CN115923621A - Occupant safety system capable of adapting to different collision directions and preparation method thereof - Google Patents

Abstract

The invention discloses a passenger safety system capable of adapting to different collision directions and a preparation method thereof. The system can provide all-round protection for passengers, and reaches the self-adaptation target of collision direction through material performance design, simple structure, reduces the motion difference between the head and the chest of a peak region while greatly reducing the acceleration of each part of the passengers, and solves the problem of injury of the passengers, particularly the neck, effectively in collision in different directions with high reliability and low cost.

Description

Occupant safety system capable of adapting to different collision directions and preparation method thereof

Technical Field

The invention relates to an occupant safety system capable of adapting to different collision directions and a preparation method thereof.

Background

With the large-scale application of the safety belt and the air bag, the casualty rate of passengers in a collision accident is greatly reduced, but because the safety belt effectively restrains the chest and abdomen and does not restrain the neck, the increase of the neck shearing force Fx, the neck axial force Fz and the neck bending torque My is inevitably caused, the injuries such as neck over-bending or over-bending and the like are easily generated, the neck is generated reverse force and bending torque due to the head rebound when the front side touches the air bag and the rear-end collision touches the headrest, the Fz is too large, the neck injury and whiplash injury is easily generated, the neck bears the bending and stretching movement in the process, and a large number of researches show that the capability of the human neck for bearing the bending is greater than the capability of the stretching, and the neck is more easily damaged due to the stretching and bending.

The main reason why the proportion of collision injuries and deaths of the neck is rising in recent years is that the popularization of safety belts and front safety airbags causes that injuries of other parts are greatly reduced, meanwhile, the motion difference between the head and the chest is increased due to the restraint of the chest, so that the neck Fz and the neck My are increased, the motion difference between the head and the chest is reduced by restraining the head, the neck Fz and the neck My can be effectively reduced, but an external restraint system is required, and the feasibility is not high;

reducing motion differences between the head and chest accelerations through non-head restraints is currently the most feasible way to reduce neck injuries.

However, due to the characteristics of the front safety airbag and the airbag in the front collision and the rear collision, the neck injury mechanism and the difference are very large due to the factors such as the pretightening force and the restraining force of the safety belt, and the like, a passenger safety system which can adapt to different collision directions is developed for different vehicle types to control the motion difference and the chest acceleration between chests, reduce the peak level of main injury acting force and moment, and obtain good protection effect.

Disclosure of Invention

The invention mainly aims to provide a passenger safety system capable of adapting to different collision directions and a preparation method thereof, wherein the passenger safety system is simple in buffering structure, greatly reduces the acceleration of each part of a passenger, reduces the motion difference between the head and the chest of a peak region, and solves the problem of effectively protecting the passenger, particularly the neck, from the collision in different directions with high reliability and low cost.

The purpose of the invention can be achieved by adopting the following technical scheme:

an occupant safety system capable of accommodating different crash directions, characterized by: the damping device comprises a viscoelastic element and a collapsible deformation energy-absorbing element.

Preferably, the viscoelastic element and the collapsible deformation energy-absorbing element are both in an annular structure, and the viscoelastic element is in an integrally formed structure or consists of two half rings.

Preferably, the semi-covered cabin is of an integrated rigid structure, and the shape of the semi-covered cabin is a fully covered shape of the side and the back of a sitting posture of a human body.

Preferably, the seat comprises a backrest, a seat cushion, a movable sliding rail, a sitting posture and front-back adjusting device and a safety belt.

A method of preparing an occupant safety system adaptable to different crash directions for use in an automobile having a occupant restraint system, comprising: the preparation method comprises the following steps

Step 1, analyzing maximum damage time points and mechanical characteristics of different collision directions aiming at damage index peak conditions of a neck axial force Fz, a neck shearing force Fx and a neck bending moment My caused by acceleration and relative displacement of each part of a passenger during collision of a specific vehicle model, and enabling a seat to rebound at a designed speed when collision occurs through fusion design of damping coefficients, elastic modulus and size elements in front and rear directions in a viscoelastic element, so as to ensure that the seat starts to rebound or finishes rebounding at a preset time;

and 2, matching design is carried out on the crushable deformation energy-absorbing element by dynamic crushing stress-strain curves and sizes of the crushable deformation energy-absorbing material in different directions, the total bearing mass of the crushable deformation energy-absorbing material and an acceleration curve during vehicle test standard collision, so that when the seat acceleration generated by collision exceeds a specific value, the crushable deformation energy-absorbing element starts to generate crushing deformation and absorb energy, and the specific crushing energy-absorbing speed ensures that the self-adaptive energy-absorbing range of the viscoelastic element covers the range of the standard collision speed.

