Pedestrian leg protection energy absorption structure, front anti-collision beam assembly and vehicle

Abstract

The invention belongs to the technical field of vehicle front anti-collision beams, and particularly relates to a pedestrian leg protection energy absorption structure, a front anti-collision beam assembly and a vehicle, the pedestrian leg protection energy absorption structure comprises an inflation and deflation pipeline assembly and an energy absorption air bag fixedly mounted on the front side face of the front anti-collision beam of the vehicle; the energy absorption air bag is in a cuboid shape and extends in the axial direction of the front anti-collision beam. The inflation and deflation pipeline assembly is communicated with an inner cavity of the energy absorption air bag, is used for inflating the inner cavity, and is also used for automatically deflating when the air pressure in the inner cavity is greater than a preset air pressure value, so that the air pressure in the inner cavity is reduced to the preset air pressure value; in the collision process, the air pressure value in the energy-absorbing air bag is always kept at the preset air pressure value, it is ensured that in the collision process of the legs of the pedestrian and the energy-absorbing air bag, the impact force borne by the legs of the pedestrian does not exceed the maximum allowable impact force of vehicle impact on the legs of the pedestrian all the time, and meanwhile the energy-absorbing efficiency of the energy-absorbing air bag is maximized; and the demand on the energy absorption arrangement space at the front end of the vehicle is reduced.

Description

Technical Field

[0001] This invention belongs to the field of vehicle front bumper beam technology, and specifically relates to a pedestrian leg protection energy absorption structure, a front bumper beam assembly, and a vehicle. Background Technology

[0002] In recent years, with increasingly busy urban traffic, collisions between cars and pedestrians have occurred frequently, making the effective protection of pedestrian safety a focus of attention for all sectors of society. As industry standards become more stringent, vehicles must meet a series of rigorous impact tests during the development phase, including different impact tests on the heads and legs of adults and children, as well as the calibration of impactors and other indicators. This has directly driven vehicle manufacturers to pay more attention to the innovation of pedestrian safety protection technologies during research and development and production.

[0003] In terms of pedestrian leg protection, existing technologies typically involve adding front bumper energy-absorbing foam or thin-walled beam energy-absorbing sheet metal to the front side of the vehicle's front bumper beam as a front-end energy-absorbing component. When a pedestrian's leg collides with the vehicle, the energy is absorbed through the crumple deformation of the front-end energy-absorbing component to achieve the corresponding leg protection effect. However, this also means that the stiffness of existing front-end energy-absorbing components usually increases with the increase of the amount of crumple deformation.

[0004] Because in the collision between the existing vehicle front energy absorber and the pedestrian's leg, the stiffness of the vehicle front energy absorber is directly proportional to the impact force on the pedestrian's leg, and the impact force on the pedestrian's leg is also directly proportional to the energy absorption efficiency of the vehicle front energy absorber (that is, the impact energy that the vehicle front energy absorber can absorb per unit crumple length); this means that during the collision, both the impact force on the pedestrian's leg and the energy absorption efficiency of the vehicle front energy absorber will gradually increase with the increase of the crumple deformation.

[0005] Meanwhile, regarding pedestrian leg protection, there are constraints such as the maximum impact force on a pedestrian's legs during a vehicle-pedestrian collision not exceeding the maximum permissible impact force on the pedestrian's legs from the vehicle impact, and the maximum energy absorption efficiency of the vehicle's front-end energy-absorbing components not exceeding the maximum permissible energy absorption efficiency corresponding to the maximum permissible impact force. Combined with the characteristic that the energy absorption efficiency of the vehicle's front-end energy-absorbing components gradually increases with the amount of crumpling deformation, existing vehicle front-end energy-absorbing components typically suffer from low energy absorption efficiency. This forces designers to increase the design thickness of the vehicle's front-end energy-absorbing components in the longitudinal direction of the vehicle. That is, the maximum impact force on a pedestrian's leg is equal to the sum of the design crumple deformation at the maximum permissible impact force and the remaining thickness of the energy-absorbing component at the front of the vehicle in the longitudinal direction after crumple. By reducing the stiffness increase caused by the energy-absorbing component at the front of the vehicle under the same crumple deformation, the permissible crumple deformation of the energy-absorbing component at the front of the vehicle is increased. This ensures that the energy-absorbing component at the front of the vehicle can completely absorb the impact kinetic energy of the pedestrian's leg before the impact force exceeds the maximum permissible impact force. This also means that existing energy-absorbing components at the front of the vehicle often have the problems of low space utilization and large space requirements for energy-absorbing components at the front of the vehicle. Summary of the Invention

[0006] This invention provides a pedestrian leg protection energy-absorbing structure, a front anti-collision beam assembly, and a vehicle, which solves the technical problems of low energy absorption efficiency, low space utilization, and large space requirements for the front energy-absorbing arrangement of vehicles that are common in existing vehicle front energy-absorbing components.

