A vehicle-mounted deflated airbag device for protecting pedestrians

Abstract

The present invention relates to the field of pedestrian protection of vehicles, and specifically to a vehicle-mounted deflated airbag device for protecting pedestrians, and is characterized in that: it comprises a deflated airbag and a deflated switch arranged on the deflated airbag; the deflated airbag is a sealed airbag, and the deflated airbag is detachably connected to the front side of the front bumper of the car; the deflated switch comprises a shell, a spring and a piston, the shell is a cylindrical structure with a hollow interior, one end of the shell is an exhaust port connected to the inner cavity of the deflated airbag, the spring and the piston are both axially arranged in the shell, and the piston is located between the exhaust port of the shell and the spring, and the side wall of the piston is sealed with the inner wall of the shell; one end of the spring is connected to the piston, and the other end of the spring is connected to the other end of the shell; at least one deflated hole for connecting the inner cavity of the shell with the outside is arranged on the side wall of the shell. The present invention is used to solve the problem of pedestrian protection in traffic accidents, and has a simple structure and good protection effect.

Description

Technical Field

[0001] The present invention relates to the field of pedestrian protection of vehicles, and in particular to a vehicle-mounted deflation airbag device for protecting pedestrians. Background Art

[0002] As society continues to progress, cars have become an indispensable part of daily life. With the increase in car ownership, casualties from car accidents have also increased dramatically. Pedestrians (including cyclists) are a vulnerable group in traffic, accounting for approximately 65% ​​of all casualties. Therefore, protecting pedestrians in traffic accidents has become a hot topic for academic research.

[0003] Safety is a key consideration in vehicle design today. Common pedestrian protection devices are often made of plastic or foam, which, given their size, cannot effectively mitigate the impact forces experienced by pedestrians. Furthermore, common pedestrian protection systems primarily protect pedestrians' heads or chests, but offer minimal protection for their legs. For example, Chinese Patent No. 200720070616.1, entitled "Pedestrian Protection Device for Automobile Bumpers," utilizes thin materials and a low impact height to protect pedestrians' legs. However, this patented solution suffers from the following drawbacks: the thin material has limited energy absorption for the legs, requires modifications to the existing vehicle structure, and is complex. Lowering the impact height may increase pedestrian injury rather than provide adequate protection. Another example is Chinese Patent No. 201020132939.0, entitled "Passenger Vehicle Airbag System for Pedestrian Protection." It protects pedestrians by ejecting airbags from the hood and front windshield after a collision. The above patented technical solution has the following defects: it only considers the protection of the pedestrian's head and chest, but not the protection of the pedestrian's legs; at the same time, if the pedestrian does not fall on the hood after being hit, this system will lose its protective effect.

[0004] In view of this, in order to overcome the above-mentioned defects, providing a vehicle-mounted deflation airbag device for protecting pedestrians has become an urgent problem to be solved in the field. Summary of the Invention

[0005] The purpose of the present invention is to provide a vehicle-mounted deflated airbag device for protecting pedestrians, which is used to solve the problem of pedestrian protection in traffic accidents and has a simple structure and good protection effect.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows: a vehicle-mounted deflation airbag device for protecting pedestrians, comprising a deflation airbag and at least one deflation switch for releasing gas in the deflated airbag; the deflated airbag is a sealed airbag and is detachably connected to the front side of the front bumper of the vehicle; the deflation switch is provided on the deflated airbag; the deflation switch comprises a housing, a spring and a piston, the housing being a hollow cylindrical structure with one end of the housing being an opening connected to the inner cavity of the deflated airbag, the spring and the piston being axially arranged in the housing, the piston being located between the exhaust port of the housing and the spring, and the side wall of the piston being sealed from the inner wall of the housing; one end of the spring being connected to the piston, and the other end of the spring being connected to the other end of the housing; at least one deflation hole being provided on the side wall of the housing for connecting the inner cavity of the housing with the outside; when the spring is in a free state, the distance between the end face of the piston closest to the exhaust port of the housing and the exhaust port of the housing is less than or equal to the distance between the tangent point of the deflation hole closest to the exhaust port of the housing and the exhaust port of the housing, and the tangent line being perpendicular to the axis of the housing.

[0007] According to the above scheme, the diameter D of the vent hole satisfies the following formula:

[0008]

[0009] Among them, v max The maximum speed of the vehicle when the airbag can effectively protect pedestrians is selected based on China's first pedestrian protection collision test and the recommended test of E-NCAP. max =40km / h; S 触 For the leg contact area in the E-NCAP pedestrian collision test, select S 触 =0.02m 2 ; u is the maximum gas flow rate of the vent hole, Where g is the acceleration due to gravity, which is 9.8 m / s 2 , p max is the maximum pressure generated in the deflated airbag during a collision. Where F max The maximum force that the human leg can withstand during a collision. The EEVC\WC17 standard recommends that the limit value of the pedestrian injury index is 5KN. max =5KN; n is the number of deflation switches on the deflation airbag; m is the number of deflation holes on a deflation switch; π is the pi.

