EP2418325A2

EP2418325A2 - Impact attenuator

Info

Publication number: EP2418325A2
Application number: EP20110175519
Authority: EP
Inventors: Yong-Soon Hwang; Gun-Tae Kim; Kyoung-Woo Nam; Ju-Tai Kim
Original assignee: Shindo Industry Co Ltd
Current assignee: SHINDO INDUSTRY CO., LTD.
Priority date: 2010-08-11
Filing date: 2011-07-27
Publication date: 2012-02-15
Also published as: CN103069078B; JP2013535601A; WO2012020975A3; EP2418325A3; WO2012020975A2; JP5592013B2; CN103069078A; KR20120015020A; KR101150938B1

Abstract

An impact attenuator includes: a plurality of support frames installed in a row at an interval, each support frame having first and second horizontal beams, a reinforcing member installed between the first and second horizontal beams, and at least one wire clip installed under the first horizontal beam; a rear support integrally formed with one of the support frames and having a vertical beam; a plurality of guard rail connecting units, each guard rail connecting unit including guard rails installed on opposite sides of each of the support frames and a fixing member for movably installing the guard rails; and an absorbing tank including a front tank installed on a front surface of one of the support frames and a plurality of cushion tanks installed between the support frames, wherein a wire rope connects the support frames and the rear support to guide linear movements of the support frames.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to an impact attenuator, and more particularly to an impact attenuator which absorbs impact energy generated during an automobile accident with a frictional force to safely stop the vehicle, thereby protecting passengers.

2. Description of the Prior Art

Conventionally, an impact attenuator is one of the traffic safety facilities installed at a branch of a road, an entrance of a tunnel or an underground road, a bridge, a tollgate, etc. The impact attenuator absorbs impact energy when a vehicle deviates from a normal travelling lane and collides with a road structure, minimizing damage to the driver or passengers and stopping the vehicle.
Such an impact attenuator can effectively absorb impact energy of a vehicle and minimize an impact applied to passengers, and is required to be easily maintained and promptly reinstalled after being damaged.
However, once a conventional impact attenuator is damaged due to the impact of a vehicle, since much time is consumed to repair and restore it, the area where the impact attenuator has been damaged is left alone with no safety structure.
Although it is well known in the art that guard rails are installed in rails on a road surface and impact absorbing members such as used tires, air bags, and rubber chips are installed between the guard rails, installation of such an impact attenuator is complex and much time and high costs are consumed to repair the impact attenuator because basic constructions such as the installation of rails are required once they are damaged.
Also, when a conventional impact attenuator is damaged due to the impact of a vehicle, the damaged remains are left alone on a road surface, increasing a danger of a secondary accident.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an impact attenuator which absorbs impact energy generated during the impact of a vehicle with a frictional force to safely stop the vehicle, thereby protecting passengers.
It is another object of the present invention to provide an impact attenuator which applies wire clips capable of connecting support frames and a wire rope during either a front impact or a side impact of a vehicle, thereby preventing the support frames from being separated and released individually.
It is still another object of the present invention to provide an impact attenuator which improves impact energy absorbing efficiency during the impact of a vehicle by filling absorbing members in a front tank and some of a plurality of cushion tanks.
It is yet another object of the present invention to provide an impact attenuator which prevents wreckage from being left alone in the event of the impact of a vehicle using absorbing members, thereby preventing the danger of a secondary accident.
In order to accomplish this object, there is provided an impact attenuator including: a plurality of support frames installed in a row at an interval, each support frame having first and second horizontal beams, a reinforcing member installed between the first and second horizontal beams, and at least one wire clip installed under the first horizontal beam; a rear support integrally formed with one of the support frames and having a vertical beam; a plurality of guard rail connecting units, each guard rail connecting unit including guard rails installed on opposite sides of each of the support frames and a fixing member for movably installing the guard rails; and an absorbing tank including a front tank installed on a front surface of one of the support frames and a plurality of cushion tanks installed between the support frames, wherein a wire rope connects the support frames and the rear support to guide linear movements of the support frames.