[0007] The technical solution adopted in this invention is: a pedestrian leg protection energy-absorbing structure, including an inflation / deflation pipeline assembly and an energy-absorbing airbag fixedly installed on the front side of the front anti-collision beam of a vehicle; The energy-absorbing airbag is rectangular in shape and extends along the axial direction of the front anti-collision beam. The inflation / deflation pipeline assembly is connected to the inner cavity of the energy-absorbing airbag. The inflation / deflation pipeline assembly is used to inflate the inner cavity. The inflation / deflation pipeline assembly is also used to automatically deflate when the air pressure in the inner cavity is greater than a preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0008] By configuring the energy-absorbing airbag and automatically deflating it when the air pressure in the inner cavity exceeds a preset pressure value using the inflation / deflation pipeline assembly, the air pressure in the inner cavity is reduced to the preset pressure value. This ensures that during a collision between a pedestrian's leg and the energy-absorbing airbag, the pedestrian leg protection energy-absorbing structure possesses the stiffness, energy absorption efficiency (i.e., the impact energy absorbed by the energy-absorbing airbag per unit collapse length), and the characteristic that the impact force on the pedestrian's leg does not change with the increase of collapse deformation. Therefore, the pedestrian leg protection energy-absorbing structure provided by this invention has both energy absorption efficiency and a constant impact force on the pedestrian's leg. By simply selecting an appropriate preset pressure value, it can be ensured that during a collision between the pedestrian's leg and the energy-absorbing airbag, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force from a vehicle impact, while maximizing the energy absorption efficiency of the energy-absorbing airbag. This makes the pedestrian leg protection energy-absorbing structure provided by this invention have the advantage of high energy absorption efficiency compared to existing vehicle front-end energy-absorbing components.

[0009] On the other hand, since almost all of the thickness of the energy-absorbing airbag in the longitudinal direction of the vehicle can be used for collapse energy absorption, and given that the impact kinetic energy received by the pedestrian's leg is the same, the pedestrian leg protection energy-absorbing structure provided by the present invention can significantly reduce the amount of collapse deformation that needs to be reserved compared with existing vehicle front energy-absorbing components, saving its size in the longitudinal direction of the vehicle; thus, the pedestrian leg protection energy-absorbing structure provided by the present invention also has the advantages of high space utilization and small space requirement for the front energy-absorbing arrangement of the vehicle compared with existing vehicle front energy-absorbing components.

[0010] Especially for large off-road vehicles with a high stance and short front overhang, which limits the space available for front-end energy-absorbing components, existing front-end energy-absorbing components often suffer from insufficient space, development difficulties, and reduced off-road performance due to their large space requirements. However, the pedestrian leg protection energy-absorbing structure provided by this invention has the advantage of requiring minimal front-end energy-absorbing space, making it better suited for the limited space available in large off-road vehicles. It does not occupy additional space and ensures that the off-road performance of large off-road vehicles is not affected.

[0011] Furthermore, when the air pressure inside the cavity is equal to the preset air pressure value, and the energy-absorbing airbag is not affected by other external forces, the thickness of the energy-absorbing airbag in the longitudinal direction of the vehicle is not less than the preset thickness value.

[0012] Furthermore, the preset thickness value is calculated using the following formula: Wherein, L is the preset thickness value; E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle; and F is the maximum permissible impact force of a pedestrian's leg being impacted by a vehicle.

[0013] By calculating the preset thickness value using the above formula, the energy-absorbing airbag will have sufficient collapse length when a pedestrian's leg collides with it, ensuring that all the impact kinetic energy received by the pedestrian's leg is absorbed.

[0014] The standard impact kinetic energy value and the maximum permissible impact force can both be obtained through the corresponding standard parameters in the pedestrian protection leg impact test. Since the pedestrian protection leg impact test is a conventional technology in this field, the method for determining the standard impact kinetic energy value and the maximum permissible impact force will not be described in detail in this invention.

[0015] Furthermore, when the air pressure inside the cavity is equal to the preset air pressure value, and the energy-absorbing airbag is not affected by other external forces, the width of the front side of the energy-absorbing airbag in the vertical direction of the vehicle is not greater than the preset width value.

[0016] Furthermore, the preset air pressure value and the preset width value satisfy the following constraints: Wherein, E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle; P is the preset air pressure value; H is the preset width value; and Z is the standard contact length value of a pedestrian's leg in the left-right direction of the vehicle when it is impacted by the vehicle.

[0017] By setting the aforementioned constraints, it is possible to calculate that during the collision between a pedestrian's leg and the energy-absorbing airbag, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force on the pedestrian's leg from the vehicle impact, and the preset air pressure value corresponding to the maximum energy absorption efficiency of the energy-absorbing airbag can be calculated. This maximizes the energy absorption efficiency of the energy-absorbing airbag and the space utilization rate of the pedestrian leg protection energy-absorbing structure, minimizes the size of the energy-absorbing airbag in the vehicle's longitudinal direction, and minimizes the space requirements of the pedestrian leg protection energy-absorbing structure for the energy absorption arrangement at the front of the vehicle.

[0018] The standard contact length value can be obtained through the corresponding standard parameters in the pedestrian protection leg impact test. Since the pedestrian protection leg impact test is a conventional technology in this field, the method for determining the standard contact length value will not be described in this invention.

