WO2020222586A1

WO2020222586A1 - Vehicle hood and vehicle panel with cell structure

Info

Publication number: WO2020222586A1
Application number: PCT/KR2020/005817
Authority: WO
Inventors: Hyerim Lee; Hyosig KIM
Original assignee: Renault-Samsung Motors Co., Ltd.
Priority date: 2019-05-02
Filing date: 2020-04-30
Publication date: 2020-11-05

Abstract

Provided is a vehicle hood or a vehicle panel, which are capable of protecting pedestrians in the event of collision. The vehicle hood according to the present invention has a sandwich structure in which cell structures are disposed between an upper panel and a lower panel. The cell structures are partitioned from each other by a partition wall and have a structure in which the cell structures are connected to each other through a pair of one-way valves, by which a fluid flows only in one direction. In the event of the collision, the fluid within the cells structure flows to the adjacent cell structure to absorb an impact, thereby preventing injury of a head of a pedestrian due to directly collision with a hard point such as an engine below the hood from occurring.

Description

VEHICLE HOOD AND VEHICLE PANEL WITH CELL STRUCTURE

The present invention relates to a vehicle, and more particularly, to a hood and/or panel among components constituting a vehicle.

Since most of the vehicle is made of metals and thus has a heavy weight and a high speed, an impact amount is huge when collision occurs. Thus, the regulations for protecting drivers and passengers are being strengthened increasingly, and technologies such as seat belt sand airbags are also being developed.

However, the issue gets more serious if it is collision with pedestrians, not collision with vehicles or building walls. This is because safety of the pedestrians who collide with the vehicle is more important than safety of the vehicle and the passengers in the vehicle.

Therefore, domestic and foreign automobile safety laws are being strengthened in items related to the pedestrian safety during vehicle crash tests. Here, the crush tests are conducted under the same conditions so that a degree of injury of the pedestrians is quantified to measure a safety level, thereby assisting consumer’s choice.

FIG. 9 illustrates an example of measuring safety by simulating collision with a pedestrian as described above. A test in which a head model 910 of a pedestrian, a head model 920 of a child pedestrian, a leg model 940 of the pedestrian, a model 930 of an upper portion of the pedestrian’s leg collide with a vehicle is conducted to measure a degree of an impact, thereby quantifying safety of the vehicle based on the measured degree of the impact.

In general, when a vehicle and a pedestrian collide with each other, the lower body of the pedestrian is impacted first by a bumper of the vehicle, and then, the head of the collapsing pedestrian is bumped secondarily against a hood. If the head is seriously injured, the pedestrian may cause serious injury or death. As a result, the vehicle hood may not be manufactured just strongly.

On the other hand, if the hood is softened against the collision, the injury of the pedestrian due to the hood may be reduced, but if the head collides with hard points such as a portion within an engine room in which an engine is located or a hood coupling portion. FIG. 10 illustrates a case in which a pedestrian’s head collides with a hood constituted by only an upper panel 1010 and a lower panel 920, like the related art. When the head collides with

hard points

1030 and 1040 in the engine room located under the hood, it show a situation in which the hood cannot absorb an impact. Alternatively, if the head collides with other portions except for the hard points, the hood may be bent to absorb the impact, but the pedestrian’s safety can’t take any chances.

In addition, if rigidity of the hood is too weak, since the hood turns over to cause a bigger accident in high-speed traveling, the hood cannot be made only weakly.

The invention of Japanese Patent Publication No. Hei 07-125605, which is one of the related arts, is attempted to solve this problem by installing an airbag on a hood. In the event of an accident, when the pedestrian falls over the hood, it may detect this situation to deploy an airbag installed on the hood, thereby preventing the pedestrian from directly colliding with the hood.

However, a system using a sensor has a limitation in that it is difficult to install the system in a small vehicle having a high installation cost and a small engine room space in the hood.

Thus, the inventors of the present invention have been tried to overcome these limitations in the related art. The present invention has been completed after a lot of efforts to complete a structure that is capable of absorbing an impact when colliding with the pedestrian while maintaining the basic structure and rigidity of the hood. Also, in this process, possibility of a vehicle panel that is capable of being used for other portions than the hood has been confirmed.

An object of the present invention is to supplement the shortcomings of the vehicle hood according to the related art so as to protect a pedestrian’s head against an impact in an event of an accident.

