric on the side not coated with adhesive material.

[0158] <Summary of Implementation Method 5>

[0159] The airbag of Embodiment 5, which is based on any one of Embodiments 1 to 4, is configured such that, in the suture line on the base fabric side coated with adhesive material, the cross-sectional area of ​​the adhesive material is 10% or more and 25% or less relative to the cross-sectional area of ​​the suture line (the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture line is 55% or more and 100% or less).

[0160] <Implementation Method 5>

[0161] Figure 29 This is a cross-sectional SEM image of the seam opening where adhesive material is applied to one side of the upper base fabric. The seam threads on the upper base fabric are pulled through the seam opening to the lower base fabric side by the seam threads on the lower base fabric. Figure 29 The white parts attached to the seams or base fabric in the photo are adhesive material.

[0162] <Implementation Method 5: Area Ratio of Adhesive Material within the Suture Cross-Section>

[0163] for Figure 29 The cross-sectional area of ​​the seam (hereinafter referred to as the top seam) on the upper base fabric is shown, and the area ratio of the adhesive material is calculated. This is used as... Figure 29 The area ratio of the adhesive material within a 500 μm diameter cross-sectional area of ​​the top thread (2904a) and the seam on the underlying base fabric (hereinafter referred to as the bottom thread (2904b)) is calculated. For the cross-sectional area of ​​the seam on the base fabric coated with adhesive material, i.e., the top thread (2904a), the cross-sectional area of ​​the adhesive material is 10% to 25% (55% to 100% of the cross-sectional area of ​​the portion other than the fibers relative to the cross-sectional area of ​​the seam (top thread)). Figure 29 In the example, the total cross-sectional area (number of pixels) of the adhesive material is 15.7% relative to the total cross-sectional area (number of pixels) of the fibers constituting the surface line (2904a), and the cross-sectional area (number of pixels) of the portion outside the fibers in the cross-sectional area of ​​the surface line (2904a) is 65%. When the range is below the lower limit, it is insufficient to bond the fibers; when it exceeds the lower limit, the adhesive material extends from the coated base fabric side through the seams and stitches to the base fabric surface on the opposite side where the adhesive material is not coated, and the adhesive material may adhere to the platform that is in contact with the lower base fabric surface.

[0164] <Effects of Implementation Method 5>

[0165] The airbag of embodiment 5, by specifying the cross-sectional area ratio of the adhesive material relative to the cross-sectional area of ​​the suture, can achieve a sufficient bond between the fibers constituting the suture, and the adhesive material can be widely diffused into the base fabric on the opposite side to the coated side without adhering to the platform.

[0166] <Summary of Implementation Method 6>

[0167] The airbag of Embodiment 6, which is based on any one of Embodiments 1 to 5, is configured such that, in the suture line on the base fabric side where the adhesive material is not coated, the cross-sectional area of ​​the adhesive material is 5% or more and 25% or less relative to the cross-sectional area of ​​the suture line (the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture line is 35% or more and 100% or less).

[0168] <Implementation Method 6>

[0169] Figure 29 This is a cross-sectional SEM image of the seam opening where adhesive material is applied to one side of the upper base fabric. The seam threads on the lower base fabric pull the seam threads on the upper base fabric through the inside of the seam opening to the lower base fabric side. Figure 29 The white parts attached to the seams or base fabric in the photo are adhesive material.

[0170] <Implementation Method 5: Area Ratio of Adhesive Material within the Suture Cross-Section>

[0171] Compared to Figure 29 The cross-sectional area of ​​the seam on the lower side of the base fabric (the bottom line) was used to calculate the area ratio of the adhesive material. This is used as... Figure 29 The ratio of the area of ​​the adhesive material within a 500 μm diameter cross-sectional area of ​​the top line (2904a) and bottom line (2904b) is used to determine the ratio. The total cross-sectional area of ​​the adhesive material is 5% to 25% of the total cross-sectional area of ​​the seam, i.e., the bottom line, on the base fabric coated with the adhesive material (and 35% to 100% of the cross-sectional area of ​​the portion excluding fibers within the seam). Figure 29 In the example, the area (number of pixels) of the adhesive material is 10.6% relative to the cross-sectional area (number of pixels) of the bottom line (2904b), and the cross-sectional area (number of pixels) of the portion outside the fibers in the cross-sectional area of ​​the bottom line (2904b) is 44%. When below the lower limit of the range, it is insufficient to bond between fibers; when above, the adhesive material extensively adheres to the base fabric on the uncoated side, and the adhesive material may adhere to the platform adjacent to the uncoated base fabric side (underlying base fabric).

[0172] <Effects of Implementation Method 6>

[0173] According to the airbag of embodiment 6, by specifying the cross-sectional area ratio of the adhesive material relative to the cross-sectional area of ​​the suture, it is possible to ensure sufficient bonding between the fibers constituting the suture and to allow the adhesive material to extensively permeate to the base fabric on the opposite side to the coated side without adhering to the platform.

[0174] <Implementation Method 7>

[0175] <Summary of Embodiment 7> Mainly claims 7

[0176] Embodiment 7, based on Embodiment 1, is configured such that, in the case where at least a portion of the seam portion of the first base fabric and / or the second base fabric is made of fabric, the fibers of the fabric constituting the seam portion are bonded by an adhesive material.

[0177] <Implementation Method 7>

[0178] Regarding the suture portion of Embodiment 7, which is based on Embodiment 1, using Figure 5 , Figure 6a , Figure 6b Please provide an explanation. Figure 6a , Figure 6b This is a schematic diagram of the cross-section of the slit portion. Figure 5 This is a plan view showing the position CC′ of the cross-section of the slit hole in Figure 6. Differences from Embodiment 1 will be explained.

[0179] <Implementation Method 7: First Base Fabric (0601), Second Base Fabric (0602)>

[0180] In cases where at least a portion of the seam of the first base fabric and / or the second base fabric is made of fabric, it is bonded by an adhesive material to prevent the fibers in the fabric constituting the seam of the first base fabric (0601) and the second base fabric (0602) from coming loose.

[0181] When at least a portion of the seam of the first and / or second base fabric is made of woven fabric, both base fabrics can be entirely made of woven fabric, or at least a portion of the seam of a nonwoven fabric can be made of woven fabric, such as at least a portion of the seam of a resin film. Even if at least a portion of the seam of the two base fabrics is not woven fabric but nonwoven fabric or woven cloth, by bonding the fibers with an adhesive material, the same effect as making the fibers near the seam less likely to loosen can be achieved.