[0019] The structure of the inflation / deflation pipeline assembly can be configured in various technical solutions, including but not limited to: In one of the technical solutions, the inflation / deflation pipeline assembly includes an inflation / deflation pipeline and a pressure regulating valve installed on the inflation / deflation pipeline; One end of the inflation / deflation pipeline is connected to the inner cavity, and the inflation / deflation pipeline is used for inflating and deflating the energy-absorbing airbag; the pressure regulating valve is used to open when inflating the inner cavity, and the pressure regulating valve is also used to open the deflation valve when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0020] In another technical solution, the inflation / deflation pipeline assembly includes an inflation nozzle and a pressure relief pipe installed on the energy-absorbing airbag, and a pressure relief valve installed on the pressure relief pipe; the inflation nozzle is used to inflate the energy-absorbing airbag, and the pressure relief pipe is used to deflate the energy-absorbing airbag. The pressure relief valve is used to open the pressure relief pipe when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0021] Furthermore, the inflation / deflation piping assembly is installed at the end of the energy-absorbing airbag.

[0022] By installing the inflation / deflation pipeline assembly at the end of the energy-absorbing airbag (including installing the inflation / deflation pipeline assembly at the left end of the energy-absorbing airbag, installing the inflation / deflation pipeline assembly at the right end of the energy-absorbing airbag, and installing a portion of the components of the inflation / deflation pipeline assembly at the left end of the energy-absorbing airbag and the remaining components at the right end of the energy-absorbing airbag, etc.), the inflation / deflation pipeline assembly can be moved away from the collision surface of the energy-absorbing airbag (i.e., the front side of the energy-absorbing airbag). When the energy-absorbing airbag collides with the pedestrian's leg, the impact of the collision on the inflation / deflation pipeline can be reduced, ensuring that the inflation / deflation pipeline can work normally during the collision. It can also avoid the inflation / deflation pipeline directly colliding with the pedestrian or secondary collision, thereby improving the safety and reliability of the pedestrian leg protection energy-absorbing structure.

[0023] Based on the pedestrian leg protection energy absorption structure provided by the present invention, the present invention also provides a front anti-collision beam assembly, including a front anti-collision beam and the pedestrian leg protection energy absorption structure provided by the present invention. The energy-absorbing airbag of the pedestrian leg protection energy-absorbing structure is fixedly installed on the front side of the front anti-collision beam.

[0024] Furthermore, the rear side of the energy-absorbing airbag is open, and the outer edge of the rear opening of the energy-absorbing airbag is bonded to the front side of the front anti-collision beam to seal the inner cavity of the energy-absorbing airbag.

[0025] The rear opening of the energy-absorbing airbag is bonded to the front side of the front bumper beam in various ways, including but not limited to: In one type of adhesive bonding, the rear opening of the energy-absorbing airbag is bonded to the front side of the front bumper beam using sealant.

[0026] In another bonding method, the energy-absorbing airbag is made of rubber, and the rear opening of the energy-absorbing airbag is bonded to the front side of the front bumper beam through a vulcanization process.

[0027] Furthermore, the outer edge of the rear opening is turned outward to form a flange, and the rear side of the flange is bonded to the front side of the front bumper beam.

[0028] By setting the flange, the bonding area between the energy-absorbing airbag and the front anti-collision beam can be increased, the bonding strength can be improved, and the structural reliability and sealing reliability of the energy-absorbing airbag can be effectively improved.

[0029] Based on the front bumper beam assembly provided by the present invention, the present invention also provides a vehicle that includes the front bumper beam assembly provided by the present invention. Attached Figure Description

[0030] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the assembly structure of the pedestrian leg protection energy-absorbing structure and the front anti-collision beam in the embodiment; Figure 2 This is a three-dimensional structural diagram of the pedestrian leg protection energy absorption structure in the embodiment; Figure 3 This is a top view schematic diagram of the pedestrian leg protection energy absorption structure in the embodiment; Figure 4 This is a front view schematic diagram of the pedestrian leg protection energy absorption structure in the embodiment; Figure 5 This is a graph showing the energy absorption characteristics of the energy-absorbing component at the front of the vehicle in the control group of the embodiment. Figure 6 This is a graph showing the energy absorption characteristics of the energy-absorbing component at the front of the vehicle in control group two of the embodiments. Figure 7 This is a graph showing the energy absorption characteristics of the pedestrian leg protection energy absorption structure in the verification group of the embodiment; Among them, 1—inflation and deflation pipeline assembly, 2—front anti-collision beam, 3—energy-absorbing airbag, 4—thigh impactor; 3.1—Upward folded edge, 3.2—Downward folded edge. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] Example 1: like Figures 1 to 4 As shown, this embodiment 1 provides a pedestrian leg protection energy absorption structure, including an inflation / deflation pipeline assembly 1 and an energy absorption airbag 3 fixedly installed on the front side of the front anti-collision beam 2 of the vehicle; The energy-absorbing airbag 3 is rectangular and extends along the axial direction of the front anti-collision beam 2. The inflation / deflation pipeline assembly 1 is connected to the inner cavity of the energy-absorbing airbag 3. The inflation / deflation pipeline assembly 1 is used to inflate the inner cavity. The inflation / deflation pipeline assembly 1 is also used to automatically deflate when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0034] By setting up an energy-absorbing airbag 3 and automatically deflating it when the air pressure in the inner cavity of the inflation / deflation pipeline assembly 1 exceeds a preset air pressure value, the air pressure in the inner cavity is reduced to the preset air pressure value. This ensures that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the pedestrian leg protection energy-absorbing structure possesses the rigidity, energy absorption efficiency (i.e., the impact energy that the energy-absorbing airbag 3 can absorb per unit collapse length), and the characteristic that the impact force on the pedestrian's leg does not change with the increase of the collapse deformation. This makes the pedestrian leg protection energy-absorbing structure provided in Embodiment 1 have the characteristics of energy absorption efficiency and constant impact force on the pedestrian's leg. By simply setting an appropriate value for the preset air pressure, it can be ensured that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force on the pedestrian's leg from the vehicle impact, while maximizing the energy absorption efficiency of the energy-absorbing airbag 3. Therefore, the pedestrian leg protection energy-absorbing structure provided by this invention has the advantage of high energy absorption efficiency compared to existing vehicle front-end energy-absorbing components.