Preferably, the matching design in step 2 specifically includes:

aiming at a specific vehicle type needing to be optimized, the peak value of the acceleration of a B column of a vehicle body of an automobile when the standard initial collision speed is 50km/h collision is set as a, the total mass of a cabin and members is set as m, and in order to ensure that the function of starting or finishing rebounding of a viscoelastic element at the preset time in the step 1 can normally work within the range of 50-90km/h, the process of the acceleration a from the peak value area of the vehicle body acceleration to 50km/h is as follows:

calculating the maximum energy in the vehicle speed range of 50-90km/h compared with 50 km/h:

E’＝1/2m(v ₁ ² -v ₂ ² )＝1/2×m×((90000/3600)2-(50000/3600)2)

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

calculating the collapse deformation critical force: f = ma, wherein a is the acceleration peak value of the B column of the automobile body at the time of 50km/h collision;

selecting the critical yield force F according to the calculation result ¹ The energy absorption coefficient is K (J/cm) ³ ) And the material with the characteristic of approximate constant stress is used as a collapsible deformation energy-absorbing element, and the minimum volume V of the required energy-absorbing material is as follows:

V＝E’/K；

finally, the allowance is properly enlarged on the basis of the V, and the shape and the size of the energy absorption material are designed according to the arrangement condition of the vehicle seat.

The method for manufacturing an occupant safety system capable of adapting to different collision directions according to claim 5, wherein the matching design in step 1 is specifically as follows:

step 1.1, matching and optimizing a forward half ring of a viscoelastic element for forward collision, defining the initial time point of rebound of the head of a passenger as a time point A for the standard forward collision working condition of a specific vehicle type to be optimized, and matching and optimizing the forward half ring of the viscoelastic element to ensure that the rebound time point of a seat is overlapped with the time point A so as to ensure that the seat and the head of the passenger synchronously move backwards after the time point A;

step 1.2, the backward half ring of the viscoelastic element is optimized in a matching mode aiming at backward rear-end collision, the time point when the head of a passenger contacts a headrest is determined as a time point B aiming at the standard rear-end collision working condition of a specific vehicle type to be optimized, the backward half ring of the viscoelastic element is optimized in a matching mode through calculation, the rebound starting time point of the seat is controlled to be consistent with the time point B, forward displacement of the head is offset by forward rebound displacement of the seat, and the damage of whiplash effect to the neck is reduced.

The invention has the beneficial technical effects that:

1. the system can provide all-round protection for passengers, and reaches the self-adaptation target of collision direction through material performance design, simple structure, reduces the motion difference between the head and the chest of a peak region while greatly reducing the acceleration of each part of the passengers, and solves the problem of injury of the passengers, particularly the neck, effectively in collision in different directions with high reliability and low cost.

2. The secondary energy absorption protection effect of the cabin is improved by a plurality of times compared with the integral energy absorption protection effect of the vehicle body; the system almost has no dead angle, and is suitable for collision and extrusion accident conditions in various directions; the low-speed collision does not generate collapse deformation, the energy absorption element does not need to be replaced after the collision, and the maintenance cost is low.

Drawings

FIG. 1 is a schematic view of a simulated bending moment of neck extension according to an embodiment of the present invention;

FIG. 2 is a graph illustrating a quasi-static compressive stress-strain curve of an aluminum foam according to an embodiment of the present invention;

FIG. 3 is a graphical representation of a dynamic compressive stress-strain curve for an aluminum foam in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a security system according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a simulated curve of neck stretching bending moment according to an embodiment of the present invention

Detailed Description

In order to make the technical solutions of the present invention more clear and definite for those skilled in the art, the present invention is further described in detail below with reference to the examples and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in fig. 4, the passenger safety system capable of adapting to different collision directions provided by this embodiment includes a damping device, a half-covered cabin 3 and seats 4, where the half-covered cabin 3 and the seats 4 are distributed adjacently, specifically, the seats are located inside the half-covered cabin 3, and can perform operations such as leveling on the seats 4, the damping device is disposed between the half-covered cabin and the vehicle body to play a good role in buffering, the damping device 2 includes a viscoelastic element 21 and a crushable deformation energy-absorbing element 22, where the viscoelastic element 21 and the crushable deformation energy-absorbing element 22 are distributed inside and outside, the crushable deformation energy-absorbing element 22 is sleeved on an outer ring of the viscoelastic element 21, and the damping device 2 is provided with four groups, and they are distributed in a rectangular array.

