Passenger safety system adaptable to different collision directions and method for producing same

Abstract

The application discloses a passenger safety system capable of adapting to different collision directions and a preparation method thereof. The passenger safety system comprises a damping device, a semi-enclosed cabin and a seat. The semi-enclosed cabin and the seat are adjacently distributed. The damping device is arranged between the semi-enclosed cabin and a vehicle body. The damping device comprises a viscoelastic element and a collapsible energy-absorbing element. The system can provide all-round protection for passengers. The self-adapting target of the collision direction is achieved through material performance design. The system has a simple structure. While greatly reducing the acceleration of each part of the passenger, the system reduces the motion difference between the head and the chest in the peak area. The system is highly reliable and low in cost, and solves the problem that the passenger, especially the neck, can be effectively protected in different direction collisions.

Description

Technical Field

[0001] This invention relates to an occupant safety system capable of adapting to different collision directions and its manufacturing method. Background Technology

[0002] With the widespread use of seat belts and airbags, the injury and death rate of occupants in collision accidents has been significantly reduced. However, because seat belts effectively restrain the chest and abdomen but not the neck, it inevitably leads to an increase in neck shear force Fx, neck axial force Fz, and neck bending torque My. This can easily cause injuries such as excessive flexion or extension of the neck. Frontal collisions with airbags and rear-end collisions with headrests can cause the head to rebound, generating a reverse force and flexion / extension torque in the neck. This can result in an excessively large Fz, which can easily lead to whiplash injuries. During this process, the neck is subjected to bending and extension movements. Numerous studies have shown that the human neck's ability to withstand bending is greater than its ability to withstand extension, and bending and extension are more likely to cause neck injuries.

[0003] The main reason for the rising proportion of neck injuries and fatalities in recent years is the widespread use of seat belts and front airbags, which has led to a significant decrease in injuries to other parts of the body. At the same time, the restraint of the chest has increased the difference in movement between the head and the chest, resulting in an increase in neck Fz and My. Restraining the head to reduce the difference in head and neck movement can effectively reduce neck Fz and My, but this requires an external restraint system, which is not very feasible.

[0004] Therefore, reducing the difference in movement between the head and chest and the acceleration of the chest through non-head restraint is currently the most feasible way to reduce neck injuries.

[0005] However, due to factors such as frontal and rear collisions, the presence or absence of frontal airbags and their characteristics, and the pretension and restraint force of seat belts, the mechanisms of neck injuries vary greatly. Therefore, it is necessary to develop an occupant safety system that can adapt to different collision directions for different vehicle models, in order to control the differences in chest movement and chest acceleration, reduce the peak levels of the main injury forces and moments, and achieve good protection. Summary of the Invention

[0006] The main objective of this invention is to provide an occupant safety system and its manufacturing method that can adapt to different collision directions. The buffer structure is simple and can significantly reduce the acceleration of various parts of the occupant while reducing the motion difference between the head and chest in the peak area. It solves the problem of effectively protecting occupants, especially the neck, from collisions from different directions with high reliability and low cost.

[0007] The objective of this invention can be achieved by adopting the following technical solution:

[0008] An occupant safety system capable of adapting to different collision directions is characterized by comprising a damping device, a semi-enclosed cockpit, and a seat, wherein the semi-enclosed cockpit and the seat are distributed adjacent to each other, the damping device is disposed between the semi-enclosed cockpit and the vehicle body, and the damping device comprises a viscoelastic element and a collapsible energy-absorbing element.

[0009] Preferably, both the viscoelastic element and the collapsible energy-absorbing element are ring-shaped, and the viscoelastic element is a one-piece molded structure or is composed of two half-rings.

[0010] Preferably, the semi-enclosed cockpit is an integrated rigid structure, and its shape is such that it fully covers the sides and back of a human body in a sitting posture.

[0011] Preferably, the seat includes a backrest, a seat cushion, a sliding rail, a seating posture and fore-and-aft adjustment device, and a seat belt.

[0012] A method for manufacturing an occupant safety system capable of adapting to different collision directions, the occupant safety system being applied to a vehicle with an occupant restraint system, characterized in that the manufacturing method includes the following steps:

[0013] Step 1: For specific vehicle models, analyze the peak values ​​of neck axial force Fz, neck shear force Fx, and neck bending moment My caused by the acceleration and relative displacement of various parts of the occupant during a collision. Analyze the maximum injury time and mechanical characteristics in different collision directions. By integrating the damping coefficient, elastic modulus, and size elements in the viscoelastic element in the front and rear directions, the seat rebounds at a designed rate when a collision occurs, ensuring that the seat starts to rebound or stops rebounding at a preset time.