Preferably, the wire clip portion includes a U-bolt, a wire clip element engaged with the U-bolt to guide the wire rope, a pair of resilient members for supporting the wire clip element and absorbing an impact, and a pair of nuts for mounting and coupling the wire clip element and the resilient members to the U-bolt.
Preferably, the vertical beam of the rear support may be installed on a base plate. A wire fixing plate may be installed at a lower portion of the vertical beam of the rear support. A reinforcing member for supporting the vertical beam may be installed on one side of the vertical beam of the rear support.
Preferably, the guard rail of the guard rail connecting unit may be installed so as to move along a plurality of slots formed lengthwise on a side surface thereof and a fixing bolt and a nut may be engaged with each other through each slot.
Preferably, the fixing member of the guard rail connecting unit may include a fixing bolt, a spacer mounted on the fixing bolt and installed in the support frame, a washer mounted on the fixing bolt, and a nut engaged with the fixing bolt.
Preferably, a reflective body may be installed on an outer side of the spacer to be easily distinguished even at night.
Preferably, first and second reflective bodies may be installed on a front surface of the front tank of the absorbing tank, and a plurality of absorbing members may be installed inside the front tank.
Preferably, a plurality of absorbing members may be installed inside some of the cushion tanks, and the remaining cushion tanks may be hollow.
Preferably, each cushion tank may include an air outlet opening formed on a front surface thereof to discharge air to the outside, curved portions formed on opposite side surfaces thereof, a wire channel formed at a lower portion thereof to guide the wire rope, and an upper surface formed at an upper portion and having a protrusion.
Preferably, cuts may be formed at an outer periphery of the air outlet opening of the cushion tank.
Preferably, the cushion tanks may be made of a synthetic resin including a polyethylene resin
Preferably, each absorbing member may be made of a ductile metal such as aluminum and has a partition wall at a central portion thereof. A plurality of first coupling grooves and a plurality of second coupling grooves may be formed at an upper portion of and on a side surface of the absorbing member respectively. A plurality of first coupling bosses and a plurality of second coupling bosses may be formed at a lower portion of and on an opposite surface of the absorbing member respectively.
Preferably, the partition wall of the absorbing member may be hollow and waved.
Preferably, one side of the wire rope may be connected to a shackle and a ring-shaped connecting member connected to a pillar and an opposite side thereof may be connected to a ring-shaped connecting member and an eye bolt with the eye bolt being fixed by means of a nut.
The impact attenuator according to the present invention can apply wire clips capable of connecting support frames and a wire rope during either a front impact or a side impact of a vehicle, thereby preventing the support frames from being separated and released individually.
Further, the impact attenuator according to the present invention can improve impact energy absorbing efficiency during the impact of a vehicle by filling absorbing members in a front tank and some of a plurality of cushion tanks.
In addition, the impact attenuator according to the present invention can prevent wreckage from being left alone in the event of the impact of a vehicle using absorbing members, thereby preventing the danger of a secondary accident.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is perspective view schematically illustrating an impact attenuator of the present invention in an assembled state;
FIG. 2 is a side view of the impact attenuator of the present invention;
FIG. 3 is a front view of the impact attenuator of the present invention;
FIG. 4 is a sectional view taken along line A-A of FIG. 2;
FIG. 5 is a perspective view of a support frame of the impact attenuator of the present invention;
FIG. 6 is a perspective view illustrating a connection between the support frame and a rear support of the impact attenuator of the present invention;
FIG. 7 is a side view illustrating a wire rope of the impact attenuator of the present invention in an installed state;
FIG. 8 is a perspective view of a cushion tank which is a main part of the impact attenuator of the present invention;
FIG. 9 is a perspective view illustrating an absorbing member which is a main part of the impact attenuator of the present invention in a coupled state;
FIG. 10 is a sectional view of the absorbing member which is a main part of the impact attenuator according to the present invention;
FIGS. 11 and 12 are views illustrating a coupled state of the support frame and a guard rail of the impact attenuator according to the present invention;
FIG. 13 is a perspective view illustrating a coupled state of the support frame, the guard rail, and a fixing member of the impact attenuator according to the present invention;
FIG. 14 is a perspective view illustrating a connection of guard rails which are main parts of the present invention; and
FIG. 15 is a perspective view illustrating a compressed state of the impact attenuator according to the present invention due to the impact of a vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an impact attenuator according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is perspective view schematically illustrating an impact attenuator of the present invention in an assembled state. FIG. 2 is a side view of the impact attenuator of the present invention. FIG. 3 is a front view of the impact attenuator of the present invention. FIG. 4 is a sectional view taken along line A-A of FIG. 2.
