WO2009072843A2

WO2009072843A2 - Tube-buffer for railway vehicles

Info

Publication number: WO2009072843A2
Application number: PCT/KR2008/007222
Authority: WO
Inventors: Tae-Su Kwon; Hyun-Seung Jung; Won-Mok Choi
Original assignee: Korea Railroad Research Institute
Priority date: 2007-12-06
Filing date: 2008-12-05
Publication date: 2009-06-11
Also published as: EP2227410A4; EP2227410A2; WO2009072843A3

Abstract

Disclosed herein is a tube buffer for railway vehicles, installed to the fore of a railway vehicle to absorb impact energy generated in the event of a collision of the railway vehicle. The die of the tube buffer expands a tube by impact energy, and simultaneously the blades of the die cut the expanded tube, so that the efficiency of absorbing impact energy is excellent and a small installation space is required. Further, a stabilizer provided on the tube buffer absorbs stage conversion impact generated when an impact energy absorbing stage is converted into a subsequent impact energy absorbing stage while the tube buffer absorbs impact energy in several stages, thus allowing the impact energy to be smoothly absorbed, therefore protecting drivers and passengers in case of an accident, and preventing a railway vehicle structure from being broken or damaged.

Description

[DESCRIPTION]

[invention Title]

TUBE-BUFFER FOR RAILWAY VEHICLES

[Technical Field] The present invention relates, in general, to a tube buffer for railway vehicles, which is installed to the fore of a railway vehicle to reduce and absorb impact energy generated in the event of a collision of the railway vehicle and, more particularly, to a tube buffer for railway vehicles, in which the die of the tube buffer expands a tube by impact energy generated in the event of the collision of a railway vehicle, and simultaneously blades provided on the die cut the expanded tube, so that the efficiency of absorbing impact energy is excellent and a small installation space is required.

Further, the present invention is directed to a tube buffer for railway vehicles, in which a stabilizer provided on the tube buffer absorbs stage conversion impact generated when an impact energy absorbing stage is converted into a subsequent impact energy absorbing stage while the tube buffer absorbs impact energy in several stages in the event of a collision of a railway vehicle, thus allowing the impact energy of the railway vehicle to be smoothly absorbed, therefore protecting drivers and passengers in case of an accident, and preventing a railway- vehicle structure from being broken or damaged.

[Background Art]

Generally, safety regulations on railway vehicles are provided to ensure the safety of drivers and passengers of a railway vehicle in the event of a collision of the railway vehicle. Railway vehicles are manufactured in accordance with the safety regulations .

For example, according to the safety regulations on railway vehicles which are commonly used in Europe, in the event of a crossing accident, when a train running at llOkph collides with a 15-ton truck which is stationary, a driver' s seat of a railway vehicle must not be crushed, and the deceleration of passengers in the railway vehicle must be 5g or less (g: gravitational acceleration, about 9.8m/s²). In the case where a railway vehicle collides with another railway vehicle, after the railway vehicles collide with each other at the relative speed of lβkph, a railway vehicle structure must not be deformed permanently and the deceleration of passengers in the railway vehicle must be 3g or less. Further, according to the regulations of the U. S department of transportation, energy of 5MJ or more must be absorbed in front of a driver' s seat of the railway vehicle (J: Joule, work done to move an object Im in the direction of force with the force of IN or energy required to move the object as described above) .

FIG. 1 is a conceptual view illustrating a conventional impact energy absorbing device which is applied to the fore of a railway vehicle 10. The device includes a coupler 20, a head stock 40 and a honeycomb part 30. The coupler 20 is crushed first by impact energy in the event of the collision of the railway vehicle 10, thus primarily absorbing the impact energy. The head stock 40 and the honeycomb part 30 function to absorb the remaining impact energy which is not absorbed by the coupler 20. In this way, most of the impact energy is absorbed.