[0182] <Implementation Method 7: Penetration of Adhesive Material into the Fabric Constituting the Base Fabric>

[0183] exist Figure 6a , Figure 6b The example shown is configured such that after sewing the first base fabric (0601) and the second base fabric (0602), an adhesive material (0605) is applied to the vicinity of the seam containing the seam thread (0604), allowing it to penetrate between at least a portion of the fibers (0603) of the seam thread (0604) or between the fibers (fibers not shown) of the fabric constituting the vicinity of the seam, and the seam is covered with the adhesive material, and the seam openings of the seam are also blocked with the adhesive material. Figure 6aIt is a cross-sectional view when the adhesive material has completely penetrated into the fabric that makes up the base fabric. Figure 6b This is a cross-sectional view showing the penetration of the material into the fabric that makes up the base fabric. Figure 6a The adhesive fully penetrates the base fabric, creating a robust structure where the two base fabrics are integrated in areas coated with bonding material. Even in areas like... Figure 6a When the adhesive material completely penetrates the fabric constituting the base fabric, if a base fabric with a pre-coated layer on its inner side is used, the coating layer acts as a stopper for the adhesive material, preventing the fabric constituting the opposite side of the base fabric from bonding together through the adhesive material. Thus, the first and second base fabrics are joined only by the adhesive material at the seams and seam openings, creating a flexible airbag that is easier to bend than if the base fabrics were bonded together. The airbag can be housed more compactly. Depending on the airbag specifications, one can choose to bond the seams of the base fabric to increase strength or leave it unbonded for greater flexibility.

[0184] Alternatively, it can be configured such that an adhesive material is applied linearly to the predetermined sewing location of each base fabric before sewing and the adhesive material penetrates into the base fabric, and then the sewing is performed by a suture line (0604) formed by allowing the adhesive material to penetrate into at least a portion of the fibers and bond together.

[0185] In addition to the methods described above, the following methods may also be considered: applying an adhesive material near the predetermined seam portion of the first or / and second base fabric before sewing, bonding the fibers of the fabric constituting at least a part of the seam portion of the base fabric with the adhesive material, and reapplying the adhesive material (which may also be an adhesive material including a material different from the adhesive material applied to the base fabric) to the seam portion after the base fabric in this state is sewn; or applying an adhesive material (which may also be an adhesive material different from the adhesive material permeating between the fibers) near the seam portion after sewing with a suture thread that has been pre-stitched to allow sufficient penetration of the adhesive material between the fibers, thereby allowing the adhesive material to penetrate into the fibers of the fabric constituting the seam portion.

[0186] <Effects of Implementation Method 7>

[0187] According to the airbag of embodiment 7, the adhesive material binds the fibers together so that the fibers of the fabric constituting the first base fabric or / and the second base fabric near the seam are not easily loosened, thereby further preventing the air for airbag inflation from leaking from the seam.

[0188] <Effective Implementation 8> is mainly based on claim 8.

[0189] <Summary of Implementation Method 8>

[0190] In Embodiment 8, which is based on either Embodiment 1 or Embodiment 7, the adhesive material used for the suture thread is the same adhesive material used for the first base fabric and / or the second base fabric.

[0191] <Implementation Method 8>

[0192] The airbag of Embodiment 8, based on any one of Embodiments 1 or 7, is configured such that the adhesive material used for the suture is the same as the adhesive material used for the first base fabric and / or the second base fabric. The configuration of Embodiment 8 will be described using FIG6, which was used in the description of Embodiment 7.

[0193] <Embodiment 8 Adhesive Material (0605)>

[0194] The adhesive material (0605) is configured such that the adhesive material used for the suture is the same adhesive material used for the first base fabric and / or the second base fabric.

[0195] <Effective Method 8: Adhesive Material: Same Material>

[0196] The adhesive material (0605) is permeated to make the fibers near the seam of the first base fabric (0601) or / and the second base fabric (0602) less likely to loosen. However, when the adhesive material (0605) of the same material system as the adhesive material (0605) that permeates the fibers (0603) of the suture (0604) is used, the adhesion between the suture and the base fabric is better compared with the adhesive material of a different material system.

[0197] <Implementation Method 8: Adhesive Material: Effect of Using the Same Material>

[0198] By using an adhesive material of the same type between the corresponding seam and the base fabric, the adhesion between the adhesive material used for the seam and the adhesive material used for the base fabric is improved, preventing peeling or displacement of the adhesive materials due to the force exerted during airbag inflation. Therefore, leakage of inflation gas near the seam opening caused by displacement of the seam (0604) and the base fabric at the seam during airbag inflation, or by further tension applied to the seam, or by fiber unraveling due to stress applied to the fabric constituting the base fabric near the seam, or by the misalignment of the warp and weft threads constituting the fabric and the resulting gaps in the base fabric, can be prevented. Reducing the leakage of inflation gas makes it easier to achieve the target value of the reaction force characteristics (the force exerted on the occupant by the airbag) in the airbag design, contributing to the occupant safety during accidents, which is the original purpose of the airbag.

[0199] <Implementation Method 8: Adhesive Material: Coating Method>

[0200] After sewing, the adhesive material is applied and dried from the first base fabric (0601) side in a manner that penetrates the fibers of the suture line (0604) and the fabric constituting the base fabric near the seam. Then, it is turned over and applied in the same manner from the second base fabric (0602) side, thereby enabling simultaneous application to both the suture line (0604) and the base fabric. The order of application to the first base fabric (0601) side and the second base fabric (0602) side can be reversed. Other adhesive materials can also be used on the first base fabric (0601) side and the second base fabric (0602) side.

[0201] Alternatively, a resin intended for use as an adhesive material may be pre-coated onto a first base fabric and a second base fabric, respectively, to bond the fibers constituting the base fabric. After sewing, the same resin as the resin coated onto the base fabric may be applied as an adhesive material.

[0202] <Implementation Method 8: Adhesive Material: Pre-penetration into the suture>

[0203] The suture can also be used as in embodiment 1. Figure 22 As explained, the adhesive material is pre-permeated before sewing. In this case, it is also possible to configure different adhesive materials (e.g., with different viscosities) to permeate and bond between at least a portion of the fibers in the top and bottom threads. Alternatively, after sewing the first and second base fabrics using such top and bottom threads, on the top thread side where the top thread is visible outside the seam opening, the same adhesive material permeating the fibers of the top thread is applied and permeated between the fibers of the fabric constituting the base fabric; similarly, on the bottom thread side, the adhesive material permeating between the fibers of the bottom thread is permeated between the fibers of the fabric constituting the bottom thread side. When using different adhesive materials on the top and bottom thread sides, materials with the same main material can be selected, or adhesive materials with good compatibility between the two adhesive materials can be selected.

[0204] <Effects of Implementation Method 8>

[0205] According to the airbag of embodiment 8, by setting the adhesive material that permeates between the fibers of the suture to be the same as the adhesive material that permeates between the fibers constituting the base fabric, the adhesion between the suture and the base fabric is improved, the displacement of the suture during airbag inflation can be reduced, and the leakage of inflation gas can be reduced.

[0206] <Effective Implementation 9> is mainly based on claim 9.

[0207] <Summary of Implementation Method 9>

[0208] Embodiment 9 is a method for manufacturing an airbag according to any one of Embodiments 1, 7, or 8, comprising: a first base fabric permeation step, in which an adhesive material is permeated from the seam portion of the first base fabric into the seam; and a second base fabric permeation step, in which a second adhesive material is permeated from the seam portion of the second base fabric into the seam. A manufacturing method for coating both sides will be described.

[0209] <Effective Method 9: Manufacturing Method>

[0210] Regarding the method for manufacturing the airbag in embodiment 9, using Figure 7 The flowchart shown Figure 9 A schematic cross-sectional view of the slit portion CC′ after the first base fabric infiltration step is shown. Figure 9 The position of the cross section CC′ Figure 8 , Figure 11 The cross-sectional view of the slit portion after the second base fabric infiltration step is shown. Figure 11 The position of the cross section CC′ Figure 10 The following explanation is provided. The method for manufacturing an airbag according to Embodiment 9 includes a second base fabric preparation step (S0701), a first base fabric preparation step (S0702), a sewing step (S0703), a first base fabric infiltration step (S0704), and a second base fabric infiltration step (S0705).