[0010] According to the above scheme, the elastic coefficient K of the spring satisfies the following formula:

[0011]

[0012] Among them, S 活is the end surface area of ​​the piston; when the diameter and elastic coefficient of the deflation switch satisfy the above formula, during a collision between a pedestrian and a vehicle, the deflation switch can adjust the size of the deflation hole opening according to the severity of the collision, ensuring that the force applied by the front end of the vehicle to the pedestrian's legs is always lower than the limit value of the pedestrian injury index (F≤5KN), thereby effectively protecting the pedestrian.

[0013] Specifically, the deflation switch is arranged on the side of the deflation airbag, and the deflation hole in the deflation switch is retained outside the deflation airbag to discharge the gas in the deflation airbag.

[0014] According to the above solution, when there are multiple vent holes on a vent switch, the center lines of the multiple vent holes are located in the same plane and the diameters of the vent holes are the same.

[0015] According to the above solution, when there are multiple vent holes, the multiple vent holes are evenly distributed along the circumference of the side wall of the shell.

[0016] According to the above scheme, the device also includes an airbag cover, which is a cover structure with a hollow interior and an open side, and its open side edge can be detachably connected to the front side of the car's front bumper; a non-enclosed cavity is formed between the airbag cover and the front bumper, which is used to install the deflated airbag and wrap the deflated airbag therein. The airbag cover is made of a material with high elasticity and easy to shape, which can be sufficiently deformed during a collision so that the pedestrian's legs and the deflated airbag can be fully squeezed. The preferred material is a shape memory alloy; once the airbag is deflated in a collision, it needs to be inflated or replaced before it can continue to be used. The detachable connection method facilitates the inflation or replacement of the airbag.

[0017] According to the above solution, the opening side of the airbag cover is provided with a connecting ear, which can be connected to the front side of the car's front bumper by bolts; other detachable connection methods can also be used between the airbag cover and the front bumper, such as the existing snap connection.

[0018] According to the above solution, the material of the deflated airbag is high-strength TPU composite fabric; the high-strength TPU composite fabric has outstanding load-bearing capacity, impact resistance and shock absorption performance; good air tightness, wear resistance and high and low temperature resistance.

[0019] According to the above scheme, an inflation hole is also provided on the side of the deflated airbag; when a collision occurs, part of the gas in the deflated airbag is released, and the deflated airbag needs to be inflated when used again to ensure the subsequent normal use of the deflated airbag; the inflation hole adopts the existing inflation hole structure, such as the inflation hole structure of a swimming ring.

[0020] The present invention has the following beneficial effects:

[0021] First, the present invention can reduce the impact at the moment of collision and absorb the energy generated by the collision on the human leg by the deflation of the deflation airbag, thereby reducing the force on the pedestrian's leg and providing good protection for pedestrians. The deflation airbag of the present invention is normally filled with gas and is deflated during a collision through a deflation switch. The deflation switch can adjust the size of the deflation hole according to the severity of the collision, so that pedestrians can be fully protected under different conditions.

[0022] 2. The device of the present invention is installed on the front side of the front bumper of the vehicle. The original structure of the vehicle is not changed. Only an airbag-deflation device is added on the basis of the original structure, which does not change the original performance of the vehicle. The device protects pedestrians by deflating the airbag. It has a simple structure, is easy to install, easy to implement, and has a low production cost. At present, there is no device that protects pedestrians in the form of a deflated airbag. The present invention has broad prospects in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention installed on a front bumper;

[0025] Figure 3 This is a schematic diagram of the deflation switch being fully closed;

[0026] Figure 4 This is a schematic diagram of the partially opened bleed switch;

[0027] Figure 5 This is a schematic diagram of the deflation switch being fully opened;

[0028] Figure 6 This is a schematic diagram of another embodiment in which the deflation switch is fully closed.