In order to absorb the impact energy in the event of the collision of the railway vehicle 10, an expansion-type cylindrical tube buffer 400 of FIG. 2 is installed to each of the coupler 20 and the head stock 40. As shown in FIG. 2, the expansion-type tube buffer 400 includes a press- fitting tube 402 having on one end thereof a wedged die 401, and an expanding tube 404 which has on one end thereof an expanded part 403 and which is coupled with the press- fitting tube. The press-fitting tube and the expanding tube are coupled to each other in such a way that the wedged die 401 comes into contact with the expanded part 403 of the expanding tube 404.

The expansion-type tube buffer 400 is installed in each of the coupler 20 and the head stock 40 which are provided on the fore of the railway vehicle. As shown in FIG. 3, the die 401 of the press-fitting tube 402 is installed to be in contact with the expanded part 403 of the expanding tube 404. In the event of a collision of the railway vehicle, as shown in FIG. 4, the wedged die 401 provided on one end of the press-fitting tube 402 moves into the expanding tube 404 in the longitudinal direction thereof, so that the die 401 expands the expanding tube 404 in the circumferential direction thereof. Thereby, the impact energy generated in the event of the collision of the railway vehicle is converted into plastic deformation energy which expands the expanding tube 404, thus absorbing and reducing the impact energy.

In a detailed description, as shown in FIGS. 5 and β, the general fore of the railway vehicle includes a drive panel 100 which is retractably installed to the front of a driver' s cab defined by a protective shell 300 of the railway vehicle. A bottom buffer 200 is mounted to the bottom of the drive panel 100 to absorb impact energy. A honeycomb part 112 is mounted to the front protective part 101 of the drive panel 100 to absorb impact energy. A lower buffer 107 is installed in the rearward moving direction of the drive panel 100 to absorb impact energy generated by the rearward movement of the drive panel 100.

As such, the drive panel 100 and the protective shell 300 are coupled to each other, thus providing the fore of the railway vehicle. Thereby, in the event of a collision of the railway vehicle, the first and second buffering tubes 202 and 204 of the bottom buffer 200 which is provided on the bottom of the drive panel 100 are crushed to primarily absorb impact energy. When the bottom buffer 200 has been completely crushed, the honeycomb part 112 provided on the front protective part 101 of the drive panel 100 is crushed, thus secondarily absorbing the impact energy. When the honeycomb part 112 has been completely crushed, the drive panel 100 slides into the protective shell 300, so that the lower buffer 107 provided on the lower portion of the drive panel 100 is crushed, thus absorbing the impact energy. In this way, the impact energy generated in the event of the collision of the railway vehicle is absorbed. Conventionally, the expansion-type tube buffer 400 shown in FIGS. 2 to 4 is mounted to each of the first and second buffering tubes 202 and 204 of the bottom buffer 200 which is installed at the bottom of the drive panel 100 and the lower buffer 107 which is mounted to the lower portion of the drive panel 100. However, the expansion-type tube buffer 400 requires the press-fitting tube 402 which has the same length as that of the expanding tube 404. Thus, in order to install the expansion-type tube buffer 400 in the railway vehicle, a large installing space which is twice as long as the press-fitting tube 402 or the expanding tube 404 is required. Further, since the die 401 absorbs impact energy through plastic deformation which simply expands the expanding tube 404, the impact energy is not effectively absorbed.

Further, because of impact resulting from the conversion between stages when impact energy is absorbed in stages, large shocks act on drivers and passengers who are in the railway vehicle, so that they may be injured. Moreover, a railway vehicle structure may be broken or damaged. Furthermore, when the tube buffer absorbs impact energy generated by the collision of the railway vehicle, the buffering tube is buckled to a side while the tube buffer of a constant thickness absorbs the impact energy, so that the impact energy may not be absorbed.