[0035] On the other hand, since almost all of the thickness of the energy-absorbing airbag 3 in the front-rear direction of the vehicle can be used for collapse energy absorption, and given that the impact kinetic energy received by the pedestrian's leg is the same, the pedestrian leg protection energy-absorbing structure provided by the present invention can significantly reduce the amount of collapse deformation that needs to be reserved compared with the existing vehicle front energy-absorbing components, saving its size in the front-rear direction of the vehicle; thus, the pedestrian leg protection energy-absorbing structure provided by the present invention also has the advantages of high space utilization and small space requirement for the front energy-absorbing arrangement of the vehicle compared with the existing vehicle front energy-absorbing components.

[0036] Especially for large off-road vehicles with a high stance and short front overhang, which limits the space available for front-end energy-absorbing components, existing front-end energy-absorbing components often suffer from insufficient space, development difficulties, and reduced off-road performance due to their large space requirements. However, the pedestrian leg protection energy-absorbing structure provided by this invention has the advantage of requiring minimal front-end energy-absorbing space, making it better suited for the limited space available in large off-road vehicles. It does not occupy additional space and ensures that the off-road performance of large off-road vehicles is not affected.

[0037] Preferably, in this embodiment 1, when the air pressure inside the cavity is equal to the preset air pressure value and the energy-absorbing airbag 3 is not affected by other external forces, the thickness of the energy-absorbing airbag 3 in the front-rear direction of the vehicle is not less than the preset thickness value.

[0038] Specifically, in this embodiment 1, the preset thickness value is calculated using the following formula: Where L is the preset thickness value; E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle; and F is the maximum permissible impact force of a pedestrian's leg being impacted by a vehicle.

[0039] By calculating the preset thickness value using the above formula, the energy-absorbing airbag 3 will have sufficient collapse length when a pedestrian's leg collides with the energy-absorbing airbag 3, ensuring that all the impact kinetic energy received by the pedestrian's leg is absorbed.

[0040] The standard impact kinetic energy value and the maximum permissible impact force can both be obtained through the corresponding standard parameters in the pedestrian protection leg impact test. Since the pedestrian protection leg impact test is a conventional technique in this field, the method for determining the standard impact kinetic energy value and the maximum permissible impact force will not be described in this invention.

[0041] Preferably, in this embodiment 1, when the air pressure inside the cavity is equal to the preset air pressure value and the energy-absorbing airbag 3 is not affected by other external forces, the width of the front side of the energy-absorbing airbag 3 in the vertical direction of the vehicle is not greater than the preset width value.

[0042] Specifically, in this embodiment 1, the preset air pressure value and preset width value satisfy the following constraints: Where E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle; P is the preset air pressure value; H is the preset width value; and Z is the standard contact length value of a pedestrian's leg in the left-right direction of the vehicle when it is impacted by the vehicle.

[0043] By setting constraints, it is possible to calculate that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force on the pedestrian's leg from the vehicle impact, and the preset air pressure value corresponding to the maximum energy absorption efficiency of the energy-absorbing airbag 3 can be calculated. This maximizes the energy absorption efficiency of the energy-absorbing airbag 3 and the space utilization of the pedestrian leg protection energy-absorbing structure, minimizes the size of the energy-absorbing airbag 3 in the front-rear direction of the vehicle, and minimizes the space requirements of the pedestrian leg protection energy-absorbing structure for the energy absorption arrangement at the front of the vehicle.

[0044] The standard contact length value can be obtained through the corresponding standard parameters in the pedestrian protection leg impact test. Since the pedestrian protection leg impact test is a conventional technique in this field, the method for determining the standard contact length value will not be described in this invention.

