CN112158159A

CN112158159A - Automobile collision energy absorption box

Info

Publication number: CN112158159A
Application number: CN202011001084.2A
Authority: CN
Inventors: 何强; 王勇辉; 周宏根; 田桂中; 顾航; 徐寅豪; 赵聪
Original assignee: Jiangsu University of Science and Technology
Current assignee: Jiangsu University of Science and Technology
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2021-01-01
Anticipated expiration: 2040-09-22
Also published as: CN112158159B

Abstract

The invention discloses an automobile collision energy absorption box, which comprises a guide device and an energy absorption core body, wherein the guide device is used for guiding the energy absorption core body to telescope, the energy absorption core body is arranged in the guide device, the energy absorption core body comprises an inner thin-wall circular tube, an outer thin-wall circular tube and a honeycomb element, the inner thin-wall circular tube and the outer thin-wall circular tube are coaxial, the honeycomb element is filled between the inner thin-wall circular tube and the outer thin-wall circular tube, a trunk is arranged between the inner thin-wall circular tube and the outer thin-wall circular tube, the trunk is intersected with the inner thin-wall circular tube and forms branches inwards along the inner. The guiding device of the energy absorption box can enable the energy absorption core to obtain a more stable and regular deformation mode, has higher specific energy absorption and load efficiency, and reduces the collision peak force; in the whole collision energy absorption process, the impact force is very stable, the passive safety of the automobile is greatly improved, and casualties are reduced.

Description

Automobile collision energy absorption box

Technical Field

The invention relates to an energy absorption box, in particular to an automobile collision energy absorption box.

Background

When a traffic accident happens, a passive safety protection device of an automobile is of great importance. When the energy absorption box in front of the automobile longitudinal beam is in a small collision, the front longitudinal beam can be protected from being damaged, and the maintenance cost is saved; when a large collision occurs, a large amount of collision energy can be absorbed, and casualties are reduced.

The metal thin-wall structure has light weight and good crashworthiness, and is widely applied to the fields of automobiles, ships, aerospace and the like. The energy absorption box of the automobile adopts a metal thin-wall structure, and is generally a smooth pipe with a round section or a smooth pipe with a square section. The metal thin-wall energy-absorbing component mainly dissipates impact kinetic energy generated by violent collision through plastic deformation, and in the actual collision process, a plurality of failure modes or deformation modes are mixed together frequently, so that the metal thin-wall energy-absorbing component has the characteristics of unpredictability and uncontrollable performance.

The ideal crash box needs to satisfy the following conditions:

(1) high specific energy absorption, namely, the ratio of the total energy absorbed by the collision energy absorption box to the self mass is large;

(2) the small collision peak force, namely the maximum collision force generated in the collision process of the energy absorption box, is small;

(3) the high load efficiency is realized, namely the ratio of the average value of the collision force of the energy absorption box in the collision process to the maximum collision force is large;

(4) the excellent anti-collision structure with high stability can convert the irreversible collision kinetic energy into the deformation potential energy of the anti-collision structure as much as possible through the plastic deformation of the structure in a stable damage mode and a controllable mode, thereby absorbing the kinetic energy, reducing the impact speed and increasing the passive safety of the automobile.

The traditional thin-wall round pipe or square pipe made of steel or aluminum alloy is widely applied to the crash energy absorption box of the automobile, but the main problem is that the initial yield load is far higher than the bearing capacity after the yield, and a large initial crash peak value can be transmitted to the automobile longitudinal beam in the crash process, so that the life safety of a driver and passengers is threatened. The existing energy absorption structure does not achieve a good energy absorption effect.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention aims to provide the automobile crash energy absorption box which can simultaneously meet the requirements of high specific energy absorption and high load efficiency.

The technical scheme is as follows: the invention relates to an automobile collision energy absorption box, which comprises a guide device and an energy absorption core body, wherein the guide device is used for guiding the energy absorption core body to telescope, the energy absorption core body is arranged in the guide device, the energy absorption core body comprises an inner thin-wall circular tube, an outer thin-wall circular tube and a honeycomb element, the inner thin-wall circular tube and the outer thin-wall circular tube are coaxial, the honeycomb element is filled between the inner thin-wall circular tube and the outer thin-wall circular tube, a trunk is arranged between the inner thin-wall circular tube and the outer thin-wall circular tube, the trunk is intersected with the inner thin-wall circular tube and forms branches inwards along the.

The number of the trunks is more than four, the trunks are uniformly arranged at intervals, and the trunks are used for connecting the space between the inner thin-wall circular tube and the outer thin-wall circular tube. The cross section of the branch is in the shape of an inwards concave octagon. When the number of the branches is more than two, the branch angle of the branch is gradually reduced. The trunk and the branches are thin plates. The cross-sectional shape of the honeycomb element is a regular hexagon or a circle.