[Disclosure]

[Technical Problem]

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a tube buffer for railway vehicles, which is constructed so that the length of the tube buffer is short, thus reducing a space for installing the tube buffer of a railway vehicle, and efficiently absorbing impact energy generated in the event of a collision of the railway vehicle. Another object of the present invention is to provide a tube buffer for railway vehicles, in which a wedged stabilizer is provided on the rear end of the tube buffer installed in the fore of a railway vehicle, so that the stabilizer provided on the tube buffer absorbs stage conversion impact generated when an impact energy absorbing stage is converted into a subsequent impact energy absorbing stage while the tube buffer absorbs impact energy in stages in the event of a collision of the railway vehicle, thus protecting drivers and passengers against the stage conversion impact, and preventing a railway vehicle structure from being broken or damaged.

A further object of the present invention is to provide a tube buffer for railway vehicles, in which a stabilizer is provided on the rear end of the tube buffer, thus preventing the tube buffer from buckling during the absorption of impact energy.

[Technical Solution]

In order to accomplish the above objects, the present invention provides a tube buffer for a railway vehicle, wherein a die of a press-fitting tube cuts a tearing tube which absorbs impact energy during a collision.

The die includes a plurality of blades for cutting the tearing tube.

The plurality of blades are radially provided on an outer circumference of the die at regular intervals . The die is constructed to be in contact with a rear end of the tearing tube.

The tearing tube is bent and expanded, thus providing an expanded part to the rear end of the tearing tube. An expanding inclined part is provided at a predetermined position on the die to contact the expanded part of the tearing tube.

A guide part protrudes from a front end of the expanding inclined part of the die. Further, in order to accomplish the above objects, the present invention provides a tube buffer for a railway vehicle, wherein a stabilizer is provided on a buffering tube for absorbing impact energy and formed such that a thickness of a rear end of the stabilizer is larger than a thickness of a front end thereof.

The stabilizer is provided on the rear portion of the buffering tube.

The stabilizer is integrated into a single structure with the buffering tube. The stabilizer is detachably mounted to the rear portion of the buffering tube.

The stabilizer has a triangular cross-section. The outer circumferential section between the front and rear ends of the stabilizer is curved. Further, the stabilizer is formed such that an outer diameter of the rear end thereof is larger than an outer diameter of the front end thereof, and includes an insertion part which is coupled to the tube buffer of the railway vehicle.

[Advantageous Effects] The tube buffer for railway vehicles according to the present invention is advantageous in that a die expands a tearing tube in the event of the collision of a railway vehicle, and simultaneously blades provided on the outer circumferential surface of the die cut the expanded tearing tube, thus doubly absorbing the impact energy of the railway vehicle. Therefore, the efficiency of absorbing the impact energy is very high.

Further, the tube buffer for railway vehicles according to the present invention is advantageous in that it is shorter than a conventional tube buffer, so that an installation space is dramatically reduced.

Further, the tube buffer for railway vehicles according to the present invention is advantageous in that a stabilizer absorbs stage conversion impact generated when an impact energy absorbing stage is converted into a subsequent impact energy absorbing stage in the event of a collision of the railway vehicle, thus preventing drivers and passengers from being injured because of the stage conversion impact, and preventing a railway vehicle structure from being broken or damaged. Further, the tube buffer for railway vehicles according to the present invention is advantageous in that the tube buffer does not buckle to a side when the tube buffer absorbs impact energy.

[Description of Drawings]

FIG. 1 is a conceptual view illustrating a conventional impact energy absorbing device applied to the fore of a railway vehicle;

FIG. 2 is an exploded perspective view illustrating a conventional expansion-type tube buffer;

FIG. 3 is a sectional view illustrating the coupled state of the conventional expansion-type tube buffer;

FIG. 4 is a sectional view illustrating the crushed state of the conventional expansion-type tube buffer; FIG. 5 is a perspective view illustrating the construction of the fore of a railway vehicle;

FIG. 6 is a perspective view illustrating a drive panel which is provided on the fore of the railway vehicle;

FIG. 7 is an exploded perspective view illustrating a tube buffer according to the first embodiment of the present invention;