A method for preparing the passenger safety system able to adapt to different collision directions includes

Step 1, analyzing maximum damage time points and mechanical characteristics in different collision directions according to three damage index peak conditions of a neck axial force Fz, a neck shearing force Fx, a neck bending moment My and the like caused by acceleration and relative displacement of each part of a passenger during collision of a specific vehicle type;

by performing fusion design (matching design) on damping coefficients, elastic moduli and sizes in the front and rear directions of the viscoelastic element 21, the seat rebounds at a designed rate when a collision occurs, and the seat is ensured to rebound at a preset time or end;

the damping coefficients A, the elastic modulus B and the size C in the front and rear directions in the viscoelastic element 21 are respectively matched with the acceleration, the neck axial force (tension) Fz, the neck shearing force Fx and the curve of the neck bending moment My of each part of an occupant of an automobile in a standard collision of the automobile (fusion design), so that the system is ensured to control the seat 4 to rebound at a designed speed in a self-adaptive mode when the collision occurs, and the rebound is ensured to start or end at a specific time, so that when the automobile collides in different directions such as the front surface and the side surface in a standard collision test speed range, the relative speed or displacement between the head and the chest is controlled to be minimum before the My or Fz peak value of the maximum neck injury factor comes, the main injury index of My or Fz is further reduced, the injury of the occupant is reduced (namely, the injury index is greatly reduced, particularly the peak injury index) aiming at the peak value of the maximum injury factor My or Fz of the neck, and the acceleration of each part of the occupant includes the chest and the head acceleration when the automobile in the standard collision: frontal crash speed per hour is 50 (kilometer, offset crash speed per hour is 64 kilometers, side crash speed per hour is 55 kilometers;

the collapsible deformation energy-absorbing element 22 (porous collapsible deformation energy-absorbing element) is designed by matching the dynamic collapse stress-strain curves and sizes of the collapsible deformation energy-absorbing material in different directions with the total bearing mass and the acceleration curve of the vehicle during the test standard collision;

when the acceleration of the seat 4 generated by collision exceeds a specific value (such as exceeding 50 km/h), the energy-absorbing element 22 starts to generate collapse deformation to absorb energy, and the collapse energy-absorbing rate of the specific (self) thereof ensures that the self-adaptive function of the viscoelastic element (when the speed exceeds a certain range, the energy-absorbing capacity of the viscoelastic element is insufficient, and when the speed exceeds a certain range, the self-adaptive function of the viscoelastic element cannot ensure the rebound time point of the original design, and the motion difference effect between the head and the chest in the peak area cannot be ensured), can basically cover the range exceeding the standard collision speed, when the vehicle collides in any direction, the damping device 2 absorbs energy, greatly reduces the stress of each part of the passenger, also carries out self-adaptive optimization on the elements most easily causing neck injury, when the side face collision occurs, the semi-covered cabin 3 can limit the side movement of each part of the body of the passenger, particularly the head of the passenger so as to prevent the secondary collision injury, and simultaneously, when the vehicle is extruded and deformed, the semi-covered cabin 3 also provides enough living space for the passenger.

In this embodiment, the half-covered cabin 3 is an integral high-strength rigid structure, the shape of which is a full-covering shape of the side and back of a sitting posture of a human body, and is made of a high-strength sheet material and a reinforcing structure, and the contactable part of passengers in the cabin is covered with an elastic damping material, so that extrusion, lateral movement and intrusion protection of the passengers without dead angles of 360 degrees can be realized by combining an airbag assembled on a vehicle.

In the present embodiment, the seat 4 includes various basic structures of a car seat, including but not limited to a backrest, a seat cushion, a movable slide rail, a sitting posture and forward and backward adjusting device, a safety belt, etc., and is fixed on the safety cabin through a bottom connection, and the semi-enclosed cabin 3 is fixed with the damping device 2.

In this embodiment, the viscoelastic element 21 and the crushable energy absorber 22 in the damping device 2 may be circular or other shapes, and the energy absorption mechanics are designed along the X axis, and may be integrally formed or assembled by splicing.

In this embodiment, the viscoelastic element 21 is a metal rubber member, which is composed of two semicircular rings disposed adjacently in front and back, and can form a complete circular ring structure;

the crushable energy absorber element 22 is a foam aluminum member that is a complete circular ring structure.

In the embodiment, for a certain brand of small SUV, the forward collision My exceeds the standard, and the initial point of contact rebound between the head of the occupant and the airbag is 85ms, the forward semicircular ring of the viscoelastic element 21 is optimized in a matching manner, the initial point of rebound is controlled to be 85ms through integral calculation, so that the front seat, the chest and the head move forward at the time, the neck and the seat start to move backward at the same time after the point of passing 85ms, a simulation collision test is performed according to the specification of GB11551, and the simulation result shows that the neck My is reduced from 60.5Nm to 39Nm, the neck stretching bending moment simulation curve is shown in fig. 1, the solid curve line is the curve before improvement, and the dotted line is the curve of the test after improvement.

