GB2519193A

GB2519193A - Impact absorbing device for a vehicle

Info

Publication number: GB2519193A
Application number: GB1413454.8A
Authority: GB
Inventors: Donald Pi Hsiang Wu
Original assignee: Energy Control Ltd
Current assignee: Energy Control Ltd
Priority date: 2013-10-11
Filing date: 2014-07-30
Publication date: 2015-04-15
Also published as: GB2519131A; GB201413454D0; GB201317989D0

Abstract

An impact absorbing device for a vehicle (C, Figure 8) includes first and second end connectors 50, 70, the first end connector 50 fixed to a chassis (C1, Figure 8), and at least two energy absorbing members 60A, 60B. Ends of energy absorbing members 60A, 60B are connected to each other and to the end connectors. Each energy absorbing member 60A, 60B comprises a plurality of annularly arranged elongate strips 61 of deformable metal, each bulging arcuately outward relative to a longitudinal axis X of the device. Energy absorbing members 60A, 60B have different fracture toughnesses, for example by being of different lengths, thicknesses or materials, and energy absorbing member 60A with the larger fracture toughness is located closer to the chassis, which may prevent direct transmission of impact energy to the chassis. End connectors 50, 70 may each have an area exceeding 30 square centimetres.

Description

IMPACT ABSORBING DEVICE FOR A VEHICLE

BACKGROUND OF THE TNVENTTON

Field of the Invention

The present invention relates to an energy absorbing device, and more particularly to an impact absorbing device for a vehicle.

Description of the Prior Art

Safety is the first priority when people buy cars. Car safety design generally includes active safety which is designed to prevent car accident, and passive safety which is designed to reduce consequences of an accident.

Early passive safety design aims at reducing the damage to tile car body The early passive safety products are mainly designed to reduce the impact force applied to the car body For example, British Patent No. GB1200464 discloses an energy absorbing device 10, as shown in Fig. I. The energy absorbing device 10 is a corrugated pipe formed with a plurality of slits 11 and disposed between a bumper A and a car body B. With the design of the corrugated structure and the slits, the energy absorbing device 10 can be elastically deformed upon an impact force to reduce damage to the car body B. However; the elastic deformation property also means that the energy absorbing device 10 is not rigid enough to withstand a high energy impact. An impact of high energy impact not only will cause damage to the car body, but also will injure the passengers inside the vehicle. The safety device as disclosed in Japanese Patent No. 1P2008302791 also suffers from the same problem.

U.S. Patent No. US 3724833 also discloses an energy absorbing bumper system 20, as shown in Figs. 2 and 3, which is disposed between the bumper A and the car body B, and comprises an elastically deformable member 21 inserted in an elastic housing 22. The elastic housing 22 is an annular hollow structure formed by a plurality of annularly spaced apart elastically deformable ribs 211. The elastic housing 22 is made of high density cellular material such as polyurethane. When the energy absorbing bumper system 20 is impacted by an impact force, the elastically deformable member 21 and the elastic housing 22 will deform to reduce damage to the car body B caused by the impact force. Similarly, the elastic deformation property also represents less rigidity, which means the passenger safety cannot be guaranteed in case of high energy impact.

British Patent No. 0B347447 discloses another energy absorbing device 30 which has two ends connected to the car body and the bumper, as shown in Fig. 4, and has a plurality of rubber pieces 3 1 connected between the two ends thereof The rubber pieces 31 will be deformed, upon impact to reduce the damage to the car body.

This energy absorbing device 30 also suffers the same problem of less rigidity, and passenger safety cannot be guaranteed in case of high energy impact.

U.S. Patents Nos. 3564688 and 3412628 disclose an energy absorbing structure 40, as shown in Fig. 5. The energy absorbing structure 40 is also disposed between the car body and bumper and in the form of a circular pipe which includes a plurality comigated portions 41 between the two ends thereof and a plurality of slits 411 in each of the corrugated portions 41. Upon impact, the corrugated portions 41 will be deformed to absorb the impact force. Since the energy absorbing structure 40 is a single unitary structure, if it is made of less rigid material, the safety of the car body and the passengers cannot be guaranteed. If the energy absorbing structure is made of rigid material, the impact force cannot be absorbed, which will add to the impact to tile car body, and cause unpredictable damage to tile passengers.