[0211] The second base fabric preparation step (S0701) involves preparing a sheet-like second base fabric. The first base fabric preparation step (S0702) involves preparing the sheet-like first base fabric. The sewing step (S0703) involves sewing the first and second base fabrics together to form a gas jet space. The first base fabric permeation step (S0704) involves permeating the first adhesive material from the seam portion of the first base fabric into the seam thread. The second base fabric penetration step (S0705) involves the process of penetrating the second adhesive material from the seam of the second base fabric into the suture line.

[0212] In cases where the bonding material is applied in a segmented manner or the penetration step is repeated multiple times in an overlapping manner, the process may be configured such that after the second base fabric penetration step (S0705), the processing is returned to before the first base fabric penetration step (S0704).

[0213] This is the manufacturing method for airbags that undergo such a series of processes.

[0214] <Implementation Method 9: First Base Fabric Preparation Step / Second Base Fabric Preparation Step>

[0215] The second base fabric preparation step (S0701) is a step for preparing to sew the sheet-like second base fabric to the first base fabric. "Preparation" refers to manufacturing the sheet-like second base fabric itself, cutting it to a workable size using a sewing manufacturing device, or pre-cutting it to a size the same as or slightly larger than the product's shape, and placing it in a designated location on the sewing device (such as the device's loading section or the starting position on the sewing table) for sewing. In the case where the base fabric in the airbag product form is a coated fabric, the preparation step may also include pre-coating the second base fabric individual units with silicone resin or polyurethane resin before sewing (including before cutting). The activation of the sewing device or the placement of the sewing thread may also be included in the "preparation" step. The first base fabric preparation step (S0702) is the same as the second base fabric preparation step (S0701). Alternatively, the order of the first and second base fabric steps may be changed.

[0216] For illustrative purposes, in the following examples, the base fabric in which the adhesive material is first impregnated is designated as the first base fabric. A second base fabric is placed on the table of the sewing apparatus, and then the first base fabric is pre-overlaid on top of the second base fabric (first base fabric preparation step / second base fabric preparation step). Fabrics with a distinct front and back (e.g., fabrics with a coating on one side of the base fabric) are envisioned as having the outer side facing out when the product is finished. This is because, after sewing the bag body, a process of turning the bag inside out is sometimes performed. In this case, the inner side of the finished bag body is placed in a way that makes it the outer side during sewing. If the bag body is not turned out after sewing, the outer side of the bag body is placed in a way that makes it the outer side during sewing.

[0217] When using base fabrics other than the first and second base fabrics to make the airbag body, an additional preparation step for a suitable base fabric is added. For example, when sewing multiple base fabrics to three-dimensionally sew the airbag body, base fabrics with different shapes are prepared for sewing. Therefore, depending on the type of base fabric, the preparation and sewing steps for suitable base fabrics are appropriately added and repeated. In the description of this embodiment 9, an airbag comprising two base fabrics, a first base fabric and a second base fabric of approximately the same shape, is used as an example.

[0218] <Implementation Method 9: Suturing Step>

[0219] The sewing step (S0703) is the process of sewing the first and second base fabrics together using sewing thread in a prescribed sewing pattern. During sewing, a sewing machine or similar sewing device is generally used, employing top and bottom threads. In the case of multiple rows of seams (e.g., two rows), when the two needles of the sewing machine are simultaneously positioned up and down and parallel to each other in the two rows, it is easier to maintain a fixed distance between the seams, allowing for the sewing of two rows with higher strength in a single operation. Furthermore, multi-row sewing may not be performed entirely in one go, but rather divided into one or more smaller rows.

[0220] <Implementation Method 9: First Base Fabric Infiltration Step>

[0221] The first base fabric penetration step (S0704) allows the first adhesive material to penetrate from the seam of the first base fabric into the seam. The order in which the second base fabric penetration step and the first base fabric penetration step are performed can be appropriately set for each product.

[0222] After the sewing step (S0703), the sewn bag is moved from the sewing device to the coating device table and placed in a designated position. This placement operation can also be included at the end of the sewing step. It is efficient when the coating device is placed in an area that does not obstruct the sewing operation on a table that is continuous with the sewing device table and the bag is moved by sliding it on the table.

[0223] A first adhesive material is applied to the seam of the first base fabric, allowing it to penetrate the seam. For example... Figure 9 As shown in the schematic cross-sectional view of the seam portion, the first adhesive material (0906) travels from the surface of the first base fabric (0902) directly above the platform, penetrating into the fibers of the fabric constituting the first base fabric around the seam portion. Preferably, a material that dries quickly (such as the drying of the first adhesive material (0906) or the polymerization of the resin constituting the first adhesive material (0906)) is selected before reaching the surface of the second base fabric. Figure 9 The location of the slit hole is Figure 8 The CC′ shown. After the surface of the first adhesive material is dry and will not adhere even upon contact, the airbag formed by sewing the first base fabric and the second base fabric together is flipped over and placed with the second base fabric (0902) on top and the first base fabric (0901) directly above the platform. Alternatively, the airbag can be flipped over after the first adhesive material has been permeated from the first base fabric side at the beginning of the second base fabric permeation step.

[0224] <Implementation Method 9: Method for Applying Adhesive Material>

[0225] When applying the adhesive material using the first base fabric penetration step and the second base fabric penetration step described later, a dispenser or syringe for spraying the adhesive material can be used, or a printing method such as screen printing can be used, or an inkjet method can be used, or a pen-based coating can be performed.

[0226] <Implementation Method 9: Second Base Fabric Infiltration Step>

[0227] The second base fabric penetration step (S0705) is performed after the first base fabric penetration step, by permeating the second adhesive material into the seams of the second base fabric. Using... Figure 11 illustrate Figure 10 A cross-sectional schematic diagram of the stitched portion of the CC′ section. The second adhesive material (1107) coated from the surface side of the second base fabric (1102) to the vicinity of the stitched portion penetrates into the fibers of the fabric constituting the second base fabric at the same time as penetrating the stitch line. The penetrating second adhesive material (1107) comes into contact with and integrates with the first adhesive material (1106) that was previously coated.

[0228] <Implementation Method 9: Second Base Fabric Infiltration Step: Coating Table>

[0229] Alternatively, in the second base fabric penetration step, a notch or recess can be provided on the adhesive material coating table to allow the raised portion of the first adhesive material on the first base fabric side, which has been coated and dried, to detach (e.g.: Figure 9 , Figure 11 , Figure 13 The height of the raised portion after drying may become uneven. In the second base fabric penetration step, when using a dispenser to spray the second adhesive material at a predetermined fixed height to achieve penetration, the distance between the second base fabric and the dispenser may shift, and the spray width may become thicker or thinner. This can be reduced by detaching the raised portion of the first adhesive material from the table side as described above. If a sensor measuring the distance between the dispenser tip and the base fabric surface is provided in the adhesive material coating dispenser, and the measured distance is controlled in a way that is fixed (including within a fixed range), or is not affected by the raised portion of the first adhesive material, then no cuts or recesses may be provided on the coating table.

