A rear window airbag arrangement and a method of checking an airbag

Abstract

This invention belongs to the field of automotive passive safety and discloses a method for rear window airbag placement and verification, as well as an airbag itself. The method first determines the airbag size based on the rear window area and assembles it into a module. Then, it verifies the module's connection strength and clearance with the vehicle's roof and roof beams. A weakening structure is placed in front of the roof to facilitate folding. Finally, the dynamic protection range is analyzed through simulation, and the dimensions are iteratively optimized. This method ensures coverage through reasonable airbag size setting and modular assembly; structural verification guarantees installation stability and deployment space; the weakening structure reduces roof drag; and the simulation process verifies and corrects the protective performance. This method effectively solves the problems of difficult airbag placement, unstable deployment, and poor protection in existing technologies, thereby improving the safety of rear-seat occupants in rear-end collisions.

Description

Technical Field

[0001] This invention belongs to the field of automotive passive safety technology, specifically relating to a method for arranging and verifying a rear window airbag and an airbag. Background Technology

[0002] As a core component of a vehicle's passive safety system, airbags function by inflating and deploying instantaneously through a chemical reaction upon a collision, forming a buffer layer between the occupants and the vehicle's interior to effectively reduce collision injuries. Currently, the automotive industry has developed a relatively mature airbag application system. Most mainstream models are equipped with airbags in front of the driver and front passenger, and a significant number of models further add airbags to the sides of the vehicle. These features effectively protect occupants in frontal and side collisions, becoming a crucial guarantee of vehicle safety performance.

[0003] In the development of automotive passive safety systems, the protection needs of rear-seat occupants in rear-end collisions have long been neglected, and the development of related protection technologies has been relatively low-priority. Although in recent years, with increased public awareness of traffic accidents, the protection of rear-seat occupants has gradually come into focus in research and development, and a very small number of models have attempted to equip rear window airbags for rear-end collisions, these airbags have significant drawbacks in existing technology: their airbags fold into a rectangular shape, significantly larger than traditional airbags, greatly increasing the difficulty of placement inside the vehicle; at the same time, due to the larger airbag volume, the gas generator needs to inflate at a higher rate, a characteristic that easily leads to instability in the airbag deployment process, thus greatly reducing the protective effect.

[0004] It is evident that existing rear window airbags suffer from problems such as difficulty in installation, unstable deployment, and poor protective effect. Summary of the Invention

[0005] This invention provides a method for arranging and verifying rear window airbags and an airbag. This method can effectively solve the problems of existing rear window airbags, such as difficulty in arrangement, unstable deployment, and poor protection effect.

[0006] To achieve the above objectives, the present invention employs the following technical content:

[0007] A method for arranging and verifying a rear window airbag, comprising:

[0008] Assembly process:

[0009] The size of the airbag is determined based on the area of ​​the rear windshield of the vehicle body, so that the airbag extends beyond the four edges of the rear windshield when laid flat.

[0010] The air bag is wound up and combined with the gas generator to form an airbag module;

[0011] Verification process:

[0012] The connection strength between the airbag module and the vehicle body is checked to ensure that the distance between adjacent positioning pieces is not greater than a first predetermined value;

[0013] The first minimum gap between the airbag module and the vehicle roof, and the second minimum gap between the airbag module and the roof crossbeam are checked, so that the first minimum gap is not less than a second predetermined value and the second minimum gap is not less than a third predetermined value.

[0014] A weakening structure is installed on the roof of the vehicle, located in front of the airbag module, to fold the roof of the vehicle when the airbag is inflated, so as to fully deploy the airbag.

[0015] Check the overlap between the interior roof and the vehicle body pillars to ensure that the overlap does not exceed the fourth predetermined value;

[0016] Simulation process:

[0017] The deployment process of the airbag module is simulated and analyzed to evaluate the dynamic protection range of the airbag.

[0018] If the dynamic protection range of the airbag does not meet the preset requirements, the size of the airbag is readjusted, and the assembly, verification and simulation processes are repeated until the dynamic protection range of the airbag meets the preset requirements, and the final size of the airbag is output.

