The present application is based on and claims priority of Japanese patent application No. 2007-187504 filed on Jul. 18, 2007, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an obstacle deflector for eliminating obstacles on railway tracks which is disposed on railway cars such as railroad vehicles, streetcars, electric trains of new urban traffic systems and monorail cars, and railway cars equipped with such obstacle deflector.
2. Description of the Related Art
Japanese Patent Laid-Open Publications No. 2005-206006 (patent document 1), No. 2001-55141 (patent document 2) and No. 2003-137094 (patent document 3) disclose structures for eliminating obstacles on railway tracks. Patent documents 1 through 3 disclose an obstacle deflector disposed on a car body at a leading end portion of the railway car and positioned above the railway track for eliminating obstacles on the railway track.
The obstacle deflector disclosed in the above patent documents is a U-shaped member when viewed from above, wherein the U-shaped member is connected at multiple locations on a lower surface of an underframe. Further, the U-shaped member is connected at its rear portion with the underframe. The U-shaped member can also be V-shaped.
The obstacle deflector has an energy absorber disposed at a rear position on a rear surface at the center of the width-direction of the U-shaped member. When the U-shaped member collides against an obstacle, the energy absorber collapses in a bellows, absorbing the collision energy.
In the structure disclosed in patent documents 1 through 3, a U-shaped member is disposed on a lower surface of the underframe, and the U-shaped member is attached at plural locations on the underframe. Therefore, the U-shaped member is large-sized, and since the U-shaped member must be attached at plural locations on the lower surface of the underframe, the attaching operation becomes difficult.
The object of the present invention is to provide an obstacle deflector that has minimum influence on the underframe and car body when colliding against an obstacle, which is small-sized and can be disposed easily.
The above object is realized by a railway car having an obstacle deflector disposed on a lower surface of an underframe of the railway car, wherein the obstacle deflector is supported on the lower surface of the underframe at two locations spaced apart from one another in a running direction of the railway car when seen from a side direction with respect to the running direction; the obstacle deflector comprises an obstacle deflection member that collides against an obstacle, a first pin positioned at one of the two locations and rotatably connecting the obstacle deflection member to the lower surface of the underframe, a connecting mechanism for connecting the obstacle deflection member and the underframe, a second pin positioned at the other one of the two locations and rotatably connecting the connecting mechanism to the lower surface of the underframe, and a third pin for connecting the obstacle deflection member and the connecting mechanism; and the first pin and the second pin has axles oriented horizontally in a width direction with respect to the running direction of the railway car.
Moreover, the above object is realized by an obstacle deflector disposed on a lower surface of an underframe of the railway car, wherein the obstacle deflector is supported on the lower surface of the underframe at two locations spaced apart from one another in a running direction of the railway car when viewed in a side direction with respect to the running direction; the obstacle deflector comprises an obstacle deflection member that collides against an obstacle, a first pin positioned at one of the two locations and rotatably connecting the obstacle deflection member to the lower surface of the underframe, a connecting mechanism for connecting the obstacle deflection member and the underframe, a second pin positioned at the other one of the two locations and rotatably connecting the connecting mechanism to the lower surface of the underframe, and a third pin for connecting the obstacle deflection member and the connecting mechanism; and the first pin and the second pin has axles oriented horizontally in a width direction with respect to the running direction of the railway car.
According to the railway car having the arrangement described above and the obstacle deflector to be attached to the railway car, the impact load generated by an obstacle colliding against the obstacle deflection member is transmitted via the connecting mechanism to the underframe. Since the obstacle deflection member and the connecting mechanism is respectively connected via pins to the underframe, they constitute a link mechanism, according to which the underframe receives the given impact load as a simple axial force, and no flexural load is applied to the underframe. Thus, since, there is no need for a guide mechanism for slidably supporting the connecting mechanism according to the present invention, the structures of the obstacle deflector and the railway car are simplified, the effect of the impact load to the underframe or the car body is simplified, and so the structure is advantageous.
Further according to the present invention, when the connecting mechanism is equipped with a distribution member and an energy absorber, the energy absorber absorbs the collision energy generated by the collision of an obstacle against the obstacle deflection member, and reduces the impact load transmitted to the underframe. Moreover, when a relatively small load is applied on the obstacle deflection member, the energy absorber will not activate, but when a large load is applied, the energy absorber collapses in a bellows and absorbs the collision energy. Since the whole body of the energy absorber receives axial force only and does not receive bending moment, the energy absorber is crushed effectively and exerts maximum energy absorbing function.
The preferred embodiments of a railway car according to the present invention will be described with reference to the drawings.
One preferred embodiment of the present invention will be described with reference to
The obstacle deflector 30 is disposed on the lower surface 3b of the underframe of the car body. In
When an obstacle collides against the obstacle deflection member 31, the obstacle deflection member 31 receives force in a direction to rotate the lower end of the obstacle deflection member 31 toward the rear direction around pins 32. There are two pins 32 disposed along the width direction of the obstacle deflection member.