In this embodiment, it can be seen from the static and dynamic stress-strain curves of the foamed aluminum that the foamed aluminum has a relatively high and wide stress plateau during the whole deformation process, the energy absorption process has an approximately constant stress characteristic, and the energy absorption capability of the foamed aluminum material is 30J-68J/cm ³ A wide range of options is available which allows the acceleration of any high speed crash reaching seat 4 within a certain range to be damped to a level approaching 50km/h, to be designed and controlled.

In the embodiment, the peak value of the acceleration a of the column B of the vehicle body at the collision initial speed of 50km/h is 0.45 mm/square millisecond, the total mass m of the cabin and the members is 80kg, and in order to ensure that the function of starting or finishing rebound of the viscoelastic element at the preset time in the step 1 can normally work in the range of 50-90km/h, the matching design process from the peak value area of the acceleration of the vehicle body to the level of 50km/h is as follows:

calculating the maximum energy in the vehicle speed range of 50-90km/h compared with 50 km/h:

E’＝1/2m(v ₁ ² -v ₂ ² )＝1/2×80kg×((90000/3600)2-(50000/3600)2)

m/s ² ＝17304J；

calculating the collapse deformation critical force: f = ma =80kg × 0.45 × 1000=36000N, wherein a is a peak value of the acceleration of the B column of the automobile body at the time of 50km/h collision;

selecting the critical yield force F according to the calculation result ¹ The energy absorption coefficient is K (J/cm) ³ ) And the foamed aluminum material with the approximate constant stress characteristic is used as a collapsible deformation energy-absorbing element, and the minimum volume V of the required energy-absorbing material is as follows: E,/K;

finally, properly enlarging allowance on the basis of V and designing the shape and size of the energy absorbing material by combining the arrangement condition of the vehicle seat;

and (3) structural calculation: each seat is designed according to 4 porous collapsible deformation energy-absorbing elements (collapsible deformation energy-absorbing elements 22), F/4=36000N/4=9000N, the critical yield force is determined to be 9000N, simulation calculation is carried out according to the structural characteristics of the vehicle model and the safety cabin, finally, an annular structure with the size of 20 cm in outer diameter and 10 cm in inner diameter and 3.3 cm in thickness is selected, and the energy-absorbing coefficient is 9.7J/cm ³ The foamed aluminum material of (c) is the most preferred (see table 3).

Outer diameter (cm)	Inner diameter (cm)	Thickness (cm)	Energy absorption coefficient J/cm 3	Results
					20	10	3.3	9.7	Superior food
18	9	3	10	Slightly superior
					22	12	3.5	9	Slightly superior

-table 3;

in the embodiment, aiming at a certain brand of small SUV vehicle, in a standard collision touchdown test with an initial speed of 20km/h, the upper neck stretching bending moment My reaches 46Nm, exceeds the maximum value 40Nm allowed by the regulation, does not meet the regulation requirement, and is collected through the test and calculated, and the neck stretching bending moment curve is shown in a red part in a graph;

through carrying out matching optimization on the backward semicircular ring of the viscoelastic element 21, analyzing that the peak torque of the My occurs 15 milliseconds at the contact rebound point of the head and the headrest, the rebound of the head forwards and the seat and the chest form larger displacement in the process, and through calculating and controlling the rebound starting point of the seat to begin to rebound at the contact point of the headrest for 90 milliseconds, the forward displacement of the head is counteracted by the rebound displacement of the seat, a simulation collision test is carried out according to the GB11551 rule, the simulation result shows that the neck My is reduced from 46Nm to 24Nm, the neck stretching bending moment simulation curve is shown in figure 5, the solid curve line is the curve of the improved test before improvement, the optimization of the collapsible deformation energy-absorbing element 22 is basically consistent with the process of the 21, and the detailed description is omitted.

The above description is only for the purpose of illustrating the present invention and is not intended to limit the scope of the present invention, and any person skilled in the art can substitute or change the technical solution of the present invention and its conception within the scope of the present invention.

Claims (7)

1. An occupant safety system capable of accommodating different crash directions, characterized by: the damping device comprises a damping device, a semi-coated cabin and seats, wherein the semi-coated cabin and the seats are distributed adjacently, the damping device is arranged between the semi-coated cabin and a vehicle body, and the damping device comprises a viscoelastic element and a collapsible deformation energy absorption element.