[0019] Furthermore, the size of the airbag is determined based on the area of ​​the rear windshield of the vehicle body, so that the airbag extends beyond the four edges of the rear windshield in the flat state, with the airbag extending at least 50mm beyond the four edges of the rear windshield in the flat state.

[0020] Furthermore, the connection strength between the airbag module and the vehicle body is checked so that the distance between adjacent positioning pieces is not greater than a first predetermined value, where the first predetermined value is 300mm.

[0021] Furthermore, the positioning piece is connected to the roof crossbeam of the vehicle body by bolts, with the bolt specification not less than M6.

[0022] Furthermore, the verification includes a first minimum gap between the airbag module and the vehicle roof, and a second minimum gap between the airbag module and the roof crossbeam, such that the first minimum gap is not less than a second predetermined value, and the second minimum gap is not less than a third predetermined value, wherein the second predetermined value is 3mm.

[0023] Furthermore, the first minimum gap between the airbag module and the vehicle roof, and the second minimum gap between the airbag module and the roof crossbeam are checked, so that the first minimum gap is not less than a second predetermined value, and the second minimum gap is not less than a third predetermined value, wherein the third predetermined value is 3mm.

[0024] Furthermore, a weakening structure is installed on the roof of the vehicle. The weakening structure is located in front of the airbag module and is used to fold the roof of the vehicle when the airbag is inflated to fully expand the airbag. The weakening structure adopts a weakening line.

[0025] The weakening line is located at least 10mm in front of the airbag module along the X direction, and the groove depth is not less than 2.5mm.

[0026] Furthermore, the step of checking the overlap between the vehicle interior roof and the vehicle body pillars to ensure that the overlap does not exceed a fourth predetermined value includes:

[0027] Check the overlap between the interior roof and the C-pillar or D-pillar to ensure that the overlap is no more than 8mm.

[0028] Furthermore, the simulation analysis of the airbag module deployment process, and the evaluation of the dynamic protection range of the airbag, include:

[0029] The deployment process of the airbag module was simulated using computer-aided engineering simulation software. The specific steps are as follows:

[0030] Finite element meshes were created for the roof crossbeams, rear seats, and airbag modules. The basic mesh size was a preset size, the minimum mesh size was not less than 3mm, and the proportion of triangular meshes did not exceed 5%.

[0031] The chemical gas composition and pressure curve of the gas generator are set, and the pressure curve is derived from experimental data and processed into a smooth curve.

[0032] Set the material properties for the airbag fabric, roof crossbeams, and rear seats;

[0033] Set the contact type, where the contact between the air bag itself and the surrounding parts is set to automatic single-sided contact type, and the contact between the air bag and the surrounding parts is set to automatic double-sided contact type.

[0034] Set the calculation time step and the calculation time of the entire model, and perform the solution calculation to obtain the dynamic protection range of the airbag;

[0035] Determine whether the dynamic protection range of the airbag meets the preset requirements: if it does, output the airbag size; if it does not, readjust the airbag size and repeat the assembly, verification and simulation processes until the dynamic protection range of the airbag meets the preset requirements, and output the final size of the airbag.

[0036] A rear window airbag, manufactured and verified based on the above-mentioned rear window airbag arrangement and verification method, includes:

[0037] An airbag module is fixed to the rear of the vehicle body; the airbag module contains a folded airbag, and the airbag has an internal air guiding structure.

[0038] It also contains a gas generator connected to the gas bag; the gas generator is filled with solid chemical substances for inflating the gas bag in the event of ignition.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] This invention provides a method for the placement and verification of rear window airbags. The method first determines the airbag size based on the rear window area and assembles it into modules. Then, it verifies the module connection strength and the gaps with the vehicle's roof and roof beams. A weakening structure is placed in front of the roof to facilitate folding. Finally, the dynamic protection range is analyzed through simulation, and the dimensions are iteratively optimized. This method ensures coverage through reasonable airbag size setting and modular assembly; structural verification guarantees installation stability and deployment space; the weakening structure reduces roof drag; and the simulation process verifies and corrects the protective performance. This method effectively solves the problems of difficult airbag placement, unstable deployment, and poor protection effect in existing technologies, thereby improving the safety of rear occupants in rear-end collisions.