Further, the obstacle deflector 30 comprises a connecting mechanism 40 including a distribution member 33 disposed parallel to the obstacle deflection member 31, two support members 47 and 47 attached to the distribution member 33, energy absorbers 35 and 35 connected via load transmitting shafts 44 and 44 to the support members 47 and 47, two rods 37 and 37 connected to the energy absorbers 35 and 35, and pins 38 and 38 connecting the rods 37 and 37 to the lower surface 3b of the underframe. The distribution member 33 is a high-strength member made of iron. The two sets of components each composed of the support member 47, the load transmitting shaft 44, the energy absorber 35 and the rod 37 disposed rearward from the distribution member 33 each constitute a parallel connecting unit.
What is meant by the term “parallel” is that the distribution member 33 is disposed in the width direction, similar to the obstacle deflection member 31.
The energy absorber 35 collapses and absorbs the collision energy when collision with an obstacle occurs.
The pin 32 is disposed at two longitudinal locations on an upper end of the obstacle deflection member 31 along the width direction. The axial direction of each pin 31 corresponds to the width direction.
The obstacle deflection member 31 and the distribution member 33 are connected via a single pin 34. The pin 34 is disposed at the center of the width direction between the obstacle deflection member 31 and the distribution member 33. The axial direction of the pin 34 corresponds to the width direction in
The rods 37 and 37 are disposed on the lower surface 3b of the underframe via pins 38 and 38. The rods 37 and 37 are connected ratatably in vertical direction via pins 38 and 38. Thus, the obstacle deflector 30 realizes a link structure which is attached via pins 32 and 38 on the lower surface 3b of the underframe when viewed from the side direction with respect to the running direction of the vehicle.
The support members 47 and 47 (and energy absorbers 35 and 35 connected thereto) are connected to the distribution member 33 at equal distanced positions in the width direction from the pin 34.
The point of connection between the rods 37 and 37 and the lower surface 3b of the underframe (the horizontal and height positions of the pins 38 and 38) can be anywhere, but it is preferable that the pins 38 are positioned at corresponding positions and as distanced from the obstacle deflection member 31 as possible. This is preferable since when the obstacle deflection member 31 collides against an obstacle, the direction of impact force conducted via rods 37 and 37 to the underframe should be as close to the plane of the underframe as possible to reduce upthrust force. The rods 37 are crossed perpendicularly with axles 39 at positions above the axles 39 supporting the car body on the rails. The rods 37 are arranged to extend above the axles 39 with a distance therebetween preventing the rods 37 from coming into contact with the axles 39 even when air cushions (not shown) blow out.
The lower end of the obstacle deflection member 31 is positioned on an extended line of the connecting line connecting the pin 34 and the pin 38. If the extended line is positioned above the lower end of the obstacle deflection member 31, the load acting on the energy absorbers 35 becomes excessive considering the balance of load acting on the obstacle deflection member 31 at the time of collision with an obstacle, which is not preferable. Further, if the extended line is positioned below the lower end, the clearance between the distribution member 33 and the rail surface becomes excessively small and is not desirable, since the lower end of the obstacle deflection member 31 is positioned as close to the rail surface as possible. In this sense, it is preferable that the lower end of the obstacle deflection member is disposed on the above-mentioned extended line. Even though it is described that the obstacle deflection member 31 is positioned “on the extended line”, a small variation in the vertical direction is permissible.
The energy absorbers 35 can adopt any structure, as long as they are capable of absorbing collision energy. One preferable example is an extruded shape member made of aluminum alloy, which collapses in a bellows with respect to the running direction when receiving impact load to absorb the collision energy.
In
The direction of operation of the impact load, that is, the running direction, is from left to right in the drawing of
The energy absorber 35 is composed of an inner cylinder 35a having an octagonal cross-section disposed at the inner side, an outer cylinder 35b having an octagonal cross-section disposed at the outer side, and a plurality of connecting plates 35c connecting the inner and outer cylinders. The connecting plates 35c are attached to intersecting points of the octagons in the form of a truss.
The closing plate 42 disposed at the front end of the energy absorber 35 is opposed to the rear end of the supporting member 47 via a gap G of 8.5 mm, for example. The closing plate 43 at the rear end of the energy absorber 35 is engaged via bolts and nuts 46 to the rod 37. The load transmitting shaft 44 attached to the front end of the rod 37 is connected via a pin 48 to the supporting member 47 at the front end portion penetrated through the hole 35d and protruded from the closing plate 42.