[0014] Step 2: By matching the dynamic crumple stress-strain curves and dimensions of the collapsible energy-absorbing material in different directions with its total load-bearing mass and the acceleration curve during a standard vehicle collision, the collapsible energy-absorbing element is designed to be compatible with the material. This ensures that when the seat acceleration generated by the collision exceeds a specific value, the collapsible energy-absorbing element begins to crumple and absorb energy. Its specific crumple energy absorption rate will ensure that the adaptive energy absorption range of the viscoelastic element covers the range exceeding the standard collision speed.

[0015] Preferably, the matching design in step 2 specifically includes:

[0016] For a specific vehicle model requiring optimization, assuming a peak acceleration of the B-pillar at a standard initial collision speed of 50 km / h, and a total mass of the passenger compartment and occupants of mass m, to ensure that the viscoelastic element can function normally within the 50-90 km / h range at the preset time mentioned in step 1, the process of acceleration a from the peak acceleration region to 50 km / h is as follows:

[0017] The calculation of maximum energy at speeds between 50-90 km / h compared to 50 km / h:

[0018] E'=1 / 2m(v1 2 -v2 2 )=1 / 2×m×((90000 / 3600)2-(50000 / 3600)2)

[0019] m / s 2 = 1 / 2 × m × (625 - 192.4) m / s 2 =216.3mJ;

[0020] Calculation of critical force for crumple deformation: F = ma, where a is the peak acceleration of the B-pillar of the car body at a collision speed of 50 km / h;

[0021] Based on the calculation results, the critical yield strength is selected as F. 1 The energy absorption coefficient is K (J / cm). 3 The minimum volume V of the energy-absorbing material required as a collapsible and deformable energy-absorbing element, which possesses approximately constant stress characteristics, is:

[0022] V = E' / K;

[0023] Finally, based on V, the margin was appropriately increased, and the shape and size of the energy-absorbing material were designed in combination with the vehicle's seating arrangement.

[0024] According to the method for manufacturing an occupant safety system capable of adapting to different collision directions as described in claim 5, the matching design in step 1 specifically includes:

[0025] Step 1.1: For forward collisions, the forward semi-ring of the viscoelastic element is matched and optimized. For the standard forward collision conditions of the specific vehicle model to be optimized, the starting point of the occupant's head rebound is defined as point A. The forward semi-ring of the viscoelastic element is matched and optimized so that the seat rebound point coincides with point A, so as to ensure that after point A, the seat and the occupant's head move backward synchronously.

[0026] Step 1.2: For rear-end collisions, the rearward semi-ring of the viscoelastic element is matched and optimized. For the standard rear-end collision conditions of the specific vehicle model to be optimized, the point when the occupant's head contacts the headrest is determined as point B. The rearward semi-ring of the viscoelastic element is matched and optimized through calculation to control the rebound start point of the seat to be consistent with point B, so that the forward rebound displacement of the seat can offset the forward displacement of the head, thereby reducing the whiplash effect injury to the neck.

[0027] Beneficial technical effects of the present invention:

[0028] 1. The system can provide all-round protection for occupants and achieve the goal of adaptive collision direction through material performance design. The structure is simple. While significantly reducing the acceleration of various parts of the occupant, it reduces the difference in motion between the head and chest in the peak area. It solves the problem of effectively protecting occupants, especially the neck, from collisions in different directions with high reliability and low cost.

[0029] 2. With viscoelastic and collapsible energy-absorbing elements of the same energy absorption capacity, the secondary energy absorption protection effect of the cabin will be several times better than the overall energy absorption protection effect of the vehicle body; it provides systematic occupant protection with almost no blind spots, adapting to collision and crushing accident conditions in various directions; it does not collapse or deform in low-speed collisions, and there is no need to replace the energy-absorbing elements after the collision, resulting in low maintenance costs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the neck elongation bending moment simulation curve according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the quasi-static compressive stress-strain curve of aluminum foam according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the dynamic compressive stress-strain curve of aluminum foam according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of a security system according to an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the neck elongation bending moment simulation according to an embodiment of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to understand the technical solution of the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0036] like Figure 4 As shown, the occupant safety system provided in this embodiment, which can adapt to different collision directions, includes a damping device, a semi-enclosed cockpit 3, and a seat 4. The semi-enclosed cockpit 3 and the seat 4 are distributed adjacently, specifically with the seat inside the semi-enclosed cockpit 3. The seat 4 can be laid flat. The damping device is set between the semi-enclosed cockpit and the vehicle body to provide a good buffering effect. The damping device 2 includes a viscoelastic element 21 and a collapsible energy-absorbing element 22, wherein the viscoelastic element 21 and the collapsible energy-absorbing element 22 are distributed inside and outside, and the collapsible energy-absorbing element 22 is fitted around the outer ring of the viscoelastic element 21. The damping device 2 has four sets, and they are distributed in a rectangular array.