[0045] The structure of the inflation / deflation pipeline assembly 1 can be configured in various technical ways, including but not limited to the two solutions described below: Option 1: The inflation / deflation pipeline assembly 1 includes an inflation / deflation pipeline and a pressure regulating valve installed on the inflation / deflation pipeline; One end of the inflation / deflation pipeline is connected to the inner cavity, and the inflation / deflation pipeline is used to inflate and deflate the energy-absorbing airbag 3; the pressure regulating valve is used to open when inflating into the inner cavity, and the pressure regulating valve is also used to open the deflation when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0046] In the above-mentioned scheme one, it is only necessary to select a pressure regulating valve with a bidirectional control structure to realize the function of allowing the medium to flow through the same pipeline during inflation and deflation on a single inlet and outlet gas pipe (i.e., inflation and deflation pipeline). Since the pressure regulating valve with a bidirectional control structure is a conventional technology in this field, the specific structure of the pressure regulating valve will not be described in detail in this invention.

[0047] Option 2: The inflation / deflation pipeline assembly 1 includes an inflation nozzle and a pressure relief pipe installed on the energy-absorbing airbag 3, and a pressure relief valve installed on the pressure relief pipe; the inflation nozzle is used to inflate the energy-absorbing airbag 3, and the pressure relief pipe is used to deflate the energy-absorbing airbag 3. The pressure relief valve is used to open the pressure relief pipe when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

[0048] Preferably, in this embodiment 1, as Figures 1 to 4 As shown, the inflation / deflation pipeline assembly 1 is installed at the end of the energy-absorbing airbag 3.

[0049] By installing the inflation / deflation pipeline assembly 1 at the end of the energy-absorbing airbag 3 (including installing the inflation / deflation pipeline assembly 1 at the left end of the energy-absorbing airbag 3, installing the inflation / deflation pipeline assembly 1 at the right end of the energy-absorbing airbag 3, and installing a portion of the components of the inflation / deflation pipeline assembly 1 at the left end of the energy-absorbing airbag 3 and the remaining components at the right end of the energy-absorbing airbag 3, etc.), the inflation / deflation pipeline assembly 1 can be kept away from the collision surface of the energy-absorbing airbag 3 (that is, the front side of the energy-absorbing airbag 3). When the energy-absorbing airbag 3 collides with the pedestrian's leg, it can reduce the impact of the collision on the inflation / deflation pipeline, ensure that the inflation / deflation pipeline can work normally during the collision, and also avoid the inflation / deflation pipeline directly colliding with the pedestrian or secondary collision, thereby improving the safety and reliability of the pedestrian leg protection energy-absorbing structure.

[0050] In one embodiment, the energy-absorbing airbag 3 is made of rubber.

[0051] To facilitate understanding, the present invention also provides a comparative test between a leg collision test based on the pedestrian leg protection energy-absorbing structure and thigh impactor provided in Embodiment 1 (hereinafter referred to as the verification group) and a leg collision test based on existing vehicle front-end energy-absorbing components and thigh impactors (hereinafter referred to as the control group) as an example to illustrate the technical effects of the present invention. The comparative test is as follows: According to the standard parameters in the leg collision test, in the control group and the verification group, the mass of the thigh impactor was 9.5 kg, the initial impact velocity of the leg was 11.1 m / s, and the maximum permissible impact force on the pedestrian's leg from the vehicle impact was 7.5 kN. Therefore, in the leg impact test, the standard impact kinetic energy value of a pedestrian's leg subjected to vehicle impact can be calculated using the following formula: Where E is the standard impact kinetic energy of the pedestrian's leg when hit by the vehicle, m is the mass of the thigh impactor, and v is the initial impact velocity of the leg.

[0052] The control group includes control group one and control group two. In control group one, the energy-absorbing component at the front of the vehicle is made of low-density foam material, while in control group two, the energy-absorbing component at the front of the vehicle is made of thin-walled beam energy-absorbing sheet metal.

[0053] Control group 1: In control group one, the energy-absorbing component at the front of the vehicle was made of low-density foam material. When the thigh impactor collided with the vehicle, the energy was absorbed by the deformation of the energy-absorbing component at the front of the vehicle to achieve the corresponding leg protection effect.

[0054] In control group one, the energy-absorbing component at the front of the vehicle uses low-density foam material, which mainly relies on its compression deformation to absorb energy. The foam has low stiffness in the early stages of compression. Based on the characteristics of foam material, its energy absorption characteristics under compression can be simplified to a triangular wave (e.g., ...). Figure 5 As shown in the diagram, under the optimal design, as the amount of crumpling deformation increases, when the impact force on the pedestrian's leg simulated by the thigh impactor increases to the maximum allowable impact force, the energy-absorbing component at the front of the vehicle just absorbs all the impact kinetic energy received by the pedestrian's leg (i.e., the standard impact kinetic energy value E of the pedestrian's leg being impacted by the vehicle). Therefore, in control group one, the standard impact kinetic energy value of the pedestrian's leg being impacted by the vehicle can also be calculated using the following formula: Where E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle, F is the maximum permissible impact force, and L1 is the design collapse deformation of the energy-absorbing component at the front of the vehicle in control group 1.

