CN108502031A - A kind of automobile door sill with special infinitesimal born of the same parents filled layer - Google Patents

Abstract

The invention belongs to the field of automobile parts, and in particular relates to an automobile threshold with a special microcellular filling layer. The automobile threshold includes: an automobile threshold plate arranged on both inner and outer sides, The micro-cell filling layer between the plates, the micro-cell filling layer is a three-dimensional structure composed of multiple unit cells arranged in sequence in the X direction, Y direction, and Z direction; the unit cell is composed of four energy-absorbing parts. Two adjacent energy-absorbing parts are arranged perpendicular to each other, and the top and bottom of the four energy-absorbing parts are connected by a square connecting block to form a whole; the energy-absorbing part includes a first transverse energy-absorbing part, a The second horizontal energy-absorbing part, the first vertical energy-absorbing part, and the second vertical energy-absorbing part symmetrically arranged with the first vertical energy-absorbing part; the advantage of the present invention is: the car door sill structure It is simple, has good energy absorption effect, is suitable for many models, reduces the peak value of side collision, and can better protect the safety of the driver.

Description

A car door sill with special microcell filling layer

technical field

The invention belongs to the field of automobile parts, and in particular relates to an automobile threshold with a special microcellular filling layer.

Background technique

With the continuous increase of car ownership, the frequency of car accidents is gradually increasing, and the active and passive safety of cars is becoming more and more important. In the survey and statistics of collision accidents in the United States, the probability of side collisions accounts for 7%, and in the statistics of collision accidents in Japan, the probability of side collisions accounts for 12.7%. Because the side collision is relatively close to the driver, it poses a great threat to the driver's life safety, so it is particularly important to strengthen the safety of side collisions.

The car door sill is the main energy-absorbing component of side collision, and it is also a hot spot for many scholars to study side collision. At present, the general measures to improve the safety of side collisions are to increase the thickness of the panels and increase the reinforcement ribs, which will cause the car to become heavier and fail to meet the trend of lightweight vehicles; in addition, although the rib structure can increase the strength of the threshold, it does not It is not conducive to the deformation of the threshold to absorb the collision energy. When the external impact energy is too large, the threshold plate will be pushed to impact the cab, causing damage to the driver.

In recent years, cellular materials have been continuously developed and applied. The superior energy-absorbing performance of cellular materials and their own lightweight performance have become research hotspots in various industries. Similarly, if they are reasonably applied to automobile thresholds , will also have a positive effect.

Contents of the invention

The purpose of the present invention is to provide a car door sill with a special microcellular filling layer, so as to solve the technical problems of poor energy absorption effect, heavy weight and high production cost in the side collision of the existing car door sill.

To achieve the above object, the present invention is achieved by adopting the following technical solutions:

A car door sill with a special microcell filling layer, including the car door sill plates arranged on the inner and outer sides, and the micro cell filling layer arranged between the car door sill plates on the inner and outer sides, the improvement is :