The impact attenuator according to the embodiment of the present invention includes a plurality of support frames 100, a rear support 200, a guard rail connecting unit 400, and an absorbing tank 500, and the support frames 100 and the rear support 200 are connected to each other by means of wire ropes 600 so that linear movements of the support frames 100 can be guided.
As illustrated in FIGS. 1 and 5, the support frames 100 are installed in a row by an interval. That is, as illustrated in FIG. 4, the support frames 100 include first to seventh support frames 101, 102, 103, 104, 105, 106, and 107, and the seventh support frame 107 is integrally installed in a base plate 162 in conjunction with the rear support 200 which will be described below.
As illustrated in FIG. 5, the support frames 100, i.e. the first to seventh frames 101, 102, 103, 104, 105, 106, and 107 have a rectangular shape, which has upper and lower surfaces 112 and 114, and a pair of side surfaces 122. First and second horizontal beams 132 and 134 are installed inside the support frames 100, and a reinforcing member 130 is installed between the first and second horizontal beams 132 and 134.
The reinforcing member 130 of the support frames 100 is installed between the first and second horizontal beams 132 and 134, and one or more wire clips 150 are installed under the first horizontal beam 132. Although two wire clips 150 are formed under the first horizontal beam 132 herein, only one wire clip may be installed at a central portion of the first horizontal beam or more than two wire clips may be installed according to the demand of the user.
As illustrated by an enlarged portion of FIG. 5 and indicated by an arrow, the wire clip portion 150 includes a U-bolt 152, a wire clip element 154 engaged with the U-bolt 152 to guide the wire rope 600, a pair of resilient members 156 for supporting the wire clip element 154 and absorbing an impact, and a pair of nuts 158 for mounting and coupling the wire clip element 154 and the resilient members 156 to the U-bolt 152. A support groove 153 is formed in the wire clip element 154 according to the shape of the wire rope 600 to reduce friction.
The nuts 158 are fastened and the U-bolt 152 is pulled to chuck the wire rope 600 in the wire clip 150, and the resilient members 156 are pulled by a tension of the resilient members 156 to chuck the wire rope 600 with a suitable force.
Since the wire clip element 154 is resiliently pushed down by the resilient members 156 mounted to the U-bolt 152, when the support frame 100 is moved due to a front impact of a vehicle, the wire clip element 154 serves to absorb impact energy using a frictional force and guide a linear movement of the support frame 100 in an extension direction (i.e. a lengthwise direction) of the wire rope 600. That is, since the wire clip element 154 chucks the wire rope 600, it serves as a guide for preventing deviation of the support frame 100 as well as generation of a frictional force when the support frame 100 is moved.
The wire rope 600 absorbs impact energy using its resiliency during a side impact of a vehicle and prevents deviation of a guard rail 300 such as the support frame 100.
Meanwhile, the rear support 200 is connected to the endmost support frame 107 of the support frames 100, and is fixed to the base plate 162 on a road surface (ground surface) by means of an anchor bolt 800 to support impact energy generated during the impact of a vehicle and prevent the impact attenuator from being moved.
The rear support 200 includes a vertical beam 210 which may be one of various beams such as an H-beam and an I-beam, but an H-beam is illustrated as the vertical beam 210 herein. As illustrated in FIG. 6, the vertical beam 210 of the rear support 200 is installed in the base plate 162. A wire fixing plate 160 having a plurality of fixing holes 168 is installed at a lower portion of the vertical beam 210 and a reinforcing member 170 for supporting the vertical beam 210 is installed on one side of the vertical beam 210. As illustrated in FIG. 7, the base plate 162 has a plurality of through-holes 172 at an outer periphery thereof, and anchor bolts 800 are installed in the through-holes 172 to fix the base plate 162 to a road surface. Eye bolts 740 connected to sides of ring-shaped connecting members 730 connected to the wire ropes 600 are fixed to the fixing holes 168 formed on the wire fixing plates 160 by means of nuts such that the wire ropes 600 are connected tightly as the nuts 755 are fastened tightly.