[0230] <Implementation Method 9: Second Base Fabric Penetration Step: Examples of Other Coating Methods>

[0231] If, before the second adhesive material is permeated in the second base fabric permeation step, the airbag that allows the first adhesive material to permeate from the seam on the first base fabric side is flipped, but an opening is provided on the platform near the seam of the second base fabric on the platform side, and the second adhesive material is permeated from the seam on the second base fabric side to the seam line through the opening using a dispenser or the like from below the platform, then it is possible to avoid flipping the bag body. In this case, the direction in which the adhesive material is applied for permeation in the first and second base fabric permeation steps becomes different.

[0232] If the first and / or second base fabric is a coated fabric, it is preferable to use an adhesive material comprising the same system as the resin coated onto each base fabric, starting from the seam of each base fabric and allowing it to penetrate into the seam. By selecting an adhesive material that matches the coating material of the coated fabric, increased adhesion to the coating material on the end face of the base fabric through the seam opening facing the seam can be expected.

[0233] Even when the first and second adhesive materials are different, or when materials in the same system have different viscosities, the colors can be changed (e.g., red and blue) to allow for quick identification based on appearance. To make the first and second base fabrics easily distinguishable during the manufacturing process, the color of the base fabric can be changed, or the color of the stitching thread (the bottom line of the stitching) used on each base fabric side can be changed.

[0234] When the airbag is a three-dimensionally sewn shape, sometimes the adhesive material is applied to all the seams in a single stroke to prevent it from penetrating. In this case, an additional penetration step can be performed as appropriate.

[0235] <Effect of coating both sides of the adhesive material in Implementation Method 9>

[0236] The inventors of this application measured how the pressure inside the airbag changes over time when the airbag is inflated in the following cases: when adhesive material is applied to only one side of the seam consisting of two base fabrics (single-sided application: dashed line); when adhesive material is applied to both sides of the base fabric from one base fabric and the opposite side of that base fabric (both sides application: solid line); and when no adhesive material is applied to the seam (no application: thin solid line). Figure 19 The horizontal axis shows the time (ms) at which the inflator starts operating, and the vertical axis shows the pressure inside the airbag (the upward direction of the vertical axis indicates the direction of the highest pressure inside the airbag). Figure 19During the "inflation time" shown, gas is released from the inflator, causing the airbag to inflate as the internal pressure rises. After the airbag is fully inflated and the internal pressure reaches its maximum, the inflation gas is gradually expelled more slowly than in the uncoated specification, causing the internal pressure to decrease. Between two specifications created by simply changing the coating method of the adhesive material—such as single-sided coating versus double-sided coating—when comparing a specified time (restraint time) elapsed from the maximum internal pressure (approximately 110 ms after the start of inflation (0 ms) required for human defense in the event of a collision), the double-sided coating maintained a slightly higher pressure than the single-sided coating. By applying double-sided coating to the seams, the leakage of inflation gas from the seam openings can be reduced.

[0237] <Effects of Implementation Method 9>

[0238] According to the airbag manufacturing method of Embodiment 9, by allowing the first adhesive material and the second adhesive material to penetrate into the suture line to prevent the twisting and tightening of the suture line fibers and the generation of a gap between the suture line and the base fabric of the seam opening, a method for manufacturing an airbag in which the inflatable gas is not easily discharged can be provided.

[0239] <Implementation Method 10> mainly refers to claim 10

[0240] <Summary of Implementation Method 10>

[0241] Embodiment 10 is a method for manufacturing an airbag based on Embodiment 9, wherein the viscosity of the first adhesive material and the second adhesive material are different.

[0242] <Reasons for increasing the viscosity of the pre-penetrating adhesive material in Implementation Method 10>

[0243] When the first adhesive material is applied from the seam of the first base fabric to the seam line, and then the fabric is turned over so that the second adhesive material is applied from the seam of the second base fabric to the seam line, the viscosity of the first adhesive material can be higher than the viscosity of the subsequently applied second adhesive material. Figure 9 The example shown illustrates a situation where the first adhesive material, initially applied from the upper base fabric side, penetrates to the pores but only reaches the middle of the first base fabric's thickness. This is because when the viscosity of the first adhesive material that penetrates first is low, it is more effective than... Figure 9 The example shown makes it easier to penetrate further into the surface of the second base fabric, and the adhesive material may reach the stage surface and adhere to the stage.

[0244] When the platform for placing the base fabric has an opening, contrary to the example described above, it can be configured such that after the first and second base fabrics are sewn together, the first and second adhesive materials permeate from the corresponding base fabric side to the seam line of the sewn portion. For example, in a structure where the adhesive material is applied to the platform, an opening is made near the seam line, and the adhesive material can be applied from either the top or bottom side via a dispenser, assuming that when the second base fabric is on the platform side, the viscosity of the second adhesive material permeating from the second base fabric side to the seam line can be higher than the viscosity of the first adhesive material permeating from the top first base fabric side to the seam line. This is because when the second base fabric is applied from the bottom, the adhesive material tends to droop away from the fabric (i.e., the side of the coating device such as the dispenser). In this case, the second adhesive material is applied and permeated before the first adhesive material permeates from the top first base fabric. This is because when the first adhesive material permeates first from the top, it is more likely to reach the surface side of the second base fabric first compared to applying the second adhesive material.

[0245] Especially when the adhesive material is a material system in which solvents within the adhesive material are released during curing, even if adhesive materials with different viscosities are used, the first and second adhesive materials will have the same composition after curing, which is therefore preferable. When the first and second adhesive materials have different viscosities, the area penetrated by the coated adhesive material with lower viscosity (along the direction of the base fabric plane and the base fabric thickness direction) tends to be wider than the area expanded by the coated adhesive material with higher viscosity (see reference). Figure 9 , Figure 11 ).

[0246] <Effects of Implementation Method 10>

[0247] According to the airbag manufacturing method of Embodiment 10, by making the viscosity of the first adhesive material and the second adhesive material different, an airbag manufacturing method that has the same leakage characteristics of the expansion gas as in Embodiment 9 can be obtained, while being easy to manufacture.

[0248] <Implementation Method 11> mainly refers to claim 11

[0249] <Summary of Implementation Method 11>

[0250] Embodiment 11 is a method for manufacturing an airbag based on any one of Embodiment 9 or Embodiment 10, wherein the viscosity of the first adhesive material and the second adhesive material is higher than the viscosity of the adhesive material that is coated first.

[0251] <Viscosity of the adhesive material applied first in Embodiment 11>

[0252] When an airbag containing a first and second base fabric is placed on a flat platform, and the adhesive material is first applied from the top side of the platform to allow it to penetrate the seams, the adhesive material adheres to the platform surface as it penetrates through the seams and reaches the platform surface. If a bag is placed on the platform before the adhesive material is sufficiently dry, it may transfer to unexpected locations on the bag's surface. This can deteriorate the bag's appearance, or hinder bending when folding for storage if clumps of adhesive material remain on the bag's surface. Alternatively, even if the adhesive material adhered to the platform surface does not transfer to other bags, it may solidify and form protrusions. When applying adhesive material, the surface of the base fabric on these protrusions may lift and potentially come into contact with the coating fixture, thus causing the adhesive material to adhere to the platform surface, which is undesirable.