The microcellular filling layer is a three-dimensional structure formed by arranging and combining a plurality of unit cells in the X direction, Y direction and Z direction; the unit cells are composed of four energy-absorbing parts, and two adjacent The energy-absorbing pieces are arranged perpendicular to each other, and the top and bottom of the four energy-absorbing pieces are connected by a square connecting block to form a whole; the energy-absorbing pieces include a first transverse energy-absorbing part, a The second horizontal energy-absorbing portion symmetrically arranged, the first vertical energy-absorbing portion, and the second vertical energy-absorbing portion symmetrically arranged with the first vertical energy-absorbing portion; wherein, the first horizontal energy-absorbing portion is obliquely arranged at On one side of the connecting block at the top, the angle _α1 between the first horizontal energy-absorbing portion and the horizontal plane of the connecting block is 140-170°; the other end of the first horizontal energy-absorbing portion is connected to the first vertical energy-absorbing portion , the angle _β1 between the first horizontal energy-absorbing portion and the first vertical energy-absorbing portion is 45-60°; the outer surface of the connecting end of the first horizontal energy-absorbing portion and the first vertical energy-absorbing portion is processed There is a horizontal connection surface and a vertical connection surface; the horizontal connection surface is used to connect with another unit cell in the Y direction; the vertical connection surface is used to connect with another unit cell in the X or Z direction connection; the first vertical energy-absorbing part and the second vertical energy-absorbing part are connected through a vertical buffer part, and the stress acting on the energy-absorbing part is decomposed through the vertical buffer part, and acts on each energy-absorbing part respectively ; The other end of the second vertical energy-absorbing portion is connected to the second transverse energy-absorbing portion, and the angle _β2 between the second vertical energy-absorbing portion and the second transverse energy-absorbing portion is 45-60°. The outer surface of the connecting end of the second vertical energy-absorbing part and the second transverse energy-absorbing part is also processed with a horizontal connecting surface and a vertical connecting surface; the other end of the second transverse energy-absorbing part is obliquely arranged on the connecting block at the bottom On one side of , the included angle α ₂ between the second transverse energy-absorbing portion and the horizontal plane of the connecting block is 140-170°.

As a preference of the present invention, the microcell filling layer is an integrated structure of 3D printing, and the first transverse energy-absorbing part and the second transverse energy-absorbing part of each energy-absorbing part on the unit cells constituting the microcell filling layer part, the first vertical energy-absorbing part, and the second vertical energy-absorbing part have the same wall thickness, wall thickness = λ×L, λ is greater than or equal to 0.6 and less than or equal to 0.4, and L is the vertical length of a single energy-absorbing part, namely The distance between the horizontal connecting surface in the first transverse energy-absorbing part and the horizontal connecting surface in the second transverse energy-absorbing part; the length of the vertical buffer part is equal to the length, width and height of the connecting block, and the two symmetrically arranged The total transverse length C of an energy-absorbing member is equal to the vertical length L of a single energy-absorbing member.

Advantage and beneficial effect of the present invention are:

(1) The car threshold provided by the present invention has simple structure, good energy absorption effect, strong adaptability, and can be adapted to many car models. The energy-absorbing parts on each unit cell reduce the peak value of the side impact; at the same time, the zero Poisson's ratio effect of the unit cell is used to prevent the material from expanding around during the collision process, but gather and compress along the impact direction to fully absorb energy and obtain The energy has been absorbed more, and compared with the hexagonal honeycomb filling material, it can better protect the safety of the driver.

(2) The automobile door sill provided by the present invention uses the pores of the multicellular structure to increase the deformation space, and at the same time utilizes the zero Poisson's ratio effect of the structure to absorb more energy. With this car threshold, its crashworthiness is enhanced and its weight is lighter when the strength requirements are met; at the same time, the microcellular filling layer inside the car threshold can be directly printed by 3D printing, which greatly reduces production costs and improves production. efficiency.

(3) In the present invention, the unit cell with four sides concave is used as the smallest unit for filling, so that the initial peak value of the collision is lower, which is similar to the stress area of the platform, which is beneficial to protect the life safety of the driver. At the same time, the stress platform area is long and stable, so that the energy absorption The process is more stable.

(4) On the basis of the traditional threshold, the automotive threshold provided by the present invention is filled with 4 layers of microcellular filling layers. The base material is aluminum. When the thickness of the filling layer is 48mm, compared with the traditional threshold, the weight is reduced by 10%; Bending stiffness increased by 15%; the initial peak value of the collision was reduced by 30%, and energy absorption increased by 20%.

(5) The present invention fills the microcellular filling layer inside the car door sill, because there are a large number of pores inside, it will produce a "sound forbidden band" within a certain frequency to the noise from the outside of the car, and it is based on the principle of "band gap". To reduce noise and increase driving comfort.

Description of drawings

Figure 1 is a partial enlarged view of the car door sill structure.

Figure 2 is a schematic diagram of the structure of a unit cell.