[0037] A method for manufacturing an occupant safety system capable of adapting to different collision directions, including...

[0038] Step 1: For specific vehicle models, analyze the peak values ​​of three injury indicators—cervical axial force Fz, cervical shear force Fx, and cervical bending moment My—caused by the acceleration and relative displacement of various parts of the occupant during a collision, and analyze the maximum injury time and mechanical characteristics in different collision directions.

[0039] By integrating the damping coefficient, elastic modulus and size of the viscoelastic element 21 in the front and rear directions (matching design), the seat rebounds at a designed rate when a collision occurs, ensuring that the seat starts to rebound or stops rebounding at a preset time.

[0040] The damping coefficient A, elastic modulus B, and size C of the viscoelastic element 21 in the front and rear directions are matched (integrated design) with the occupant restraint system on the vehicle and the curves of acceleration of various parts of the occupant, axial force (tension) Fz of the neck, shear force Fx of the neck, and bending moment My of the neck during the standard collision. This ensures that the system adaptively controls the seat 4 to rebound at a designed rate when a collision occurs, ensuring that the rebound begins or ends at a specific time. When the vehicle is involved in frontal or side collisions within the standard collision test speed range, the relative velocity or displacement between the head and chest is controlled to be minimized before the peak of My or Fz of the maximum neck injury factor My or Fz, in order to further reduce the main injury index My or Fz and mitigate occupant injury (i.e., significantly reduce injury index, especially peak injury index). The acceleration of various parts of the occupant during the standard vehicle collision includes chest acceleration and head acceleration. The standard vehicle collision speed is 50 km / h for frontal collision, 64 km / h for offset collision, and 55 km / h for side collision.

[0041] The collapsible deformable energy-absorbing element 22 (porous collapsible deformable energy-absorbing element) is designed to match the dynamic collapsible stress-strain curves and dimensions of the collapsible deformable energy-absorbing material in different directions with its total load-bearing mass and the acceleration curve during a vehicle test standard collision.

[0042] When the acceleration of seat 4 caused by the collision exceeds a certain value (such as exceeding 50km / h), the collapsible energy-absorbing element 22 begins to collapse and absorb energy. Its specific (self-)collapse energy absorption rate will ensure that the adaptive function of the viscoelastic element (when the speed exceeds a certain range, the viscoelastic element's energy absorption capacity is insufficient, and the originally designed rebound point cannot be guaranteed, so the effect of reducing the difference in movement between the head and chest in the peak area cannot be guaranteed) can basically cover the range exceeding the standard collision speed. When the vehicle is involved in a collision in any direction, the damping device 2, in addition to absorbing energy and greatly reducing the force on various parts of the occupants, also adaptively optimizes the elements most likely to cause neck injuries. The semi-enclosed cabin 3 can limit the lateral displacement of various parts of the occupants' bodies, especially the head, to prevent secondary collision injuries during a side collision. At the same time, it can also prevent intrusion injuries other than those from the front. When the vehicle is crushed and deformed, the semi-enclosed cabin 3 will also provide the occupants with sufficient survival space.

[0043] In this embodiment, the semi-enclosed cockpit 3 is an integrated high-strength rigid structure. Its shape is a full-coverage form of the human body in a sitting posture, covering the sides and back. It is made of high-strength sheet material and reinforced structure. All parts of the cockpit that can be touched by the occupants are wrapped with elastic damping material. Combined with the airbags already installed in the vehicle, it can achieve 360° protection against compression, lateral displacement and intrusion of the occupants.

[0044] In this embodiment, the seat 4 includes the basic structures of a car seat, including but not limited to the backrest, seat cushion, sliding rail, posture and fore-and-aft adjustment device, seat belt, etc., and is fixed to the safety cabin through bottom connection. The semi-enclosed cabin 3 is connected and fixed to the damping device 2.

[0045] In this embodiment, the viscoelastic element 21 and the collapsible energy-absorbing element 22 in the damping device 2 can be circular or other shapes. Their energy absorption is designed symmetrically along the X-axis and can be integrally formed or assembled by splicing.