The wire rope 600 passes through the wire clips 150 of the support frames 101, 102, 103, 104, 105, 106, and 107 and are fixed to the fixing holes 168 of the fixing plate 160 by means of the eye bolt 740. That is, as illustrated in FIG. 7, one side of the wire rope 600 is connected to a shackle 710 and a ring-shaped connecting member 720 connected to a pillar 700 and an opposite side thereof is connected to a ring-shaped connecting member 730 and an eye bolt 740 with the eye bolt 740 being fixed by means of a nut 755.
The wire rope 600 supports the support frames 100, and allows the support frames 100 to absorb impact energy through a frictional force during the impact of a vehicle and guides linear movements of the support frames 100.
Meanwhile, as illustrated in FIGS. 1, 4, and 13, the guard rail connecting unit 400 includes guard rails 300 installed on opposite surfaces of the support frames 100, and fixing members 350 for movably installing the guard rails 300 in the support frames 100.
As illustrated in FIG. 2, a plurality of guard rails 300 are installed on opposite sides of the support frames 100. Although the guard rails 300 include six guard rails 301, 302, 303, 304, 305, and 306, their number may be increased or decreased according to a demand of the user. As illustrated in FIG. 14, a plurality of slots 310 are formed lengthwise at an interval on a side surface of the guard rail 300.
As illustrated in FIG. 13, the fixing member 350 includes a fixing bolt 352, a spacer 354 mounted on the fixing bolt 352 and installed in the support frame 100, a washer 356 mounted on the fixing bolt 352, and a nut 358 engaged with the fixing bolt 352.
The fixing members 350 are installed in a plurality of through-holes 126 formed on opposite surfaces 121 and 122 of the support frame 100. That is, the spacer 354 is mounted on the fixing bolt 352 which in turn passes through the through-hole 126 formed on a side surface of the support frame 100, and the washer 356 is additionally mounted on the fixing bolt 352 which in turn is engaged with the nut 358. A reflective body 364 is installed on an outer side of the spacer 354 to be easily distinguished even at night.
As illustrated in FIGS. 1 and 2, a plurality of guard rails 300 are sequentially installed in a manner in which the second guard rail 302 is installed inside the first guard rail 301 and the third guard rail 303 is installed inside the second guard rail 302. This is because as the number of guard rails 300 increases as it goes rearward, an angle by which the guard rails 300 are widened and absorption energy increase during the impact of a vehicle. In this way, as illustrated in FIG. 15, when the guard rails 300 are widened while overlapping each other, a frictional force applied between the guard rails 300 increases, while reducing the speed of a vehicle and absorbing the impact (impact energy) transferred to the vehicle. That is, impact energy generated during the impact of a vehicle is absorbed by a contact pressure between the support frame 100 and the ground surface, frictional forces generated in the guard rails 300 and the wire ropes 600, and inertial forces generated by the gravity of the support frame, thereby making it possible to safely stop the vehicle.
Meanwhile, as illustrated in FIGS. 1, 3, and 8, the absorbing tank 500 includes a front tank 430 installed on a front side of the support frames 100, and a plurality of cushion tanks 450 installed between the support frames 100.
As illustrated in FIG. 3, first and second reflective bodies 432 and 434 are installed on the front tank 430 of the absorbing tank 500. Also, as illustrated in FIG. 11, a plurality of tube-like absorbing members 380 are installed inside the front tank 430. The details of the absorbing members 380 will be described below. Here, although five absorbing members 380 are illustrated in FIG. 11, their number may be changed according to a demand of the user.
As illustrated in FIG. 8, the cushion tank 450 includes an air outlet opening 454 formed on a front surface 452 thereof to discharge air to the outside, curved portions 464 formed on opposite side surfaces 462 thereof, a wire channel formed at a lower portion thereof to guide the wire rope 600, and an upper surface 480 formed at an upper portion and having a protrusion 482.