Figure 3 is a schematic diagram of the arrangement of two unit cells.

Figure 4 is a schematic diagram of the arrangement of four unit cells.

Fig. 5 is a schematic diagram of arrangement of multiple unit cells.

Fig. 6 is a structural schematic diagram of two energy-absorbing parts connected symmetrically.

Fig. 7 is a diagram of the two-dimensional in-plane deformation process of the filling layer during the impact process.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions and advantages of the present invention, the following describes the application in detail with reference to the accompanying drawings, but it is not intended to limit the protection scope of the present invention.

With reference to Fig. 1, a kind of car door sill 1 with special microcellular filling layer provided by the present invention comprises: comprise the car door sill plate 3 that is arranged on inner and outer two sides, is arranged on the car door sill plate 3 between inner and outer two sides The micro-cell filling layer 2, the micro-cell filling layer 2 and the vehicle door sill plate 3 are connected by bonding to form a sandwich structure.

Referring to Figures 2 to 5, the microcellular filling layer 2 is a three-dimensional structure composed of a plurality of unit cells arranged and combined sequentially in the X direction, Y direction, and Z direction; the unit cells are composed of four energy-absorbing components 4 combined structure, two adjacent energy-absorbing parts 4 are arranged perpendicularly to each other, and the top and bottom of the four energy-absorbing parts 4 are connected by a square connecting block 11 to form a whole; the energy-absorbing parts 4 include The first horizontal energy-absorbing part 41, the second horizontal energy-absorbing part 42 symmetrically arranged with the first horizontal energy-absorbing part, the first vertical energy-absorbing part 43, the second vertical energy-absorbing part symmetrically arranged with the first vertical energy-absorbing part Energy-absorbing part 44; wherein, the first transverse energy-absorbing part 41 is obliquely arranged on one side of the connecting block 11 at the top, and the included angle _α1 between the first transverse energy-absorbing part 41 and the horizontal plane of the connecting block 11 is 140-170° °, the other end of the first horizontal energy-absorbing portion 41 is connected to the first vertical energy-absorbing portion 43, and the angle _β1 between the first horizontal energy-absorbing portion 41 and the first vertical energy-absorbing portion 43 is 45° -60°, a horizontal connection surface 411 and a vertical connection surface 431 are processed on the outer surface of the connecting end of the first transverse energy-absorbing portion 41 and the first vertical energy-absorbing portion 43; the horizontal connection surface 411 is used for Connect with another unit cell in the Y direction; the vertical connection surface 431 is used to connect with another unit cell in the X or Z direction; the first vertical energy-absorbing part 43 and the second vertical energy-absorbing part 43 The energy part 44 is connected by a vertical buffer part 45, and the stress acting on the energy-absorbing member is decomposed by the vertical buffer part 45, and acts on each energy-absorbing part respectively; the other end of the second vertical energy-absorbing part 44 Connected with the second horizontal energy-absorbing portion 42, the angle _β2 between the second vertical energy-absorbing portion 44 and the second horizontal energy-absorbing portion 42 is 45-60°, between the second vertical energy-absorbing portion 44 and the second energy-absorbing portion 42 The outer surface of the connection end of the two transverse energy-absorbing parts 42 is also processed with a horizontal connecting surface and a vertical connecting surface; the other end of the second transverse energy-absorbing part 42 is obliquely arranged on one side of the connecting block 11 at the bottom, the second The angle _α2 between the two transverse energy-absorbing parts 42 and the horizontal plane of the connecting block 11 is 140-170°.