[0029] Reference numerals:

[0030] 1. Deflate the airbag;

[0031] 2. Deflation switch; 201. Housing; 201a. Exhaust port; 201b. Deflation hole; 202. Spring; 203. Piston;

[0032] 3. Airbag cover; 301. Connecting ear;

[0033] 4. Car front bumper. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Please refer to Figures 1 to 6 The present invention is a vehicle-mounted deflation airbag device for protecting pedestrians, which includes an airbag housing 3, a deflation airbag 1, and at least one deflation switch 2 for releasing gas in the deflation airbag 1;

[0036] The airbag cover 3 is a cover structure with a hollow interior and an opening on one side. The open side of the airbag cover 3 is provided with a connecting ear 301, and the connecting ear 301 can be detachably connected to the front side of the front bumper 4 of the car by bolts; the deflated airbag 1 is a sealed airbag, which is placed in a non-enclosed cavity formed by the airbag cover 3 and the front bumper 4 of the car; the deflated airbag 1 is provided with a deflated switch 2; the deflated airbag 1 comprises a shell 201, a spring 202 and a piston 203, the shell 201 is a cylindrical structure with a hollow interior, one end of the shell 201 is an opening connected to the inner cavity of the deflated airbag 1, the spring 202 and the piston 203 are both axially arranged in the shell 201 and the piston 203 is located Between the outer shell exhaust port 201a and the spring 202, the piston 203 can move axially in the outer shell, and the side wall of the piston 203 and the inner wall of the outer shell 201 are sealed; one end of the spring 202 is connected to the piston 203, and the other end of the spring 202 is connected to the other end of the outer shell 201; at least one vent hole 201b for connecting the inner cavity of the outer shell 201 and the outside is provided on the side wall of the outer shell 201; when the spring 202 is in a free state, the distance L between the end face of the piston 203 close to the outer shell exhaust port 201a and the outer shell exhaust port 201a is less than or equal to the distance H between the closest tangent point of the vent hole 201b to the outer shell exhaust port 201a and the outer shell exhaust port 201a.

[0037] The deflated airbag 1 is constructed from a high-strength TPU composite fabric. In this embodiment, the composite is manufactured by Jiaxing Yingcheng Textile Co., Ltd. Specifically, it consists of nylon 420D laminated with a 0.15mm thick TPU film. The airbag cover 3 is made of a highly elastic and easily shaped material, allowing sufficient deformation during a collision to ensure adequate compression between the pedestrian's legs and the deflated airbag 1. In this embodiment, the material used is a shape-memory alloy. The housing 201 of the deflated switch 2 is made of a metal material such as aluminum and is sewn to the side of the deflated airbag 1.

[0038] The deflated airbag 1 is also provided with an inflation hole. When a collision occurs, part of the gas in the deflated airbag 1 is released. When it is used again, the deflated airbag 1 needs to be inflated to ensure the subsequent normal use of the deflated airbag 1; the inflation hole adopts the existing inflation hole structure, such as the inflation hole structure of a swimming ring.

[0039] The deflation switch 2 is sewn onto the side of the deflation airbag 1. The deflation hole 201b in the deflation switch 2 is retained on the outside of the deflation airbag 1 to release the gas within the deflation airbag 1. If there are multiple deflation holes 201b on a deflation switch 2, the centerlines of the multiple deflation holes 201b lie in the same plane, the diameters of the multiple deflation holes 201b are the same, and the multiple deflation holes 201b are evenly distributed along the circumference of the sidewall of the housing 201. The deflation airbag 1 is normally inflated and deflated by the deflation switch 2 during a collision.

[0040] See Figures 3 to 6 , is a schematic diagram of the open and closed states of the deflation switch 2, wherein a piston 203 is connected to a spring 202 inside the housing 201, the piston 203 is close to the exhaust port 201a of the housing, and the other end of the spring 202 is connected to the bottom of the housing 201; Figure 3 and Figure 6 When no collision occurs, the distance L between the upper end surface of the piston 203 and the exhaust port 201a of the shell is less than or equal to the distance H between the closest tangent point of the deflation hole 201b to the exhaust port 201a of the shell and the exhaust port 201a. The piston 203 isolates the inner cavity of the deflated airbag 1 from the deflation hole 201b, and the deflation switch 2 is in a closed state. In order to achieve timely deflation of the deflated airbag 1 when a vehicle collides with a pedestrian, the distance L between the upper end surface of the piston 203 and the exhaust port 201a of the shell is equal to or slightly less than the distance H between the closest tangent point of the deflation hole 201b to the exhaust port 201a of the shell and the exhaust port 201a; refer to Figure 4 When the pressure on the deflated airbag 1 during the collision is relatively small, the distance L between the upper end surface of the piston 203 and the exhaust port 201a of the shell is greater than the distance H between the tangent point of the deflated hole 201b closest to the exhaust port 201a of the shell and the exhaust port 201a of the shell, and the upper end surface of the piston 203 is within the diameter range of the deflated hole 201b. The portion between the upper end surface of the piston 203 and the deflated hole 201b is partially open to connect the inner cavity of the deflated airbag 1 with the outside world, and the deflated switch 2 is partially open; refer to Figure 5 , Figure 5 When the maximum force that the human leg can withstand during a collision is the limit of the pedestrian injury index, the distance L between the upper end surface of the piston 203 and the outer shell exhaust port 201a is greater than the distance H between the closest tangent point of the deflation hole 201b to the outer shell exhaust port 201a and the outer shell exhaust port 201a, and the distance L between the upper end surface of the piston 203 and the outer shell exhaust port 201a is equal to the sum of the distance H and the diameter D of the deflation hole 201b. The upper end surface of the piston 203 and the deflation hole 201b are completely connected to the inner cavity of the deflation airbag 1 and the outside world, and the deflation switch 2 is fully opened; the deflation switch 2 automatically adjusts the deflation amount according to the degree of collision, that is, the different contact forces between the deflation airbag 1 and the pedestrian's legs; therefore, it is necessary to calculate the elastic coefficient of the spring 202 and the diameter of the deflation hole 201b.