[0041] Preferably, in this invention, the planar coverage of the airbag is further required to ensure that the airbag has sufficient coverage area after it is fully deployed, extending beyond the boundary of the rear windshield, thereby forming a larger and continuous protection area. This effectively prevents the occupant's head from coming into contact with the vehicle body structure due to insufficient protection during a collision, thus enhancing the completeness of the protection.

[0042] Preferably, in this invention, by setting the distribution density of the connection points between the airbag module and the vehicle body, an appropriate interval is ensured between the connection points, avoiding the risk of local stress concentration or module loosening under impact due to too few fixing points or too large spacing, thereby ensuring the firmness and integrity of the connection between the entire airbag module and the vehicle body at the moment of triggering.

[0043] Preferably, in this invention, high-specification mechanical fasteners are used to provide a solid and reliable installation base for the airbag module, ensuring that the module can be firmly fixed in the designed position when the gas generator detonates and generates huge thrust, without displacement or separation, thus ensuring the stability of the initial conditions during the deployment process.

[0044] Preferably, in this invention, a minimum safe distance is set between the airbag module and the vehicle's roof and roof beams. This provides necessary physical space as a buffer, preventing the module from interfering with, rubbing against, or even making abnormal noises with surrounding components during normal vehicle operation or due to vibration. This ensures product durability and creates conditions for unobstructed and rapid airbag deployment.

[0045] Preferably, in this invention, by pre-setting precisely controlled weak points in key areas along the airbag deployment path, the canopy can be accurately guided to tear and fold smoothly along a predetermined path under the pressure of the airbag inflation, which greatly reduces the resistance and uncertainty of the canopy to the airbag deployment and ensures that the airbag can be rapidly and completely inflated into the passenger compartment.

[0046] Preferably, in this invention, the overlap size between the vehicle interior roof and the side pillars is set to avoid excessive pulling force or jamming when the roof is folded by the airbag due to excessive overlap, thus ensuring that the roof can move smoothly as designed and clearing lateral obstacles for the full deployment of the airbag.

[0047] Preferably, in this invention, by simulating material properties, contact relationships and inflation process in detail, the actual deployment shape and protection range of the airbag can be predicted with high fidelity before the physical prototype is manufactured. This allows problems to be identified and parameters to be optimized during the design phase, significantly shortening the development cycle, reducing costs, and improving the predictability and effectiveness of the final product performance.

[0048] This invention also provides a rear window airbag, manufactured based on the aforementioned rear window airbag arrangement and verification method. This airbag includes an airbag module fixed to the rear of the vehicle body. The module contains a folded airbag with a gas guiding structure and a gas generator connected to the airbag, which generates gas through the combustion of solid chemicals. Through rigorous methodological guidance, the structural layout, connection strength, and deployment path of the airbag module are ensured to have been precisely calculated and verified. The internal gas guiding structure effectively guides and distributes the gas, working in conjunction with the verified roof weakening zone to provide a smooth and controllable deployment environment for the airbag. Therefore, this airbag fundamentally overcomes the core defects commonly found in existing technologies, such as difficulties in in-vehicle arrangement and unstable inflation and deployment processes, ultimately achieving reliable and effective collision protection for rear-seat occupants. Attached Figure Description

[0049] Figure 1 A schematic diagram of the structure of the rear window airbag in a folded state provided in an embodiment of the present invention;

[0050] Figure 2 This is a flowchart illustrating a method for arranging and verifying a rear window airbag, as provided in an embodiment of the present invention.

[0051] Figure label:

[0052] 1. Air bag; 2. Clamp; 3. Gas generator; 4. Positioning plate. Detailed Implementation

[0053] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0056] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0057] The technical terms involved in this invention will be explained below:

[0058] CAE (Computer Aided Engineering) is a method that uses computer technology for engineering design and analysis.