FIG. 8 is a perspective view illustrating the tube buffer according to the first embodiment of the present invention; FIG. 9 is a sectional view taken along line A-A of FIG . 8 ;

FIG. 10 is a view sequentially illustrating the crushing process of the tube buffer according to the first embodiment of the present invention; FIGS. 11 to 16 are views sequentially illustrating the process of absorbing impact energy at the fore of a railway vehicle equipped with the tearing tube buffer according to the present invention;

FIG. 17 is a graph illustrating the amount of impact energy absorbed by the fore of a railway vehicle equipped with the conventional tube buffer as a function of the stage;

FIG. 18 is a sectional view illustrating an expansion-type tube buffer according to the second embodiment of the present invention;

FIG. 19 is a sectional view illustrating the crushed state of the tube buffer of FIG. 18;

FIG. 20 is a graph illustrating the amount of impact energy absorbed by the fore of a railway vehicle equipped with the tube buffer of FIG. 18 as a function of the stage;

FIG. 21 is a sectional view illustrating an inversion-type tube buffer according to the third embodiment of the present invention;

FIG. 22 is a sectional view illustrating the crushed state of the inversion-type tube buffer of FIG. 21;

FIG. 23 is a sectional view illustrating the state in which a stabilizer is coupled to a tube buffer according to the fourth embodiment of the present invention;

FIG. 24 is a sectional view illustrating the tube buffer equipped with the stabilizer of FIG. 23; and FIG. 25 is a sectional view illustrating a tube buffer according to the fifth embodiment of the present invention.

[Best Mode]

Herein below, a tube buffer for railway vehicles according to the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings .

FIG. 7 is an exploded perspective view illustrating a tube buffer according to the first embodiment of the present invention, FIG. 8 is a perspective view illustrating the tube buffer according to the first embodiment of the present invention, FIG. 9 is a sectional view taken along line A-A of FIG. 8, and FIG. 10 is a view sequentially illustrating the crushing process of the tube buffer according to the first embodiment of the present invention.

As shown in FIG. 7, a tube buffer 500 mounted to the fore of a railway vehicle according to the present invention includes a tearing tube 504 which has on one end thereof an expanded part 505, and a die 501 which is in contact with the expanded part 505 of the tearing tube 504 and expands and cuts the tearing tube 504 because of the impact energy of the railway vehicle. The tearing tube 504 is expanded outwards at a predetermined angle, thus forming the expanded part 505. The outer diameter of the expanded part 505 is formed to be larger than that of the tearing tube 504.

Further, the die 501 contacting the expanded part of the tearing tube 504 has an expanding inclined part 503 at a junction between the expanded part 505 of the tearing tube 504 and the die. A guide part 506 protrudes from the front end of the expanding inclined part 503, and blades 502 each having the shape of a knife edge are provided on the outer circumference of the die 501 at regular intervals .

The die 501 constructed as described above is coupled to the tearing tube 504 to be in contact with the expanded part 505. As shown in FIG. 9, the guide part 506 of the die 501 is inserted into the tearing tube 504, and the expanding inclined part 503 of the die 501 is in contact with the expanded part 505 of the tearing tube 504.

The tube buffer of the present invention constructed as described above is mounted to the fore of the railway vehicle. Hence, when impact energy is transmitted to the tube buffer in the event of a collision of the railway vehicle, as shown in FIG. 10, the die 501 enters the tearing tube 504 and the expanding inclined part 503 expands the tearing tube 504 in the outward radial direction. Further, the blades 502 provided on the outer circumference of the die 501 at regular intervals cut the expanded tearing tube 504, thus absorbing the impact energy of the railway vehicle.

At this time, as shown in the last portion of FIG. 10, the tearing tube 504 cut by the blades 502 of the die 501 becomes curled, so that the die 501 expands and cuts the tearing tube 504 along its entire length. Therefore, the efficiency of absorbing the impact energy is very high and the reduction of an installation space is realized.