[0055] The design crumple deformation L1 of the energy-absorbing component at the front of the vehicle in control group 1 can be calculated using the above formula as 156mm. Since the energy-absorbing component at the front of the vehicle in control group 1 still needs to occupy a certain amount of additional space after the crumple deformation reaches 156mm (that is, the space occupied by the remaining thickness of the energy-absorbing component at the front of the vehicle in the longitudinal direction after the crumple), the energy absorption arrangement space requirement of the energy-absorbing component at the front of the vehicle in control group 1 is much greater than 156mm.

[0056] Control group 2: In control group one, the energy-absorbing component at the front of the vehicle uses thin-walled beam-type sheet metal, which mainly utilizes the plastic deformation of the sheet metal to absorb impact energy. Based on the energy absorption characteristics of sheet metal, its compressive energy absorption characteristics can be simplified to a sine wave (e.g., Figure 6 As shown in the diagram, under the optimal design, as the amount of crumpling deformation increases, when the impact force on the pedestrian's leg simulated by the thigh impactor increases to the maximum allowable impact force, the energy-absorbing component at the front of the vehicle just absorbs all the impact kinetic energy received by the pedestrian's leg (i.e., the standard impact kinetic energy value E of the pedestrian's leg being impacted by the vehicle). Therefore, in control group two, the standard impact kinetic energy value of the pedestrian's leg being impacted by the vehicle can also be calculated using the following formula: Where E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle, F is the maximum permissible impact force, L is the amount of collapse deformation of the energy-absorbing component at the front of the vehicle in control group 2, and L2 is the design amount of collapse deformation of the energy-absorbing component at the front of the vehicle in control group 2.

[0057] The design crumple deformation L2 of the energy-absorbing component at the front of the vehicle in control group 1 can be calculated using the above formula as 123mm. In control group 2, after the crumple deformation of the energy-absorbing component at the front of the vehicle reaches 123mm, it still needs to occupy a certain amount of additional space (that is, the space occupied by the remaining thickness of the energy-absorbing component at the front of the vehicle in the longitudinal direction after the crumple). Therefore, in control group 2, the energy absorption arrangement space requirement of the energy-absorbing component at the front of the vehicle in the longitudinal direction is much greater than 123mm.

[0058] Verification group: In the verification group, leg impact tests were conducted based on the pedestrian leg protection energy-absorbing structure provided in Example 1. Since the pedestrian leg protection energy-absorbing structure provided in Example 1 has the characteristic of a constant impact force on the pedestrian's leg, its compressive energy absorption characteristics can be expressed as a rectangular waveform (e.g., ...). Figure 7 As shown in the diagram, under the optimal design, as the amount of crumpling deformation increases, the impact force on the pedestrian's leg simulated by the thigh impactor from a vehicle impact always equals the maximum permissible impact force; therefore, in the verification group, the standard impact kinetic energy value of the pedestrian's leg under vehicle impact can also be calculated using the following formula: Where E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle, F is the maximum permissible impact force, and L3 is the designed collapse deformation of the energy-absorbing airbag of the pedestrian leg protection energy-absorbing structure in the verification group (which can be equivalent to the aforementioned preset thickness).

[0059] The design collapse deformation L3 of the energy-absorbing airbag in the pedestrian leg protection energy-absorbing structure of the verification group can be calculated using the above formula. It is 78mm. Since almost all of the thickness of the energy-absorbing airbag in the front-rear direction of the vehicle in the verification group can be used for collapse energy absorption, when designing the thickness of the energy-absorbing airbag in the front-rear direction of the vehicle (when the air pressure in the inner cavity of the energy-absorbing airbag is equal to the preset air pressure value and the energy-absorbing airbag is not affected by other external forces), the thickness of the energy-absorbing airbag in the front-rear direction of the vehicle only needs to be slightly greater than 78mm. Therefore, in the verification group, the energy absorption arrangement space requirement of the pedestrian leg protection energy-absorbing structure in the front-rear direction of the vehicle is only slightly greater than 78mm, which is much smaller than the energy absorption arrangement space requirement of the front-end energy-absorbing component in the front-rear direction of the vehicle in control group 1 and control group 2.

[0060] It should be noted that, in the verification group, the preset air pressure value was calculated using the following formula: Where E is the standard impact kinetic energy value of a pedestrian's leg being impacted by a vehicle; P is the preset air pressure value; H1 is the width of the front side of the energy-absorbing airbag in the vertical direction of the vehicle when the air pressure inside the energy-absorbing airbag in the verification group is equal to the preset air pressure value and the energy-absorbing airbag is not affected by other external forces; Z is the standard contact length value of the pedestrian's leg being impacted by the vehicle in the horizontal direction of the vehicle (that is, the width value of the thigh impactor 4 in the horizontal direction of the vehicle, such as...). Figure 4 (As shown).

[0061] By maintaining the air pressure in the energy-absorbing airbag at a preset value during the collision, the impact force on the pedestrian's leg can be kept at 7.5 kN.

[0062] It should be noted that, in the above verification group, as a preferred embodiment, the formula for calculating the preset air pressure value is used. The air pressure inside the cavity of the energy-absorbing airbag in the verification group is equal to the preset air pressure value. When the energy-absorbing airbag is not affected by other external forces, the width H1 of the front side of the energy-absorbing airbag in the vertical direction of the vehicle is equal to the aforementioned preset width value.