[0059] As mentioned in the background section, airbags are generally folded into cylinders or elongated strips; however, the rear window airbag folds into a cuboid, which is large and difficult to place inside the vehicle. In addition, due to the large size of the airbag, the gas generator needs to inflate it at a relatively fast rate, which can lead to unstable airbag deployment and easily reduce the protective effect.

[0060] To address the aforementioned issues, this embodiment provides a method for the arrangement and verification of rear window airbags. This method combines static analysis and verification using 3D software with dynamic simulation using CAE, providing a basis for judging the protective effect of rear window airbags during the digital design phase of a project. This improves the accuracy of risk identification and judgment, avoids design risks, and reduces the waste of new model development costs and the risk of market launch for enterprises.

[0061] This embodiment provides a method for rear window airbag placement and verification, including: assembly process, verification process, and simulation process. The specific implementation process is as follows:

[0062] Assembly process: Determine the size of airbag 1 according to the area of ​​the rear windshield of the vehicle body so that airbag 1 extends beyond the four edges of the rear windshield when laid flat; roll up airbag 1 and combine it with gas generator 3 to form an airbag module;

[0063] Verification process: Verify the connection strength between the airbag module and the vehicle body to ensure that the distance between adjacent positioning pieces 4 is not greater than a first predetermined value; verify the first minimum gap between the airbag module and the vehicle interior roof, and the second minimum gap between the airbag module and the roof crossbeam, to ensure that the first minimum gap is not less than a second predetermined value and the second minimum gap is not less than a third predetermined value; install a weakening structure on the vehicle interior roof, the weakening structure being located in front of the airbag module, for folding the vehicle interior roof when the airbag 1 is inflated to fully deploy the airbag 1; verify the overlap between the vehicle interior roof and the vehicle body pillars to ensure that the overlap is not greater than a fourth predetermined value;

[0064] Simulation process: The deployment process of the airbag module is simulated and analyzed to evaluate the dynamic protection range of the airbag; if the dynamic protection range of the airbag does not meet the preset requirements, the size of airbag 1 is readjusted, and the assembly process, verification process and simulation process are repeated until the dynamic protection range of the airbag meets the preset requirements, and the final size of airbag 1 is output.

[0065] The rear window airbag arrangement and verification method provided in this embodiment will be further explained below with reference to the accompanying drawings:

[0066] like Figure 1As shown, this embodiment provides a rear window airbag installed at the rear of the vehicle body, including: an airbag module fixed to the rear of the vehicle body, the airbag module containing a folded airbag 1, the airbag 1 having an internal air guiding structure to limit the gas flow direction within the airbag 1: the gas entering the airbag 1 is diverted to both sides along the width direction of the vehicle body and downwards along the height direction of the vehicle body, the airflow on both sides flows along the side edges of the airbag 1, and the airflow in the middle flows along the center of the airbag 1, the three airflows converge at the bottom of the airbag 1 until the entire airbag is filled. Also included is a gas generator 3, connected to the airbag of the airbag module, containing solid chemical substances, which, upon impact, are rapidly detonated, immediately undergoing a violent chemical reaction, generating a large amount of chemical mixture gas in a very short time; clamps 2 are fixed to both sides of the gas generator 3.

[0067] like Figure 2 As shown, for example, the aforementioned rear window airbag is obtained through arrangement and verification using the rear window airbag arrangement and verification method. The specific steps of the method are as follows:

[0068] Step (1): Based on the size of the rear windshield of the vehicle, design the size of airbag 1 in advance. The perimeter of airbag 1 should extend about 50mm beyond the four edges of the rear windshield. Use three-dimensional software measurement tools to check one by one to ensure that the flat boundary of airbag 1 meets the requirement of being greater than 50mm.