[0253] Therefore, the pre-coated adhesive material needs to have a viscosity such that it does not reach the bag surface on the opposite side from the coated side, at least before the initial adhesive coating of the base fabric is completed, through penetration into the fibers constituting the seam at the seam opening and into the gap between the seam opening and the base fabric (including penetration into the fabric near the seam opening of the base fabric). Conversely, if the post-coated adhesive material does not penetrate into the gap between the fibers constituting the seam at the seam opening and the seam opening of the base fabric where the seam opening is inserted, a sufficient bonding effect cannot be obtained. Therefore, it is preferable that the viscosity of the post-coated adhesive material is lower than that of the pre-coated adhesive material. Moreover, it is preferable that the adhesion between the first and second adhesive materials is better when they are adhesive materials with different viscosities in the same material system.

[0254] The seams or seam openings on the side of the base fabric closest to the side coated with the adhesive material are blocked by the first-coated adhesive material. Therefore, the adhesive material applied later can also use a resin with a lower viscosity than the adhesive material used in coatings applied only on one side. Thus, in principle, the next layer of adhesive is applied only after the first-coated, relatively high-viscosity adhesive has reached a state where it can prevent the subsequent adhesive from reaching the work surface. The time required to reach this state of prevention can be appropriately determined by factors such as the size of the air bladder or the stitching method (e.g., the number of rows of stitches, whether it's one or two rows, or the length of the stitches). Furthermore, to shorten the processing time, the application of low-viscosity adhesives can also be performed by applying a certain level of coating pressure (higher pressure than natural dripping), such as through jet coating.

[0255] <Advantage of the high viscosity of the pre-coated adhesive material in Embodiment 11>

[0256] In the same material system, adhesives with higher viscosity generally have a lower solvent content compared to adhesives with lower viscosity, resulting in higher viscosity. With a lower solvent content, the time until the solvent evaporates after coating and the adhesive reaches a dry state (at least surface-dry without adhering to other parts of the cured material) is shorter than with adhesives with lower viscosity. It is advantageous when coating both sides after turning the bag inside out if the drying time of the first-coated high-viscosity adhesive is shorter than that of the second-coated low-viscosity adhesive. In particular, the first-coated high-viscosity adhesive has the effect that the time until the coated adhesive surface is dry and does not adhere even upon contact can be short, and even when a drying process is set using an infrared heater or warm air after coating, the drying time until at least surface-dry and does not adhere even upon contact can be kept short.

[0257] Conversely, as in the variation described in Embodiment 10, even when the adhesive material is applied from below through the aperture, the higher the viscosity of the adhesive material on the lower side, the better, and therefore it is preferable to apply it first. The reason is that when the viscosity of the adhesive material on the lower side is low, as mentioned above, it may easily droop from the front end of the dispenser towards the lower part of the dispenser body. Also, when the viscosity of the adhesive material on the upper side is low and it is applied first, the adhesive material applied from the upper side may penetrate into the area where the adhesive material on the lower side should be applied, making it difficult to apply the adhesive material on the lower side properly.

[0258] <Effects of Implementation Method 11>

[0259] According to the airbag manufacturing method of Embodiment 11, by making the viscosity of the first coated adhesive material higher than the viscosity of the subsequently coated adhesive material, a method for manufacturing an airbag capable of effectively coating the adhesive material can be provided.

[0260] <Implementation Method 12> mainly refers to claim 12

[0261] <Summary of Implementation Method 12>

[0262] Embodiment 12 is a method for manufacturing an airbag based on any one of Embodiments 9 to 11. It is a method in which a relatively high viscosity adhesive material initially coated is applied to the surface line side bound to the base fabric by the bottom thread during a one-line through-seam stitching of the base fabric.

[0263] <Implementation Method 12: Method for Applying Adhesive Material>

[0264] Regarding the bonding material, it can be applied after sewing, transferred to a coating device different from the sewing device, or it can be manufactured by applying the bonding material to the sewn portion while it is placed on the table of the sewing device, using a combination machine also equipped with a coating fixture or device. In various airbags with multiple sewing methods, in order to handle, for example, a single coating device, since it is not possible to provide holes (or cuts) on the table that match the sewing pattern, the bag body is placed on a flat table for coating. In this case, coating is performed from the upper, visible side of the base fabric on the table, and after coating and drying on the upper side, the bag is flipped over to coat the opposite side.

[0265] use Figure 14-16 The airbag of Embodiment 12 will be described. Figure 14 A planar schematic diagram of the suture section is shown from the side of the facet line (1404a). Figure 15 The middle shows Figure 14 A schematic diagram of the longitudinal section of the part indicated by AA′. Figure 16 The middle shows Figure 14 A cross-sectional schematic diagram of the portion indicated by CC′. When suturing the airbag of Example 7, as... Figure 15 As shown in the longitudinal cross-sectional schematic diagram, the face line (1504a) penetrates the first base fabric (1501) and the second base fabric (1502) and is stretched to the surface of the second base fabric (1502) on the side of the base line (1504b) and fixed (in the description of this embodiment 12, the first base fabric is the face line (1504a) side, but it can also be the opposite). The manufacturing method of initially coating from the base fabric side located on the upper side on the table during sewing (e.g., from the first base fabric (1501)) is the manufacturing method of the airbag of this embodiment 12. Figure 16 As shown, the surface line (1604a) is drawn out to the vicinity of the surface of the base fabric (1602) on the lower side and penetrates the two base fabrics.

[0266] Therefore, as Figure 9 As shown, compared to the case where the top and bottom threads are located near the boundary between the first and second base fabrics, when the first adhesive material (1606) is applied from the top thread (1604a) side to the seam (top thread) (1604a) of the seam and allowed to penetrate between the fibers, it easily penetrates from the pores of the seam towards the second base fabric (1602) side. As the first adhesive material, by using an adhesive material with a higher viscosity than the subsequently applied second adhesive material (1607), although it does not penetrate to the base fabric surface on the bottom thread (1604b) side, its penetration to the bottom thread is not strong (normal or strong on the top thread). An example of normal penetration is: Figure 2 , Figure 4 Compared to the suture section in the suture section state, since there is only surface thread in the suture section hole, it is easier for the surface thread fibers to penetrate.

[0267] Furthermore, in the description of this embodiment, it will be... Figure 15 The lines illustrated in the attached diagram using 1504a are designated as surface lines, and the lines illustrated using 1504b are designated as bottom lines. However, it is also possible to configure 1504a as the bottom line and 1504b as the surface line, and initially apply a relatively high viscosity adhesive material starting from the bottom line side of 1504a.

[0268] <Effects of Implementation Method 12>

[0269] According to the airbag manufacturing method of embodiment 12, even if a high-viscosity adhesive material is used as the initial coating adhesive material, sufficient penetration into the sutures on the coated side is possible.

[0270] <Implementation Method 13>

[0271] <Summary of Implementation Method 13>

[0272] Embodiment 13 is a method for manufacturing an airbag according to Embodiment 1. It is a method for manufacturing an airbag by applying an adhesive material to the sewn portion of the surface of either a first base fabric or a second base fabric, allowing the adhesive material to penetrate from the sewn hole portion into the fibers between the sewn lines running through the sewn hole portion, and allowing the adhesive material to penetrate into at least a portion of the fibers between the sewn lines exposed on the surface of the base fabric on the side opposite to the side coated with the adhesive material.