That is, the die 501 expands the tearing tube 504 in the outward radial direction and cuts the expanded tearing tube 504, so that the tearing bube buffer of the present invention absorbs the impact energy of the railway vehicle.

The tearing tube buffer 500 of the present invention constructed as described above is mounted to each of the first and second buffering tubes 202 and 204 of the bottom buffer 200 which is provided on the fore of the railway vehicle and shown in FIG. 5, and the lower buffer 107 of the drive panel 100 which is shown in FIG. 6.

The process of absorbing impact energy using the fore of the railway vehicle equipped with the tearing tube buffer 500 according to the present invention in the event of a collision of the railway vehicle will be described below .

FIGS. 11 to 16 are views sequentially illustrating the process of absorbing impact energy by the fore of the railway vehicle equipped with the tearing tube buffer 500 according to the present invention. When a collision accident happens, the fore of the railway vehicle is changed from the state of FIG. 11. That is, as shown in FIG. 12, the first buffering tube 202 of the bottom buffer 200 is crushed, thus primarily absorbing impact energy. Next, as shown in FIG. 13, the second buffering tube 204 of the bottom buffer 200 is crushed, thus secondarily absorbing the impact energy. In this state, because of the impact energy of the railway vehicle, the bottom buffer 200 becomes separated from the railway vehicle via an end slope 111 formed on the lower portion of the drive panel 100, as shown in FIG. 14.

As such, after the bottom buffer 200 has separated from the railway vehicle, the honeycomb part 112 provided on the front protective part 101 of the drive panel 100 is crushed to absorb the impact energy, as shown in FIG. 15. When the honeycomb part 112 has been completely crushed, as shown in FIG. 16, the drive panel 100 provided on the fore of the railway vehicle slides into the protective shell 300, the lower buffer 107 provided in a support 104 of the drive panel 100 is crushed, thus absorbing the impact energy. At this time, the tearing tube buffer 500 of the present invention applied to each of the first and second buffering tubes 202 and 204 of the bottom buffer 200 and the lower buffer 107 absorbs the impact energy, thus absorbing the impact energy generated by the collision of the railway vehicle, therefore protecting drivers and passengers.

Herein, the embodiment in which the tearing tube buffer 500 is installed in each of the bottom buffer 200 provided on the fore of the railway vehicle and the lower buffer 107 has been described. But, the tearing tube buffer 500 of the present invention is not installed restrictively to each of the bottom buffer 200 and the lower buffer 107, but may be installed at various places so as to absorb the impact energy of the railway vehicle.

Meanwhile, while the impact energy of the railway vehicle is absorbed in stages using the first buffering tube 202, the second buffering tube 204, the honeycomb part 112 and the lower buffer 107, impact is generated during the conversion of the stages. The stage conversion impact is absorbed as shown in FIG. 17. That is, when the impact energy generated in the event of the collision of the railway vehicle is 150OkN, the first buffering tube 202 is crushed to absorb the impact energy. After the first buffering tube 202 has been completely crushed, the impact energy of 200OkN is absorbed while the second buffering tube 204 is crushed. After the second buffering tube 204 has been completely crushed, the impact energy of 230OkN is absorbed while the honeycomb part 112 is crushed. After the honeycomb part 112 has been completely crushed, the impact energy of 260OkN is absorbed while the lower buffer 107 is crushed.

While the impact energy is absorbed in stages by the first and second buffering tubes 202 and 204, the honeycomb part 112, and the lower buffer 107, the stage conversion impacts Ai to A₄ are generated.

For example, the stage conversion impact Ai generated before the second buffering tube 204 is crushed and after the first buffering tube 202 has been completely crushed is equal to the stage conversion impact Ai generated when the stage of absorbing the impact energy of 50OkN (this is the difference between the impact energy of 150OkN at which the first buffering tube 202 starts to be crushed and the impact energy of 200OkN at which the second buffering tube 204 starts to be crushed) is converted from the first buffering tube 202 to the second buffering tube 204.