[0069] Step (2): Roll the air bag 1 into a cuboid and combine it with the gas generator 3 to form an airbag module; use 3D software to design the folding of the flat air bag 1, and combine the folded air bag 1 with the gas generator 3 to form a cuboid airbag module.

[0070] Step (3): To ensure the connection strength between the airbag module and the vehicle body, the distance between adjacent positioning pieces 4 is measured using a three-dimensional software measurement tool to ensure that the distance is ≤300mm; and the connection between the positioning piece 4 and the roof crossbeam of the vehicle body is a bolt connection, with the bolt specification not less than M6.

[0071] Step (4): In order to avoid interference between the airbag module and the car roof, and to prevent the airbag module from pressing down on the car roof and causing bulges or other poor shapes, use three-dimensional software measurement tools to perform static verification of the surrounding parts of the airbag module to ensure that the minimum gap is ≥3mm.

[0072] Step (5): In order to avoid interference between the airbag module and the roof beam, which would cause the airbag 1 to be damaged by friction during long-term use, the surrounding parts of the airbag module are statically checked using three-dimensional software measurement tools to ensure that the minimum gap is ≥3mm.

[0073] Step (6): To ensure that the airbag 1 can smoothly emerge from between the rear roof and the roof beam during the initial inflation phase, the roof should be designed with a weakening line. The weakening line should be at least 10mm in front of the airbag module in the X direction, and the groove depth should be no less than 2.5mm. During the inflation and deployment of the airbag by the gas generator, the roof should fold at the weakening line to facilitate the deployment of the airbag.

[0074] Step (7): During the airbag deployment process, in order to make the airbag more smoothly burst out of the car roof and deploy correctly, the car roof is required to be able to be smoothly separated from the hard interior panel of the C-pillar or D-pillar. The overlap amount between the car roof and the C-pillar or D-pillar is statically checked using three-dimensional software. The overlap amount is ≤8mm.

[0075] Step (8): The perimeter of the airbag after deployment should at least cover the entire rear window. To ensure the dynamic protection range of the airbag deployment, CAE simulation software is used to perform CAE simulation analysis in conjunction with the rear of the vehicle body. The dynamic protection range of the airbag is evaluated based on the simulation results.

[0076] In the CAE preprocessing software, finite element meshes are generated for components such as the roof crossbeam, rear seats, and airbag module. The basic size of the finite mesh is 6mm, with a minimum of 3mm, and the proportion of triangular meshes should not exceed 5%. The chemical gas composition and pressure curves of the gas generator should be derived from experimental data, processed into smooth curves, and then input into the CAE simulation software. The material properties of components such as the airbag fabric, roof crossbeam, and rear seats should be assigned appropriate material characteristics based on actual conditions. To accurately simulate the contact patterns between the entire airbag module and surrounding components, as well as the airbag itself, during deployment, the keyword for contact with the airbag itself is selected when setting the contact type.

[0077] *CONTACT_AUTOMATIC_SINGLE_SURFACE (Automatic single-sided contact type);

[0078] Key words for selecting the contact between the air bag and surrounding components:

[0079] *AUTOMATIC_SURFACE_TO_SURFACE (Automatic double-sided contact type);

[0080] Once you've set the appropriate computation time step and the overall computation time for the model, you can submit it to the solver for calculation and output the simulation results.

[0081] After the calculation in step (9) is completed, in the CAE post-processing software, the windshield airbag is evaluated in conjunction with the simulation animation to determine whether the deployment is smooth and whether the protection range is normal. If the protection range is not satisfied, the airbag boundary is increased according to the area that is not satisfied by the simulation results, and then steps (1) to (8) are performed.