Although interest in protecting pedestrians as well as drivers and passengers is increasing in the event of the vehicle accident, it is a reality that a hood that is faithful to the pedestrian protection has not been developed due to structural or economic limitations. Accordingly, another object of the present invention is to develop a vehicle hood that is faithful to pedestrian protection without additional equipment such as a sensor.

Another object of the present invention is to provide a new panel that is capable be made much lighter than the vehicle panel according to the related art.

Other objects that are not specified in the present invention will be additionally considered within a range that is easily deduced from the following detailed description and its effects.

An embodiment of the present invention provides a vehicle hood having a cell structure includes an upper panel, a lower panel, and a plurality of cell structures disposed between the upper panel and the lower panel, wherein each of the cell structures has a structure that is partitioned from the other cell structure by a partition wall, and the partition wall between the cell structure and the other cell structure comprises a first one-way valve by which a fluid flows only from the cell structure to the other cell structure and a second one-way valve by which the fluid flows only from the other cell structure to the cell structure.

Each of the first valve and the second valve may include a spring loaded ball check valve or a membrane valve.

The inside of the plurality of cell structures may be filled with an oil.

The plurality of cell structures may be installed at only a portion of the vehicle hood.

The cell structure may have a triangular pillar shape, a square pillar shape, a hexagonal pillar shape, or a cylindrical shape.

The cell structure may be provided by a combination of two or more polygonal pillars different from each other.

Another embodiment of the present invention provides a vehicle panel having a region with a structure in which unit cells containing a fluid are continuously connected to each other in a lattice shape between an upper panel and a lower panel in a sandwich form in which the upper panel and the lower panel face each other, wherein a first one-way valve by which a flow flows only in a first direction and a second one-way valve by which the fluid flows only in a second direction opposite to the first direction are installed between adjacent unit cells.

Due to the technical solution, the present invention may manufacture the vehicle hood that is light and maintained in rigidity. The lightweight of the vehicle may be achieved by being applied to various portions of the vehicle, which are capable of absorbing the impact, as well as the vehicle hood.

In addition, the impact in the event of the collision may be absorbed by the fluid within the cell structure to reduce the injury of the pedestrian in the event of the accident.

Although effects are not considered herein, the effects described in this specification and their provisional effects, which are expected by the technical features of the present invention, may be considered as the effects described in this specification.

FIG. 1 is a cross-sectional view of a hood of a cell structure according to a preferred embodiment of the present invention.

FIG. 2 is a view of a connection structure between cells according to a preferred embodiment of the present invention.

FIG. 3 is a view illustrating a structure of a check valve connecting cells to each other according to a preferred embodiment of the present invention.

FIG. 4 is a view illustrating an example of an arrangement of a cell structure according to a preferred embodiment of the present invention.

FIG. 5 is a view illustrating an example of an arrangement of various cell structures according to a preferred embodiment of the present invention.

FIG. 6 is a view illustrating an example of a principle of absorbing an impact by a hood having the cell structure according to a preferred embodiment of the present invention.

FIG. 7 is a view illustrating an example of a position at which the cell structure is installed according to a preferred embodiment of the present invention.

FIG. 8 is a view according to preferred another embodiment.

FIG. 9 is a view illustrating an example of a pedestrian crush test.

FIG. 10 is a schematic view illustrating problems of a hood according to the related art.

※ The attached drawings are presented for purposes of explanation only, and the technical scope of the present invention is not limited thereto.

Hereinafter, a configuration of the present invention according to various embodiments of the present invention and effects resulting from the configuration will be described with reference to the drawings. Moreover, detailed descriptions related to well-known functions or configurations will be ruled out in order not to unnecessarily obscure subject matters of the present invention.

A hood according to the present invention includes a plurality of cell structures 110, a pair of one-

way valves

120 and 130, an upper panel 140, and a lower panel 150. In the hood according to the related art, the lower panel is made of a material that is more rigid and heavier than steel of the upper panel to protect the internal components of the vehicle against a physical impact. However, according to a preferred embodiment of the present invention, the upper panel 140 and the lower panel 150, which are made of the same material, may be used, and thus, a lighter hood than that according to the related art may be used.

The cell structure 110 is provided as a partition wall and is filled with gas or a liquid therein. The partition wall is made of a material such as a metal, a synthetic resin, or a carbon fiber, which is selected in consideration of rigidity and weight.