[0273] <Effective Method 13: Manufacturing Method>

[0274] Regarding the method for manufacturing the airbag in embodiment 13, using Figure 30 The flowchart shown Figure 25 A plan view of the seam of the base fabric with the adhesive material coated on it is shown (in this embodiment 13, an example with the adhesive material coated on the first base fabric side is used for illustration). Figure 26 The longitudinal cross-sectional schematic diagram of the suture shown is used for illustration. The method for manufacturing the airbag in Embodiment 13 includes an adhesive material infiltration step (S3001) and an adhesive material infiltration step (S3002) for the suture fibers on the opposite base fabric side.

[0275] The adhesive material penetration step (S3001) involves applying adhesive material to the seam portion of the surface of either the first or the second base fabric, and then penetrating the adhesive material from the seam opening into the spaces between the fibers forming the suture thread within the seam opening. The opposite base fabric side seam fiber bonding material penetration step (S3002) is a process in which the bonding material penetrates from the seam opening into at least a portion of the fibers forming the seam openings (different from the seam openings exposed on the base fabric surface opposite to the base fabric coated with the bonding material) that constitute the seam openings. When the bonding material penetration step is performed in a segmented manner, or when the penetration step is repeated multiple times in an overlapping coating manner, such as... Figure 30 As shown, it can also be configured such that after the bonding material penetration step (S3002) of the suture fiber on the opposite base fabric side, the processing is returned to before the bonding material penetration step (S3001).

[0276] This is the manufacturing method for airbags that undergo such a series of processes.

[0277] <Implementation Method 13 Adhesive Material Penetration Step (S3001)>

[0278] In the "adhesive material penetration step" (S3001), an adhesive material is applied to the seam portion on the surface of either the first or second base fabric from the surface side of that base fabric. This step involves allowing the applied adhesive material to penetrate from the seam opening into the spaces between the fibers constituting the suture thread within the seam opening. When the adhesive material penetrates into the spaces between the fibers constituting the suture thread, as... Figure 17 , Figure 18 The diagram shown, or Figure 29 As shown in the cross-sectional SEM image, the bonding material penetrates between the fibers, bonding at least a portion of them together.

[0279] The adhesive material that has penetrated into the seam opening penetrates along the gap between the cross-section of the first and second base fabrics and the suture line, or between the fibers of the suture line, into the base fabric surface opposite to the coated base fabric (or the second base fabric surface opposite to the coated base fabric surface if the coating has been applied from the first base fabric surface).

[0280] <Implementation Method 13: Infiltration Step of Fiber Bonding Material into the Backing Fabric Side Stitch (S3002)>

[0281] In the "opposite base fabric side suture fiber bonding material penetration step" (S3002), the bonding material, which has penetrated through the seam openings to the surface of the base fabric opposite to the base fabric coated with the bonding material (the second base fabric in this embodiment 13), appears from the seam openings on the surface side of the second base fabric. This allows the bonding material to penetrate through the second base fabric surface into at least a portion of the fibers constituting the suture connecting the seam openings. The penetration of the bonding material into the fibers constituting the suture occurs through the movement of the bonding material within the tiny gaps between the fibers using capillary action.

[0282] In addition, the above example illustrates the case where the adhesive material is applied only from the first base fabric side, but it is also possible to apply the adhesive material from the first base fabric side, cure it after the suture fiber adhesive material penetration step on the opposite base fabric side, and then further apply the adhesive material from the second base fabric side.

[0283] As in Embodiment 13, by permeating the adhesive material into at least a portion of the fibers between the seam threads forming the suture holes on the surface of the base fabric opposite to the coated side, it is possible to bond not only the fibers between the seam threads forming the surface of the base fabric on the coated side, but also at least a portion of the fibers between the seam threads forming the suture threads on the opposite side of the coated side. As a result, due to the tightening of the twist caused by the tension generated in the seam threads, it is possible to prevent gaps from forming between the seam threads and the base fabric in the suture holes.

[0284] In the airbag manufacturing method of Embodiment 13, when the adhesive material is applied only from one side, the lower limit of the viscosity of the applied adhesive material is preferably higher than the viscosity of the adhesive material applied later when both sides are coated. In the case of both-side coating, the seams or seam openings near the first-coated base fabric side are bonded by the first-coated and cured adhesive material and are less prone to penetration, while the later-coated adhesive material is blocked by the first-coated adhesive material. In the case of single-side coating, since the applied adhesive material is not blocked, the lower limit of viscosity is increased, so that it does not penetrate excessively into the base fabric side opposite to the coated side.

[0285] <Effects of Implementation Method 13>

[0286] In the airbag manufacturing method of embodiment 13, even when coating is performed on one side instead of both sides, the fibers of the stitching between the seam portions forming the base fabric surface opposite to the coated side can be bonded using an adhesive material. As a result, gaps are less likely to form in the seam portions between the stitching and the stitching cross-section of the base fabric.

[0287] <Implementation Method 14>

[0288] <Summary of Implementation Method 14>

[0289] Based on the airbag manufacturing method of embodiment 13, it further includes a base fabric bonding step in which a portion of the adhesive material that permeates from the slit portion remains between the first base fabric and the second base fabric, and the first base fabric and the second base fabric are bonded together.

[0290] <Effective Method 14: Manufacturing Method>

[0291] use Figure 31 This describes a method for manufacturing the airbag in Embodiment 14, based on the manufacturing method of Embodiment 13. For example... Figure 31 As shown, in addition to the steps of the manufacturing method of Embodiment 13, there is also a base fabric bonding step (S3103). Since the steps other than the base fabric bonding step (S3103) are the same as those in Embodiment 13, they are omitted from the description.

[0292] <Implementation Method 14: Bonding Step Between Base Fabrics (S3103)>

[0293] The "inter-fabric bonding step" (S3103) involves applying an adhesive to the seam portion of the surface of either the first or second base fabric, allowing a portion of the adhesive material that permeates through the seam opening to remain between the first and second base fabrics, thus bonding the first and second base fabrics together. In the adhesive material permeation step (S3101) and the opposite base fabric side seam fiber adhesive material permeation step (S3102), after the adhesive material permeates to at least a portion between the seam opening and the fibers constituting the seam, the adhesive material remaining between the first and second base fabrics during curing also cures in a manner that bonds the first and second base fabrics near the seam opening. If the adhesive material is a thermosetting resin, it cures by raising the temperature to a predetermined temperature and maintaining it after permeation. If the adhesive material is a photocurable resin, it is cured using methods and conditions corresponding to the resin constituting the adhesive material, such as irradiating it with light of a predetermined wavelength and a predetermined cumulative amount of light, and then curing it.

[0294] Figure 32 This is a schematic cross-sectional view of the seam opening along the direction of the seam in Embodiment 14. Figure 32 In this example, an adhesive material is applied to the seam portion of the surface of the first base fabric (3201). The adhesive material (3205) penetrates into the surface side of the second base fabric (3202) through the seam openings and the seam. The adhesive material extends from the seam openings and also remains between the first base fabric (3201) and the second base fabric (3202). When the adhesive material (3205) cures, the first base fabric and the second base fabric are bonded together.