[0063] Example 2: like Figure 1 As shown, based on the pedestrian leg protection energy absorption structure provided in Embodiment 1, Embodiment 2 provides a front anti-collision beam assembly, including a front anti-collision beam 2 and the pedestrian leg protection energy absorption structure provided by the present invention; The energy-absorbing airbag 3 of the pedestrian leg protection energy-absorbing structure is fixedly installed on the front side of the front anti-collision beam 2.

[0064] Preferably, in this embodiment 2, the rear side of the energy-absorbing airbag 3 is open, and the outer edge of the rear open side of the energy-absorbing airbag 3 is bonded to the front side of the front anti-collision beam 2 to seal the inner cavity of the energy-absorbing airbag 3.

[0065] The rear opening of the energy-absorbing airbag 3 is bonded to the front side of the front bumper beam 2 in various ways, including but not limited to: In one type of adhesive bonding, the rear opening of the energy-absorbing airbag 3 is bonded to the front side of the front bumper beam 2 using sealant.

[0066] In another bonding method, the energy-absorbing airbag 3 is made of rubber, and the rear opening of the energy-absorbing airbag 3 is bonded to the front side of the front anti-collision beam 2 through a vulcanization process.

[0067] Preferably, in this embodiment 2, as Figure 1 and Figure 2 As shown, the outer edge of the rear opening is turned outward to form a flange, and the rear side of the flange is bonded to the front side of the front bumper beam 2.

[0068] By setting a flange, the bonding area between the energy-absorbing airbag 3 and the front anti-collision beam 2 can be increased, the bonding strength can be improved, and the structural reliability and sealing reliability of the energy-absorbing airbag 3 can be effectively improved.

[0069] The flange can be set in various ways, including but not limited to: Method 1: The flanged part is a ring-shaped flange formed by the outward turning of the outer edge of the rear opening.

[0070] Method 2: The flanged portion includes an upper flange 3.1 formed by the upper edge of the rear opening turning upward, and a lower flange 3.2 formed by the lower edge of the rear opening turning downward.

[0071] Specifically, in this embodiment 2, as follows Figure 1 , Figure 2 and Figure 4 As shown, the flange is designed using the second method described above.

[0072] Example 3: Based on the front bumper beam assembly provided in Embodiment 2, Embodiment 3 also provides a vehicle that includes the front bumper beam 2 assembly provided in Embodiment 2.

[0073] The pedestrian leg protection energy-absorbing structure, front anti-collision beam assembly, and vehicle provided by this invention have at least the following technical effects or advantages: 1. By setting up an energy-absorbing airbag 3 and utilizing the inflation / deflation pipeline assembly 1 to automatically deflate when the air pressure in the inner cavity exceeds a preset air pressure value, the air pressure in the inner cavity is reduced to the preset air pressure value. This ensures that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the pedestrian leg protection energy-absorbing structure possesses the rigidity, energy absorption efficiency (i.e., the impact energy that the energy-absorbing airbag 3 can absorb per unit collapse length), and the characteristic that the impact force on the pedestrian's leg does not change with the increase of the collapse deformation. This makes the pedestrian leg protection energy-absorbing structure provided in Embodiment 1 have the characteristics of energy absorption efficiency and constant impact force on the pedestrian's leg. By simply setting an appropriate value for the preset air pressure, it can be ensured that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force on the pedestrian's leg from the vehicle impact, while maximizing the energy absorption efficiency of the energy-absorbing airbag 3. This makes the pedestrian leg protection energy-absorbing structure provided by the present invention have the advantage of high energy absorption efficiency compared to existing vehicle front-end energy-absorbing components.

[0074] 2. On the other hand, since almost all of the thickness of the energy-absorbing airbag 3 in the front-rear direction of the vehicle can be used for collapse energy absorption, and the impact kinetic energy received by the pedestrian's leg is the same, the pedestrian leg protection energy-absorbing structure provided by the present invention can significantly reduce the amount of collapse deformation that needs to be reserved compared with the existing vehicle front energy-absorbing components, saving its size in the front-rear direction of the vehicle; thus, the pedestrian leg protection energy-absorbing structure provided by the present invention has the advantages of high space utilization and small space requirement for the front energy-absorbing arrangement of the vehicle compared with the existing vehicle front energy-absorbing components.

[0075] 3. Especially for large off-road vehicles with a high stance and short front overhang, which limits the space available for front-end energy-absorbing components, existing front-end energy-absorbing components often suffer from insufficient space, development difficulties, and reduced off-road performance due to their large space requirements. However, the pedestrian leg protection energy-absorbing structure provided by this invention has the advantage of requiring less front-end energy-absorbing space, making it more suitable for the limited front-end energy-absorbing space of large off-road vehicles. It does not occupy additional space and ensures that the off-road performance of large off-road vehicles is not affected.