The cell structure 110 is connected to the adjacent cell structure 110 through two one-

way valves

120 and 130. The

valves

120 and 130 control the fluid within the cell structure 110 to flow only in one direction. This is illustrated in more detail in FIG. 2.

A first cell structure 210 and a second cell structure 240 are separated from each other by a partition wall and have a structure in which the insides of the first and

second cell structures

210 and 240 are connected to each other by a first valve 220 and a second valve 230. Therefore, when each of the first cell structure 210 and the second cell structure 240 are in a stable state, an internal pressure is balanced so that the fluid within each cell structure does not flow.

The first valve 220 controls the fluid to flow only from the first cell structure 210 to the second cell structure 240. On the other hand, the fluid may flow only from the second cell structure 240 to the first cell structure 210 by the second valve 230.

Due to the above-described structure, for example, when a pressure within the first cell structure 210 increases, the fluid within the first cell structure 210 flows to the second cell structure 240. Here, the fluid flows through the first valve 220 but does not flow through the second valve 230.

FIG. 3 is a view illustrating a structure of a check valve as a one-way valve that connecting cells to each other according to a preferred embodiment of the present invention.

The check valve having a shape illustrated in FIG. 3 is called a spring loaded check valve.

FIG. 3(a) illustrates an example of a state in which a fluid does not flow. When the fluid flows from a spring side, a ball moves in a direction opposite to the spring to close a passage, and thus, the fluid does not flow in an opposite direction.

On the other hand, FIG. 3(b) illustrates an example of a state in which the fluid flows. When the fluid flows from a ball side, the ball moves toward the spring to open the passage through which the fluid flows, thereby allowing the fluid to flow in the opposite direction.

The spring loaded check valve may adjust strength of the spring, i.e., a velocity at which the fluid flows by adjusting a spring constant (k). When a spring having a high spring constant is used, the ball is difficult to move, and thus the fluid velocity is slowed. On the other hand, if a spring having a low spring constant is used, the ball moves easily to increase in fluid velocity.

FIG. 4 is a view illustrating an example of an arrangement of the cell structure according to a preferred embodiment of the present invention.

The cell structure 410 may be provided in a square pillar shape. Upper and lower portions of the square pillar shape are covered by the upper panel and the lower panel, respectively, and side surfaces of the square pillar shape are connected to other cell structures.

When the cell structure 410 is connected to other cell structures, as described above, the cell structures are connected to each other by the one-

way valves

420 and 430.

First valves

420, 422, 424, and 426 are one-way valves through which a fluid flows only from the cell structure 410 only to other cell structures, and

second valves

430, 432, 434, and 436 are one-way valves through which a fluid flows in an opposite direction.

As described above, since the cell structure 410 is connected to other cell structures through the one-way valves, if an impact is applied to any one cell structure, the fluid within the cell structure continuously moves to the adjacent cell structures to absorb the impact. When the impact is released, the fluid serially moves again in the opposite direction to return to its original position within the cell structure.

Each of unit cell structures may be provided in the form of a cell having a triangular pillar shape or a hexagonal pillar shape such as FIGS. 5(a) or (b). The unit cell having the hexagonal pillar shape is also called a honeycomb and has a light and strong structure.

As illustrated in FIG. 5(c), the unit cells, each of which has a cylindrical shape, may be continued to be filled in the vehicle panel.

FIG. 5(b) illustrates an example in which a structure of the unit cell is constituted by combining several polygons. FIG. 5(d) illustrates an example in which unit cells are provided in a lattice shape by a combination of pentagon and a rhombus. In addition, the cell structure may be provided through a combination of various polygons such as octagon and a dodecagon.

When the unit cells are adjacent to each other and connected to each other through the one-way valves as illustrated in FIGS. 4 to 5, the one-way valves may be arranged at left and right sides or may be disposed vertically as illustrated in FIG. 1.

FIG. 6 is a view illustrating an example of a principle of absorbing an impact by the hood having the cell structure according to a preferred embodiment of the present invention.

Before the impact is applied, the pressure of the fluid within the cell structure 610 is equilibrium with that of the fluid within the adjacent cell structure, and thus, the fluid does not flow. Theoretically, the fluid may flow from the cell structure 610 to the adjacent cell structures by the

first valves

620 and 630 and also may flow from the adjacent cell structures to the cell structure 610 by the second valves 640 and 650. However, if the pressure between the cells is the same, since the fluid is in a stable state, the fluid movement through the valve may not occur.