In order to absorb the stage conversion impact while the impact energy is absorbed in stages, as shown in FIG. 18, a stabilizer 600 is provided on the rear end of the expanding tube 404 of the expansion-type tube buffer 400. The stabilizer 600 provided on the rear end of the expanding tube 404 as such is formed such that its thickness is gradually increased in a direction from the front end of the stabilizer to the rear end thereof.

The process of absorbing the impact energy while the expansion-type tube buffer 400 on which the stabilizer 600 is formed is crushed is as follows. As shown in FIG. 19, while the wedged die 401 provided on the rear end of the press-fitting tube 402 expands the expanding tube 404 through plastic deformation by the impact energy, the wedged die is inserted into the expanding tube 404. At this time, the amount of impact energy absorbed by the expansion-type tube buffer 400 is proportional to the length of the die 401 inserted into the expanding tube 404 while the die 401 expands the expanding tube 404, and is proportional to the thickness of the expanding tube 404 expanded by the die 401. According to the present invention, the stabilizer 600 gradually increases the thickness of the expanding tube 404 which is to be expanded by the die 401, so that it absorbs stage conversion impact generated before a subsequent impact absorbing unit absorbs impact after the expansion-type tube buffer 400 has been completely crushed.

The expansion-type tube buffer 400 having the stabilizer 600 as such is mounted to each of the first and second buffering tubes 202 and 204 and the lower buffer 107 which are shown in FIGS. 5 and 6, thus absorbing the stage conversion impact. In a detailed description, as shown in FIG. 20, when impact energy generated by the collision of the railway vehicle reaches 150OkN, the first buffering tube 202 starts to be crushed first. While the first buffering tube 202 is being crushed, the impact energy which can be absorbed by the first buffering tube 202 is increased because of the stabilizer 500, so that a buffering section S is formed. If comparing the result with FIG. 17, when the impact absorbing stage is converted from the first buffering tube 202 to the second buffering tube 204, each of which is not provided with the stabilizer 600, the stage conversion impact Ai is abruptly generated as shown in FIG. 17. Meanwhile, if the stabilizer 600 is provided on each of the buffering tubes, the stage conversion impact is absorbed by the stabilizer 600, so that the stage conversion impact is gently generated as shown in FIG. 20.

Hereinbefore, the embodiment wherein the stabilizer 600 of the present invention is applied to the expansion- type tube buffer 400 has been described. However, the stabilizer 600 of the present invention may be applied to all kinds of tube buffers for absorbing impact energy through plastic deformation without being limited to the expansion-type tube buffer 400. That is, the stabilizer may be applied to even an inversion-type tube buffer, as shown in FIG. 21.

The inversion-type tube buffer is constructed so that an inversion tube 407 contacts the inversion groove 406 of a die 405. When impact energy is generated, the inversion tube 407 is inverted by the inversion groove 406 of the die 405, thus absorbing the impact energy. As shown in FIG. 22, when the inversion tube 407 having on its rear end the stabilizer 600 is inverted by the inversion groove 406 of the die 405 because of the impact energy of the railway vehicle, the stage conversion impact is absorbed by the stabilizer 600 which is provided on the rear end of the inversion tube 407.

Hereinbefore, the construction in which the stabilizer 600 is integrated with the tube buffer into a single structure has been described. However, as shown in FIGS. 22 and 23, a stabilizer 700 may be separately provided and mounted to a conventional tube buffer.

The stabilizer 700 which is separately provided and mounted to the tube buffer as such includes an insertion part 701 having the inner diameter which is the same as the outer diameter of the expanding tube 404 or the inversion tube 407, as shown in FIG. 23.. The stabilizer 700 is constructed so that its thickness is increased in a direction from the front end thereof to the rear end.