[0041] According to the relationship between pressure and pressure, in the deflated airbag 1:

[0042]

[0043] Where p max F is the maximum pressure generated in the deflated airbag 1 during the collision; max The maximum force that the human leg can withstand during a collision. The EEVC\WC17 standard recommends that the limit value of the pedestrian injury index is F max ≤5KN, so in this embodiment, F is selected max =5kN;S 触 The contact area between the human leg and the deflated airbag 1 is selected in the present invention from the leg contact area in the E-NCAP pedestrian collision test, i.e. S 触 =0.02m 2 ; Therefore, F max and S 触 The value of p is calculated max The value of .

[0044] When the deflated airbag 1 can effectively protect the pedestrian, the contact time t between the human leg and the deflated airbag 1 is lim :

[0045]

[0046] Where t lim is the contact time between the human leg and the deflated airbag 1 when the deflated airbag 1 can effectively protect the pedestrian; h is the thickness of the deflated airbag 1. In this embodiment, the thickness of the deflated airbag 1 is selected in the range of 0.15 to 0.2 m; v max The maximum speed of the vehicle when the airbag 1 is inflated and can effectively protect the pedestrian is selected based on the first pedestrian protection collision test in China and the recommended test of E-NCAP. max =40km / h; therefore, according to h and v max The value of t can be calculated lim .

[0047] Maximum gas flow rate u of the vent hole 201b of the vent switch:

[0048]

[0049] Where u is the maximum gas flow rate of the vent hole 201b of the vent switch; g is the acceleration of gravity, which is 9.8m / s 2 ;p max is the maximum pressure generated in the deflated airbag 1 during the collision, which has been obtained in formula (1); therefore, the value of u can be calculated.

[0050] Diameter D of the air release hole 201b of the air release switch:

[0051]

[0052] Where S 总放 is the total cross-sectional area of ​​the deflation holes 201b of all deflation switches 2 on the deflated airbag 1, S 单排 is the cross-sectional area of ​​all the bleed holes 201b on a bleed switch 2, S 单放 is the cross-sectional area of ​​a deflation hole 201b; n is the number of all deflation switches 2 on the deflation airbag 1; m is the number of all deflation holes 201b on a deflation switch 2. In this embodiment, n=2, m=2; S 触 is the contact area between the human body and the deflated airbag 1, S 触 =0.02m 2 ;v max is the maximum speed of the vehicle when the airbag 1 is deflated and can effectively protect the pedestrian, v max =40km / h; u is the maximum gas flow rate of the vent hole 201b of the vent switch, which has been obtained in formula (3); π is the pi; therefore, the diameter D of the vent hole 201b can be calculated by formula (4).

[0053] Elastic coefficient K of the deflation switch spring 202:

[0054]

[0055] Where, K is the elastic coefficient of the deflation switch spring 202; p max is the maximum pressure generated in the deflated airbag 1 during the collision, calculated by formula (1); S 活 is the end surface area of ​​the bleed switch piston 203. Its size can be determined by the designer based on actual conditions and can be adapted to the inner cavity of the housing 201. There is no design key here. D is the diameter of the bleed hole 201b, which has been calculated using formula (4). Therefore, the elastic coefficient of the bleed switch spring 202 can be obtained.