To solve tile above problems, an impact-absorbing car body which is designed to protect the passengers has been developed. The cabin of the vehicle is strengthened, while the rear and front of the car body have less structural strength than the cabin, so as to provide crumple zones to absorb impact force during a collision, thus reducing injuries. The front and rear crumple zones will crumple, upon a collision, to reduce the impact force transferred to the cabin, so as to provide protection to the occupants. However, some main components of the vehicle, such as engine, water tank and gearbox, have to be disposed in front end of the cabin, which requires holistic spatial planning, and therefore substantially restricts the flexibility of spatial and mechanism arrangements.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF TITlE INVENTION

The primary objective of the present invention is to provide an impact absorbing device for a vehicle, which solves the problem that the conventional impact absorbing device is only capable of reducing the damage to the vehicle and but is unable to ensure the safety of the passengers. Furthermore, the impact absorbing device in accordance with the present invention is able to reduce crumple zone, so as to improve the spatial arrangement flexibility of the vehicle.

To achieve above objective, an impact absorbing device for a vehicle in accordance with the present invention comprise: a first end connector, at least two energy absorbing members, and a second end connector, a direction extending from the first end connector to the second end connector being defined as an axial direction, the first end connector having one end fixed to a chassis, the energy absorbing members having their one ends connected to each other, and having another ends connected to another end of the first end connector and to tile second end connector, respectively. The impact absorbing device is characterized in that: each of the energy absorbing members includes a plurality of energy absorbing units, each of the energy absorbing units is an elongated piece made of deformable metal, and includes an arc-shaped section between two ends thereof, the arc-shaped section is configured as an arc-shaped protrusion with respect to the axial direction, the energy absorbing units are annularly arranged to form the energy absorbing member; and the energy absorbing members each have a fracture toughness, and the fracture toughnesses are different from each other, and the energy absorbing member with a larger fracture toughness value is located closer to the first end connector than the energy absorbing member with a smaller fracture toughness value.

The energy absorbing device of the present invention is provided with at least two energy absorbing members with different fracture toLlghnesses, and the energy absorbing member with a smaller fracture toughness is first subjected to the impact force before other energy absorbing members to absorb most of the impact energy. The energy absorbing member with larger fracture toughness is located closer to the chassis to stop the impact energy from being transmitted directly to the chassis. In addition to absorbing the impact energy and reducing the impact force transmitted to tile chassis, the first energy absorbing member can also prevent the passengers from being injured by violent shaking. It is to be noted that the energy absorbing device itself deforms upon an application of an impact force to the vehicle, the energy absorbing device can be independently mounted on the chassis and therefore has an improved applicability. Furthermore, the energy absorbing device as a whole deforms upon an impact force, therefore, the vehicle does not have to be designed with additional crumple zone, thus improving the spatial arrangement flexibility of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows an energy absorbing device disclosed in British Patent No. 031200464; Fig. 2 shows an energy absorbing bumper system disclosed in U.S. Patent No. 3724833; Fig. 3 shows the deformation of the energy absorbing bumper system of Fig.2, upon impact; Fig. 4 shows an energy absorbing device disclosed in British Patent No. GB347447; Fig. 5 shows an energy absorbing bumper system disclosed in U.S. patent No. 3564688; Fig. 6 is a perspective view of an impact absorbing device for a vehicle in accordance with a preferred embodiment of the present invention; Fig. 7 is a cross sectional view of the impact absorbing device for a vehicle in accordance with the present invention; Fig. 8 shows that tile impact absorbing device for a vehicle in accordance with the present invention is mounted on the chassis; Fig. 9 shows that the impact absorbing device for a vehicle in accordance with the present invention is mounted on the chassis and crumples upon impact; Fig. 10 shows deformation of the impact absorbing device for a vehicle in accordance with the present invention; Fig. 11 is a side view of Fig. 10; Fig. 12 shows that the impact absorbing device for a vehicle in accordance with another preferred embodiment of the present invention is provided with three energy absorbing members; and Fig. 13 shows another embodiment of the impact absorbing device for a vehicle in accordance with the present invention, wherein the energy absorbing members are arranged into a square cage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention.

Referring to Figs. 6-8, an impact absorbing device for a vehicle in accordance with a preferred embodiment of the present invention is mounted on a chassis Cl of a vehicle C, and comprises: a first end connector 50, at least two energy absorbing members 60, and a second end connector 70. A direction extending from the first end connector 50 to the second end connector 70 is defined as an axial direction X. The first end connector 50 has one end fixed to the chassis C, and both ends of the first end connector 50 each have an area larger than 30 square centimeters. In this embodiment, the first end connector 50 is a circular member with a diameter larger than 6 ciii.