The microcell filling layer 2 is an integrated structure of 3D printing, and the first transverse energy-absorbing part 41 and the second transverse energy-absorbing part 42 of each energy-absorbing part 4 on the unit cells constituting the microcell filling layer 2 , the wall thicknesses of the first vertical energy absorbing part 43 and the second vertical energy absorbing part 44 are the same, wall thickness=λ×L, λ is greater than or equal to 0.6 and less than or equal to 0.4, and L is the vertical length of a single energy absorbing member ( That is, the distance between the horizontal connecting surface in the first transverse energy-absorbing part 41 and the horizontal connecting surface in the second transverse energy-absorbing part 42); the length of the vertical buffer part is equal to the length, width and height of the connecting block; symmetrical The total transverse length C of the two energy-absorbing components (that is, the distance between the vertical connecting surface on one energy-absorbing component and the vertical connecting surface on the other energy-absorbing component) is equal to the vertical length L of a single energy-absorbing component.

The unit cell of the present invention is designed so that the above structure can make the unit cell stress deformation stable, and the force transmission effect is good; when the above parameters exceed the set range, the unit cell stress deformation will be unstable, and the force transmission effect will be poor.

In the automobile threshold of the present invention, the thicker the thickness of the middle microcellular filling layer 2 is, the more layers are accommodated, and the better the energy absorption effect is, but the more layers, not only limited by space, but also the heavier the threshold structure, this means It is a game between light weight and safety. Because the filling of cellular materials is used, it will definitely become lighter when other conditions remain unchanged. Therefore, on the premise of ensuring the weight of the original car threshold, we can make the interior space In such a case, add as many layers as possible to increase energy absorption. According to the internal space of the existing automobile threshold, the number of layers of the unit cells in the Y direction in the microcellular filling layer 2 is generally controlled to be 4-15 layers, preferably 6-10 layers.

In the automobile door sill described in the present invention, the microcellular filling layer 2 is made of aluminum or other metal materials, and has excellent ductility under large deformation.

Referring to Fig. 7, according to the two-dimensional in-plane deformation process of the microcellular filling layer 2 during the collision and impact process, the cell walls of the unit cells (the first transverse energy-absorbing part 41, the second transverse energy-absorbing part 42, the second transverse energy-absorbing part 42, and the The first vertical energy-absorbing part 43 and the second vertical energy-absorbing part 44) gradually fill the pore part, and the pore part is the so-called energy-absorbing space, which provides space conditions for the deformation of the unit cell structure, thereby absorbing more energy; in addition , it can be observed that the structure has a zero Poisson's ratio phenomenon. During the collision and impact process, the material does not extend to the surroundings, but only deforms in the direction of compression. The material of each unit cell gathers towards its center, and the later stage becomes harder and harder as the pressure increases. , which also ensures the rigidity of the threshold of the car, so that it will not be damaged. Combining these two advantages, through a reasonable design, it will absorb as much collision energy as possible while ensuring the rigidity and strength of the threshold of the car. On the one hand, it protects the safety of the driver, and on the other hand, it also reduces the degree of damage to the threshold of the car. The unit cell structure of the present invention is used in the impact collision process, because each energy-absorbing part is concave, so it is relatively easier to deform, so that the initial peak value is greatly reduced, and at the same time, due to the zero Poisson's ratio effect brought by the concave, the impact process In the middle, with a long and stable stress plateau area, the energy absorption process is more stable, and the energy absorption is also greatly increased.

working principle:

When the car is side-impacted, the micro-cell filling layer 2 inside the door sill will be compressed, and the energy-absorbing parts on the unit cells will gradually fill the surrounding pores, and the collision energy will be absorbed and lost by deformation; at the same time, due to the structure of the unit cells Zero Poisson's ratio effect, the material does not extend to the surroundings, and only deforms in the direction of compression. The material of each unit cell gathers towards its center, and the later stage becomes harder and harder as the pressure increases. This process will form a stable and long platform area. The stress value in this area remains basically unchanged, forming a platform. The longer the platform area, the larger the area surrounded and the more energy absorbed, effectively protecting the driver's life safety; the smaller the fluctuation of the platform area, the more stable the energy absorption process. In addition, by rationally designing the geometric dimensions of the unit cell (cell wall thickness, width, concave angle, etc.), the plateau area in the stress-strain curve is close to the limit value, that is, under the premise of ensuring the safety of the driver, absorb as much as possible After passing the platform area, the energy will enter the dense area. The more compact the material, the harder it is to ensure the rigidity of the threshold and reduce the damage to the threshold. At this time, the collision energy is basically absorbed and consumed.