When the stabilizer 700 constructed as described above is coupled to the rear end of the expanding tube 404 of the expansion-type tube buffer 400 or the inversion tube 407 of the inversion-type tube buffer, the tube buffer having the stabilizer 700 is completed. Here, the stabilizer 700 is secured to the expanding tube 404 or the inversion tube 407 through force-fitting, welding, or bolting. Further, as shown in FIG. 25, the outer circumferential section between the front and rear ends of the stabilizer 700 may comprise a curve. As such, when the outer circumferential section between the front and rear ends of the stabilizer 700 is curved, the stage conversion impact absorbed by the stabilizer 700 forms a non-linear absorption curve, thus more smoothly absorbing the impact of the railway vehicle.

Hereinbefore, the tube buffer for railway vehicles according to the present invention has been described. It is to be understood by those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope thereof .

The present embodiment is illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the meets and bounds of the claims, or equivalence of such meets and bounds are therefore intended to be embraced by the claims .

[industrial Applicability] As described above, the present invention provides a tube buffer for railway vehicles, which is installed to the fore of a railway vehicle to reduce and absorb impact energy generated in the event of a collision of the railway vehicle. Particularly, the present invention provides a tube buffer for railway vehicles, in which the die of the tube buffer expands a tube by impact energy generated in the event of the collision of a railway vehicle, and simultaneously blades provided on the die cut the expanded tube, so that the efficiency of absorbing impact energy is excellent and a small installation space is required.

Further, the present invention provides a tube buffer for railway vehicles, in which a stabilizer provided on the tube buffer absorbs stage conversion impact generated when an impact energy absorbing stage is converted into a subsequent impact energy absorbing stage while the tube buffer absorbs impact energy in several stages in the event of a collision of a railway vehicle, thus allowing the impact energy of the railway vehicle to be smoothly absorbed, therefore protecting drivers and passengers in case of an accident, and preventing a railway vehicle structure from being broken or damaged.

Claims

[CLAIMS]

[Claim l]

A tube buffer for a railway vehicle, wherein a die of a press-fitting tube cuts a tearing tube which absorbs impact energy during a collision.

[Claim 2]

The tube buffer according to claim 1, wherein the die comprises a plurality of blades for cutting the tearing tube.

[Claim 3]

The tube buffer according to claim 2, wherein the plurality of blades are radially provided on an outer circumference of the die at regular intervals .

[Claim 4] The tube buffer according to claim 1, wherein the die is constructed to be in contact with a rear end of the tearing tube.

[Claim 5]

The tube buffer according to claim 4, wherein the tearing tube is bent and expanded, thus providing an expanded part to the rear end of the tearing tube.

[Claim 6]

The tube buffer according to claim 5, wherein an expanding inclined part is provided at a predetermined position on the die to contact the expanded part of the tearing tube.

[Claim 7]

The tube buffer according to claim β, wherein a guide part protrudes from a front end of the expanding inclined part of the die.

[Claim 8]

A tube buffer for a railway vehicle, wherein a stabilizer is provided on a buffering tube for absorbing impact energy and formed such that a thickness of a rear end of the stabilizer is larger than a thickness of a front end thereof.

[Claim 9]

The tube buffer according to claim 8, wherein the stabilizer is provided on a rear portion of the buffering tube.

[Claim 10]

The tube buffer according to claim 8, wherein the stabilizer is integrated into a single structure with the buffering tube .

[Claim 11]

The tube buffer according to claim 8, wherein the stabilizer is detachably mounted to the rear portion of the buffering tube.

[Claim 12]

The tube buffer according to claim 10 or 11, wherein the stabilizer has a triangular cross-section.

[Claim 13] The tube buffer according to claim 10 or 11, wherein an outer circumferential section between the front and rear ends of the stabilizer is curved.

[Claim 14]

The tube buffer according to claim 11, wherein the stabilizer is formed such that an outer diameter of the rear end thereof is larger than an outer diameter of the front end thereof, and comprises an insertion part which is coupled to the tube buffer of the railway vehicle.