The air outlet opening 454 has a diameter of approximately 50 mm, and cuts 455 having a size of approximately 10 to 20 mm are formed at an outer periphery of the air outlet opening 454 at an interval of 90 degrees so that the cuts 455 of the air outlet opening 454 can be easily damaged if an impact is applied to the cushion tank 450.
The cushion tank 450 is adapted to absorb impact energy while being compressed by an impact applied during the impact of a vehicle. That is, the cushion tank 450 serves as an air cushion while air in the cushion tank 450 is compressed and reduces impact energy as compressed air is discharged through the air outlet opening 454 during the impact of a vehicle. In this case, since the air outlet opening 454 serves as a damper for slowly reducing the speed of a vehicle (not shown) during the impact of a vehicle, it can restrict a vehicle from returning to the travelling lane due to the impact of the vehicle, thereby preventing a secondary accident.
The cushion tank 450 is preferably made of metallocene polyethylene to be restored to the original shape when a force pressing the cushion tank is removed by moving a vehicle after the impact of the vehicle.
The curved portion 464 is grooved lengthwise to increase resistance and restorability against compression when the cushion tank 450 is deformed. The wire channel 470 formed at a lower portion of the cushion tank 450 has a predetermined depth to guide the wire rope 600 and prevent deviation of the wire rope 600. The wire channel 470 is a passage through which the wire rope 600 extends while not being interfered by the support frame 100.
Meanwhile, as illustrated in FIG. 8, the upper surface 480 of the cushion tank 450 has a protrusion 482 protruding rearward. The protrusion 484 protrudes to correspond to the width of the support frame 100 by a predetermined length to prevent the support frame 100 from being exposed to the outside when it covers the upper surface of the support frame 100.
As illustrated in FIG. 11, a plurality of tube-like absorbing members 380 the cushion tanks 450 are installed inside at least two cushion tanks, and the remaining cushion tanks are hollow. In this way, the absorbing members 380 are inserted only into the two cushion tanks of the cushion tanks 450 which are installed on the rear side, and they are not installed in the cushion tanks 450 installed on the front side to sequentially attenuate an impact of a vehicle.
Although eighteen absorbing members 380 are inserted into the two cushion tanks 450 installed on the rear side, the number of absorbing members 380 may be changed according to a demand of the user. The number of cushion tanks 450 into which absorbing members 380 are inserted may also be changed. The cushion tank 450 may be made of a synthetic resin including a polyethylene resin.
Meanwhile, as illustrated in FIG. 10, each absorbing member 380 has a partition wall at a central portion thereof. Also, a plurality of first coupling grooves 388 and a plurality of second coupling grooves 398 are formed at an upper portion of and on a side surface of the absorbing member 380 respectively, and a plurality of first coupling bosses 382 and a plurality of second coupling bosses 392 are formed at a lower portion of and on an opposite surface of the absorbing member 380 respectively. The absorbing member 380 is made of a ductile metal such as aluminum to absorb impact energy generated due to an impact. The material of the absorbing member 380 is not limited thereto, but may be made of a metal equivalent to aluminum.
As illustrated in FIGS. 9 and 10, when the absorbing member 380 is to be extended lengthwise (transversely), another absorbing member 380 is connected to it in a sliding manner using the second coupling boss 392 and the second coupling groove 398 installed opposite to its outer peripheral surface. When the absorbing member 380 is to be extended vertically (longitudinally), another absorbing member 380 is connected to it in a sliding manner using a pair of first coupling bosses 382 and a pair of first coupling grooves 388 formed at its upper and lower portions.
Meanwhile, the partition wall 384 of the absorbing member 380 is hollow and waved lengthwise. The partition wall 384 is adapted to further absorb impact energy while being deformed together with the absorbing member 380, and the waves of the absorbing member advantageously disperse a force applied along a compression direction as compared with a linear configuration.
Now, the installation and operation of the impact attenuator according to the embodiment of the present invention will be described.