[0295] Figure 29 This is a SEM image of a cross-section of an airbag manufactured using the method of the present invention, with the direction of the sutures running transversely. In this example, with... Figure 32 The diagrams are different. Figure 29 The upper suture (2904a) is pulled by the lower suture (2904b) and led towards the second base fabric (2902). Then, it is shown that the adhesive material remains between the first base fabric (2901) and the second base fabric (2902), bonding the two base fabrics near the seam opening.

[0296] The two base fabrics are bonded together by an adhesive material that permeates from the seam opening and remains near the seam. This prevents gaps from forming between the first and second base fabrics when the airbag inflates with gas, thus reducing the risk of leakage of inflation gas from such gaps. Furthermore, the sutures, particularly those containing the seam opening, are bonded between the two base fabrics near the inner seam opening, further preventing suture movement at the seam opening during airbag inflation. This prevents suture movement, seam slippage, and the creation of gaps between the first and second base fabrics.

[0297] The manufacturing method of this embodiment 14 can also be applied to the airbag of embodiment 1, and the airbag can also be configured such that a portion of the adhesive material that permeates from the slit portion is retained between the first base fabric and the second base fabric, thus bonding the first base fabric and the second base fabric together.

[0298] <Effects of Implementation Method 14>

[0299] According to the airbag manufacturing method of embodiment 14, by bonding the first base fabric and the second base fabric together, gaps are less likely to form between the first and second base fabrics when the airbag inflates by gas injection, thus preventing leakage of inflation gas from such gaps. Furthermore, in particular, the suture line including the seam opening is bonded between the two base fabrics near the inner seam opening, thereby preventing the suture line from moving at the seam opening when the airbag inflates. This prevents suture line movement, seam thread movement, and the formation of gaps between the first and second base fabrics.

[0300] <Implementation Method 15> is mainly based on claim 15

[0301] <Summary of Implementation Method 15>

[0302] Embodiment 15 is a method for manufacturing an airbag based on any one of Embodiments 9 to 12, wherein the viscosity of the adhesive material during coating, expressed in Pascals-seconds, ranges from 3.0 mPa for both high-viscosity and low-viscosity adhesive materials. s~90Pa The manufacturing method of s.

[0303] <Viscosity of the adhesive material in Implementation Method 15>

[0304] The viscosities of the first and second adhesive materials are measured in Pascals per second (Pa), with the viscosity range for the high-viscosity and low-viscosity adhesive materials being 3.0 mPa. s~90Pa s. In Figure 20This diagram illustrates the relationship between the viscosity of the adhesive material and the gas retention within the airbag. The horizontal axis represents the viscosity of the adhesive material, and the vertical axis represents the gas retention within the airbag. The results are from tests where materials of the same viscosity were applied to both sides of the airbag suture. When using a widely used compressed air dispenser to spray gas at pressures above 0 to below 3.0 mPa... Viscosity exceeding 90 Pa at s When using adhesives with s, manufacturability is poor. 0~less than 3.0 mPa If the viscosity of the adhesive material is too low, controlling the amount ejected under air pressure becomes difficult, making it prone to spreading on the base fabric surface and flowing towards the back of the base fabric. (Exceeding 90 Pa) The adhesive material of type s has an excessively high viscosity when extruded under air pressure, making it difficult to spray out. If it is 3.0 mPa... s~90Pa If the range of s is large, then the manufacturability is good.

[0305] <Viscosity of the adhesive material in Implementation Method 15: Experimental Results>

[0306] As described in Embodiment 4, the inventors of this application investigated the conditions under which the pressure inside the airbag does not easily decrease after airbag inflation, and obtained the result that the pressure inside the airbag does not easily decrease when the adhesive material is applied to the suture, and that applying the adhesive material to both sides is less likely to cause a decrease compared to applying the adhesive material to only one side of the suture. Experiments were conducted by changing the viscosity of the adhesive material subsequently applied to both sides, and increasing the viscosity of the initially applied adhesive material was a more preferable result. Specifically, the viscosity is on the lower end of the above-mentioned viscosity range, and preferably the viscosity H of the initially applied adhesive material is 1.0 to 20 Pa. s. The viscosity L of the post-coated adhesive material is 1.0 mPa. s~1.0Pa The range of s (where is the relationship between H and L). More preferably, the viscosity of the pre-coated adhesive material can be 1.5 to 4.0 Pa. s. The viscosity of the post-coated adhesive material is 100–600 mPa. The range of s. At a viscosity ratio of 90 Pa. In adhesive materials with high viscosity, the pressure inside the airbag decreases rapidly. The presumed reason is that high-viscosity adhesive materials become harder than those in the preferred range after drying and curing, making them more prone to cracking at the pores during airbag inflation, thus allowing the expanding gas to leak through these cracks.

[0307] <Effects of Implementation Method 15>

[0308] In the airbag manufacturing method of embodiment 15, by setting the viscosity of the adhesive material to the above-mentioned range, it is possible to set a manufacturing method that has good coating properties and is easy to manufacture.

[0309] <Effective Implementation 16> is mainly based on claim 16

[0310] <Summary of Implementation Method 16>

[0311] Embodiment 16 is a method for manufacturing an airbag based on any one of Embodiments 13 to 14, wherein the viscosity of the adhesive material applied is in Pascal-seconds and the viscosity range is 3.0 mPa. s~90Pa The manufacturing method of s.

[0312] <Viscosity of the adhesive material in Implementation Method 16>

[0313] The viscosity of adhesive materials is measured in Pascal-seconds (Pa). The viscosity range between high-viscosity and low-viscosity adhesive materials is 3.0 mPa. s~90Pa s. In Figure 19 The figure shows the airbag pressure (horizontal axis: ms) at each time interval during airbag inflation. The figure also shows test results for three airbag specifications—two-sided coating (thick solid line), one-sided coating (thick dashed line), and no coating (thin solid line)—based on the application of the adhesive material. The maximum airbag pressure was 2 minutes with and without coating. Compared to one-sided coating, two-sided coating maintains the airbag pressure for a longer restraint time after full inflation. However, the difference is small, and considering the manufacturing cost difference between two-sided and one-sided coating, it is possible to design airbags that allow for this difference.

[0314] A viscosity of less than 3.0 mPa was used as the adhesive material applied to the base fabric of the bag body, which was not coated with adhesive material. In the case of adhesive materials with a low viscosity range such as s, before the adhesive material is fully coated onto the base fabric, the coated adhesive material penetrates from the coating side surface of the base fabric placed on the coating apparatus table through the slits or seams, reaching the table surface. When the adhesive material reaches and adheres to the table surface, it is possible for unwanted portions to re-adhere to the surface of other base fabrics to be coated next. Adhesion to the seams on the base fabric surface in contact with the table surface or to the slits may also hinder the penetration of the coated adhesive material. Therefore, adhesive materials with a viscosity less than 3.0 mPa are not used. For adhesive materials with a viscosity range of s, a viscosity of 3.0 mPa is used. s to 90Pa s adhesive material.

[0315] The viscosity of the adhesive material for single-sided coating is preferably 3.0 mPa within the specified range. s~15Pa s, more preferably 3.0 mPa s to 10Pa The optimal viscosity is 3.0 mPa. s~3.0Pa If this is the extent, then even a coating applied to only one side can penetrate to at least a portion of the fibers forming the stitching that is exposed between the seams on the surface of the base fabric opposite to the coated base fabric.