2. An occupant safety system as recited in claim 1, being adaptable to different crash directions, wherein: the viscoelastic element and the collapsible deformation energy absorption element are both in an annular structure, and the viscoelastic element is in an integrally formed structure or consists of two semi-rings.

3. An occupant safety system as recited in claim 1, being adaptable to different crash directions, wherein: the semi-covered cabin is of an integrated rigid structure, and the shape of the semi-covered cabin is a shape of fully covering the side and the back of a sitting posture of a human body.

4. An occupant safety system as recited in claim 1, being adaptable to different crash directions, wherein: the seat comprises a backrest, a seat cushion, a movable sliding rail, a sitting posture and front and back adjusting device and a safety belt.

5. A method for producing an occupant safety system capable of coping with different collision directions, the occupant safety system being the occupant safety system capable of coping with different collision directions according to any one of claims 1 to 4, the occupant safety system being applied to an automobile having a occupant restraint system, characterized in that: the preparation method comprises the following steps

Step 1, analyzing maximum damage time points and mechanical characteristics of different collision directions aiming at damage index peak conditions of a neck axial force Fz, a neck shearing force Fx and a neck bending moment My caused by acceleration and relative displacement of each part of a passenger during collision of a specific vehicle type, and enabling a seat to rebound at a designed speed when collision occurs through fusion design of damping coefficients, elastic modulus and size elements in front and back directions in a viscoelastic element, so as to ensure that the seat starts to rebound or finishes rebounding at a preset time;

and 2, matching design is carried out on the crushable deformation energy absorption element through dynamic crushing stress-strain curves and sizes of the crushable deformation energy absorption material in different directions, the total bearing mass of the crushable deformation energy absorption material and an acceleration curve of the crushable deformation energy absorption material during vehicle test standard collision, so that when the seat acceleration generated by the collision exceeds a specific value, the crushable deformation energy absorption element starts to generate crushing deformation and absorb energy, and the specific crushing energy absorption rate of the crushable deformation energy absorption element ensures that the self-adaptive energy absorption range of the viscoelastic element covers the range exceeding the standard collision speed.

6. A method of making an occupant safety system that can accommodate different crash directions as recited in claim 5, wherein; the matching design in the step 2 specifically comprises the following steps:

aiming at a specific vehicle type to be optimized, setting the peak value of the acceleration of a B column of an automobile body of the automobile when the standard initial collision speed is 50km/h collision as a and the total mass of a cabin and members as m, and ensuring that the function of starting or finishing rebounding the viscoelastic element at the preset time in the step 1 can normally work within the range of 50-90km/h, so that the process of the acceleration a from the peak value area of the acceleration of the automobile body to 50km/h is as follows:

calculating the maximum energy in the vehicle speed range of 50-90km/h compared with 50 km/h:

E’＝1/2m(v ₁ ² -v ₂ ² )＝1/2×m×((90000/3600)2-(50000/3600)2)

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

calculating the collapse deformation critical force: f = ma, wherein a is the acceleration peak value of the B column of the automobile body at the time of 50km/h collision;

selecting the critical yield force F according to the calculation result ¹ The energy absorption coefficient is K (J/cm) ³ ) And the material with the characteristic of approximate constant stress is used as a collapsible deformation energy-absorbing element, and the minimum volume V of the required energy-absorbing material is as follows:

V＝E’/K；

and finally, properly enlarging allowance on the basis of V and designing the shape and size of the energy absorbing material by combining the arrangement condition of the vehicle seat.

7. The method for manufacturing an occupant safety system capable of adapting to different collision directions according to claim 5, wherein the matching design in step 1 is specifically as follows:

step 1.1, matching and optimizing a forward half ring of a viscoelastic element for forward collision, defining the initial time point of rebound of the head of a passenger as a time point A for the standard forward collision working condition of a specific vehicle type to be optimized, and matching and optimizing the forward half ring of the viscoelastic element to ensure that the rebound time point of a seat is overlapped with the time point A so as to ensure that the seat and the head of the passenger synchronously move backwards after the time point A;

step 1.2, the backward half ring of the viscoelastic element is optimized in a matching mode aiming at backward rear-end collision, the time point when the head of a passenger contacts a headrest is determined as a time point B aiming at the standard rear-end collision working condition of a specific vehicle type to be optimized, the backward half ring of the viscoelastic element is optimized in a matching mode through calculation, the rebound starting time point of the seat is controlled to be consistent with the time point B, forward displacement of the head is offset by forward rebound displacement of the seat, and the damage of whiplash effect to the neck is reduced.

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