Performance testing:

On the basis of the structure of the traditional car threshold, 4 layers of microcellular filling layer 2 are added. The base material is aluminum, and the thickness of the filling layer is 48mm. The side impact simulation test is carried out according to the enterprise standard, and the weight, bending stiffness and initial peak value of the collision are tested. , Energy absorption.

Test results: Compared with the traditional car threshold, the weight is reduced by 10%; the bending stiffness is increased by 15%; the initial peak value of the collision is reduced by 30%, and the energy absorption is increased by 20%.

Claims (2)

1. A car threshold with a special microcell filling layer, including the car threshold plate arranged on the inner and outer sides, and the microcellular filling layer arranged between the inner and outer two sides car threshold plate, characterized in that : The microcellular filling layer is a three-dimensional structure formed by arranging and combining a plurality of unit cells in the X direction, Y direction and Z direction; the unit cells are composed of four energy-absorbing parts, and two adjacent The energy-absorbing pieces are arranged perpendicular to each other, and the top and bottom of the four energy-absorbing pieces are connected by a square connecting block to form a whole; the energy-absorbing pieces include a first transverse energy-absorbing part, a The second horizontal energy-absorbing portion symmetrically arranged, the first vertical energy-absorbing portion, and the second vertical energy-absorbing portion symmetrically arranged with the first vertical energy-absorbing portion; wherein, the first horizontal energy-absorbing portion is obliquely arranged at On one side of the connecting block at the top, the angle _α1 between the first horizontal energy-absorbing portion and the horizontal plane of the connecting block is 140-170°; the other end of the first horizontal energy-absorbing portion is connected to the first vertical energy-absorbing portion , the angle _β1 between the first horizontal energy-absorbing portion and the first vertical energy-absorbing portion is 45-60°; the outer surface of the connecting end of the first horizontal energy-absorbing portion and the first vertical energy-absorbing portion is processed There is a horizontal connection surface and a vertical connection surface; the horizontal connection surface is used to connect with another unit cell in the Y direction; the vertical connection surface is used to connect with another unit cell in the X or Z direction connection; the first vertical energy-absorbing part and the second vertical energy-absorbing part are connected through a vertical buffer part, and the stress acting on the energy-absorbing part is decomposed through the vertical buffer part, and acts on each energy-absorbing part respectively ; The other end of the second vertical energy-absorbing portion is connected to the second transverse energy-absorbing portion, and the angle _β2 between the second vertical energy-absorbing portion and the second transverse energy-absorbing portion is 45-60°. The outer surface of the connecting end of the second vertical energy-absorbing part and the second transverse energy-absorbing part is also processed with a horizontal connecting surface and a vertical connecting surface; the other end of the second transverse energy-absorbing part is obliquely arranged on the connecting block at the bottom On one side of , the included angle α ₂ between the second transverse energy-absorbing portion and the horizontal plane of the connecting block is 140-170°. 2. A car door sill with a special micro-cell filling layer according to claim 1, characterized in that: the micro-cell filling layer is an integrated structure of 3D printing, which constitutes the unit of the micro-cell filling layer The wall thicknesses of the first horizontal energy-absorbing part, the second horizontal energy-absorbing part, the first vertical energy-absorbing part and the second vertical energy-absorbing part of each energy-absorbing part on the cell are the same, wall thickness = λ×L, λ is greater than or equal to 0.6 and less than or equal to 0.4, L is the vertical length of a single energy-absorbing member, that is, the distance between the horizontal connecting surface in the first transverse energy-absorbing part and the horizontal connecting surface in the second transverse energy-absorbing part; The length of the straight buffer is equal to the length, width and height of the connecting block, and the total transverse length C of the two symmetrically arranged energy-absorbing pieces is equal to the vertical length L of a single energy-absorbing piece.