[0316] <Effects of Implementation Method 16>

[0317] In embodiment 16, a viscosity of 3.0 mPa was used. s to 90Pa The adhesive material of s can be used as an adhesive material to create a manufacturing method that is easy to coat and manufacture.

[0318] <Effect>

[0319] The present invention is configured such that at least a portion of the fibers of the suture thread in the seam opening is bonded with an adhesive material, thereby preventing gaps from forming in the seam opening between the suture thread and the suture thread insertion section of the base fabric as a result of the suture thread twisting and tightening during airbag inflation. This is because the presence of an adhesive material layer between the fibers prevents the fiber spacing from narrowing. Therefore, when an adhesive material is applied to the seam opening, which is configured to prevent gaps from forming between the suture thread and the base fabric, the exposure rate of the adhesive material on the portion of the suture thread outside the seam opening on the base fabric and the percentage of the suture thread covered by the adhesive material are specified to prevent adhesion to the surface opposite to the coated surface. Furthermore, regarding the ratio of the bonding material between the fibers constituting the suture, it is configured such that the area ratio of the suture cross-section is specified (the cross-sectional area ratio of the bonding material relative to the cross-sectional area of ​​the suture), or, in order to optimize the viscosity of the bonding material, it is configured such that the bonding material is not applied from only one side (equivalent to the "coating agent" mentioned in Patent Document 1), but from both sides, and the bonding material initially applied uses a bonding material with a higher viscosity than the bonding material applied to the opposite side. This prevents the bonding material from adhering to the support table through the bag body and the seam of the bag body during operation.

[0320] By specifying the viscosity during single-sided coating, the seam can be sealed efficiently. The flow of the adhesive material into the base fabric surface opposite to the coating surface can be adjusted, and a specified ratio of adhesive material can be dispersed between the fibers constituting the seam. In the case of double-sided coating, by using an adhesive material with a lower viscosity than the initially coated adhesive material as the subsequent coating on the opposite side, the adhesive material can easily penetrate between the fibers constituting the twist and integrate with the initially coated adhesive material, thus efficiently sealing the seam. Furthermore, a method for manufacturing an airbag can be provided, in which at least a portion of the fibers constituting the seam can be bonded in a manner that minimizes gaps between the seam and the seam insertion section of the base fabric in the seam opening, resulting from the "twisting" and tightening of the twisted thread (i.e., the seam fiber).

[0321] Explanation of reference numerals in the attached figures

[0322] First base fabric 0201

[0323] Second base fabric 0202

[0324] fiber 0203

[0325] sutures 0204

[0326] Adhesive material 0205.

Claims

1. An airbag comprising a sheet-like first base fabric, a sheet-like second base fabric, and a suture, wherein the suture is formed by twisting multiple fibers together to bind them together in order to create a gas injection space using the first and second base fabrics, and by sewing the first and second base fabrics together to form a seam. In the suture, at least a portion of the fibers are bonded together with an adhesive material so that gaps are not easily generated between the suture and the base fabric in the seam opening portion of the suture, as a result of the tightening of its twist due to the tension generated by the suture.

2. The airbag according to claim 1, wherein, At least a portion of the stitching is exposed from the adhesive material in the portion other than the perforated portion of at least one of the first or second base fabrics.

3. The airbag according to claim 2, wherein, In an area on the surface of the base fabric on the side where the adhesive material is applied to the seam of one of the base fabrics, the two-dimensional area ratio of at least a portion of the suture exposed from the adhesive material is greater than 0% and less than 30%.

4. The airbag according to claim 2, wherein, In an area on the surface of the base fabric on the side of the base fabric where the adhesive material is not applied to the seam of the base fabric, the area covered by the adhesive material (including both the seam and the base fabric) is approximately the same width as the suture line along the seam direction (which may include suture lines from the opposite side of the base fabric), the two-dimensional area ratio of the portion covered by the adhesive material is 5% or more.

5. The airbag according to any one of claim 1 or claim 2, wherein, In the suture on the base fabric side coated with adhesive material, the cross-sectional area of ​​the adhesive material is 10% or more and 25% or less relative to the cross-sectional area of ​​the suture (and the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture is 55% or more and 100% or less).

6. The airbag according to any one of claim 1 or claim 2, wherein, In the suture on the base fabric side where the adhesive material is not applied, the cross-sectional area of ​​the adhesive material is 5% to 25% of the cross-sectional area of ​​the suture (35% to 100% of the cross-sectional area of ​​the portion other than the fibers in the cross-sectional area of ​​the suture).

7. The airbag according to claim 1, wherein, In cases where at least a portion of the seam of the first base fabric and / or the second base fabric is composed of fabric, The fibers of the fabric forming the seam are bonded together by an adhesive material so that the fibers of the fabric forming the seam of the first base fabric or / and the second base fabric are not easily loosened.

8. The airbag according to claim 7, wherein, The adhesive material used for the suture is the same adhesive material used for the first base fabric and / or the second base fabric.

9. A method for manufacturing an airbag, which is the method for manufacturing an airbag according to claim 1, characterized in that, have: In the first base fabric infiltration step, the first adhesive material is infiltrated from the seam portion of the first base fabric into the seam. as well as The second base fabric penetration step involves permeating the second adhesive material from the seam of the second base fabric into the suture line.

10. The method for manufacturing an airbag according to claim 9, wherein, The first and second adhesive materials have different viscosities.

11. The method for manufacturing an airbag according to claim 10, wherein, A first adhesive material and a second adhesive material are applied onto a flat platform, wherein the first adhesive material applied has a higher viscosity than the second adhesive material applied.

12. The method for manufacturing an airbag according to claim 11, wherein, The initially applied, relatively high-viscosity adhesive material is applied to the face line side, which is bound to the surface of the base fabric by the bottom line, during the one-line through-stitching of the base fabric.

13. A method for manufacturing an airbag, the method for manufacturing an airbag according to claim 1, comprising: The adhesive material penetration step involves applying an adhesive material to the seam portion of the surface of either a first or a second base fabric, and penetrating the adhesive material from the seam opening into the spaces between the fibers forming the suture thread within the seam opening; and The opposite base fabric side stitch fiber bonding material penetration step causes the bonding material to penetrate from the seam portion into at least a portion of the fibers forming the stitch line (a different stitch line from the stitch line exposed between the seams on the base fabric surface opposite to the base fabric coated with the bonding material) that is exposed between the seams on the base fabric surface opposite to the base fabric coated with the bonding material.

14. The method for manufacturing an airbag according to claim 13, wherein, It also has a base fabric bonding step, in which a portion of the adhesive material that seeps out from the slit portion remains between the first base fabric and the second base fabric, thus bonding the first base fabric and the second base fabric together.

15. The method for manufacturing an airbag according to claims 9 to 12, wherein, The viscosity of the adhesive material during application is measured in Pascal-seconds, with a viscosity range of 3.0 mPa for both high-viscosity and low-viscosity adhesive materials. s~90Pa s.

16. The method for manufacturing an airbag according to claims 13 to 14, wherein, The viscosity range of the adhesive material during application is 3.0 mPa·s. s~90Pa s.

Images