[0082] For example, the method provided in this embodiment is implemented in practice, and the specific implementation process is as follows:

[0083] This embodiment takes the rear window airbag arrangement and verification of a certain family sedan as an example to illustrate the specific implementation process of the present invention. The rear window airbag is manufactured based on the arrangement and verification method described in the present invention, and its structure and arrangement verification steps are as follows:

[0084] The assembly process begins with obtaining the actual dimensions of the car's rear windshield using 3D scanning. The calculated windshield area is 1.2m². 2 The size of airbag 1 was determined based on the area of ​​the rear windshield, ensuring that all four edges of airbag 1 extend at least 50mm beyond the four edges of the rear windshield when laid flat. The final design of airbag 1, when laid flat, is 100mm longer than the length of the rear windshield (50mm on each side) and 100mm wider than the width of the rear windshield (50mm on each top and bottom). This was verified using 3D software measurement tools to confirm that the flat boundaries of airbag 1 meet the requirements. Airbag 1 has an internal air-guiding structure that limits the gas flow within it. The gas entering airbag 1 is divided into two streams: one along the width of the vehicle body to the sides, and the other along the height of the vehicle body downwards. The airflow on the sides flows along the side edges of airbag 1, while the airflow in the middle flows along the center of airbag 1. The three airflows converge at the bottom of airbag 1 until it fills the entire airbag 1. Subsequently, the flat airbag 1 was folded using 3D software, and the airbag 1 was rolled into a cuboid structure. The rolled airbag 1 was then combined with the gas generator 3 to form an airbag module. The gas generator 3 was connected to the airbag 1 and was filled with solid chemical substances. These solid chemical substances were rapidly ignited after the collision, and a violent chemical reaction occurred immediately, generating a large amount of chemical mixture gas in a very short time to drive the airbag 1 to expand and unfold.

[0085] Next, the verification process is carried out: To ensure the connection strength between the airbag module and the vehicle body, the airbag module is bolted to the roof crossbeam of the vehicle body through the positioning piece 4. The bolt specification is M6 (meeting the requirement of not less than M6). The distance between adjacent positioning pieces 4 is measured using a 3D software measurement tool. A total of 4 positioning pieces 4 are set and evenly distributed on the edge of the airbag module. The distance between adjacent positioning pieces 4 is controlled at 250mm. This distance is not greater than the first predetermined value of 300mm to ensure that the connection strength meets the usage requirements. To avoid interference between the airbag module and the vehicle's headliner, which could cause bulges or other shape defects, and to prevent interference between the airbag module and the roof crossbeam, which could lead to damage to the airbag 1 due to friction during prolonged use, a 3D software measurement tool was used to statically verify the surrounding components of the airbag module. This ensured that the first minimum gap between the airbag module and the headliner was not less than a second predetermined value of 3mm, and the second minimum gap between the airbag module and the roof crossbeam was not less than a third predetermined value of 3mm. Measurements showed that the actual first minimum gap was 4mm and the second minimum gap was 4mm, both meeting the verification requirements. To ensure that the airbag 1 could smoothly emerge from between the headliner and the roof crossbeam at the rear of the vehicle during initial inflation, a weakening structure was installed on the headliner. This weakening structure uses a weakening line located in front of the airbag module. The weakening line is 10mm in front of the airbag module along the X-axis, and the groove depth is 2.5mm. This ensures that the headliner can fold at the weakening line during inflation, allowing the airbag 1 to fully deploy. To ensure the airbags can be deployed more smoothly from the roof and deploy correctly, 3D software was used to statically check the overlap between the roof and the vehicle pillars. The overlap between the roof and the C and D pillars was checked in particular to ensure that the overlap was not greater than the fourth predetermined value of 8mm. After checking, the actual overlap was 6mm, which met the requirements.