The energy absorbing members 60 include a first energy absorbing member 60A with a first fracture toughness and a second energy absorbing member 60B with a second fracture toughness. Namely, the energy absorbing members 60 each have a fracture toughness, and the fracture toughnesses are different from each other. The energy absorbing member 60 with a larger fracture toughness value is located closer to the first end connector 50 than the energy absorbing member 60 with a smaller fracture toughness value. Namely, the fracture toughness of the energy absorbing member 60 which is located farther to the first end connector 50 is smaller than that of the energy absorbing member 60 which is located closer to the first end connector 50. The fracture toughness is the proportion of the energy absorbed (during the time period from the time point of application of an external force on the energy absorbing member to the time point of fracture of the energy absorbing member) by the energy absorbing member to the volume of the energy absorbing member.

The at least two energy absorbillg members 60 are disposed between the first and second end connectors 50, 70. The two energy absorbing members 60 have their one ends connected to each other, and have another ends connected to another end of the first end connector 50 and to the second end connector 70, respectively.

Fig. 1 shows an embodiment of the arrangement of the two energy absorbing members 60, wherein the first energy absorbing member 60A has one end connected to another end of the first end connector 50 and another end connected to one end of the second energy absorbing member 60B. In this embodiment, the fracture toughness of the first energy absorbing member 60A is larger than that of the second energy absorbing member 60B. The second energy absorbing member 60B is longer than the first energy absorbing member 60A so as to achieve different fracture toughnesses.

Each of the energy absorbing members 60 includes a plurality of energy absorbing units 61. In this embodiment, each of the energy absorbing units 61 is an elongated piece made of deformable metal, and includes an arc-shaped section 611 between two ends thereof The arc-shaped section 611 is configured as an arc-shaped protrusion with respect to the axial direction X. The energy absorbing units 61 are annularly arranged to form the energy absorbing member 60 which is in the shape of a cylindrical cage with the middle bulging out. Fracture toughness variation can be achieved by changing the length, thickness or material of the energy absorbing units 61 of the energy absorbing members 60.

The second end connector 70 is connected another end of the second energy absorbing member 60B, and both ends of the second end connector 70 each have an area larger than 30 square centimeters. In this embodiment, the second end connector 70 is a circular member with a diameter larger than 6 cm.

What mentioned above are the structure relations and characteristics of the impact absorbing device for a vehicle in accordance with the present invention, for its operation, reference should be made to Figs. 8-11. The impact absorbing device

S

for a vehicle in accordance with the present invention is mounted on a chassis Clof a vehicle C. upon impact, the second energy absorbing member 60B which is located farther from the chassis Cl will be first subjected to the impact force. Since the second energy absorbing member 60B has a fracture toughness smaller than the first energy absorbing member 60A, the second energy absorbing member 60B will absorb the impact energy and deform (crumple) at the beginning of the impact action, at this moment, the deformation of the second energy absorbing member 60B is elastic deformation. When the second energy absorbing member 60B is continuously subjected to the impact force, and the impact force is larger than the yield strength of the second energy absorbing member 60B, the second energy absorbing member 603 continues to deform, at this moment, the deformation of the second energy absorbing member 60B is plastic deformation and used to absorb the impact energy.

So far, most of the impact energy has been absorbed by the second energy absorbing member 60B.

Then the rest of the impact energy which is not absorbed by the second energy absorbing member 60B will be continuously transmitted to the first energy absorbing member 60A. The first energy absorbing member 60A will also absorb the impact energy through deformation. Since the first energy absorbing member 60A has a fracture toughness larger than the second energy absorbing member 60B, in addition to absorbing the impact energy and reducing the impact force transmitted to the chassis Cl, the first energy absorbing member 60A can also stop the impact energy from being transmitted directly to the chassis Cl, preventing the passengers from being injured by violent shaking.

Since the energy absorbing members 60 absorb impact force through deformation, and the energy absorbing unit 61 is configured as an arc-shaped protrusion with respect to the axial direction X, the energy absorbing unit 61 can deform along its own shape, as shown in Figs. 9 and 10, making the deformation of the energy absorbing members predictable.