[0076] 4. By setting constraints, it is possible to calculate that during the collision between the pedestrian's leg and the energy-absorbing airbag 3, the impact force on the pedestrian's leg will never exceed the maximum permissible impact force on the pedestrian's leg from the vehicle impact, and the preset air pressure value corresponding to the maximum energy absorption efficiency of the energy-absorbing airbag 3 can maximize the energy absorption efficiency of the energy-absorbing airbag 3 and the space utilization rate of the pedestrian leg protection energy-absorbing structure, minimize the size of the energy-absorbing airbag 3 in the front-rear direction of the vehicle, and minimize the space requirements of the pedestrian leg protection energy-absorbing structure for the energy absorption arrangement at the front of the vehicle.

[0077] 5. By installing the inflation / deflation pipeline assembly 1 at the end of the energy-absorbing airbag 3 (including installing the inflation / deflation pipeline assembly 1 at the left end of the energy-absorbing airbag 3, installing the inflation / deflation pipeline assembly 1 at the right end of the energy-absorbing airbag 3, and installing a portion of the components of the inflation / deflation pipeline assembly 1 at the left end of the energy-absorbing airbag 3 and the remaining components at the right end of the energy-absorbing airbag 3, etc.), the inflation / deflation pipeline assembly 1 can be kept away from the collision surface of the energy-absorbing airbag 3 (that is, the front side of the energy-absorbing airbag 3). When the energy-absorbing airbag 3 collides with the pedestrian's leg, it can reduce the impact of the collision on the inflation / deflation pipeline, ensure that the inflation / deflation pipeline can work normally during the collision, and also avoid the inflation / deflation pipeline directly colliding with the pedestrian or secondary collision, thereby improving the safety and reliability of the pedestrian leg protection energy-absorbing structure.

[0078] 6. By setting the flange, the bonding area between the energy-absorbing airbag 3 and the front anti-collision beam 2 can be increased, the bonding strength can be improved, and the structural reliability and sealing reliability of the energy-absorbing airbag 3 can be effectively improved.

[0079] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of protection of the present invention.

Claims

1. A pedestrian leg protection energy-absorbing structure, characterized in that: This includes an inflation / deflation piping assembly and an energy-absorbing airbag that is fixedly mounted on the front side of the vehicle's front bumper beam. The energy-absorbing airbag is rectangular in shape and extends along the axial direction of the front anti-collision beam. The inflation / deflation pipeline assembly is connected to the inner cavity of the energy-absorbing airbag. The inflation / deflation pipeline assembly is used to inflate the inner cavity. The inflation / deflation pipeline assembly is also used to automatically deflate when the air pressure in the inner cavity is greater than a preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

2. The pedestrian leg protection energy-absorbing structure according to claim 1, characterized in that: When the air pressure inside the cavity is equal to the preset air pressure value, and the energy-absorbing airbag is not affected by other external forces, the thickness of the energy-absorbing airbag in the longitudinal direction of the vehicle is not less than the preset thickness value.

3. The pedestrian leg protection energy-absorbing structure according to claim 1, characterized in that: When the air pressure inside the cavity is equal to the preset air pressure value, and the energy-absorbing airbag is not affected by other external forces, the width of the front side of the energy-absorbing airbag in the vertical direction of the vehicle is not greater than the preset width value.

4. The pedestrian leg protection energy-absorbing structure according to claim 1, characterized in that: The inflation / deflation pipeline assembly includes an inflation / deflation pipeline and a pressure regulating valve installed on the inflation / deflation pipeline; One end of the inflation / deflation pipeline is connected to the inner cavity, and the inflation / deflation pipeline is used for inflating and deflating the energy-absorbing airbag; the pressure regulating valve is used to open when inflating the inner cavity, and the pressure regulating valve is also used to open the deflation valve when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

5. The pedestrian leg protection energy-absorbing structure according to claim 1, characterized in that: The inflation / deflation piping assembly includes an inflation nozzle and a depressurization pipe installed on the energy-absorbing airbag, and a depressurization valve installed on the depressurization pipe; the inflation nozzle is used to inflate the energy-absorbing airbag, and the depressurization pipe is used to deflate the energy-absorbing airbag. The pressure relief valve is used to open the pressure relief pipe when the air pressure in the inner cavity is greater than the preset air pressure value, so as to reduce the air pressure in the inner cavity to the preset air pressure value.

6. The pedestrian leg protection energy-absorbing structure according to claim 1, characterized in that: The inflation / deflation piping assembly is installed at the end of the energy-absorbing airbag.

7. A front bumper beam assembly, characterized in that, Includes a front bumper beam and a pedestrian leg protection energy-absorbing structure as described in any one of claims 1-6; The energy-absorbing airbag of the pedestrian leg protection energy-absorbing structure is fixedly installed on the front side of the front anti-collision beam.

8. The front bumper beam assembly according to claim 7, characterized in that: The rear side of the energy-absorbing airbag is open, and the outer edge of the rear opening of the energy-absorbing airbag is bonded to the front side of the front anti-collision beam to seal the inner cavity of the energy-absorbing airbag.

9. The front bumper beam assembly according to claim 8, characterized in that: The outer edge of the rear opening is turned outward to form a flange, and the rear side of the flange is bonded to the front side of the front bumper beam.

10. A vehicle, characterized in that: Includes the front bumper beam assembly as described in claim 7.

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