[0086] Finally, a simulation process was conducted: Computer-aided engineering (CAE) simulation software was used to simulate and analyze the deployment process of the airbag module in order to evaluate the dynamic protection range of the airbag. The specific steps are as follows: In the CAE preprocessing software, finite element meshes are generated for components such as the roof crossbeam, rear seats, and airbag module. The basic mesh size is set to 6mm (preset size), the minimum mesh size is controlled to 3mm (not less than 3mm), and the proportion of triangular meshes is controlled to 4% (not exceeding 5%). The chemical gas composition and pressure curve of the gas generator 3 are set. The pressure curve is derived from the actual test data of the gas generator 3 and is processed into a smooth curve before being input into the CAE simulation software. According to the actual component parameters, the material properties of the airbag 1 fabric, roof crossbeam, and rear seats are set. The airbag 1 fabric uses high-strength nylon cloth, the roof crossbeam uses high-strength steel, and the rear seats use polyurethane foam. To accurately simulate the contact pattern between the entire airbag module and surrounding components, as well as the airbag 1 itself, during deployment, the contact type is set. The contact of the airbag 1 itself uses the keyword automatic single-sided contact type CONTACT_AUTOMATIC_SINGLE_SURFACE. For contact with surrounding components (roof beams, rear seats, interior headliner, etc.), the keyword "AUTOMATIC_SURFACE_TO_SURFACE" was selected. Appropriate calculation time steps and the overall model calculation time were set and submitted to the solver for calculation. After calculation, in the CAE post-processing software, the smooth deployment of the rear window airbag and the normality of its dynamic protection range were evaluated in conjunction with the simulation animation (the preset requirement is that the airbag's deployed edges must at least cover the entire rear window). The evaluation showed that in the first simulation, the airbag's dynamic protection range did not completely cover the upper left and upper right corners of the rear window, failing to meet the preset requirement. Therefore, based on the unsatisfactory areas in the simulation results, the size of airbag 1 was adjusted, increasing the excess on both sides by 20mm. That is, the length of airbag 1 in its flat state is 140mm larger than the length of the rear window, while the width remains unchanged. The assembly, verification, and simulation processes were then repeated. After another simulation, the evaluation showed that the dynamic protection range of the airbag completely covered the entire rear window, meeting the preset requirements. At this point, the final size of airbag 1 was output, and the arrangement and verification of the window airbag were completed.

[0087] The rear window airbag manufactured using the above arrangement and verification method includes an airbag module fixed to the rear of the vehicle body. The airbag module contains a folded airbag 1 and a gas generator 3. The airbag 1 has an internal air guiding structure. The gas generator 3 is connected to the airbag 1 and is filled with solid chemical substances for inflating the airbag 1 in the ignition state. It can be rapidly deployed in the event of a vehicle collision to effectively protect the rear window area.

[0088] In summary, this invention provides a method for arranging and verifying rear window airbags, as well as an airbag itself, which has the following advantages compared to existing rear window airbag technologies:

[0089] This method allows for the verification of rear window airbags during the deployment phase, enabling early detection and prevention of risks associated with rear window airbags. Furthermore, the rapid initial verification eliminates the need for any testing, reducing verification costs and making it highly convenient to use. Simultaneously, rear window airbags deployed and verified using this method ensure that, in the event of a rear-end collision, the chemical gas produced by the gas generator rapidly flows into the airbag. During inflation, the airbag bursts through the roof and forms a barrier between the rear window and the seat inside the vehicle, effectively preventing injury to occupants from windshield debris or collisions with the vehicle body.

[0090] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A method for arranging and verifying rear window airbags, characterized in that, include: Assembly process: The size of the airbag (1) is determined according to the area of ​​the rear windshield of the vehicle body, so that the airbag (1) extends beyond the four edges of the rear windshield when laid flat. The air bag (1) is wound up and combined with the gas generator (3) to form an airbag module; Verification process: The connection strength between the airbag module and the vehicle body is checked so that the distance between adjacent positioning pieces (4) is not greater than the first predetermined value; The first minimum gap between the airbag module and the vehicle roof, and the second minimum gap between the airbag module and the roof crossbeam are checked, so that the first minimum gap is not less than a second predetermined value and the second minimum gap is not less than a third predetermined value. A weakening structure is installed on the roof of the vehicle. The weakening structure is located in front of the airbag module and is used to fold the roof of the vehicle when the airbag (1) is inflated so as to fully deploy the airbag (1). Check the overlap between the interior roof and the vehicle body pillars to ensure that the overlap does not exceed the fourth predetermined value; Simulation process: The deployment process of the airbag module is simulated and analyzed to evaluate the dynamic protection range of the airbag. If the dynamic protection range of the airbag does not meet the preset requirements, the size of the airbag (1) is readjusted, and the assembly process, verification process and simulation process are repeated until the dynamic protection range of the airbag meets the preset requirements, and the final size of the airbag (1) is output.