The number of the energy absorbing members 60 is not limited to the embodiment as described above (in Figs. 6-li), where there two energy absorbing members 60. The energy absorbing device in accordance with the present invention can also be provided with three energy absorbing members 60, as shown in Fig. 12, where the energy absorbing members 60 have their one ends connected to each other, and the energy absorbing members 60 at two sides have another ends connected to the first and second end connectors 50, 70, respectively. In this embodiment, the fracture toughness of the energy absorbing member 60 which is located farther to the first end connector 50 is also smaller than that of the energy absorbing member 60 which is located closer to the first end connector 50.

Figs. 6-12 show that the first and second end connectors 50, 70 are circular-shaped, and the energy absorbing units 61 are annularly arranged into a cylindrical cage. However, the energy absorbing device of the present invention is not limited to this, and it can also be as shown in Fig. 13, wherein the first and second end connectors 50, 70 are square-shaped, and the energy absorbing units 61 are annularly arranged into a rectangular cage.

The energy absorbing device of the present invention is provided with at least two energy absorbing members 60 with different fracture toughnesses, and the I0 energy absorbing member 60 with a smaller fracture toughness is first subjected to the impact force before other energy absorbing members to absorb most of the impact energy. The energy absorbing member 60 with larger fracture toughness is located closer to the chassis Cl to stop the impact energy from being transmitted directly to the chassis CI. Tn addition to absorbing the impact energy and reducing the impact force transmitted to the chassis Cl, the first energy absorbing member 60A can also prevent the passengers from being injured by violent shaking. It is to be noted that the energy absorbing device itself deforms upon an application of an impact force to the vehicle, the energy absorbing device can be independently mounted on the chassis Cl and therefore has an improved applicability. Furthermore, the energy absorbing device as a whole deforms upon an impact force, therefore, the vehicle does not have to be designed with additional crumple zone, thus improving the spatial arrangement flexibility of the vehicle.

While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. I!

Claims

WHAT IS CLAIMED IS: 1. An impact absorbing device for a vehicle comprising: a first end connector, at least two energy absorbing members, and a second end connector, a direction extending from the first end connector to the second end connector being defined as an axial direction, the first end connector having one end fixed to a chassis, the energy absorbing members having their one ends connected to each other, and having another ends connected to another end of the first end connector and to the second end connector, respectively; the impact absorbing device being characterized in that: each of the energy absorbing members includes a plurality of energy absorbing units, each of the energy absorbing units is an elongated piece made of deformable metal, and includes an arc-shaped section between two ends thereof, the arc-shaped section is configured as an arc-shaped protrusion with respect to the axial direction, the energy absorbing units are annularly arranged to form the energy absorbing member; and the energy absorbing members each have a fracture toughness, and the fracture toughnesses are different from each other, and the energy absorbing member with a larger fracture toughness value is located closer to the first end connector than the energy absorbing member with a smaller fracture toughness value.
2. The impact absorbing device for the vehicle as claimed in claim 1, wherein both ends of the first end connector each have an area larger than 30 square centimeters, and both ends of the second end connector each have an area larger than square centimeters.
3. An impact absorbing device for a vehicle substantially as hereinbefore described with reference to and as shown in Figures 6 to 13 of the accompanying drawings.Amendments to the claim has been made as follows WHAT IS CLAIMED IS: I. An impact absorbing device for a vehicle comprising: a first end connector, at least two energy absorbing members, and a second end connector, a direction extending from the fir st end connector to the second end connector being defmed as an axial direction, the first end connector having one end fixed to a chassis, the energy absorbing members having their one ends connected to each other, and having another ends connected to another end of the first end connector and to the second end connector, respectively; the impact absorbing device being characterized in that: each of the energy absorbing members includes a plurality of energy absorbing units, each of the energy absorbing units is an elongated piece made of deformable metal, and includes an arc-shaped section between two ends thereof, the arc-shaped section is configured as an arc-shaped protrusion with respect to the axial L:> direction, the energy absorbing units are annularly arranged to form the energy * absorbing member; re:: the energy absorbing members each have a fracture toughness, and the * fracture toughnesses are different from each other, the energy absorbing member * C* :. * with a larger fracture toughness value is located closer to the first end connector than the energy absorbing member with a smaller fracture toughness value; and both ends of the first end connector each have an area larger than 30 square centimeters, and both ends of the second end connector each have an area larger than square centimeters.2. An impact absorbing device for a vehicle substantially as hereinbefore described with reference to and as shown in Figures 6 to 13 of the accompanying drawings. * .s * t 4 r* **.* . *! * , * . P...I * 0I * I