On the other hand, when an impact is applied from the outside, the cell structure is distorted to increase in pressure as illustrated in FIG. 6(b), and the fluid flows to the adjacent cell structures through the

first valves

620 and 630 by the increasing pressure. However, since the second valves 640 and 650 prevent the fluid from flowing from the cell structure 610 to other cell structures, the fluid flows only from the cell structure 610 to other cell structures until the pressure of the fluid within the cell structure 610 is balanced with that of the fluid within each of other cell structures.

The cell structure may be installed over the entire hood, but may also be installed on a portion of the hood. In the engine room below the hood, the cell structures are selectively disposed only at positions at which there are hard points.

For example, the cell structures may be inserted only into the hood at positions corresponding to the hard points such as a position 720 within the engine room, at which the engine is located, or a connection part 710 between the hood and a vehicle body. As a result, the hood may be manufactured lighter, and the manufacturing cost may also be reduced.

Also, the cell structures in which the one-way valves according to the present invention are installed may be applied at any places as panels disposed at portions that need to absorb an impact while requiring rigidity, such as a side door or a trunk as well as a vehicle hood.

The vehicle body panel according to the present invention may have a region with a structure in which the unit cells (including the pair of one-way valves installed in the adjacent unit cells) described in this specification are continuously connected to each other in a lattice shape between the upper panel and the lower panel in a state in which the upper panel and the lower panel face each other in a sandwich form. The sandwich-structured vehicle panel having the unit cells may be manufactured in a 3D printing manner.

FIG. 8 is a view illustrating an example of a one-way valve according to preferred another embodiment. In this embodiment, a one-way membrane valve made of rubber may be used. For example, a case in which two

membrane valves

750 and 760 that block passages 731&732 and 735&736 in different directions are installed between a first unit cell 710 and a second unit cell 720 adjacent to the first unit cell 710 by using fixing

units

752 and 762 will be considered. When a pressure between the first unit cell 710 and the second unit cell 720 is balanced (P₁ = P₂), a fluid may not pass through the

membrane valves

750 and 760.

If a pressure is generated in the first unit cell 710 by an impact, force F₁ by which the first unit cell 710 pushes a membrane diaphragm 751 of the membrane valve 750 increases. When this force F₁is greater than force F₂ by which the fluid of the second unit cell 720 pushes the membrane valve 750, a shape of the membrane diaphragm 751 of the membrane valve 750 is deformed. Therefore, the fluid may move from the first unit cell 710 to the second unit cell 720. If the impact is removed, the fluid moving to the second unit cell 720 moves back to the first unit cell 710, and thus, the cell structure of the compartment returns to its original shape.

In the present invention, the fluid filled in the unit cells may be oil. In order to suppress generation of foreign substances and prevent rust from occurring, the fluid may be used for an engine oil.

The scope of the present invention is not limited to the description and expression of the embodiments explicitly described above. Further, it will be understood that the protective scope of the present invention is not limited by obvious modifications or substitutions in the technical fields of the present invention.

Claims

A vehicle hood having a cell structure, the vehicle hood comprising an upper panel, a lower panel, and a plurality of cell structures disposed between the upper panel and the lower panel,

wherein each of the cell structures has a structure that is partitioned from the other cell structure by a partition wall, and

the partition wall between the cell structure and the other cell structure comprises a first one-way valve by which a fluid flows only from the cell structure to the other cell structure and a second one-way valve by which the fluid flows only from the other cell structure to the cell structure.
The vehicle hood of claim 1, wherein each of the first valve and the second valve comprises a spring loaded ball check valve or a membrane valve.
The vehicle hood of claim 1, wherein the inside of the plurality of cell structures is filled with an oil.
The vehicle hood of claim 1, wherein the plurality of cell structures are installed at only a portion of the vehicle hood.
The vehicle hood of claim 1, wherein the cell structure has a triangular pillar shape, a square pillar shape, a hexagonal pillar shape, or a cylindrical shape.
The vehicle hood of claim 1, wherein the cell structure is provided by a combination of two or more polygonal pillars different from each other.
A vehicle panel having a region with a structure in which unit cells containing a fluid are continuously connected to each other in a lattice shape between an upper panel and a lower panel in a sandwich form in which the upper panel and the lower panel face each other,

wherein a first one-way valve by which a flow flows only in a first direction and a second one-way valve by which the fluid flows only in a second direction opposite to the first direction are installed between adjacent unit cells.