[0046] In this embodiment, the viscoelastic element 21 is a metal rubber component, which is composed of two semi-circular rings distributed in a front-to-back manner, and can form a complete ring structure.

[0047] The collapsible and deformable energy-absorbing element 22 is made of aluminum foam and has a complete circular ring structure.

[0048] In this embodiment, for a certain brand of small SUV, the My value in a forward collision exceeded the standard, and the starting point of the rebound of the occupant's head after contact with the airbag was 85ms. Based on this, the forward semi-circular ring of the viscoelastic element 21 was matched and optimized, and its rebound starting point was controlled at 85ms through integral calculation. This ensures that before this point, the seat, chest, and head all move forward, and after the 85ms point, the neck and seat simultaneously begin to move backward. A simulated collision test was conducted according to GB11551. The simulation results show that the neck My value decreased from 60.5Nm to 39Nm. The simulated neck elongation bending moment curve is shown in [Figure showing the curve]. Figure 1 The solid line represents the curve before the improvement, and the dashed line represents the curve after the improvement.

[0049] In this embodiment, the static and dynamic stress-strain curves of aluminum foam show that aluminum foam has a relatively high and wide stress plateau throughout the deformation process, and its energy absorption process exhibits approximately constant stress characteristics. Furthermore, the energy absorption capacity of aluminum foam is between 30J and 68J / cm². 3 With a wide range of options, it becomes possible to design and control the attenuation of the acceleration of any high-speed collision reaching seat 4 to a level close to 50 km / h.

[0050] In this embodiment, the peak acceleration α of the B-pillar of the vehicle body at an initial velocity of 50 km / h is 0.45 mm / sq.m², and the total mass m of the cabin and occupants is 80 kg. To ensure that the viscoelastic element can function normally within the range of 50-90 km / h at the preset time in step 1, the matching design process from the peak acceleration region of the vehicle body to the 50 km / h horizontal body is as follows:

[0051] The calculation of maximum energy at speeds between 50-90 km / h compared to 50 km / h:

[0052] E'=1 / 2m(v1 2 -v2 2 )=1 / 2×80kg×((90000 / 3600)2-(50000 / 3600)2)

[0053] m / s 2 =17304J;

[0054] Calculation of critical force for crumple deformation: F=ma=80kg×0.45×1000=36000N, where a is the peak acceleration of the B-pillar of the car body at a collision speed of 50km / h;

[0055] Based on the calculation results, the critical yield strength is selected as F. 1 The energy absorption coefficient is K (J / cm). 3Furthermore, the minimum volume V of the energy-absorbing material required for collapsible and deformable energy-absorbing elements, which has approximately constant stress characteristics, is E, / K.

[0056] Finally, based on V, the margin was appropriately increased and the shape and size of the energy-absorbing material were designed in combination with the vehicle's seating arrangement.

[0057] Structural calculations: Each seat is designed with four porous collapsible energy-absorbing elements (collapsible energy-absorbing element 22). F / 4 = 36000N / 4 = 9000N, determining the critical yield strength as 9000N. Based on the vehicle model and the structural characteristics of the safety cabin, simulation calculations were performed. A ring-shaped structure with an outer diameter of 20cm, an inner diameter of 10cm, and a thickness of 3.3cm was ultimately selected, with an energy absorption coefficient of 9.7J / cm². 3 The best foamed aluminum material is (see Table 3).

[0058] Outer diameter (cm) Inner diameter(cm) Thickness (cm) <![CDATA[Energy absorption coefficient J / cm 3 > result 20 10 3.3 9.7 excellent 18 9 3 10 Slightly better 22 12 3.5 9 Slightly better

[0059] —Table 3;

[0060] In this embodiment, for a certain brand of small SUV model, in the standard crash test with an initial speed of 20km / h, the upper neck elongation bending moment My reached 46Nm, which exceeded the maximum allowable value of 40Nm and did not meet the regulatory requirements. The neck elongation bending moment curve collected and calculated through the test is shown in the red part of the figure.

[0061] By optimizing the matching of the viscoelastic element 21 to the rearward semi-circular ring, analysis showed that the peak torque My occurs 15 milliseconds after the head rebounds from the headrest. During this process, the head rebounds forward, creating a significant displacement with the seat and chest. The seat's rebound initiation point was calculated to begin 90 milliseconds after contact with the headrest, using the seat's rebound displacement to offset the head's forward displacement. A simulated crash test was conducted according to GB11551. Simulation results showed that the neck torque My decreased from 46 Nm to 24 Nm. The simulated neck elongation moment curve is shown below. Figure 5 The solid line represents the curve before improvement, and the dashed line represents the curve after improvement. The optimization of the collapsible energy-absorbing element 22 is basically the same as that of 21, and will not be described in detail.