Further, the guiding device comprises a first circular ring plate, a second circular ring plate and a plurality of negative Poisson ratio structural units, and the negative Poisson ratio structural units are arranged between the first circular ring plate and the second circular ring plate. The negative Poisson ratio structural units form a circular ring array with the circular ring plate I as an axis, the negative Poisson ratio structural units are connected end to form unit bodies, and the unit bodies are manufactured by stamping. The first circular ring plate and the second circular ring plate are parallel and coaxial with each other and are manufactured through 3D printing. In order to facilitate the installation and fixation of the energy absorption core, the first circular ring plate and the second circular ring plate extend towards the inner wall side of the first circular ring plate and the second circular ring plate.

The automobile collision energy absorption box is welded on the mounting bottom plate, and the mounting bottom plate is connected and fixed on the anti-collision cross beam and the longitudinal beam through bolts.

The working principle is as follows: when the automobile collision energy absorption box designed by the invention is subjected to a frontal collision force, the bottom plate transmits the collision force to the guide device and the energy absorption core body at the same time, the guide device and the energy absorption core body both generate plastic deformation along the load action direction to absorb energy, the guide device has a negative Poisson ratio structural unit, and the guide device can generate radial contraction to a certain degree due to the negative Poisson ratio characteristic of the negative Poisson ratio structural unit when being compressed and deformed along the load action direction, so that the transverse expansion of the energy absorption core in the deformation process can be inhibited, the energy absorption core body can obtain a more stable and regular deformation mode, and the energy absorption efficiency and the load efficiency of the energy absorption box are greatly.

Has the advantages that: compared with the prior art, the invention has the following remarkable characteristics:

1. when the automobile energy absorption box is collided by the guide devices with the negative Poisson ratio structural units distributed around the energy absorption core, the guide devices can generate plastic deformation along the load action direction to absorb energy and can also generate radial contraction due to the negative Poisson ratio characteristics of the negative Poisson ratio structural units, so that the transverse expansion of the energy absorption core in the deformation process is inhibited, the energy absorption core body obtains a more stable and regular deformation mode, the specific energy absorption and load efficiency are higher, and the collision peak force is reduced;

2. the automobile collision energy absorption box and the anti-collision beam are connected by the bolts, so that the anti-collision beam can be recycled under the condition of small collision (the anti-collision beam is not damaged), and only the energy absorption box needs to be replaced, so that the maintenance cost is saved;

3. the automobile collision energy absorption box can be used together with an anti-collision beam to improve the passive safety of an automobile, and the energy absorption core can also be used as an independent buffering energy absorption material and can be used for various devices needing energy absorption.

Drawings

FIG. 1 is a schematic diagram of an application structure of the present invention;

FIG. 2 is a schematic structural view of the present invention;

FIG. 3 is a schematic structural view of an energy absorbing core 2 of the present invention;

FIG. 4 is a cross-sectional view of an energy absorbing core 2 of the present invention;

FIG. 5 is a schematic view of the structure of the guide device 1 of the present invention;

FIG. 6 is a close-up view of the negative Poisson's ratio structural unit 103 of the present invention;

FIG. 7 is a force versus displacement graph for a frontal impact of the present invention.

Detailed Description

The directions shown in the drawings of the specification are up, down, left and right.

Referring to fig. 1-2, one end of the automobile crash box is symmetrically arranged on two sides of the anti-collision beam 3, and the other end of the automobile crash box is arranged on the longitudinal beam. The energy absorption box is fixedly connected with the groove mounting bottom plate 4 and the anti-collision beam 3 through bolts, and the other end of the energy absorption box is fixedly connected with the longitudinal beam through the groove-free mounting bottom plate 5. The anti-collision beam 3 is connected with the energy absorption box through bolts, so that the anti-collision beam 3 can be recycled under the condition that the smaller anti-collision beam 3 is not damaged, and only the energy absorption box needs to be replaced, thereby saving the maintenance cost. The energy absorbing core 2 is nested in the guiding device 1. The guide 1 and the energy absorber core 2 are welded to the mounting base plate 5 at the same time.

Referring to fig. 3 to 4, the honeycomb member 203 is filled in a cell divided by the trunk 204 between the outer thin-walled circular tube 202 and the inner thin-walled circular tube 201. The filling method of the cellular device 203 includes a full cell filling method and an alternate cell filling method, the full cell filling method fills the cellular device 203 in all cells, and the alternate cell filling method fills the cellular device 203 by one cell. The honeycomb element 203 is composed of a plurality of tubular metal columns welded and extending along the axis of the inner thin-walled circular tube 201, the cross-sectional shape of the metal columns is preferably regular hexagon or circle, and can be other shapes, and the cross-sectional shape is not limited uniquely here and is selected according to specific situations and actual needs. The outer thin-walled circular tube 202 is coaxial with the inner thin-walled circular tube 201, and the m trunks 204 are arranged in a circumferential array with an angle of 360/m as an interval, with the central axis of the inner thin-walled circular tube 201 or the outer thin-walled circular tube 202 as an axis. The number m of the trunks 204 is greater than or equal to 4. The stem 204 starts from the inner wall of the outer thin-walled tube 202 and ends at the outer wall of the inner thin-walled tube 201. The trunk 204 intersects the inner thin-walled circular tube 201, branches 205 are formed by branching at a certain angle inward along the inner thin-walled circular tube 201, and ends at the intersection with the adjacent branch 205. The diameter of the outer thin-wall round tube 202 is constant, the diameter of the inner thin-wall round tube 201 changes with the ratio gamma of the diameters of the two (the outer thin-wall round tube 202/the inner thin-wall round tube 201), and gamma is more than 0 and less than 1. The number k of branches 205 is ≧ 1. The trunk 204 may be branched for a plurality of times, the branching angle of the branch 205 decreases sequentially, and the branching angle of the branch 205 increases closer to the inner wall of the inner thin-walled tube 201.