As illustrated in FIGS. 1 and 2, according to the impact attenuator according to the embodiment of the present invention, the rear support 200 is fixedly installed first, and after the guard rail connecting unit 400 and the absorbing tank 500 having the front tank 430 and the cushion tank 450 are installed in the support frames 100, they are fixedly installed on a road surface.
The base plate 162 of the rear support 200 is located at a predetermined installation position (not shown), and is fixed by means of the anchor bolts 800. The wire ropes 600 are inserted into the wire fixing plate 160 of the rear support 200 and then are arranged in a row. In this state, as illustrated in FIG. 5, the support frames 100 are disposed at an interval while the wire ropes 600 are inserted into the support frames 100.
As illustrated in FIGS. 13 and 14, the guard rails 300 are installed on opposite sides of the support frames 100 by means of the fixing members 350. The cushion tank 450 is inserted between the support frames 100, and then the front tank 430 is inserted. The absorbing members 380 are inserted into the front tank 430 and two of the cushion tanks 450. The rear plate (not shown) is installed behind the rear support 200. Finally, the wire ropes 600 are fixed firmly.
If a vehicle (not shown) collides with the front tank 430 of the impact attenuator of FIG. 1, the front tank 430 is deformed, thereby absorbing some of the impact energy and reducing the speed of the vehicle. Then, if the vehicle proceeds further, the support frames 100 are moved rearward so that the spaces between the support frames 100 are reduced.
That is, as illustrated in FIG. 7, if the vehicle proceeds further, the first support frame 101 is moved and the first guard rails 301 installed on opposite sides of the support frame 101 is moved together at the same time, in which case the space 354 of the second support frame 102 fixed by means of the fixing bolt 352 and the nut 358 generates a frictional force, thereby absorbing impact energy once more. They can be moved while being fixed by means of the fixing bolt 352 and the nut 358 because the slot 310 is formed in the guard rail 300.
Since the support frames 100 are connected to each other by the wire rope 600 inserted into the wire clip 150 installed under the support frames 100, movement of the support frame 100 is guided by the guard rail connecting unit 400 and the wire rope 600.
Since a plurality of guard rails 300 are sequentially installed in a manner in which the second guard rail 302 is installed inside the first guard rail 301 and the third guard rail 303 is installed inside the second guard rail 302, the energy absorbed by the guard rails 300 increases as it goes rearward and the number of guard rails 300 increases.
In this way, as illustrated in FIG. 15, when the guard rails 300 overlap each other, a frictional force applied between the guard rails 300 increases, while reducing the speed of a vehicle and absorbing the impact (impact energy) transferred to the vehicle.
The absorbing member 380 installed inside the front tank 430 is deformed primarily, thereby absorbing impact energy. If the vehicle further pushes the guard rails 300 rearward, the air in the hollow cushion tanks 450 is discharged to the outside through the air outlet opening 454 by compression, thereby absorbing impact energy. Since the cuts 455 are formed at an outer periphery of the air outlet opening 454, the cuts 455 are easily damaged (that is, absorb impact energy) when the cushion tank 450 is deformed, thereby absorbing an impact. Although the hollow cushion tank 450 is deformed greatly by an impact, a repulsive force is reduced, making it possible to prevent a secondary accident and protect the driver and passengers of the vehicle.
Meanwhile, if the impact energy of the vehicle which has not been diminished further pushes the guard rails 300 rearward, the rear cushion tank 450 where the absorbing member 380 is installed further absorbs the impact energy of the vehicle and stops the vehicle while the absorbing member 380 is deformed.
Since the impact attenuator of the present invention absorbs an impact of a vehicle in almost three steps by using the front tank 430, the hollow cushion tanks 450 and the cushion tanks 450 having the absorbing members 380, and the guard rail connecting unit 400, the driver and passengers can be protected safely.
The impact attenuator of the present invention is installed at a branch of a road, an entrance of a tunnel or an underground road, a bridge, a tollgate, etc. Also, the impact attenuator can be widely applied to a traffic safety facility field related to traffic safety, and a safety facility field such as civil engineering, architecture, construction, a port, a flight, etc.
Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

An impact attenuator comprising:
a plurality of support frames (100) installed in a row at an interval, each support frame having first and second horizontal beams (132,134), a reinforcing member (130) installed between the first and second horizontal beams, and at least one wire clip portion(150) installed under the first horizontal beam (132);

a rear support (200) integrally formed with one of the support frames (100) and having a vertical beam (210);

a plurality of guard rail connecting units (400), each guard rail connecting unit including guard rails (300) installed on opposite sides of each of the support frames (100) and a fixing member (350) for movably installing the guard rails (300); and

an absorbing tank (500) including a front tank (430) installed on a front surface of one of the support frames (100) and a plurality of cushion tanks (450) installed between the support frames (100),

wherein a wire rope (600) connects the support frames (100) and the rear support (200) to guide linear movements of the support frames (100).
The impact attenuator as claimed in claim 1, wherein the wire clip portion (150) includes a U-bolt (152), a wire clip element (154) engaged with the U-bolt (152) to guide the wire rope (600), a pair of resilient members (156) for supporting the wire clip element (154) and absorbing an impact, and a pair of nuts (158) for mounting and coupling the wire clip element (154) and the resilient members (156) to the U-bolt (152).
The impact attenuator as claimed in claim 1, wherein the vertical beam (210) of the rear support (200) is installed on a base plate (162), a wire fixing plate (160) is installed at a lower portion of the vertical beam (210) of the rear support (200), and a reinforcing member (170) for supporting the vertical beam (210) is installed on one side of the vertical beam (210) of the rear support (200).
The impact attenuator as claimed in claim 1, wherein the guard rail (300) of the guard rail connecting unit (400) is installed so as to move along a plurality of slots (310) formed lengthwise on a side surface thereof and a fixing bolt (352) and a nut (358) are engaged with each other through each slot (310).
The impact attenuator as claimed in claim 1, wherein the fixing member (350) of the guard rail connecting unit (400) includes a fixing bolt (352), a spacer (354) mounted on the fixing bolt (352) and installed in the support frame (100), a washer (356) mounted on the fixing bolt (352), and a nut (358) engaged with the fixing bolt (352).
The impact attenuator as claimed in claim 5, wherein the spacer (354) includes a reflective body (364) installed on an outer side of the spacer to be easily distinguished even at night.
The impact attenuator as claimed in claim 1, wherein the front tank (430) of the absorbing tank (500) includes first and second reflective bodies (432,434) installed on a front surface thereof, and a plurality of absorbing members (380) installed at inside thereof.
The impact attenuator as claimed in claim 1, wherein some of the cushion tanks (450) are filled with a plurality of absorbing members (380) inside thereof, and the remaining cushion tanks are empty.
The impact attenuator as claimed in claim 1, wherein each cushion tank (450) includes an air outlet opening (454) formed on a front surface thereof to discharge air to the outside, curved portions (464) formed on opposite side surfaces thereof, a wire channel (470) formed at a lower portion thereof to guide the wire rope (600), and an upper surface (480) formed at an upper portion and having a protrusion (482).
The impact attenuator as claimed in claim 9, wherein the air outlet opening (454) of the cushion tank (450) includes cutting portions (455) formed at outer periphery thereof.
The impact attenuator as claimed in claim 1, wherein the cushion tanks (450) are made of a synthetic resin including a polyethylene resin
The impact attenuator as claimed in claim 7 or 8, wherein each absorbing member (380) is made of a ductile metal such as aluminum and has a partition wall (384) at a central portion thereof, a plurality of first coupling grooves (388,388) and a plurality of second coupling grooves (398) are formed at an upper portion of and on a side surface of the absorbing member respectively, and a plurality of first coupling bosses (382,382) and a plurality of second coupling bosses (392) are formed at a lower portion of and on an opposite surface of the absorbing member respectively.
The impact attenuator as claimed in claim 12, wherein the partition wall (384) of the absorbing member (380) is formed with hollow and wavelike.
The impact attenuator as claimed in claim 1, wherein one side of the wire rope (600) is connected to a shackle (710) and a ring-shaped connecting member (720) connected to a pillar (700) and an opposite side thereof is connected to a ring-shaped connecting member (720) and an eye bolt (740), said the eye bolt (740) being fixed by means of a nut (755).