The pin 48 is passed through a hole 44c formed to the load transmitting rod 44 and the hole 47c formed to the supporting member 47. Notched grooves 48c are formed to the outer surface of the pin 48 between the side surface of the load transmitting shaft 44 facing the outer side of the width direction of the car body and the side surface of the supporting member 47 facing the inner side of the width direction of the car body, and the notched grooves 48c enable the pin 48 to break easily by impact load. In other words, the notched grooves 48c formed on the outer circumference of the pin 48 between the load transmitting shaft 44 and the supporting member 47 are formed so as to enable the pin to break easily when impact load is applied to the support member 47, enabling the supporting member 47 to collide against the closing plate 42 by the impact load. A hole 33b is formed on the opposing side of the distribution member 33 to allow the load transmitting shaft 44 to pass therethrough when the pin 48 breaks when the distance between the front end of the load transmitting shaft 44 and the rear end of the distribution member 33 is short.
The support members 47 and 47 are attached to the distribution member 33. Each support member 47 has a substantially same outer shape as the energy absorber 35. That is, the energy absorber 35 has an octagonal cross-section, and the support member 47 also has an octagonal cross-section. If the support member 47 is a hollow shape member, a closing plate (not shown) is attached to the rear end thereof.
As described, the rear end of the support member 47 is opposed via a gap G to a closing plate 42. According to such structure, the function of the energy absorber 35 can be turned on and off according to the level of impact load.
In other words, when a small load is applied on the obstacle deflection member 31, the front end of the energy absorber 35 is opposed to the support member 47 with a gap G therebetween, so the impact load is not applied on the energy absorber 35. This state is referred to as “off”.
On the other hand, when a large load is applied on the obstacle deflection member 31, the impact load is applied via the obstacle deflection member 31, the pin 34, the distribution member 33 and the support members 47 to pins 48 and load transmitting shafts 44. Thereby, the pins 48 break and the support members 47 collide against the energy absorbers 35. This state in which the pins 48 are broken is referred to as “on”. In other words, the rear end portion of the support members 47 collide against the closing plates 42, by which the impact load is transmitted to the energy absorbers 35, making the energy absorbers 35 collapse in a bellows with respect to the direction of operation of the impact load. The collision energy is absorbed by this collapse.
As described, since the operation of impact load to the energy absorbers 35 is turned on and off, it becomes possible to prevent replacement of the energy absorbers 35 when only a small load is applied thereto, and to prevent the occurrence of lack of function of the energy absorbers 35 when a large load is applied thereto.
Furthermore, the obstacle deflection member 31, the rods 37 and the underframe 3 are respectively connected via pins 32 and 38, by which a link mechanism is composed. Thus, even when an obstacle collides against the obstacle deflection member 31, only a load in the axial direction (substantially a compressive load) connecting the pin 34 and the pin 38 in
Furthermore, the above-described link mechanism enables only simple compressive load to be applied to the energy absorbers 35, so the energy absorbers 35 can be collapsed in a straight direction without fail to absorb the collision energy efficiently. Thus, there is no need to add any extra structure such as a guide mechanism for guiding the energy absorbers 35 to be collapsed in a straight direction. In replacement of the link mechanism, it is possible to arrange energy absorbers 35 horizontally between the obstacle deflection member 31 and the underframe 3, but in order to enable the energy absorbers 35 to be collapsed in the correct horizontal direction, a guide mechanism must be provided between the underframe 3 to enable the energy absorbers 35 to slide in the horizontal direction. As described in the present embodiment, the guide mechanism is no longer necessary when a link mechanism using pins 32, 34 and 38 is adopted, and the structure of the obstacle deflector can be simplified.
Furthermore, the distribution member 33 and the obstacle deflection member 31 are connected at the center portion in the width direction via a pin 34. Moreover, since the energy absorbers 35 and 35 are attached to the distribution member 33 at equal distances from the pin 34, load is applied uniformly to the absorbers 35 and 35 and rods 37 and 37. Thereby, regardless of the width-direction position in which the obstacle collides against the obstacle deflection member 31, the impact load is transmitted via the pin 34 to the distribution member 33, and load is transmitted uniformly to the energy absorbers 35 and 35 positioned at equal distances from the pin 34.
This is described in further detail with reference to
According to the present invention (having the structure illustrated in
Moreover, according to the present structure, even when a large load is applied, the obstacle deflector 30 can be replaced with a new one by replacing the energy absorbers 35, the bolts and nuts 46 and the pins 48.
Moreover, it is also possible to adopt a structure in which the support members 47 also collapse to absorb the collision energy when a large load is applied.
According to embodiment 1 illustrated in
When the pin 34 is arranged perpendicularly, there is a risk that when the energy absorbers 35 collapse, the absorbers are deformed in an upward curved state, by which the energy absorption efficiency is deteriorated. However, by arranging the pin 34 in the perpendicular direction, the impact load can be distributed more uniformly in the left and right directions, that is, to the two energy absorbers 35 and 35, compared to the case of embodiment 1.
According to embodiment 1, each energy absorber 35 is composed of a hollow shape member having an octagonal cross-sectional shape, but as illustrated in
Though the width direction of the hollow shape member 35A is arranged horizontally, it can also be arranged perpendicularly. Further, the member does not necessarily have to be hollow.
Number | Date | Country | Kind |
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2007-187504 | Jul 2007 | JP | national |