[0056] The present invention does not involve any electrical detection or control, but is a purely mechanical structure with a simple structure and easy implementation. During a collision between a pedestrian and a vehicle, the pedestrian's legs squeeze the inflated deflated airbag 1, preventing the pedestrian's legs from directly colliding with the vehicle's more rigid bumper, thereby protecting the pedestrian's legs. When the deflation switch 2 is opened, the gas in the deflated airbag 1 is squeezed and discharged into the atmosphere through the deflation switch 2, reducing the impact force on the pedestrian's legs and protecting the pedestrian. The deflation switch 2 can automatically adjust the size of the exhaust hole opening according to the severity of the collision, ensuring that the force applied to the pedestrian's legs by the front end of the vehicle is always below the limit value of the pedestrian injury index (F≤5KN), providing effective protection for the pedestrian. The present invention provides a new method of pedestrian protection. By installing a deflated airbag 1 device to protect pedestrians on the front bumper of a vehicle, not only can pedestrians be fully protected under different conditions, but the device does not change the original structure of the vehicle, ensuring the original performance of the vehicle, and has broad prospects in practical applications.

[0057] The above content is a further detailed description of the present invention in conjunction with specific embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A vehicle-mounted deflated airbag device for protecting pedestrians, characterized in that: It comprises a deflated airbag (1) and at least one deflated switch (2) for releasing the gas in the deflated airbag (1); The deflated airbag (1) is a sealed airbag, and the deflated airbag (1) is detachably connected to the front side of the front bumper (4) of the automobile; The deflation switch (2) is arranged on the deflation airbag (1); the deflation switch (2) comprises a housing (201), a spring (202) and a piston (203); the housing (201) is a cylindrical structure with a hollow interior; one end of the housing (201) is an exhaust port (201a) connected to the inner cavity of the deflation airbag (1); the spring (202) and the piston (203) are both axially arranged in the housing (201); the piston (203) is located between the exhaust port (201a) and the spring (202) and moves axially in the housing (201); the side wall of the piston (203) and the housing (201) are connected to each other. 201); one end of the spring (202) is connected to the piston (203), and the other end of the spring (202) is connected to the other end of the housing (201); at least one venting hole (201b) for connecting the inner cavity of the housing (201) and the outside is provided on the side wall of the housing (201); when the spring (202) is in a free state, the distance between the end surface of the piston (203) close to the exhaust port (201a) and the exhaust port (201a) is less than or equal to the distance between the tangent point of the venting hole (201b) closest to the exhaust port (201a) and the exhaust port (201a); The diameter D of the vent hole (201b) satisfies the following formula: Among them, v max v is the maximum speed of the vehicle when the airbag (1) can effectively protect pedestrians. According to China's first pedestrian protection collision test and the recommended test of E-NCAP, v is selected. max =40km / h; S 触 is the leg contact area in the E-NCAP pedestrian collision test, and S is selected 触 =0.02m 2 ; u is the maximum gas flow rate of the vent hole (201b), In the formula, g is the acceleration due to gravity, which is 9.8 m / s 2 , p max is the maximum pressure generated in the deflated airbag (1) during a collision, Where F max The maximum force that the human leg can withstand during a collision. The EEVC\WC17 standard recommends that the limit value of the pedestrian injury index is 5KN. max =5KN; n is the number of deflation switches (2) on the deflation airbag (1); m is the number of deflation holes (201b) on a deflation switch (2); π is the ratio of a circle to a circle; The elastic coefficient K of the spring (202) satisfies the following formula: Among them, S 活 is the end surface area of ​​the piston (203).

2. The vehicle-mounted deflated airbag device for protecting pedestrians according to claim 1, characterized in that: When there are multiple air release holes (201b) on a air release switch (2), the center lines of the multiple air release holes (201b) are located in the same plane and the diameters of the air release holes (201b) are the same.

3. The vehicle-mounted deflated airbag device for protecting pedestrians according to claim 2, characterized in that: The plurality of air release holes (201b) are evenly distributed along the circumference of the side wall of the outer shell (201).

4. The vehicle-mounted deflated airbag device for protecting pedestrians according to any one of claims 1 to 3, characterized in that: The device also comprises an airbag outer cover (3), which is a cover structure with a hollow interior and an open side, and the open side edge portion is detachably connected to the front side of the front bumper (4) of the automobile.

5. The vehicle-mounted deflated airbag device for protecting pedestrians according to claim 4, characterized in that: The opening side edge of the airbag cover (3) is provided with a connecting ear (301), and the connecting ear (301) can be connected to the front side of the front bumper (4) of the automobile by means of bolts.

6. The vehicle-mounted deflated airbag device for protecting pedestrians according to claim 1, characterized in that: The material of the deflated airbag (1) is a high-strength TPU composite fabric.

7. The vehicle-mounted deflated airbag device for protecting pedestrians according to claim 1, characterized in that: The deflated airbag (1) is also provided with an inflation hole.

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