2. The rear window airbag arrangement and verification method according to claim 1, characterized in that, The size of the airbag (1) is determined according to the area of ​​the rear windshield of the vehicle body, so that the airbag (1) extends beyond the four edges of the rear windshield in the flat state, and the airbag (1) extends beyond the four edges of the rear windshield by at least 50mm in the flat state.

3. The method for arranging and verifying rear window airbags according to claim 1, characterized in that, The connection strength between the airbag module and the vehicle body is checked so that the distance between adjacent positioning pieces (4) is not greater than the first predetermined value, which is 300mm.

4. The rear window airbag arrangement and verification method according to claim 3, characterized in that, The positioning piece (4) is connected to the roof crossbeam of the vehicle body by bolts, and the bolt specification is not less than M6.

5. The method for arranging and verifying a rear window airbag according to claim 1, characterized in that, The verification is performed on the first minimum gap between the airbag module and the vehicle roof, and the second minimum gap between the airbag module and the roof crossbeam, so that the first minimum gap is not less than a second predetermined value and the second minimum gap is not less than a third predetermined value, wherein the second predetermined value is 3mm.

6. The method for arranging and verifying a rear window airbag according to claim 1, characterized in that, The first minimum gap between the airbag module and the vehicle roof, and the second minimum gap between the airbag module and the roof crossbeam are checked to ensure that the first minimum gap is not less than a second predetermined value and the second minimum gap is not less than a third predetermined value, wherein the third predetermined value is 3mm.

7. The rear window airbag arrangement and verification method according to claim 1, characterized in that, The weakening structure employs a weakening line; The weakening line is located at least 10mm in front of the airbag module along the X direction, and the groove depth is not less than 2.5mm.

8. The rear window airbag arrangement and verification method according to claim 1, characterized in that, The step of checking the overlap between the vehicle interior roof and the vehicle body pillars to ensure that the overlap does not exceed a fourth predetermined value includes: Check the overlap between the interior roof and the C-pillar or D-pillar to ensure that the overlap is no more than 8mm.

9. The method for arranging and verifying a rear window airbag according to claim 1, characterized in that, The simulation analysis of the airbag module deployment process, and the evaluation of the dynamic protection range of the airbag, include: The deployment process of the airbag module was simulated using computer-aided engineering simulation software. The specific steps are as follows: Finite element meshes were created for the roof crossbeams, rear seats, and airbag modules. The basic mesh size was a preset size, the minimum mesh size was not less than 3mm, and the proportion of triangular meshes did not exceed 5%. The chemical gas composition and pressure curve of the gas generator are set, and the pressure curve is derived from experimental data and processed into a smooth curve. Set the material properties for the airbag fabric, roof crossbeams, and rear seats; The contact type is set, wherein the contact of the air bag (1) itself is set to automatic single-sided contact type, and the contact between the air bag (1) and the surrounding parts is set to automatic double-sided contact type. Set the calculation time step and the calculation time of the entire model, and perform the solution calculation to obtain the dynamic protection range of the airbag; Determine whether the dynamic protection range of the airbag meets the preset requirements: if it does, output the size of the airbag (1); if it does not, readjust the size of the airbag (1) and repeat the assembly process, verification process and simulation process until the dynamic protection range of the airbag meets the preset requirements, and output the final size of the airbag (1).

10. A rear window airbag, characterized in that, The rear window airbag arrangement and verification method according to any one of claims 1-9 is used to arrange and verify the airbag, including: An airbag module is fixed to the rear of the vehicle body; the airbag module contains a folded airbag (1), and the airbag (1) has an internal air guiding structure. It also contains a gas generator (3) connected to the gas bag (1); the gas generator (3) is filled with solid chemical substances for inflating the gas bag (1) in the ignition state.

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