As shown in fig. 5 to 6, the guiding device 1 includes a first annular plate 101, a second annular plate 102 and a plurality of end-to-end negative poisson's ratio structures 103 which are disposed in parallel and coaxial. The negative poisson's ratio structure 103 is arranged between the first annular plate 101 and the second annular plate 102. The negative Poisson ratio structures 103 are arranged in a circumferential array mode with the central axis of the first annular plate 101 as the axis and the angle alpha as the interval, so that a stable annular structure is formed. Where 0< alpha < 360. In order to facilitate the installation and fixation of the energy absorbing core 2, the inner walls of the first annular plate 101 and the second annular plate 102 extend inwards for a certain length. When the guide device 1 with the negative Poisson ratio structural unit 103 is subjected to frontal collision, radial contraction is generated, the energy-absorbing core 2 is protected from being extruded, and the longitudinal compression guides the telescoping of the energy-absorbing core 2 and absorbs energy at the same time. The negative Poisson ratio structural units 103 are connected end to form unit bodies, and are manufactured by stamping, so that compared with the traditional metal sheet welding forming method, the stress value at the welding seam is reduced. The unit body is connected with the first annular plate 101 and the second annular plate 102 through welding.

TABLE 1 energy absorption test results

Energy-absorbing box form	Round section energy absorption box	Square section energy absorption box	Automobile collision energy-absorbing box
				Energy absorption (KJ)	5.97	6.27	7.448
Performance enhancement (%)	24.62	18.66	/

In order to verify that the automobile crash energy absorption box of the embodiment has the advantages of light structure and high energy absorption ratio, the comparison analysis is carried out on the automobile crash energy absorption box and the traditional round-section energy absorption box and square-section energy absorption box, the total mass of the energy absorption cores of the three energy absorption boxes is kept consistent and is 16.3Kg, and the energy absorption core energy results are shown in the table 1. As can be seen from table 1, compared with the conventional round-section crash box and square-section crash box, the total energy absorption amount of the automobile crash box of the embodiment is respectively increased by 24.62% and 18.66%, and the automobile crash box of the embodiment has better energy absorption performance and better passive safety compared with other two structures under the same quality.

FIG. 7 is a graph of the curve of the forward collision and displacement of the crash box for an automobile according to the present embodiment, and it can be seen from FIG. 6 that during the whole collision process of the crash box, the initial impact force rapidly increases to a certain value (274.956KN), then the impact force steadily increases with the increase of the compression displacement, and finally the impact force oscillates up and down, and the bearing capacity of the crash box begins to decline. In the whole collision energy absorption process, the energy absorption efficiency is high, the impact force is very stable, and the collision peak force is low.

Claims

1. The utility model provides an automobile collision energy-absorbing box which characterized in that: including guider (1) and energy-absorbing core (2), energy-absorbing core (2) set up in guider (1), energy-absorbing core (2) are including interior thin wall pipe (201), outer thin wall pipe (202) and honeycomb component (203), interior thin wall pipe (201) and outer thin wall pipe (202) are coaxial, honeycomb component (203) are filled in between interior thin wall pipe (201), outer thin wall pipe (202), set up trunk (204) between interior thin wall pipe (201), outer thin wall pipe (202), trunk (204) and interior thin wall pipe (201) are crossing and form branch (205) to the inboard along interior thin wall pipe (201), branch (205) end in the nodical with adjacent branch (205).

2. The automobile crash box according to claim 1, wherein: the number of the trunks (204) is four or more.

3. The automobile crash box according to claim 1, wherein: the cross section of the branch (205) is in the shape of a concave octagon.

4. The automobile crash box according to claim 1, wherein: when the number of the branches (205) is more than two, the branch angle of the branches (205) is gradually reduced.

5. The automobile crash box according to claim 1, wherein: the cross-sectional shape of the honeycomb element (203) is a regular hexagon or a circle.

6. The automobile crash box according to claim 1, wherein: the guide device (1) comprises a first circular ring plate (101), a second circular ring plate (102) and a plurality of negative Poisson ratio structural units (103), wherein the negative Poisson ratio structural units (103) are arranged between the first circular ring plate (101) and the second circular ring plate (102).

7. The automobile crash box according to claim 6, wherein: the negative Poisson ratio structural units (103) form a circular ring array taking the circular ring plate I (101) as an axis.

8. The automobile crash box according to claim 6, wherein: the first annular plate (101) and the second annular plate (102) are parallel to each other and coaxial.

9. The automobile crash box according to claim 6, wherein: the first annular plate (101) and the second annular plate (102) extend towards the inner wall side of the first annular plate and the second annular plate.