[0062] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing an occupant safety system capable of adapting to different collision directions, the occupant safety system being applied to a vehicle with an occupant restraint system, the occupant safety system comprising a damping device, a semi-enclosed cabin and a seat, wherein the semi-enclosed cabin and the seat are distributed adjacent to each other, the damping device being disposed between the semi-enclosed cabin and the vehicle body, the damping device comprising a viscoelastic element and a collapsible energy-absorbing element; Both the viscoelastic element and the collapsible energy-absorbing element are ring-shaped, and the viscoelastic element is composed of two semi-rings. Its features are: The preparation method includes the following steps: Step 1: For specific vehicle models, analyze the peak values ​​of neck axial force Fz, neck shear force Fx, and neck bending moment My caused by the acceleration and relative displacement of various parts of the occupant during a collision. Analyze the maximum injury time and mechanical characteristics in different collision directions. By integrating the damping coefficient, elastic modulus, and size elements in the viscoelastic element in the front and rear directions, the seat rebounds at a designed rate when a collision occurs, ensuring that the seat starts to rebound or stops rebounding at a preset time. Step 2: By analyzing the dynamic crumple stress-strain curves and dimensions of the collapsible energy-absorbing material in different directions, along with its total load-bearing mass and the acceleration curve during a standard vehicle crash, a matching design is made for the collapsible energy-absorbing element. This ensures that when the seat acceleration generated by the collision exceeds... When the value exceeds a certain threshold, the collapsible energy-absorbing element begins to collapse and absorb energy. Its specific collapse energy absorption rate will ensure that the adaptive energy absorption range of the viscoelastic element covers the range exceeding the standard collision speed. The matching design in step 1 specifically involves: Step 1.1: Optimize the matching of the forward semi-ring of the viscoelastic element for forward collisions. For the standard forward collision conditions of the specific vehicle model requiring optimization, define the occupant head rebound threshold. The starting point is point A. The forward semi-ring of the viscoelastic element is matched and optimized so that the seat rebound point coincides with point A, so as to ensure that after point A, the seat and the occupant's head move backward synchronously. Step 1.2: For rear-end collisions, the rearward semi-ring of the viscoelastic element is matched and optimized. For the standard rear-end collision conditions of the specific vehicle model to be optimized, the point when the occupant's head contacts the headrest is determined as point B. The rearward semi-ring of the viscoelastic element is matched and optimized through calculation to control the rebound start point of the seat to be consistent with point B, so that the forward rebound displacement of the seat can offset the forward displacement of the head, thereby reducing the whiplash effect injury to the neck.

2. The method for manufacturing an occupant safety system capable of adapting to different collision directions according to claim 1, characterized in that: The semi-enclosed cockpit is an integrated rigid structure, and its shape is designed to fully enclose the side and back of a human body in a sitting posture.

3. The method for manufacturing an occupant safety system capable of adapting to different collision directions according to claim 1, characterized in that: The seat includes a backrest, seat cushion, sliding rails, posture and fore-and-aft adjustment devices, and a seat belt.

4. The method for manufacturing an occupant safety system capable of adapting to different collision directions according to claim 1, characterized in that; The matching design in step 2 specifically involves: For a specific vehicle model requiring optimization, assuming a peak acceleration of the B-pillar at a standard initial collision speed of 50 km / h, and a total mass of the passenger compartment and occupants of mass m, to ensure the viscoelastic element's function of starting or ending rebound at the preset time described in step 1 can operate normally within the range of 50-90 km / h, the process of the acceleration a from the peak acceleration region to 50 km / h is as follows: The calculation of maximum energy at speeds between 50-90 km / h compared to 50 km / h: ； The critical force for crumple deformation is calculated as F=ma, where a is the peak acceleration of the B-pillar of the car body at a collision speed of 50km / h. Based on the calculation results, the critical yield strength is selected as F. 1 A material with an energy absorption coefficient of K (J / cm³) and approximately constant stress characteristics is used as a collapsible energy-absorbing element. The minimum volume V of the required energy-absorbing material is: V=E' / K; Finally, based on V, the margin was appropriately increased, and the shape and size of the energy-absorbing material were designed in combination with the vehicle's seating arrangement.

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